BACKGROUND
[0001] Some oil and gas wells are completed in unconsolidated formations that contain loose
fines and sand. When fluids are produced from these wells, the loose fines and sand
can migrate with the produced fluids and can damage equipment, such electric submersible
pumps (ESP) and other systems. For this reason, completions can require screens for
sand control.
[0002] Horizontal wells that require sand control are typically open hole completions. In
the past, stand-alone sand screens have been used predominately in these horizontal
open holes. However, operators have also been using gravel packing in these horizontal
open holes to deal with sand control issues. The gravel is a specially sized particulate
material, such as graded sand or proppant, which is packed around the sand screen
in the annulus of the borehole. The gravel acts as a filter to keep any fines and
sand of the formation from migrating with produced fluids.
[0003] A prior art gravel pack system 20 illustrated in Fig. 1A extends from a packer 14
downhole from casing 12 in a borehole 10, which is a horizontal open hole. To control
sand, operators attempt to fill the annulus between the assembly 20 and the borehole
10 with gravel (particulate material) by pumping slurry of fluid and gravel into the
borehole 10 to pack the annulus. For the horizontal open borehole 10, operators can
use an alpha-beta wave (or water packing) technique to pack the annulus. This technique
uses a low-viscosity fluid, such as completion brine, to carry the gravel. The system
20 in Fig. 1A represents such an alpha-beta type.
[0004] Initially, operators position a wash pipe 40 into a screen 25 and pump the slurry
of fluid and gravel down an inner workstring 45. The slurry passes through a port
32 in a crossover tool 30 and into the annulus between the screen 25 and the borehole
10. As shown, the crossover tool 30 positions immediately downhole from the gravel
pack packer 14 and uphole from the screen 25. The crossover port 32 diverts the flow
of the slurry from the inner workstring 45 to the annulus downhole from the packer
14. At the same time, another crossover port 34 diverts the flow of returns from the
wash pipe 40 to the casing's annulus uphole from the packer 14.
[0005] As the operation commences, the slurry moves out the crossover port 32 and into the
annulus. The carrying fluid in the slurry then leaks off through the formation and/or
through the screen 25. However, the screen 25 prevents the gravel in the slurry from
flowing into the screen 25. The fluids passing alone through the screen 25 can then
return through the crossover port 34 and into the annulus above the packer 14.
[0006] As the fluid leaks off, the gravel drops out of the slurry and first packs along
the low side of the borehole's annulus. The gravel collects in stages 16a, 16b, etc.,
which progress from the heel to the toe in what is termed an alpha wave. Because the
borehole 10 is horizontal, gravitational forces dominate the formation of the alpha
wave, and the gravel settles along the low side at an equilibrium height along the
screen 25.
[0007] When the alpha wave of the gravel pack operation is done, the gravel then begins
to collect in stages (not shown) of a beta wave. This forms along the upper side of
the screen 25 starting from the toe and progressing to the heel of the screen 25.
Again, the fluid carrying the gravel can pass through the screen 25 and up the wash
pipe 40. To complete the beta wave, the gravel pack operation must have enough fluid
velocity to maintain turbulent flow and move the gravel along the topside of the annulus.
To recirculate after this point, operators have to mechanically reconfigure the crossover
tool 30 to be able to washdown the pipe 40.
[0008] Although the alpha-beta technique can be economical due to the low-viscosity carrier
fluid and regular types of screens that can be used, some situations may require a
viscous fluid packing technique that uses an alternate path. In this technique, shunts
disposed on the screen divert pumped packing slurry along the outside of the screen.
Fig. 1B shows an example system 20 having shunts 50 and 52 (only two of which are
shown). Typically, the shunts 50/52 for transport and packing are attached eccentrically
to the screen 25. The transport shunts 50 feed the packing shunts 52 with slurry,
and the slurry exits from nozzles 54 on the packing shunts 52. By using the shunts
50/52 to transport and pack the slurry, the gravel packing operation can avoid areas
of high leak off in the borehole 10 that would tend to cause bridges to form and impair
the gravel packing.
[0009] Prior art gravel pack assemblies 20 for both techniques of Figs. 1A-1B have a number
of challenges and difficulties. During a gravel pack operation in a horizontal well,
for example, the crossover ports 32/34 may have to be re-configured several times.
During a frac pack operation, the slurry pumped at high pressure and flow rate can
sometimes dehydrate within the system's crossover tool 30 and associated sliding sleeve
(not shown). If severe, settled sand or dehydrated slurry can stick to service tools
and can even junk the well. Additionally, the crossover tool 30 is subject to erosion
during frac and gravel pack operations, and the crossover tool 30 can stick in the
packer 14, which can create extremely difficult fishing jobs.
[0011] In cased hole operations, it is very common to install multiple gravel pack installations
in a process referred to as "stacked packs". Each zone is addressed in a distinct
operation to perforate it, install the gravel pack equipment, pump the gravel and
then the process is repeated. Other multi-zone gravel pack systems have been developed
that are generally referred to as single trip, multi-zone systems. These systems are
of a conventional design in that they introduce slurry into the annulus outside the
screen from the topside of the screen and pump fluid towards the bottom of the zone.
Additionally, these systems have been specifically used for cased hole applications
and have only recently been adapted for open hole applications.
[0012] US 2013/000899 A1 (Broussard) describes a gravel packing assembly gravel for packing a horizontal borehole. Operators
wash down the borehole using an inner string in a first position by flowing fluid
from the inner string through the apparatus toe. Operators then gravel pack by moving
the inner string to one or more flow ports between a screen and the toe. Slurry flows
into the borehole from the flow ports, and returns from the borehole flow through
the screen. The gravel in the slurry can pack the borehole in an alpha-beta wave from
toe to heel. In another condition, operators can move the inner string to a second
flow port so slurry can flow into the borehole through a shunt extending from the
second flow port. When gravel packing is done, operators move the inner string to
a port collar in a liner of the assembly to cement the liner in the borehole.
[0013] US 2013/062066 A1 (Broussard) describes a multi-zone formation treatment assembly having sections disposed on
a tubular structure in a borehole. An isolation element disposed on the tubular structure
that isolates a borehole annulus around the section from the other sections, and a
flow valve disposed on the tubular structure is selectively operable between opened
and closed conditions permitting and preventing fluid communication between the through-bore
and the borehole annulus. A screen disposed on the tubular structure communicates
with the borehole annulus, and a closure disposed on the tubular structure at least
prevents fluid communication from the through-bore to the screen. A workstring of
the assembly can be manipulated in the tubular structure relative to each section
in the same trip to: open the flow valve, position in the through-bore relative to
the open flow valve, deliver the treatment from an outlet to the section through the
open flow valve, and close the flow valve.
[0014] The subject matter of the present disclosure is directed to overcoming, or at least
reducing the effects of, one or more of the problems set forth above.
SUMMARY
[0015] According to an aspect of the present disclosure there is provided a formation treatment
method for a borehole according to the appended claims.
[0016] A multi-zone apparatus and method are used for treating a formation. The apparatus
can be used for formation treatments, such as frac operations, frac pack operation,
gravel pack operations, or other operations. The apparatus includes a body (e.g.,
tubular structure, liner, production string, etc.) and a workstring. The body of the
assembly is disposed in the borehole and defines a through-bore. One or more sections
are disposed on the body, and each of the one or more sections comprises isolation
element, a port, a screen, and a closure.
[0017] The isolation element disposed on the body isolates a borehole annulus around the
section from the other sections. The port disposed on the body permits fluid communication
between the through-bore and the borehole annulus, and the screen disposed on the
body communicates with the borehole annulus. The closure disposed on the body at least
preventing fluid communication from the through-bore to the screen.
[0018] The workstring defines an outlet and is manipulated in the body relative to each
section. The workstring in a first mode of operation delivers the treatment from the
outlet to the borehole annulus of section through the port. The workstring in a second
mode of operation receives reverse circulation from the through-bore into the outlet.
[0019] In one embodiment, the port for a given one of the one or more sections is disposed
toward the toe, and the screen for the given section is disposed toward the heel.
During treatment, the port delivers slurry as the treatment and gravel packs the annulus
of the given section from toe to heel. The screen filters the fluid returns from the
slurry into the through-bore of the body.
[0020] In another embodiment, the port for a given one of the one or more sections is disposed
toward the heel, and the screen for the given section is disposed toward the toe.
During treatment, the port delivers slurry as the treatment and gravel packs the annulus
of the given section from heel to toe. The screen filters the fluid returns from the
slurry, and the section has a bypass delivering the fluid returns to the through-bore
of the body uphole of the port.
[0021] In one embodiment, the port comprises a flow valve selectively operable between opened
and closed conditions permitting and preventing fluid communication between the through-bore
and the borehole annulus. The flow valve can include a sleeve movable in the through-bore
between (a) the closed condition preventing fluid communication through the port and
(b) the opened condition permitting fluid communication through the port. The workstring
can be configured to at least open the flow valves of the one or more sections. For
example, the workstring can have an actuating tool operable to open and close the
flow valves of the one or more sections in the same trip in the through-bore.
[0022] In one embodiment, the closure is selectively operable between (a) a closed condition
preventing fluid communication between the through-bore and the screen and (b) an
opened condition permitting fluid communication between the through-bore and the screen.
For example, the closure can include a sleeve movable in the through-bore between
(a) the closed condition preventing fluid communication through at least one flow
port in the body, the at least one flow port in communication with the screen, and
(b) the open condition permitting fluid communication through the at least one flow
port.
[0023] In another example, the closure can include a one-way valve disposed in fluid communication
between the screen and the through-bore, the one-way valve in the open condition permitting
fluid communication from the screen into the through-bore and in the closed condition
preventing fluid communication from the through-bore to the screen.
[0024] The foregoing summary is not intended to summarize each potential embodiment or every
aspect of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
Figs. 1A-1B illustrate gravel pack assemblies according to the prior art.
Figs. 2A-2B show multi-zone screened system according to the present disclosure being
run-in hole for a wash down operation.
Figs. 3A-3B show the system during setting and testing of the packer.
Figs. 4A-4B show the system during gravel pack operations.
Figs. 5A-5B show the system during filling of the annulus around the shoe track to
dump excess slurry.
Figs. 6A-6B show yet another multi-zone screened system according to the present disclosure
having alternating shunts for gravel pack operations.
Fig. 7 shows a multi-zone screened system having screen sections separated by packers.
Fig. 8 illustrates a multi-zone screened system according to the present disclosure
disposed in an uncased borehole and using a workstring in conjunction with valves
and flow devices.
Fig. 9 illustrates the multi-zone screened system of Fig. 8 having bypass tubes.
Fig. 10A illustrates a partial cross-sectional view of a flow device for the disclosed
multi-zone screened assemblies.
Fig. 10B illustrates a detailed view of a check valve device for the flow device of
Fig. 10A.
Fig. 10C illustrates an isolated, partial cross-sectional view of the flow device
of Fig.10A.
Figs. 11A-11B illustrate another multi-zone screened system according to the present
disclosure disposed in a uncased borehole and using a workstring in conjunction with
valves and flow devices.
Figs. 12A-12D illustrate yet another multi-zone screened system according to the present
disclosure having a toe-to-heel configuration.
DETAILED DESCRIPTION
[0026] Figs. 2A-2B show a multi-zone screened system 200 according to the present disclosure
being run-in hole. The system 200 can be used for formation treatments, such as frac
operations, frac pack operation, gravel pack operations, or other operations. The
system 200 includes a production string or liner 225 (e.g., tubular structure or body)
that extends into a borehole 10 from a liner packer 14 supported in casing 12. This
borehole 10 can be a horizontal or deviated open hole. The system 200 also has a hydraulic
service tool 202 made up to the packer 14 and has an inner workstring 210 made up
to the service tool 202.
[0027] As shown in Figure 12B, the liner 225 can have a float shoe 220 at its end. Meanwhile,
along its length, the liner 225 can have one or more screen sections 240A-B (Fig.
2B) and one or more ported housings 230A-B. In general, the ported housings 230A-B
may be disposed next to or integrated into one or more of the screen sections 240A-B.
As discussed below, use of the one or more screen sections 240A-B and ported housings
230A-B provide one or more slurry packing points for a gravel packing operation.
[0028] Each of the ported housings 230A-B has body or flow ports 232A-B for diverting flow.
Internally, each of the ported housings 230A-B has seats 234 defined above and below
the outlet ports 232A-B for sealing with the distal end of the inner workstring 210
as discussed below. To prevent erosion, the flow ports 232A-B on the ported housings
230A-B can have a skirt, such as the skirt 236 for the flow ports 232A on the ported
housings 230A.
[0029] The flow ports 232B on an upper one of the ported housings 230B communicate with
alternate path devices 250 disposed along the length of the lower screen section 240A.
These alternate path devices 250 can be shunts, tubes, concentrically mounted tubing,
or other devices known in the art for providing an alternate path for slurry. For
the purposes of the present disclosure, however, the alternate path devices 250 are
referred to as shunts herein for simplicity. In general, the shunts 250 communicate
from the flow ports 232B to side ports 222 toward the distal end of the system 200
or other directions for use during steps of the operation.
[0030] As shown in Fig. 2B, the inner workstring 210 extending from the service tool 202
(Fig. 2A) disposes through the screen sections 240A-B of the system 200. (The inner
workstring 210 can have a reverse taper to reduce circulating pressures if desired.)
On the end of the screen sections 240A-B, the system 200 has a shoe track 220 with
a float shoe 226 and seat 224. The float shoe 226 has a check valve, sleeve, or the
like (not shown) that allows for washing down or circulating fluid around the outside
the screen sections 240A-B when running in the well and before the packer 14 is set.
[0031] On its distal end, the inner workstring 210 has outlet ports 212 isolated by seals
214. When running in, one of the seals 214 can seal the end of the inner workstring
210 inside the shoe track 220, as shown in Fig. 2B. In this way, fluid pumped downhole
the inner workstring 210 can exit the check valve (not shown) in the float shoe 226
at the end of the shoe track 220 to washout the borehole 10.
[0032] During the gravel pack operations, however, the outlet ports 212 can locate and seal
by the seals 214 in the ported housings 230A-B disposed between each of the screen
sections 240A-B. In particular, seals 214 located on either side of the string's outlet
ports 212 seal inside seats 234 on the ported housings 230A-B. The seals 214 can use
elastomeric or other types of seals disposed on the inner workstring 210, and the
seats 234 can be polished seats or surfaces inside the housings 230A-B to engage the
seals 214. Although shown with this configuration, the reverse arrangement can be
used with seals on the inside of the housings 230A-B and with seats on the inner workstring
210.
[0033] When fluid is pumped through the inner workstring 210, pumped fluid exits from the
string 210 and through the flow ports 232A-B on the ported housings 230A-B depending
on the location of the string 210 to the flow ports 232A-B. In this arrangement, the
flow ports 232A in the lower ported housing 230A direct the slurry directly into the
annulus, whereas the flow ports 232B in the upper ported housing 230B direct the slurry
into shunts 250 as discussed below. Other similar arrangements can be used. In any
event, this selective location and sealing between the string 210 and housings 230A-B
changes fluid paths for the delivery of slurry into the annulus around the screen
sections 240A-B during the gravel pack operations discussed in more detail below.
[0034] As shown in Figs. 2A-2B, the system 200 is run-in hole for wash down. The service
tool 202 sits on the unset packer 14 in the casing 12, and seals 204 on the service
tool 202 do not seal in the packer 14 to allow for transmission of hydrostatic pressure.
The distal end of the inner workstring 210 fits through the screen sections 240A-B,
and one of the string's seals 214 seals against the seat 224 near the float shoe 226.
Operators circulate fluid down the inner workstring 210, and the circulated fluid
flows out the check valve in the float shoe 226, up the annulus, and around the unset
packer 14.
[0035] As shown in Figs. 3A-3B, operators then set and test the packer 14. To set the packer
14, operators pump fluid downhole to hydraulically or hydrostatically set the packer
14 using procedures well known in the art, although other packer setting techniques
can be used. To test the packer 14, the seals 204 on the service tool 202 are raised
into the packer's bore after releasing from the packer 14. Operators then test the
packer 14 by pressuring up the casing 12. Fluid passing through any pressure leak
at the packer 14 will go into formation around the screen sections 240A-B. In addition,
any leaking fluid will pass into the inner workstring's outlet ports 212 and up to
the surface through the inner workstring 210. Regardless, the system 200 allows operators
to maintain hydrostatic pressure on the formation during these various stages of operation.
[0036] Once the packer 14 is set and tested, operators begin the gravel pack operation.
As shown in Figs. 4A-4B, operators raise the inner workstring 210 to locate in a first
gravel pack position. As shown in Fig. 4B, the string's seals 214 engage the seats
234 around the lower ports 232A below the lower screen section 240A. When this is
done, the tool ports 212 communicate with the housing's ports 232A.
[0037] When manipulating the inner workstring 210, operators are preferably given an indication
at surface that the outlet ports 212 are located at an intended position, whether
it is a blank position, a slurry circulating position, or an evacuating position.
One way to accomplish this is by measuring tension or compression at the surface to
determine the position of the inner workstring 210 relative to the ported housings
230A-B and seats 234. This and other procedures known in the art can be used.
[0038] With the ports 212/232A isolated by the engaged seals 214 and seats 234, operators
pump the slurry of carrying fluid and gravel down the inner workstring 210 in a first
direction to the string's ports 212. The slurry passes out of the pipe's ports 212
and through the housing's ports 232A to the open hole annulus. The carrying fluid
in the slurry then leaks off through the formation and/or through the screen sections
240A-B along the length of the system 200. However, the screen sections 240A-B prevent
the gravel in the slurry from flowing into the system 200. Therefore, the fluid passes
alone through the screen sections 240A-B and returns through the casing annulus above
the packer 14.
[0039] As described herein, the gravel can pack the annulus in an alpha-beta wave, although
other variations can be used. As the fluid leaks off, for example, the gravel drops
out of the slurry and first packs along the low side of the annulus in the borehole
10. The gravel collects in stages that progress from the toe (near housing 230A) to
the heel in an alpha wave. Gravitational forces dominate the formation of the alpha
wave, and the gravel settles along the low side at an equilibrium height along the
screen sections 240A-B.
[0040] After the alpha wave, the borehole 10 fills in a beta wave along the system 200.
The gravel begins to collect in the beta wave along the upper side of the screen sections
240A-B starting from the heel (near the packer 14) and progressing to the toe of the
assembly 200. Again, the fluid carrying the gravel can leak through the screen sections
240A-B and up the annulus between the inner workstring 210 and the liner 225.
[0041] Eventually, the operators reach a desired state while pumping slurry at the ports
232A in this ported housing 230A. This desired state can be determined by a particular
rise in the pressure levels and may be termed as "sand out" in some contexts. At this
stage, operators raise the inner workstring 210 again as shown in Figs. 5A-5B. The
seals 214 now seat on seats 234 around the ports 232B on the next ported housing 230B
between the screen sections 240A-B. Operators pump slurry down the inner workstring
210 again in the first direction to the outlet 212, and the slurry flows from the
pipe's ports 212 and through the housing's ports 232B.
[0042] In general, the slurry can flow out of the ports 232B and into the surrounding annulus
if desired. This is possible if one or more of the ports 232B communicate directly
with the annulus and do not communicate with one of the alternate path devices or
shunt 250. All the same, the slurry can flow out of the ports 232B and into the alternate
path devices or shunts 250 for placement elsewhere in the surrounding annulus. Although
shunts 250 are depicted in a certain way, any desirable arrangement and number of
transport and packing devices for an alternate path can be used to feed and deliver
the slurry.
[0043] Depending on the implementation, this second stage of pumping slurry may be used
to further gravel pack the borehole. Yet, as shown in the current implementation,
pumping the slurry through the shunts 250 enables operators to evacuate excess slurry
from the inner workstring 210 to the borehole without reversing flow in the string
210 from the first flow direction (
i.e., toward the string's port 212). This is in contrast to a reverse direction of flowing
fluid down the annulus between the string 210 and the housings 230A-B/screens 240A-B
to evacuate excess slurry from the string 210.
[0044] As shown in Figure 5B, the slurry travels from the port 212, through flow ports 232B,
and through the shunts 250. From the shunts 250, the slurry then passes out the side
ports or nozzles 254 in the shunts 250 and fills the annulus around shoe track 220.
This provides the gravel packing operation with an alternate path different from the
system's primary path of toe-to-heel. In this way, the shunts 250 attached to the
ported housing 230B above the lower screen section 240A can be used to dispose of
excess gravel from the workstring 210 around the shoe track 220. The shunts 250 carry
the slurry down the lower screen section 240A so a wash pipe is not needed at the
end of the section 240A. However, a bypass 258 defined in a downhole location of the
system 200 (or elsewhere) allows for returns of fluid during this process. This bypass
258 can be a check valve, a screen portion, sleeve, or other suitable device that
allows flow of returns and not gravel from the borehole to enter the system 200. In
fact, the bypass 258 as a screen portion can have any desirable length along the shoe
track 220 depending on the implementation.
[0045] At some point, operation may reach a "sand out" condition or a pressure increase
while pumping slurry at ports 232B. At this point, a valve, rupture disc, or other
closure device 256 in the shunts 250 can open so the gravel in the slurry can then
fill inside the shoe track 220 after evacuating the excess around the shoe track 220.
In this way, operators can evacuate excess gravel inside the shoe track 220. As this
occurs, fluid returns can pass out the lower screen section 240A, through the packed
gravel in the annulus, and back through upper screen section 240B to travel uphole.
In other arrangements, the lower ported housing 230A can have a bypass, another shunt,
or the like (not shown), which can be used to deliver fluid returns past the seals
214 and seats 234 and uphole.
[0046] The previous system 200 filled the open hole annulus with an alpha-beta type wave
and then filled the annulus around the toe with an alternate path. As shown in Figs.
6A-6B, the system 200 can use an additional alternative path device or shunt 260 to
fill the open hole annulus while circulating in the gravel pack operation. In this
arrangement, the operation of the system 200 is similar to that discussed previously.
Again, the system 200 has one or more ported housings 230A-B for the slurry to exit
and has one or more screen sections 240A-B.
[0047] When operators raise the inner workstring 210 to locate in the gravel pack position
shown in Fig. 6B, operators pump at least some of the slurry into the open hole annulus
using the additional shunts 260 in an alternative path gravel pack. The shunts 260
may be used exclusively. Alternatively, the slurry can be pumped out through one or
more of the housing's ports 232A at the same time. By using an arrangement of shunts
250/260 and open flow ports 232, the system 200 can gravel pack zones from toe-to-heel,
from heel-to-toe, and combinations thereof.
[0048] As can be seen in Figs. 2A through 6B, the disclosed system 200 can be used in a
number of versatile ways to gravel pack the annulus of a borehole. For example, the
string's outlet ports 212 can locate in one or more different ported housings 230A-B
to gravel pack around the screen sections 240A-B in an alpha-beta wave or alternative
path. Additionally, the inner workstring 210 can be moved to multiple housings 230A-B
to pack a single zone from multiple points or to gravel pack the same zone from a
first direction and then from a different direction (e.g., first from bottom to top
and then from top to bottom using shunts 250/260).
[0049] Moreover, the inner workstring 210 can be used to pump treatments of different types
into a surrounding zone. For example, the system 200 of Figs. 2A through 6B can be
used to perform frac packing from one point and then gravel packing (via shunts 250
and/or 260) from another point along the screen sections 240A-B. In frac packing,
operators perform a frac treatment by delivering large volumes of graded sand, proppant,
or the like into the annulus and into the formation at pressures exceeding the frac
gradient of the formation. The graded sand or proppant enters fractures in the borehole
10 to keep the fractures open. After the frac treatment, operators can then perform
a gravel pack operation to fill the annulus with gravel. Alternatively, the gravel
pack and frac treatment can be performed at the same time.
[0050] In a frac packing arrangement, the disclosed system 200 can deliver the frac treatment
and gravel slurry through the multiple ported housing 230A-B into the annulus around
the screen sections 240A-B. Dispersing the frac treatment and slurry through the multiple
ports 232A-B can provide more even distribution across a greater area. For the fracturing
part of the process, the frac treatment can exit from the lower ported housing 230A,
and fluid returns can pass through the screen section 240B adjacent to the casing
annulus until the fracture is complete. Afterwards, the inner workstring 210 can be
moved to the upper ported housing 230B so that gravel slurry can flow through shunts
250 and/or 260 to gravel pack the annulus. A reverse operation could be done in which
frac treatment can exit upper housing 230B so that gravel packing can be done primarily
at the lower housing 230A using toe-to-heel gravel packing.
[0051] When used for frac/gravel packing, the system 200 may reduce the chances of sticking.
Because the system 200 can have a smaller volumetric area around the exit points,
there may be less of a chance for proppant sticking around the gravel pack ports 212.
As slurry exits near the end of the inner workstring 210, only a short length of pipe
has to travel upward through remaining slurry or dehydrated sand that may be left.
If sticking does occur around the gravel pack ports 212, a shear type disconnect (not
shown) can be incorporated into the inner workstring 210 so that the lower part of
the inner workstring 210 can disconnect from an upper part of the inner workstring
210. This allows for the eventual removal of the inner workstring 210.
[0052] Expanding on the versatility of the disclosed system, Figure 7 shows a system 300
segmenting several compartmentalized reservoir zones. Again, the system 300 can be
used for formation treatments, such as frac operations, frac pack operation, gravel
pack operations, or other operations. The system 300 includes a production string
or liner 325 (e.g., tubular structure or body) and includes an inner workstring 310.
The liner 325 extends into a borehole 10 from a liner packer 14 supported in casing
12. Again, this borehole 10 can be a horizontal or deviated open hole.
[0053] The liner 325 has multiple gravel pack sections 302A-C separated by packers 360/370.
The packers 360/370 and gravel pack sections 302A-C are deployed into the well in
a single trip. One packer 360/370 or a combination of packers 360/370 can be used
to isolate the gravel pack sections 302A-C from one another. Any suitable packers
can be used and can include hydraulic or hydrostatic packers 360 and swellable packers
370, for example. Each of these packers 360/370 can be used in combination with one
another as shown, or the packers 360 or 370 can be used alone.
[0054] The hydraulic packers 360 provide more immediate zone isolation when set in the borehole
10 to stop the progression of the gravel pack operations in the isolated zones. For
their part, the swellable packers 370 can be used for long-term zone isolation. The
hydraulic packers 360 can be set hydraulically with the inner workstring 310 and its
packoff arrangement 314, or the packers 360 can be set by shifting sleeves (not shown)
in the packers 360 with a shifting tool (not shown) on the inner workstring 310.
[0055] Each gravel pack section 302A-C can be similar to the assemblies 200 as discussed
above in Figures 2A through 6B. As such, each gravel pack section 302A-C has two screens
340A-B, alternate path devices or shunts 350, and ports 332A-B and can have the ported
housings and other components discussed previously. After the inner workstring 310
deploys in the first gravel pack section 302A and performs wash down, the string's
outlet ports 312 with its seals 314 isolates to the lower flow ports 332A to gravel
pack and/or frac the first gravel pack section 302A. Then, the inner workstring 310
can be moved so that the outlet ports 312 isolates to upper flow ports 332B connected
to the shunts 350 to fill the annulus around the lower end of the first gravel pack
section 302A. A similar process can then be repeated up the hole for each gravel pack
section 302A-C separated by the packers 360/370. Using the procedures disclosed above,
excess slurry can be evacuated from the inner workstring 310 to the annulus before
the workstring 310 is moved between sections 302A-C.
[0056] Turning now to Figures 8-9, another multi-zone screened system 400 includes an inner
workstring 410 and a screened assembly 420. Again, the system 400 can be used for
formation treatments, such as frac operations, frac pack operation, gravel pack operations,
or other operations. The screened assembly 420 has a production string or liner 425
(e.g., tubular structure or body) that extends into a borehole 10 from a liner packer
14 supported in casing 12. At its end, the liner 425 can have a float shoe 422 or
the like, and sections 428A-C disposed on the liner 425 can each have an isolation
element 429, a flow valve 430, a screen 440, and a closure 450.
[0057] As shown in Figure 8, the workstring 410 positions in the assembly 420 to open the
various valves 430 and treat portions of the formation. As shown, the workstring 410
has external seals 416 disposed near outlet ports 412. A dropped ball 414 can seat
in a distal seat of the workstring 410 to divert fluid flow down the workstring 410,
out the outlet ports 412, and to the open ports 432 in the valve 430 to treat the
surrounding formation.
[0058] The flow devices 440 disposed on the assembly 420 include wellscreens 446 and the
closures 450 (
i.e., one-way or check valves, sliding sleeves, etc.). As one-way or check valves, the
closures 450 can be configured in different ways and can include ball, poppet, or
disk type check valves that are concentrically or eccentrically mounted on the outer
radius of the screen's basepipe. The closures 450 can be part of a housing that directs
flow into a basepipe and can attach to the wellscreens to ensure fluid flow is filtered
of solids. Preferably, multiple closures 450 can be installed on each joint to reduce
and even out pressure drops across the screen joints to promote complete development
of the beta wave during gravel packing. Alternatively, the closures 450 can be mounted
into the basepipe and can allow flow into a housing mounted on the radial exterior
of the basepipe and attached to the wellscreen 446.
[0059] The operation for the system 400 of Figure 8 involves running the screened assembly
420 downhole and setting the packers 429 to create the multiple isolated sections
428A-C down the borehole annulus 15. Once the packers 429 are set, operators apply
a frac treatment successively to each of the isolated sections 428A-C by selectively
opening the selective valves 430 with a shifting tool 418 on the workstring 410.
[0060] In general, the shifting tool 418 can be a "B" shifting tool for shifting the inner
sleeve 434 in the valve 430 relative to the valve's ports 432. Thus, opening a given
valve 430 involves engaging the shifting tool 418 in an appropriate profile of the
valve's inner sleeve 434 and moving the inner sleeve 434 with the workstring 410 to
an opened condition so that the assembly's through-bore 425 communicates with the
borehole annulus 15 via the now opened ports 432.
[0061] Once a given valve 430 is opened, the seals 416 on the workstring 410 can engage
and seal against inner seats 438, surfaces, seals, or the like in the valve 430 or
elsewhere in the assembly 420 on both the uphole and downhole sides of the opened
ports 432. The seals 416 can use elastomeric or other types of seals disposed on the
inner workstring 410, and the seats 438 can be polished seats or surfaces inside the
valve 30 or other parts of the screened assembly 420 to engage the seals 416. Although
shown with this configuration, the reverse arrangement can be used with seals on the
inside of the valve 430 or the screened assembly 420 and with seats on the workstring
410.
[0062] Once the workstring 410 is seated, treatment fluid is flowed down the through-bore
415 of the workstring 410 to the sealed and opened ports 432 in the valve 430. The
treatment fluid flows through the outlet ports 412 in the workstring 410 and through
the opened ports 432 to the surrounding borehole annulus 15, which allows the treatment
fluid to interact with the adjacent zone of the formation.
[0063] Once treatment is completed for the given zone 428A-C, operators manipulate the workstring
410 to engage the shifting tool 418 in the valve 430 to close the ports 432. For example,
the shifting tool 418 can engage another suitable profile on the inner sleeve 434
of the valve 430 to move the sleeve 434 and close the ports 432. At this point, the
workstring 410 can be moved in the assembly 420 to open another one of the valves
430 to perform treatment. Operators repeat this process up the assembly 420 to treat
all of the sections 428A-C. Once the treatment is complete, the system 400 may not
need a clean-out trip.
[0064] The multi-zone system 400 of Figure 8 can have higher rates compared to a conventional
single trip multi-zone system and can improve reservoir performance. The system 400
can have any suitable length and spacing, offers the option to step down one casing
size, does not require perforating, and does not require a clean-out trip. Consideration
should be given to potential sticking the workstring 410 during operation and to annulus
packing that can occur for a particular implementation.
[0065] In another embodiment, the multi-zone screened system 400 of Figure 9 also has a
workstring 410 and screened assembly 420, as with the previous embodiment of Figure
8. In addition to all of the same components, this system 400 has slurry dehydration
or bypass tubes 480 disposed along the various sections 428A-C.
[0066] During a treatment operation similar to that discussed above, the tubes 480 help
dehydrate slurry intended to frac or gravel pack the borehole annulus 15 of the sections
428 during a frac pack or gravel pack type of operation. In addition, the tubes 480
can act as a bypass for fluid returns during the operation. As treatment fluid flows
from the workstring 410 seated in a valve 430, through the opened ports 432, and into
the borehole annulus 15, the wellscreen 446 screens fluid returns from the annulus
15, and the fluid returns can flow into the assembly 420 downhole of the engagement
of the workstring 410 in the assembly 420. The tubes 480 can, therefore, allow these
fluid returns to flow from the downhole section of the assembly 420 to the micro-annulus
between the workstring 410 and the inside of the assembly 420 uphole of the sealed
engagement of the workstring 410 with the ports 432. From this point, the fluid returns
can then flow to the surface.
[0067] The multi-zone system 400 of Figure 9 can have higher rates compared to a conventional
single trip multi-zone system 400 and can improve reservoir performance. Furthermore,
the system 400 can have any length and spacing, offers the option to step down one
casing size, does not require perforating, does not require a clean-out trip, and
can give good annulus packing. Consideration should be given to potential sticking
of the workstring 410 for a particular implementation.
[0068] As noted above, the multi-zone system 400 can use flow devices 440 disposed on the
assembly 420, and the flow device 440 includes the wellscreen 446 and the closure
450 (
i.e., one-way or check valves). Turning now to Figures 10A-10B, one embodiment of a flow
device 540 that can be used for the disclosed systems 400 is shown in a partial cross-sectional
view and a detailed view, respectively. The flow device 540 is a screen joint having
a screen jacket 550 (
i.e., wellscreen) and an inflow control device 560 (
i.e., one-way or check valve) disposed on a basepipe 542. (Figure 10C shows the inflow
control device 560 in an isolated view without the basepipe 542 and the screen jacket
160.)
[0069] The flow device 540 is deployed on a completion string (422: Figs. 8-9) with the
screen jacket 550 typically mounted upstream of the inflow control device 560, although
this may not be strictly necessary. The basepipe 542 defines a through-bore 545 and
has a coupling crossover 546 at one end for connecting to another joint or the like.
The other end 544 can connect to a crossover (not shown) of another joint on the completion
string (422). Inside the through-bore 545, the basepipe 542 defines pipe ports 548
where the inflow control device 560 is disposed.
[0070] As noted above, the inflow control device 560 can be similar to a FloReg deploy-assist
(DA) device available from Weatherford International. As best shown in Figure 10B,
the inflow control device 560 has an outer sleeve 562 disposed about the basepipe
152 at the location of the pipe ports 548. A first end-ring 564 seals to the basepipe
542 with a seal element 565, and a second end-ring 566 attaches to the end of the
screen jacket 550. Overall, the sleeve 562 defines an annular space around the basepipe
542 communicating the pipe ports 548 with the screen jacket 550. The second end-ring
566 has flow ports 570 that separate the sleeve's annular space into a first inner
space 576 communicating with the screen 550 and second inner space 578 communicating
with the pipe ports 548.
[0071] For its part, the screen jacket 550 is disposed around the outside of the basepipe
542. As shown, the screen jacket 550 can be a wire wrapped screen having rods or ribs
554 arranged longitudinally along the base pipe 542 with windings of wire 552 wrapped
thereabout to form various slots. Fluid can pass from the surrounding borehole annulus
to the annular gap between the screen jacket 550 and the basepipe 542. Although shown
as a wire-wrapped screen, the screen jacket 550 can use any other form of screen assembly,
including metal mesh screens, pre-packed screens, protective shell screens, expandable
sand screens, or screens of other construction.
[0072] Internally, the inflow control device 560 has a number (e.g., ten) of flow ports
570. Rather than providing a predetermined pressure drop along the screen jacket 550
by using multiple open or closed nozzles (not shown), the inflow control device 560
as shown in Figures 10A-10C may lack the typically used restrictive nozzles and closing
pins for the internal flow ports 570. Instead, the flow ports 570 may be relatively
unrestricted flow passages and may lack the typical nozzles, although a given implementation
may use such nozzles if a pressure drop is desired from the screen jacket 550 to the
basepipe 542.
[0073] Internally, however, the inflow control device 560 does include port isolation balls
572, which allow the device 560 to operate as a one-way or check valve. Depending
on the direction of flow or pressure differential between the inner spaces 576 and
578, the port isolation balls 572 can move to an open condition (to the right in Fig.
10B) permitting fluid communication from the screen's inner space 576 to the pipe's
inner space 578 or to a closed condition (to the left in Fig. 10B against a seat end
574 of the flow port 570) preventing fluid communication from the pipe's inner space
578 to the screen's inner space 576.
[0074] In general, the inflow control device 560 can facilitate fluid circulation during
deployment and well cleanup and can be used in interventionless deployment and setting
of openhole packers. In deployment, for example, the isolation balls 572 maximize
fluid circulation through the completion shoe (420: Figs. 8-9) of the frac system
(20) to aid efficient deployment of the completion string (22) and system (20). When
the housing components (562, 564, 565, & 566) are disposed on the basepipe 540, the
isolation balls 572 are retained in-place. During initial installation and production,
the isolation balls 572 can prevent formation surging, thereby reducing damage to
the formation. In some arrangements, the isolation balls 572 within the device 560
can be configured to erode over a period of time, allowing access to the interval
for workover activity such as stimulation.
[0075] Should a pressure drop be desired from the screen jacket 550 to the basepipe 542,
the flow ports 570 can include nozzles (not shown) that restrict flow of screened
fluid (
i.e., inflow) from the screen jacket 550 to the pipe's inner space 578. For example, the
inflow control device 560 can have ten nozzles, although they all may not be open.
Operators can set a number of these nozzles open at the surface to configure the device
560 for use downhole in a given implementation. Depending on the number of open nozzles,
the device 560 can thereby produce a configurable pressure drop along the string of
such flow devices 540.
[0076] Figures 11A-11B illustrate another multi-zone screened system 400 according to the
present disclosure used for an open hole completion. Again, the system 400 can be
used for formation treatments, such as frac operations, frac pack operation, gravel
pack operations, or other operations. As with some previous arrangements, the system
400 has a workstring 410 that disposes in a screened assembly 420 to open the various
valves 430 and treat portions of the formation, but the workstring 410 in this arrangement
does not seal inside the assembly 420 when delivering the treatment at various points
in the formation.
[0077] As shown, a service packer 17 can be used between the workstring 410 and the casing
12 to isolate the internal through-bore 425 of the assembly 420. As also shown, the
workstring 410 has a service tool 417 disposed above the liner packer 16. The service
tool 417 can be used for hydraulically setting the packer 16. Regardless of the configuration
used, the uphole components of the system 400 can be used for circulating, squeeze,
and reverse out operations as is known in the art.
[0078] The workstring 410 has one or more outlet ports 412 and has hydraulically actuated
shifting tools 418a-b. Both of the shifting tools 418a-b can be actuated with applied
pressure against a ball when seated in the workstring 410. One shifting tool 418b
can open the valves 430 when the workstring 410 is run downhole in the assembly 420,
while the other shifting tool 418a can close the valves 430 when the workstring 410
is run uphole in the assembly 420. The same can be true for opening and closing the
flow devices 440 with the shifting tools 418a-b as discussed below. Thus, one shifting
tool 418b is run facing down, while the other tool 418a is run facing up. Other arrangements
can be used, and other types of shifting tools can be used as well.
[0079] As an example, the shifting tools 418a-b can each be a hydraulically actuated version
of an industry standard B shifting tool. When the shifting ball (74) is dropped in
the workstring 410, the application of hydraulic pressure down the workstring 410
actuates the shifting tools 418a-b so that they expose spring-loaded keys for shifting
the valves 430 and flow devices 440 open or closed. The shifting tools 418a-b may
be actuated together with the same ball 414 or actuated separately with different
sized balls 414 depending on the configuration.
[0080] As before, the assembly 420 has a production string 422 supported from a packer 16
in the casing 12. Along its length, the string 422 has isolation devices 429, valves
430, and flow devices 440. The isolation devices 429, which can be packers, seal the
borehole annulus 15 around the assembly 420 and separate the annulus 15 into various
zones or sections 428A-C. Each section 428A-C has at least one of the valves 430 and
at least one of the flow devices 440, both of which can selectively communicate the
string's through-bore 425 with the borehole annulus 15 as detailed below. At its downhole
end, the assembly 420 has a bottom seat 422 for engaging a setting ball 424 to close
off the shoe 420 during frac, gravel pack, or frac pack operations.
[0081] As shown, the selective valve 430 is disposed uphole of the flow device 440 in each
of the various sections 428A-C. As an alternative, the selective valve 430 can be
disposed downhole of the flow device 440 in each section 428A-C. Moreover, a given
section 428A-C may have more than one valve 30 and/or flow device 440.
[0082] The selective valves 430 have one or more ports 432 that can be selectively opened
and closed during operation. In this arrangement as with others discussed above, each
of the selective valves 430 can be opened to communicate their ports 432 with the
surrounding annulus 15 by using the shifting tool 418a on the workstring 410. As before,
the valves 430 can be sliding sleeves having a movable closure element 434, such as
an inner sleeve or insert, which isolates or exposes ports 432 in the sliding sleeve's
housing.
[0083] Similar to the valves 430, the flow devices 440 also have one or more ports 442 that
can be selectively opened and closed during operation. Each of the flow devices 440
also includes a closure and a screen 446. The closure in this arrangement includes
a first closure element 444 that selectively opens and closes flow through the flow
ports 442 and includes a second closure element 450 that at least prevents fluid flow
from the through-bore 425 through the screen 446.
[0084] This system 400 is a single trip, multi-zone system as discussed in previous embodiments.
Briefly, the assembly 420 is run downhole as part of the production string 422 or
liner system deployed in the borehole, and the liner packer 16 is set hydraulically.
Treatments are then performed for the various zones or sections 428A-B of the borehole
annulus 15 by selectively opening the valves 430.
[0085] After treatment (e.g., gravel packing or fracing) is completed, excess gravel or
proppant is cleaned out of the assembly 420, and the valves 430 are closed because
they are used primarily for outlet ports for the treatment. To prepare the assembly
420 for production, the flow devices 40 are then opened in the assembly 420 with the
workstring 410 in the same trip in the wellbore by opening the first closure element
444 (e.g., inner sleeve) to expose the flow ports 442. Once open, the flow devices
440 screen fluid from the borehole annulus 15 into the string's through-bore 425.
At the same time, the flow device's second closure element 450 functions to prevent
flow in the reverse direction. As discussed in more detail below, for example, the
flow device's second closure element 450, which can use one-way or check valve, can
prevent fluid loss into the formation while pulling out the workstring 410 from the
assembly 420 and while performing production.
[0086] With a general understanding of how the assembly 420 is used, discussion now turns
to how treatment operations are performed in more detail. Initially, all of the valves
430 and flow devices 440 are closed on the assembly 420 when run in the borehole.
After setting the liner packer 16 and closing off the bottom seat 450 with the setting
ball 454, operators set the packers 429 along the assembly 420 with the appropriate
procedures to create the multiple isolated sections 428A-C down the borehole annulus
15. Once the packers 429 are set, operators can then commence with applying treatment
successively to each of the isolated sections 428A-C by selectively opening and then
closing the selective valves 430 with the shifting tools 418a-b on the workstring
410.
[0087] As shown in Figure 11A, for example, the selective valve 430 for the lower section
428A is opened, but its accompanying flow device 440 remains closed. To open this
lower valve 430, operators position the workstring 410 near the valve 430 and drop
the shifter ball (414) to the shifting tools 418a-b on the workstring 410. Operators
then pressure up the workstring 410, and the applied pressure in the workstring's
bore 415 acts against the seated ball (414) and actuates the shifting tools 418a-b.
Using the opening tool (e.g., 418b), operators open the valve 430 (e.g., by shifting
the inner sleeve 434 in the valve 430 open). Once the valve 430 is open, operators
then bleed off the applied pressure and reverse the flow so that the seated ball (414)
in the workstring 410 can be reversed out through the workstring's bore 415 to the
surface.
[0088] For example, the flow device 440 can be a sliding sleeve having a movable closure
element 444, such as an inner sleeve or insert, which isolates or exposes the ports
442 in the sliding sleeve's housing. The flow device 440 can be opened to communicate
its ports 442 with the surrounding annulus 15 through its screen 446 by using the
shifting tool 418a on the workstring 410. In this way, the flow device 440 when closed
does not communicate the string's through-bore 425 with the borehole annulus 15 through
screens 446, but the flow device 440 when opened allows screened fluid from the annulus
15 to pass through the screen 446 on the device 440 and into the through-bore 425.
[0089] Now, operators position the workstring 410 uphole of the open valve 30 as shown in
Figure 11A. In manipulating the workstring 410 in the assembly 420, the workstring
410 is positioned unsealed in the assembly's through-bore 425 relative to the open
ports 432 in the valve 430. In other words, the workstring 410 at the section 428A
to be treated is not engaged with seals or seats inside the assembly's through-bore
425 as in previous embodiment.
[0090] Without sealing the workstring 410 in the assembly's section 428A, operators apply
the treatment down the workstring 410 to treat the borehole annulus 15 for this section
428A. The fluid leaves the ports 412 in the workstring 410 and flows along a first
flow path through the open ports 432 of the valve 430 and into the formation around
the open section's borehole annulus 15. To maintain the pressure in the assembly 420
during the operation, the system 400 can use a live annulus technique (if the service
packer 17 is not used or can be removed, or the system 400 can use a pure squeeze
technique with the service packer 17 in the casing 12.
[0091] At the same time as the treatment, the closure on the flow device 440 at least prevents
fluid flow through the ports 442 and screen 446 from the through-bore 425 to the borehole
annulus 15. Preventing the flow out of the screen 446 can be accomplished by either
the first or second closure elements 444 and 450 or by both. Preferably, the first
closure element 444 also prevents fluid flow from the borehole annulus 15 into the
through-bore 425 via the screen 446.
[0092] Once treatment of the first section 428A is done, operators reverse out at least
some of the excess slurry from the workstring 410 so treatment can commence with the
next section 428B. Operators drop the shifter ball (not shown) down the workstring
70 again, and pressure up the workstring 410 to actuate the shifting tools 418a-b
with the seated ball 414. With the tools 418a-b actuated, operators close the open
valve 30 for the lower section 428A with the closing tool 418a. After bleeding off
the pressure, the workstring 410 is raised to the valve 430 in the next section 428B.
At this point, operators then pressure up on the seated shifter ball 414 in the workstring
410 again and open this valve 430 with the actuated opening tool 418b. After bleeding
off the applied pressure in the workstring 410 and reversing out the seated ball 414,
the treatment process for this new section 428B is then repeated as before.
[0093] Similar procedures are then repeated for all of the subsequent sections (
i.e., 428C) of the assembly 420. Once treatment is complete for all of the sections 428A-C,
all of the valves 430 and flow device 440 on the assembly 420 are closed. Operators
perform a washout operation. To do this, the workstring 410 is lowered down toward
the shoe 420 of the assembly 420, and operators pump a washout fluid down the casing
12 to reverse out any residual gravel, proppant or other treatment up the workstring
410. Because all of the valves 430 are closed, operators have no issues with reversing
flow for the washout operation.
[0094] When washout is complete, operators then open all of the flow devices 440 so their
ports 442 communicate with the string's through-bore 425 to accept production. The
workstring 410 positions toward the bottom shoe 426, and operators drop the shifter
ball 414 again. Pressure is applied to the seated ball 414 to actuate the shifter
tools 418a-b on the workstring 410, and operators raise the workstring 410 and open
the first closure elements 444 (e.g., inner sleeve) of the flow devices 440 up the
assembly 420 using the opening tool 418b.
[0095] As the flow devices 440 are opened, fluid from the borehole annulus 15 can flow along
a second flow path through the screens 446, closure elements 450, and opened ports
442. As the flow devices 440 are opened up the assembly 420, the second closure elements
48 (e.g., one-way or check valves) of the flow devices 440 prevent fluid loss from
the string's through-bore 425 to the annulus 15 during this process. As shown in Figure
11B, once all of the flow devices 440 are open, the workstring 410 is removed from
the assembly 420. At this point, the assembly 420 is prepared to receive production
through the screens 446, closure elements 450, and opened ports 442 via the second
flow path.
[0096] As can be seen, operation of this system 400 can reduce the time and risk involved
in performing the treatment because no service tool needs to seal in the assembly
420. Moreover, pickup and operations time are reduced. Essentially, the workstring
410 can be run in during the liner setting trip so that no added runs are needed.
Cleanout and opening/closing of the ports 432 and 442 in the valves 430 and flow devices
440 are all done in the same trip.
[0097] The present example of the system 400 is described for an open hole, but the system
400 for a cased hole would be the same except that the isolation packers 429 may be
different. Because the system 400 does not use dropped balls in the assembly 420 to
open the valve 430 or flow devices 440, the number of stages that can be deployed
downhole is not limited by the required step-down sizes in balls and seats. Moreover,
no balls or seats are left in the assembly 420 after treatment operations so the operation
does not need a separate milling operation, which can be time consuming and can encounter
its own issues. In essence, the wellbore is ready to receive production tubing after
the operation is completed.
[0098] As noted above, in a conventional gravel pack systems, sand slurry is introduced
into the annulus uphole of the wellscreens and is circulated downhole
(i.e., from heel to toe). The toe-to-heel system as disclosed for example in Figures 2A-7
reverses that flow path and introduces the sand slurry into the screen annulus at
the toe of the well and circulates it uphole. Further details related to this system
are provided in
U.S. Appl. 12/913,981, filed 28-OCT-2010. The toe-to-heel system of Figures 2A-7 is designed so that any excess sand slurry
in the workstring can be disposed of downhole in a dedicated annulus in the well.
This is so because reverse circulating excess slurry from the workstring with the
toe-to-heel system of Figures 2A-7 is not practical. In particular, the reverse circulation
would require exerting pressure inside the screens and against the formation, and
that additional pressure applied to the formation can result in inducing fluid loss
into the formation or worse, fracturing the formation. Accordingly, the toe-to-heel
system of Figures 2A-7 is designed so that any excess sand slurry in the workstring
can be emptied downhole in a dedicated annulus in the well.
[0099] To allow for reverse circulating, the systems of Figures 8 through 11B disclosed
above have added pressure holding integrity to the inside of the screens without requiring
a separate string of pipe or devices to be run and actuated through intervention.
Further details related to this system are provided in
U.S. Appl. 13/670,125, filed 06-NOV-2012. The systems of Figures 8 through 11B still allow for fluid entry so the well can
be produced. By extension then, such pressure holding integrity added to the inside
of the screens can be included in a toe-to-heel system, such as mentioned above with
reference to Figures 11A-11B.
[0100] To that end, a toe-to-heel system 600 disclosed in Figures 12A-12D equips each wellscreen
640 with closure elements 645 (e.g., check valves or the like). During use, the closure
elements 645 on the screens 640 prevent fluid flow inside the screens 640 from passing
outside the screens 640, but allow fluid flow from outside the screens 640 to pass
inside the assembly 620. This allows operators to apply pressure inside the screen
liner assembly 620 after gravel packing in order to reverse circulate and remove excess
slurry from the workstring 610 after completing a gravel pack.
[0101] Turning to Figure 12A, the system 600 includes a packer 14 that sets in the casing
12 above the area of a wellbore to be produced from or injected into. Below the packer
14, a screen liner assembly 620 is spaced out across one or more zones of interest.
If there are multiple zones, packers 670 (either open hole or cased hole) are spaced
out to isolate one screen section 602A-C from the other. The packers 670 do not require
shunts running through them to gravel pack multiple zones, but they could be equipped
this way.
[0102] The assembly 620 and packers 670 are run downhole in a single trip. This system 600
segments several compartmentalized reservoir zones so that multiple gravel pack operations
as well as frac operations can be performed. As shown herein, the system 600 has several
gravel pack sections 602A-C separated by packers 670, which seal in the open hole
to isolate one zone from another. One or more packers 670 can be used to isolate each
of the gravel pack sections 602A-C from one another. Any suitable packers can be used
and can include hydraulic packer, hydrostatic packers, and swellable packers, for
example. The packers 670 provide zone isolation when set in the borehole 10 to stop
the progression of the treatment operations in the isolated zones.
[0103] Each section 602A-C can be similar to the systems 200, 300, and 400, as discussed
above. Each section 602A-C has a screen 640 and ports 650. The screens 640 include
a closure element 645 (e.g., one-way valve, check valves, or the like). Ports 650
adjacent the screens 640 may or may not include valves 652 or selective sleeves.
[0104] This system 600 has a workstring 610 that disposes in the assembly 620 to treat (
e.g., gravel or frac pack) portions of the formation. As shown, the workstring 610 has
external seals 612 disposed near outlet ports 614. A dropped ball 414 can seat in
a distal seat of the workstring 610 to divert fluid flow down the workstring 610,
out the outlet ports 612, and to the ports 650 in the assembly 620 to treat the surrounding
formation. However, other configurations can be used for the workstring 610.
[0105] The workstring 610 deploys in the first section 602A and performs washdown by communicating
the string's outlet port 612 with the float valve 626 on the float shoe 620 of the
system 600. After washdown, the packers 670 are set to create the multiple isolated
sections down the borehole annulus 15. The packers 670 can be set hydraulically, hydrostatically,
with RFID tags, or with pressure pulses.
[0106] Once the packers 670 are set, operators can begin applying a treatment
(i.e. fracture, gravel pack, frac-pack, etc.) successively to each of the isolated sections
602A-C. In particular, the string 610 can be selectively positioned at any one of
the various sections 602A-C along the system 600. In the selective position, the string's
outlet ports 612 with its seals 614 isolate to the flow ports 650 to gravel pack and/or
frac pack the annulus 15 around given gravel pack section 602A-C. Then, the inner
workstring 610 can be moved so that the outlet ports 612 isolate from these flow ports
650 so reverse circulation can be performed to remove excess slurry from the workstring
610 before moving it to the next gravel pack section 602A-C. A similar process can
then be repeated up the hole for each gravel pack section 602A-C separated by the
packers 670.
[0107] As shown in Figure 12B in particular, after washdown, the string's outlet ports 612
with its seals 614 isolates to the flow ports 650 to gravel pack and/or frac pack
the first gravel pack section 602A. If the flow ports 650 include a valve, then the
valve may be opened, for example, by shifting a sleeve open. Slurry communicated down
the workstring 610 exits the outlet ports 612 and passes through the section's ports
650 to flow into the isolated annulus of this first section 602A. Gravel from the
slurry then gravel packs in the annulus from toe-to-heel as described herein, and
fluid returns from the slurry pass through the screen 640 and into the annular space
between the liner 630 and the workstring 610. The fluid returns can then flow uphole
past the packer 14 to the casing 12 and the surface.
[0108] As shown, the ports 650 may have selective valves or sleeves 652 that can be opened
with a shifting tool 616 on the workstring 610, although these components may not
be necessary in every embodiment. In general, the shifting tool 616 can be a "B" shifting
tool for shifting the valve 652 relative to the ports 650. Thus, opening a given valve
652 involves engaging the shifting tool 616 in an appropriate profile of the valve
652 and moving the valve 652 with the workstring 610 to an opened condition so that
the assembly's through-bore 625 communicates with the borehole annulus 15 via the
now opened ports 650.
[0109] As shown in Figure 12B, the seals 614 on the workstring 610 can engage and seal against
inner seats 654, surfaces, seals, or the like at the ports 650 in the assembly 620
on both the uphole and downhole sides. The seals 614 can use elastomeric or other
types of seals disposed on the inner workstring 610, and the seats 654 can be polished
seats or surfaces inside the assembly 620 to engage the seals 614. Although shown
with this configuration, the reverse arrangement can be used with seals on the inside
of the assembly 620 and with seats on the workstring 610. Additionally, some embodiments
may lack seals and seats altogether and may instead rely on opening and closing the
valves 652 on the ports 650 to control fluid flow.
[0110] Once the workstring 610 is seated, treatment fluid is flowed down the through-bore
of the workstring 610 to the ports 650 at the first zone 602A. The treatment fluid
flows through the outlet ports 612 in the workstring 610 and through the ports 650
to the surrounding borehole annulus 15, which allows the treatment fluid to interact
with the adjacent zone of the formation. For example, fracture treatment with proppant
can be pumped, or gravel in a slurry can be pumped into the annulus.
[0111] Gravel packing from toe-to-heel in the system 600 allows fluid returns to pass through
the screen 640 and dehydrate the slurry intended to gravel pack the borehole annulus
15 of the sections 602A-C during a gravel or frac pack type of operation. Different
from the arrangement in Figure 9, no separate bypass or tube is needed for fluid returns
during the operation. Instead, fluid returns R can flow through the screen 640 and
pass through the check valve 645 on the screen 640 and into the through-bore 625 of
the assembly 620. As treatment fluid flows from the workstring 610 seated at the ports
650 and into the borehole annulus 15, the wellscreen 640 screens fluid returns from
the annulus 15, and the fluid returns can flow into the assembly 620 uphole of the
engagement of the workstring 610 in the assembly 620. From this point, the fluid returns
can then flow to the surface.
[0112] Eventually, sandout will occur when the first section 602A is sufficiently gravel
packed. As then shown in Figure 12C, the workstring 610 can be manipulated to an intermediate
position so that the outlet ports 612 communicate inside the screen liner assembly
620. Once treatment is completed for the given zone 602A, operators can manipulate
the workstring 610 to engage the shifting tool 616 in the valve 652 to close the ports
650. For example, the shifting tool 616 can engage another suitable profile on the
valve 652 to move the valve 652 and close the ports 650.
[0113] At this point, the workstring 610 can be moved in the assembly 620 to an intermediate
position that allows for excess slurry to be removed from the workstring 610 before
moving the workstring 610 to a new zone 602B. As will be appreciated, any excess slurry
in the workstring 610 can flow into the assembly 620 while the workstring 610 is manipulated,
and any gravel, proppant, sand, or the like in the slurry can cause problems with
the workstring 610 sticking, fouling valves, etc.
[0114] Therefore, in the intermediate position, the outlet ports 612 on the workstring 610
are exposed to the through-bore 625 of the assembly 620. Reverse circulation can then
be pumped down the borehole 12 and into the annular space between the workstring 610
and assembly 620. This clears the excess slurry, which travels back up the workstring
610.
[0115] Once reverse circulation is complete, the workstring 610 can be moved in the assembly
620 to another zone 602B to perform treatment. Operators repeat this process up the
assembly 620 to treat all of the sections 602A-C. Once the treatment is complete,
the system 600 may not need a clean-out trip.
[0116] Having the system 600 noted above, gravel packing can be accomplished where the wellscreens
640 are able to be pressurized on the inside. This allows the system 600 to be operated
under reverse circulation that exerts pressure inside the assembly 620. Being able
to reverse circulation this way makes it possible to perform single zone toe-to-heel
gravel packs and subsequently reverse out the excess slurry. The system 600 also makes
it possible to perform multiple gravel packs at different points in the wellbore,
reversing out after each individual gravel pack operation. The workstring 610 inside
the assembly 620 can be positioned at each pumping point in the assembly 620, starting
at the lowest point for example, and deliver the gravel pack slurry into the annulus
15, circulating in a toe-to-heel fashion. Once sufficient sand has been pumped, the
workstring 610 is repositioned so that pressure applied to the casing 12 and inside
the assembly 620 results in reverse circulating of any excess slurry up the workstring
610. Once that slurry has been removed, the workstring 610 is raised to the next pumping
location, and the steps are repeated.
[0117] The foregoing description of preferred and other embodiments is not intended to limit
or restrict the scope or applicability of the inventive concepts conceived of by the
Applicants. It will be appreciated with the benefit of the present disclosure that
elements of one embodiment can be combined with or exchanged for components of other
embodiments disclosed herein. References have been made herein to use of the gravel
pack assemblies in boreholes, such as open boreholes. In general, these boreholes
can have any orientation, vertical, horizontal, or deviated. For example, a horizontal
borehole may refer to any deviated section of a borehole defining an angle of 50-degrees
or greater and even over 90-degrees relative to vertical.
[0118] In exchange for disclosing the inventive concepts contained herein, the Applicants
desire all patent rights afforded by the appended claims. Therefore, it is intended
that the appended claims include all modifications and alterations to the full extent
that they come within the scope of the following claims or the equivalents thereof.
1. A formation treatment method for a borehole (10), the method comprising:
isolating a borehole annulus (15) of the borehole (10) around an assembly (600) into
a plurality of isolated zones (602), the assembly (600) in each isolated zone (602)
having a port (650) and a screen (640) communicating a through-bore (625) of the assembly
(600) with the borehole annulus (15);
positioning a workstring (610) in the through-bore (625) of the assembly (600);
treating the borehole annulus (15) of each of the isolated zones (602) by:
opening a first valve (652) at the port (650) of the isolated zone (602) with the
workstring (610);
sealing an outlet (612) of the workstring (610) at the port (650) of the isolated
zone (602),
flowing slurry as the treatment down the workstring (610), out the outlet (612), and
to the port (650),
gravel packing the borehole annulus (15) of the isolated zone (602) with gravel in
the slurry,
filtering fluid returns of the slurry from the borehole annulus (15) of the isolated
zone (602) into the through-bore (625) of the assembly (600) through the screen (640)
and through a second valve (645) at the screen (640),
preventing flow of the fluid returns in the through-bore (625) from flowing back to
the borehole annulus (15) out the first and second valves (652, 645) of the other
isolated zones (602) on the assembly (600); and
removing excess of the treatment from the workstring (610) by: sealing the outlet
(612) from the open first valve (652) of the port (650), reverse circulating down
the through-bore (625) of the assembly (600) and into the outlet (612) of the workstring
(610), and preventing the reverse circulation in the through-bore (625) from communicating
to the borehole annulus (15) through the first and second valves (645, 625) of the
screens (640) and the ports (650) of the isolated zones (602).
2. The method of claim 1, comprising initially positioning the assembly in casing having
perforations, in an expanded liner having slots, or in an open hole, and optionally
wherein isolating the borehole annulus of the borehole (10) around the assembly into
the isolated zones comprises engaging isolation elements (670) on the assembly against
a wall of the casing, a wall of the expanded liner, or a wall of the open hole.
3. The method of claim 1 or 2, wherein opening the first valve (652) at the port (650)
at the isolated zone (620) with the workstring (610) comprises shifting a sleeve (652)
in the assembly (600) away from the port (650) with the workstring (610).
4. The method of claim 1, 2 or 3, further comprising closing the first valve (652) of
the port (650) at the isolated zone (602) with the workstring (610) after removing
excess slurry from the workstring (610).
5. The method of any one of claims 1 to 4, wherein treating the isolated zone (602) comprises:
flowing the slurry as the treatment from the port (650) disposed toward the toe,
gravel packing the annulus (15) of the isolated zone (602) from toe to heel, and
filtering the fluid returns into the through-bore (625) of the assembly (600) through
the screen (640) disposed toward the heel.
6. The method of any one of claims 1 to 4, wherein treating the isolated zone (602) comprises:
flowing the slurry as the treatment from the port (650) disposed toward the heel,
gravel packing the annulus (15) of the isolated zone (602) from heel to toe, filtering
the fluid returns into the through-bore (625) of the assembly (600) through the screen
(640) disposed toward the toe, and
bypassing the fluid returns to the through-bore (625) of the assembly (600) uphole
of the port (650).
7. The method of any one of claims 1 to 6, wherein preventing the flow of the fluid returns
in the through-bore (625) back to the borehole annulus (15) out of the second valves
(645) at the screens (640) comprises operating check valves (645) disposed in communication
between the screens (640) and the through-bore (625).
8. The method of any one of claims 1 to 7, further comprising preparing the isolated
zones (602) for production by:
closing the first valves (652) at the ports (650) of the assembly (600) at the isolated
zones (602) with the workstring (610); and
permitting fluid communication from the borehole annulus (15) into the through-bore
(625) through the screen (640) and the second valves (645) at the isolated zones (602).
9. The method of claim 8, further comprising screening production fluid from the borehole
annulus (15) of the isolated zone into the through-bore (625) of the assembly through
the screen (640) and the second valves (645).
10. The method of any one of claims 1 to 9, wherein the assembly (600) comprises:
a body (620) disposed in the borehole (10) and defining a through-bore (625);
one or more sections (602) disposed on the body (620), each of the one or more sections
(602) comprising:
an isolation element (670) disposed on the body (620) and isolating borehole annulus
(15) around the section (602) from the other sections (602),
the port (650) disposed on the body (620) and permitting fluid communication between
the through-bore (625) and the borehole annulus (15),
the first valve (652) disposed on the body (620) and being selectively operable to
open fluid flow through the port (650) and to close fluid flow through the port (650);
the screen (640) disposed on the body (620) and communicating with the borehole annulus
(15), and
the second valve (645) disposed on the body (620), the second valve (645) permitting
fluid communication from the screen (640) to the through-bore (625) and preventing
fluid communication from the through-bore (625) to the screen (640).
11. The method of any one of claims 1 to 10, wherein the first valve (652) comprises a
sleeve movable in the through-bore (625) between (a) a closed condition preventing
fluid communication through the port (650) and (b) an opened condition permitting
fluid communication through the port (650).
12. The method of any one of claims 1 to 11, wherein the workstring (610) comprises an
actuating tool (616) operable to open and close the first valves (652) in the same
trip in the through-bore (625), the actuating tool (616) optionally being hydraulically
operable.
13. The method of any one of claims 1 to 12, wherein the workstring (610) comprises first
seals (614) adjacent the outlet (612), and wherein the assembly (600) comprises second
seals (654) disposed in the through-bore (625) adjacent the port (650), the second
seals (654) engaging with the first seals (614) and isolating fluid communication
of the outlet (612) with the port (650).
14. The method of any one of claims 1 to 13, wherein the isolation element (670) comprises
at least one of a swellable packer, a hydraulically-set packer, a hydrostatically-set
packer, and a mechanicallyset packer.
15. The method of any one of claims 1 to 14, wherein the second valve (645) comprises
a one-way valve disposed in fluid communication between the screen (640) and the through-bore
(625), the one-way valve in the open condition permitting fluid communication from
the screen (640) into the throughbore and in the closed condition preventing fluid
communication from the through-bore (625) to the screen (640) and optionally wherein
the one-way valve comprises: a housing disposed on the body (620) and communicating
the screen (640) with at least one flow port in the body (620); and a check ball movably
disposed in the housing, the check ball permitting fluid communication from the screen
(640) to the at least one flow port and preventing fluid communication from the at
least one flow port to the screen (640).
1. Formationsbehandlungsverfahren für ein Bohrloch (10), wobei das Verfahren Folgendes
umfasst:
Isolieren eines Bohrloch-Ringraums (15) des Bohrlochs (10) um eine Baugruppe (600)
herum in eine Vielzahl von isolierten Zonen (602), wobei die Baugruppe (600) in jeder
isolierten Zone (602) eine Öffnung (650) und ein Sieb (640), das eine Durchbohrung
(625) der Baugruppe (600) mit dem Bohrloch-Ringraum (15) verbindet, hat,
Positionieren eines Arbeitsstrangs (610) in der Durchbohrung (625) der Baugruppe (600),
Behandeln des Bohrloch-Ringraums (15) von jeder der isolierten Zonen (602) durch:
Öffnen eines ersten Ventils (652) an der Öffnung (650) der isolierten Zone (602) mit
dem Arbeitsstrang (610);
Abdichten eines Auslasses (612) des Arbeitsstrangs (610) an der Öffnung (650) der
isolierten Zone (602),
Strömenlassen von Schlamm als die Behandlung nach unten entlang des Arbeitstrangs
(610), aus dem Auslass (612) hinaus und zur Öffnung (650),
Kiesfüllen des Bohrloch-Ringraums (15) der isolierten Zone (602) mit Kies im Schlamm,
Filtern von Fluidrückläufen des Schlamms aus dem Bohrloch-Ringraum (15) der isolierten
Zone (602) in die Durchbohrung (625) der Baugruppe (600) durch das Sieb (640) und
durch ein zweites Ventil (645) am Sieb (640),
Verhindern, dass ein Strom der Fluidrückläufe in der Durchbohrung (625) zurück zum
Bohrloch-Ringraum (15) aus dem ersten und dem zweiten Ventil (652, 645) der anderen
isolierten Zonen (602) an der Baugruppe (600) strömt, und
Entfernen von überschüssiger Behandlung aus dem Arbeitsstrang (610) durch: Abdichten
des Auslasses (612) aus dem offenen ersten Ventil (652) der Öffnung (650), Umkehrzirkulation
nach unten in der Durchbohrung (625) der Baugruppe (600) und in den Auslass (612)
des Arbeitsstrangs (610) und Verhindern einer Verbindung der Umkehrzirkulation in
der Durchbohrung (625) zum Bohrloch-Ringraum (15) durch das erste und das zweite Ventil
(645, 625) der Siebe (640) und die Öffnungen (650) der isolierten Zonen (602).
2. Verfahren nach Anspruch 1, umfassend anfängliches Positionieren der Baugruppe in einem
Bohrrohr mit Perforationen, in einer aufgeweiteten Auskleidung mit Schlitzen oder
in einem offenen Loch, und optional wobei das Isolieren des Bohrloch-Ringraums des
Bohrlochs (10) um die Baugruppe herum in die isolierten Zonen das Ineingriffbringen
von Isolierungselementen (670) an der Baugruppe gegen eine Wand des Bohrrohrs, eine
Wand der aufgeweiteten Auskleidung oder eine Wand des offenen Lochs umfasst.
3. Verfahren nach Anspruch 1 oder 2, wobei das Öffnen des ersten Ventils (652) an der
Öffnung (650) an der isolierten Zone (620) mit dem Arbeitsstrang (610) das Verschieben
einer Hülse (652) in der Baugruppe (600) weg von der Öffnung (650) mit dem Arbeitsstrang
(610) umfasst.
4. Verfahren nach Anspruch 1, 2 oder 3, ferner umfassend das Schließen des ersten Ventils
(652) der Öffnung (650) an der isolierten Zone (602) mit dem Arbeitsstrang (610) nach
dem Entfernen von überschüssigem Schlamm aus dem Arbeitsstrang (610).
5. Verfahren nach einem der Ansprüche 1 bis 4, wobei das Behandeln der isolierten Zone
(602) Folgendes umfasst:
Strömenlassen des Schlamms als die Behandlung aus der Öffnung (650), die in Richtung
der Zehe angeordnet ist, Kiesfüllen des Ringraums (15) der isolierten Zone (602) von
Zehe bis Ferse und Filtern der Fluidrückläufe in die Durchbohrung (625) der Baugruppe
(600) durch das Sieb (640), das in Richtung der Ferse angeordnet ist.
6. Verfahren nach einem der Ansprüche 1 bis 4, wobei das Behandeln der isolierten Zone
(602) Folgendes umfasst:
Strömenlassen des Schlamms als die Behandlung aus der Öffnung (650), die in Richtung
der Ferse angeordnet ist, Kiesfüllen des Ringraums (15) der isolierten Zone (602)
von Ferse bis Zehe,
Filtern der Fluidrückläufe in die Durchbohrung (625) der Baugruppe (600) durch das
Sieb (640), das in Richtung der Zehe angeordnet ist, und
Umleiten der Fluidrückläufe zur Durchbohrung (625) der Baugruppe (600) oberhalb der
Öffnung (650).
7. Verfahren nach einem der Ansprüche 1 bis 6, wobei das Verhindern des Strömens der
Fluidrückläufe in der Durchbohrung (625) zurück zum Bohrloch-Ringraum (15) aus den
zweiten Ventilen (645) an den Sieben (640) das Betreiben von Rückschlagventilen (645)
umfasst, die in Verbindung zwischen den Sieben (640) und der Durchbohrung (625) angeordnet
sind.
8. Verfahren nach einem der Ansprüche 1 bis 7, ferner umfassend das Vorbereiten der isolierten
Zonen (602) zur Produktion durch:
Schließen der ersten Ventile (652) an den Öffnungen (650) der Baugruppe (600) an den
isolierten Zonen (602) mit dem Arbeitsstrang (610) und
Erlauben einer Fluidverbindung vom Bohrloch-Ringraum (15) in die Durchbohrung (625)
durch das Sieb (640) und die zweiten Ventile (645) an den isolierten Zonen (602).
9. Verfahren nach Anspruch 8, ferner umfassend das Sieben von Produktionsfluid aus dem
Bohrloch-Ringraum (15) der isolierten Zone in die Durchbohrung (625) der Baugruppe
durch das Sieb (640) und die zweiten Ventile (645).
10. Verfahren nach einem der Ansprüche 1 bis 9, wobei die Baugruppe (600) Folgendes aufweist:
einen Körper (620), der im Bohrloch (10) angeordnet ist und eine Durchbohrung (625)
definiert,
einen oder mehrere Abschnitte (602), die am Körper (620) angeordnet sind, wobei jeder
des einen oder der mehreren Abschnitte (602) Folgendes aufweist:
ein Isolierungselement (670), das am Körper (620) angeordnet ist und den Borhloch-Ringraum
(15) um den Abschnitt (602) herum von anderen Abschnitten (602) isoliert,
die Öffnung (650), die am Körper (620) angeordnet ist und eine Fluidverbindung zwischen
der Durchbohrung (625) und dem Bohrloch-Ringraum (15) erlaubt,
das erste Ventil (652), das am Körper (620) angeordnet ist und selektiv betreibbar
ist, um einen Fluidstrom durch die Öffnung (650) zu öffnen und einen Fluidstrom durch
die Öffnung (650) zu schließen,
das Sieb (640), das am Körper (620) angeordnet ist und mit dem Bohrloch-Ringraum (15)
verbunden ist, und
das zweite Ventil (645), das am Körper (620) angeordnet ist, wobei das zweite Ventil
(645) eine Fluidverbindung vom Sieb (640) zur Durchbohrung (625) erlaubt und eine
Fluidverbindung von der Durchbohrung (625) zum Sieb (640) verhindert.
11. Verfahren nach einem der Ansprüche 1 bis 10, wobei das erste Ventil (652) eine Hülse
aufweist, die in der Durchbohrung (625) zwischen (a) einem geschlossenen, Fluidverbindung
durch die Öffnung (650) verhindernden Zustand und (b) einem offenen, Fluidverbindung
durch die Öffnung (650) erlaubenden Zustand bewegbar ist.
12. Verfahren nach einem der Ansprüche 1 bis 11, wobei der Arbeitsstrang (610) ein Betätigungswerkzeug
(616) aufweist, das betreibbar ist, um die ersten Ventile (652) in der gleichen Versetzung
in der Durchbohrung (625) zu öffnen und zu schließen, wobei das Betätigungswerkzeug
(616) optional hydraulisch betätigbar ist.
13. Verfahren nach einem der Ansprüche 1 bis 12, wobei der Arbeitsstrang (610) erste Dichtungen
(614) neben dem Auslass (612) aufweist und wobei die Baugruppe (600) zweite Dichtungen
(654) aufweist, die in der Durchbohrung (625) neben der Öffnung (650) angeordnet sind,
wobei die zweiten Dichtungen (654) mit den ersten Dichtungen (614) in Eingriff kommen
und eine Fluidverbindung des Auslasses (612) mit der Öffnung (650) isolieren.
14. Verfahren nach einem der Ansprüche 1 bis 13, wobei das Isolierelement (670) mindestens
eines von einem quellbaren Dichtungsstück, einem hydraulisch einstellten Dichtungsstück,
einem hydrostatisch einstellten Dichtungsstück und einem mechanisch eingestellten
Dichtungsstück aufweist.
15. Verfahren nach einem der Ansprüche 1 bis 14, wobei das zweite Ventil (645) ein Ein-Weg-Ventil
aufweist, das in Fluidverbindung zwischen dem Sieb (640) und der Durchbohrung (625)
angeordnet ist, wobei das Ein-Weg-Ventil im offenen Zustand eine Fluidverbindung vom
Sieb (640) in die Durchbohrung erlaubt und im geschlossenen Zustand eine Fluidverbindung
von der Durchbohrung (625) zum Sieb (640) verhindert und optional wobei das Ein-Weg-Ventil
Folgendes aufweist: ein Gehäuse, das am Körper (620) angeordnet ist und das Sieb (640)
mit mindestens einer Strömungsöffnung im Körper (620) verbindet, und eine Sperrkugel,
die bewegbar im Gehäuse angeordnet ist, wobei die Sperrkugel eine Fluidverbindung
vom Sieb (640) zur mindestens einen Strömungsöffnung erlaubt und eine Fluidverbindung
von der mindestens einen Strömungsöffnung zum Sieb (640) verhindert.
1. Procédé de traitement de formation pour un trou de forage (10), le procédé comprenant
les étapes consistant à :
isoler un espace annulaire de trou de forage (15) du trou de forage (10) autour d'un
ensemble (600) pour créer une pluralité de zones isolées (602), l'ensemble (600) de
présentant dans chaque zone isolée (602) un orifice (650) et un crible (640) faisant
communiquer un trou traversant (625) de l'ensemble (600) avec l'espace annulaire de
trou de forage (15) ;
positionner un train de tiges de travail (610) dans le trou traversant (625) de l'ensemble
(600) ;
traiter l'espace annulaire de trou de forage (15) de chacune des zones isolées (602)
grâce aux étapes consistant à :
ouvrir un premier clapet (652) au niveau de l'orifice (650) de la zone isolée (602)
avec le train de tiges de travail (610) ;
fermer de manière étanche une sortie (612) du train de tiges de travail (610) au niveau
de l'orifice (650) de la zone isolée (602),
faire s'écouler de la boue faisant office de traitement vers le bas du train de tiges
de travail (610), hors de la sortie (612), et vers l'orifice (650),
créer un massif de gravier dans l'espace annulaire de trou de forage (15) de la zone
isolée (602) grâce à du gravier présent dans la boue,
filtrer des retours fluides de la boue en provenance de l'espace annulaire de trou
de forage (15) de la zone isolée (602) et allant dans le trou traversant (625) de
l'ensemble (600) à travers le crible (640) et à travers un deuxième clapet (645) situé
au niveau du crible (640),
empêcher la circulation des retours fluides dans le trou traversant (625) de revenir
vers l'espace annulaire de trou de forage (15) en sortant des premier et deuxième
clapets (652, 645) des autres zones isolées (602) présentes sur l'ensemble (600) ;
et
retirer le traitement excédentaire, hors du train de tiges de travail (610) grâce
aux étapes consistant à : fermer de manière étanche la sortie (612) par rapport au
premier clapet ouvert (652) de l'orifice (650), faire circuler de manière inverse
vers le bas dans le trou traversant (625) de l'ensemble (600) et jusque dans la sortie
(612) du train de tiges de travail (610), et empêcher la circulation inverse dans
le trou traversant (625) de communiquer avec l'espace annulaire de trou de forage
(15) à travers les premier et deuxième clapets (645, 625) des cribles (640) et les
orifices (650) des zones isolées (602).
2. Procédé selon la revendication 1, comprenant une étape consistant à positionner initialement
l'ensemble dans un tubage présentant des perforations, dans une colonne perdue élargie
présentant des fentes, ou dans un trou en découvert, et éventuellement dans lequel
l'étape d'isolation de l'espace annulaire de trou de forage du trou de forage (10)
autour de l'ensemble pour créer des zones isolées comprend une étape consistant à
mettre en prise des éléments d'isolation (670) présents sur l'ensemble contre une
paroi du tubage, une paroi de la colonne perdue élargie, ou une paroi du trou en découvert.
3. Procédé selon la revendication 1 ou 2, dans lequel l'étape d'ouverture du premier
clapet (652) au niveau de l'orifice (650) au niveau de la zone isolée (620) avec le
train de tiges de travail (610) comprend une étape consistant à décaler un manchon
(652) dans l'ensemble (600) en l'éloignant de l'orifice (650) avec le train de tiges
de travail (610).
4. Procédé selon la revendication 1, 2 ou 3, comprenant en outre une étape consistant
à fermer le premier clapet (652) de l'orifice (650) au niveau de la zone isolée (602)
avec le train de tiges de travail (610) après l'étape de retrait de la boue excédentaire
hors du train de tiges de travail (610).
5. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel l'étape de traitement
de la zone isolée (602) comprend les étapes consistant à :
faire circuler la boue faisant office de traitement à partir de l'orifice (650) agencé
en direction de la pointe, créer un massif de gravier dans l'espace annulaire (15)
de la zone isolée (602) à partir de la pointe vers le talon, et filtrer les retours
fluides dans le trou traversant (625) de l'ensemble (600) à travers le crible (640)
agencé en direction du talon.
6. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel l'étape de traitement
de la zone isolée (602) comprend les étapes consistant à :
faire circuler la boue faisant office de traitement à partir de l'orifice (650) agencé
en direction de la zone d'inflexion, créer un massif de gravier dans l'espace annulaire
(15) de la zone isolée (602) entre la zone d'inflexion et les fonds de trou,
filtrer les retours fluides allant dans le trou traversant (625) de l'ensemble (600)
à travers le crible (640) agencé en direction du fonds de trou, et
dériver les retours fluides vers le trou traversant (625) de l'ensemble (600) au-dessus
de l'orifice (650).
7. Procédé selon l'une quelconque des revendications 1 à 6, dans lequel l'étape consistant
à empêcher la circulation des retours fluides dans le trou traversant (625) de revenir
vers l'espace annulaire de trou de forage (15) en sortant des deuxièmes clapets (645)
au niveau des cribles (640) comprend une étape consistant à faire fonctionner des
clapets anti-retour (645) agencés en communication entre les cribles (640) et le trou
traversant (625).
8. Procédé selon l'une quelconque des revendications 1 à 7, comprenant en outre une étape
consistant à préparer les zones isolées (602) en vue d'une production grâce aux étapes
consistant à :
fermer les premiers clapets (652) présents au niveau des orifices (650) de l'ensemble
(600) au niveau des zones isolées (602) avec le train de tiges de travail (610) ;
et
permettre une communication fluidique à partir de l'espace annulaire de trou de forage
(15) jusque dans le trou traversant (625) à travers le crible (640) et les deuxièmes
clapets (645) au niveau des zones isolées (602).
9. Procédé selon la revendication 8, comprenant en outre une étape consistant à tamiser
un fluide de production en provenance de l'espace annulaire de trou de forage (15)
de la zone isolée et allant dans le trou traversant (625) de l'ensemble à travers
le crible (640) et les deuxièmes clapets (645).
10. Procédé selon l'une quelconque des revendications 1 à 9, dans lequel l'ensemble (600)
comprend :
un corps (620) agencé dans le trou de forage (10) et définissant un trou traversant
(625) ;
une ou plusieurs section(s) (602) agencée(s) sur le corps (620), chacune parmi la
ou les section(s) (602) comprenant :
un élément d'isolation (670) agencé sur le corps (620) et isolant l'espace annulaire
de trou de forage (15) autour de la section (602) par rapport aux autres sections
(602),
l'orifice (650) agencé sur le corps (620) et permettant une communication fluidique
entre le trou traversant (625) et l'espace annulaire de trou de forage (15),
le premier clapet (652) agencé sur le corps (620) et pouvant être utilisé de manière
sélective pour ouvrir une circulation de fluide à travers l'orifice (650) et pour
fermer une circulation de fluide à travers l'orifice (650) ;
le crible (640) agencé sur le corps (620) et communiquant avec l'espace annulaire
de trou de forage (15), et
le deuxième clapet (645) agencé sur le corps (620), ledit deuxième clapet (645) permettant
une communication fluidique entre le crible (625) et le trou traversant (625) et empêchant
une communication fluidique entre le trou traversant (625) et le crible (640).
11. Procédé selon l'une quelconque des revendications 1 à 10, dans lequel le premier clapet
(652) comprend un manchon pouvant être déplacé dans le trou traversant (625) entre
(a) un état fermé empêchant une communication fluidique à travers l'orifice (650)
et (b) un état ouvert permettant une communication fluidique à travers l'orifice (650).
12. Procédé selon l'une quelconque des revendications 1 à 11, dans lequel le train de
tiges de travail (610) comprend un outil d'actionnement (616) pouvant servir à ouvrir
et fermer les premiers clapets (652) dans le trou traversant (625) au cours de la
même manoeuvre, l'outil d'actionnement (616) pouvant éventuellement être utilisé de
manière hydraulique.
13. Procédé selon l'une quelconque des revendications 1 à 12, dans lequel le train de
tiges de travail (610) comprend des premiers joints étanches (614) adjacents à la
sortie (612), et dans lequel l'ensemble (600) comprend des deuxièmes joints étanches
(654) agencés dans le trou traversant (625) à proximité adjacente de l'orifice (650),
les deuxièmes joints étanches (654) venant en prise avec les premiers joints étanches
(614) et isolant une communication fluidique de la sortie (612) avec l'orifice (650).
14. Procédé selon l'une quelconque des revendications 1 à 13, dans lequel l'élément d'isolation
(670) comprend au moins une parmi une garniture d'étanchéité gonflable, une garniture
d'étanchéité mise en place de manière hydraulique, une garniture d'étanchéité mise
en place de manière hydrostatique, et une garniture d'étanchéité mise en place de
manière mécanique.
15. Procédé selon l'une quelconque des revendications 1 à 14, dans lequel le deuxième
clapet (645) comprend un clapet anti-retour agencé en communication fluidique entre
le crible (640) et le trou traversant (625), le clapet anti-retour à l'état ouvert
permettant une communication fluidique entre le crible (640) et le trou traversant
et, à l'état fermé, empêchant une communication fluidique entre le trou traversant
(625) et le crible (640) et éventuellement dans lequel le clapet anti-retour comprend
: une enveloppe agencée sur le corps (620) et faisant communiquer le crible (640)
avec au moins un orifice de circulation situé dans le corps (620) ; et une bille anti-retour
agencée mobile dans l'enveloppe, ladite bille anti-retour permettant une communication
fluidique entre le crible (640) et le au moins un orifice de circulation et empêchant
une communication fluidique entre le au moins un orifice de circulation et le crible
(640).