BACKGROUND
[0001] Downhole operations often include a downhole string that extends from an uphole system
into a formation. The uphole system may include a platform, pumps, and other systems
that support resource exploration, development, and extraction. In some instances,
fluids may be passed from the uphole system into the formation through the downhole
string. In other instances, fluid may pass from the formation through the downhole
string to the uphole system. The downhole string may include various sensors that
detect downhole parameters including formation parameters and parameters associated
with the downhole string.
[0002] It is desirable to communicate information from downhole sensors to the uphole system.
Communication may take place through wired, optical, or acoustical systems. Acoustical
systems rely upon passage of pressure pulses generated downhole to an uphole receiver.
The pressure pulses are created by a mud pulser by moving a piston into a choke valve
in order to create an additional temporary pressure increase at the pump system on
the surface. The generated pressure pulse travels with sound speed to the surface.
The uphole receiver converts the pressure pulses to data indicative of sensed parameters.
The pressure pulses provide useful information to uphole operators. Therefore, advances
in downhole communication systems would be well received by resource exploration and
recovery companies.
[0003] During drilling, a typical mud pulser substantially continuously generates pressure
pulses over long time periods, often several days. In addition, a number of wellbores
are currently drilled in formations having temperatures that are above 300 °F (149
°C). A majority of currently utilized mud pulsers include oil fillings, elastomers
and/or electrical high pressure connectors, all of which tend to deteriorate over
time and thus are not suitable for use in high temperature environments. The disclosure
herein provides pulsers that are suitable for high temperature environments while
also being made without oil fillings, elastomers or electrical high pressure connectors.
SUMMARY
[0004] Disclosed is a control valve assembly for a downhole wellbore including a body having
a first fluid passage defining a fluid inlet and a second fluid passage defining a
fluid outlet. The body is formed partially from a magnetic material. A plunger is
moveably mounted within the body. The plunger includes a third fluid passage including
a plunger fluid inlet and a plunger fluid outlet. The plunger fluid outlet is configured
to selectively align and misalign with the second fluid passage. A portion of the
plunger is formed from a magnetic material. A magnetic circuit having a gap is arranged
within the control valve assembly. The portion of the body formed from a magnetic
material defines a first portion of the magnetic circuit and the portion of the plunger
formed from magnetic material forms another portion of the magnetic circuit. A solenoid
is mounted at the body about at least a part of the magnetic material in at least
one of the body and the plunger. The solenoid is selectively activated to create a
magnetic field across the gap in the magnetic circuit. The magnetic field causes the
plunger to move thereby narrowing the gap to produce a pressure pulse in the wellbore.
[0005] Also disclosed is a resource exploration system including an uphole system and a
downhole system including a downhole tool in a wellbore operatively connected to the
uphole system. The downhole tool includes a pulser having a control valve assembly
including a body having a first fluid passage defining a fluid inlet and a second
fluid passage defining a fluid outlet. The body is formed partially from a magnetic
material. A plunger is moveably mounted within the body. The plunger includes a third
fluid passage including a plunger fluid inlet and a plunger fluid outlet. The plunger
fluid outlet is configured to selectively align and misalign with the second fluid
passage. A portion of the plunger is formed from a magnetic material. A magnetic circuit
having a gap arranged within the control valve assembly. The portion of the body formed
from a magnetic material defines a first portion of the magnetic circuit and the portion
of the plunger formed from magnetic material forms another portion of the magnetic
circuit. A solenoid is mounted at the body about at least a part of the magnetic material
in at least one of the body and the plunger. The solenoid is selectively activated
to create a magnetic field across the gap in the magnetic circuit. The magnetic field
causes the plunger to move thereby narrowing the gap to produce a pressure pulse in
the wellbore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Referring now to the drawings wherein like elements are numbered alike in the several
Figures:
FIG. 1 depicts a resource exploration system having an uphole system operatively connected
to a downhole string including a pulser alternator generator (PAG) having a plunger-type
control valve assembly, in accordance with an exemplary embodiment;
FIG. 2 depicts a partial cross-sectional view of the PAG of FIG. 1;
FIG. 3 depicts a partial cross-sectional view of the plunger-type control valve assembly
in a first or open position; and
FIG. 4 depicts a partial cross-sectional view of the plunger-type control valve assembly
in a second or closed position.
DETAILED DESCRIPTION
[0007] A resource exploration system, in accordance with an exemplary embodiment, is indicated
generally at 2, in FIG. 1. Resource exploration system 2 should be understood to include
well drilling operations, resource extraction and recovery, CO
2 sequestration, and the like. Resource exploration and recovery system 2 may include
an uphole system 4 operatively connected to a downhole system 6. Uphole system 4 may
include pumps 8 that aid in completion and/or extraction processes as well as fluid
storage 10. Fluid storage 10 may contain a gravel pack fluid or slurry (not shown)
that is introduced into downhole system 6.
[0008] Downhole system 6 may include a downhole string 20 that is extended into a wellbore
21 formed in formation 22. Downhole string 20 may include a number of connected downhole
tools or tubulars 24. One of tubulars 24 may include a pulser alternator generator
(PAG) assembly 28. PAG assembly 28 may receive signals from one or more sensors (not
shown) indicating one or more of formation parameters, downhole fluid parameters,
tool condition parameters and the like. PAG assembly 28 creates one or more pressure
pulses that are received at uphole system 4. The one or more pressure pulses define
a code that may contain information regarding data received by the sensors. In accordance
with an exemplary embodiment, PAG assembly 28 creates pressure pulses by selectively
stopping a flow of pressurized downhole fluid or mud as will be detailed more fully
below.
[0009] In accordance with an exemplary embodiment illustrated in FIG. 2, PAG assembly 28
includes a body portion 30 having an outer surface portion 32 and an inner portion
34. An inner housing 36 is arranged within inner portion 34. Inner housing 36 includes
an outer surface 38 and an inner surface 40 that defines an interior portion 42. Interior
portion 42 houses an alternator assembly 46, a control valve assembly (CVA) 48, and
a main valve assembly (50) having a mud flow inlet portion (not separately labeled)
and a mud flow outlet portion (also not separately labeled). As will be detailed more
fully below, alternator assembly 46 provides signals to CVA 48 that allow drilling
mud to flow through MVA 50 and creates pressure pulses in the mud flow according to
the signals. CVA 48 creates pressure pulses in the mud flow that provide downhole
data from sensors (not shown) operatively coupled to alternator assembly 46 to uphole
operators.
[0010] As shown in FIGS. 3 and 4, CVA 48 includes a body 60 having a first body portion
62 and a second body portion 64 joined by a sleeve member 66. Second body portion
64 may be formed from a corrosion resistant magnetic material such as a soft magnetic
material e.g., Vacoflux® 9CR from Vacuumschmelze GmbH and Co. Magnetic and soft-magnetic
materials are defined as having a magnetic permeability µ greater than about 1.26
∗ 10
-4 N/A
2 (ferromagnetic or ferrimagnetic material). First body portion 62 includes a mud flow
or fluid passage 70 having a first passage portion 72 and a second passage portion
74. At this point, it should be understood that the term magnetic material comprises
any suitable material that may form part of a magnetic circuit including soft magnetic
material.
[0011] First passage portion 72 defines a mud flow inlet 76 that receives a flow of mud
from MVA 50 and second passage portion 74 defines a mud flow outlet 78. The number
and location of second passage portions may vary. Correspondingly, the number and
location of mud flow outlets may vary. First body portion 62 also includes a central
passage 82 having an increased diameter portion 84 that defines a mud flow outlet
chamber 86. A mud flow or fluid sleeve 90 is arranged in central passage 82. Mud flow
sleeve 90 includes an outer surface (not separately labeled)and an inner surface 93
that defines a channel 95. Mud flow sleeve 90 includes, a plunger fluid inlet (not
separately labeled) and a third passage portion 100 and a fourth passage portion 101,
third and fourth passage portions 100 and 101 may take the form of a first plunger
fluid outlet and second plunger fluid outlet respectively. Third and fourth passage
portion 100 and 101 fluidically connect first passage portion 72 with second passage
portion 74. The number and location of passage portions extending through mud flow
sleeve 90 may vary.
[0012] Second body portion 64 may also be formed from soft magnetic material and includes
a solenoid support 108 having an axial end 110. A solenoid carrier 114 is supported
on solenoid support 108. Solenoid carrier 114 may be formed from high-strength, non-magnetic
material such as Inconel and provides support for a solenoid 120. Solenoid 120 is
operatively connected to alternator assembly 46 through a conductor (not shown) extending
through a conductor passage 124 formed in second body portion 64. A housing 128, which
may take the form of a pressure sleeve, is mounted in second body portion 64 about
solenoid 120. Housing 128 may be formed from magnetic material and provides protection
to solenoid 120 from downhole fluids passing through CVA 48 as well as from the high
downhole pressure.
[0013] Housing 128 may be made from a magnetic material that is also corrosion resistant.
In the embodiment of control valve 48, the solenoid 120 may be placed in a sealed
and clean 1-bar environment. In the embodiment of the device 48 in FIG. 3 and 4, plunger
assembly 160 moves when the solenoid in the control valve 48 is energized. The plunger
assembly also referred to as a plunger. While moving plunger assembly 160 slides in
an environment that is flooded with fluid (mud). The presence of mud allows plunger
assembly 160 to slide back and forth with relative low friction.
[0014] Sleeve member 66 includes a first end section 134 and a second end section 135. First
end section 134 may include a plurality of threads 137 that engage first body portion
62. Second end section 135 may be mechanically linked to second body portion 64 through,
for example, a press fit, a threaded connection, or a joining process such as welding.
Sleeve member 66 includes an annular flange 140 extending radially inwardly from an
inner surface (not separately labeled). Annular flange 140 together with housing 128
may define a plunger support 144. Sleeve member 66 may be formed from a high strength,
non-magnetic material, such as steel or Inconel so as to withstand downhole fluids.
Of course, it should be understood, that the particular materials employed for solenoid
carrier 114, and sleeve member 66 may vary depending on desired operating parameters
and downhole conditions.
[0015] In accordance with an aspect of an exemplary embodiment, CVA 48 includes a plunger
assembly 160, also referred to as a plunger, including a valve portion 162 and an
actuator shaft 164, also referred to as a drive portion of the plunger. Valve portion
162 is operatively connected with actuator shaft 164. Actuator shaft 164 may be formed
from soft magnetic material. Valve portion 162 may be formed from hard abrasion resistant
material such as Tungsten Carbide and may be provided with a diamond coating of may
employ other processes to form a hardened outer surface. The use of hard abrasion
resistant material allows valve portion 162 to withstand high pressure corrosive and
abrasive downhole mud passing from MVA 50 at high downhole temperatures as will be
discussed more fully below. Valve portion 162 includes a central chamber 167 fluidically
connected with first passage portion 72. A fifth passage portion 169 and a sixth passage
portion 170 extend through valve portion 162. A spring 174 biases plunger assembly
160 in a first position as shown in FIG. 3, wherein fifth and sixth passage portions
169 and 170 register with third and fourth passage portions 100 and 101 (control valve
open position). Solenoid 120 is selectively activated to shift plunger assembly 160
to a second position (FIG. 4) wherein fifth and sixth passage portions 169 and 170
are offset from third and fourth passage portions 100 and 101 (control valve closed
position). CVA 48 may also include a washout passage 180 that provides passage for
particles to be guided out from a back side (not separately labeled) of actuator shaft
164. Plunger support 144 may be either incorporated into or abutting on housing 128.
Plunger support 144 is formed from a magnetic material, e.g. a soft magnetic material,
and is part of the magnetic circuit. Plunger support 144 slidingly supports plunger
assembly 160 by slidingly supporting actuator shaft 164.
[0016] In accordance with an aspect of an exemplary embodiment, third and fourth passage
portions 100, 101 and fifth and sixth passage portions 169,170 may extend at an angle
of between about 20° and about 80° relative to a longitudinal axis (not separately
labeled) of CVA 48. In accordance with another aspect, third and fourth passage portions
100, 101 and fifth and sixth passage portions 169,170 may extend at an angle of about
60° relative to the longitudinal axis. In this manner, shifting plunger assembly 160
between the first position and the second position shears mud flow passing from first
passage portion 72 through valve portion 162 into mud flow outlet chamber 86. Further,
with this arrangement, the amount of force necessary to shift plunger assembly 160
is reduced over that which would be needed if third, fourth, fifth and sixth passage
portions 100, 101, 169, and 170 projected substantially perpendicularly relative to
the longitudinal axis.
[0017] Further, second passage portion 74 may extend at an angle of between about 20° and
about 80° relative to a longitudinal axis (not separately labeled) of CVA 48. In accordance
with another aspect, second passage portion 74 may extend at an angle of about 60°
relative to the longitudinal axis. The angle of second passage portion 74 reduces
impact forces associated with pulses of mud passing from mud flow outlet 78 onto inner
surface 40 may be reduced over those which would be realized if mud flow outlet 78
extended perpendicularly to the longitudinal axis.
[0018] In accordance with an aspect of an exemplary embodiment, alternator assembly 46 provides
signals to selectively activate, e.g., energize through an application of electric
energy, solenoid 120 creating a magnetic flux 200 in a magnetic circuit (not separately
labeled) that flows through second body portion 64, actuator shaft 164, plunger supports
144, and housing 128. The magnetic circuit includes a gap 171 between actuator shaft
164 and axial end 110 of solenoid support 108. At this point, it should be understood
that the term "magnetic circuit" defines a pathway of material within CVA 48 through
which magnetic flux 200 will flow. Activating solenoid 120 causes a magnetic field
(not separately labeled) across the gap 171. The magnetic field creates a magnetic
force that acts across gap 171 causing plunger assembly 160 to move toward second
body portion 64. More specifically actuator shaft 164 moves toward solenoid support
108 thereby shifting plunger assembly 160 from the first position (FIG. 3) to the
second position (FIG. 4). Plunger assembly 160 moves along a longitudinal axis of
the body towards solenoid support 108 narrowing gap 171. Gap 171 need not fully close
in order to close the control valve.
[0019] Solenoid 120 may then be de-activated opening (interrupting) the magnetic circuit
cutting off magnetic flux 200 allowing spring 174 to bias plunger assembly 160 back
to the first position, opening the control valve. In the first position the width
of gap 171 is larger than the width of gap 171 in the second position. The first position
is also referred to as a gap open position, the second position is also referred to
as a gap closed position. The gap closed position does not require that the gap to
be fully closed.. In the first position, mud may flow from MVA 50, through plunger
assembly 160, into mud flow outlet chamber 86 and be expelled from mud flow outlets
78. When CVA 48 is operated rapidly, MVA 50 creates mud pulses that travel through
downhole string 20. An uphole receiver captures pressure waves created by the pulses
of mud. The pressure pulses are presented in a pattern dictated by signals received
from one or more sensors at alternator assembly 46. The pressure pulses may be decrypted
to provide data regarding one or more downhole parameters to uphole operators.
[0020] Splitting the plunger assembly into at least two parts allows separating the valve
portion from the magnetic circuit. Therefore, the valve portion 162 does not need
to be made from magnetic material. The valve portion may be made from a material that
is much better suited to withstand harsh downhole conditions, like high temperatures
and corrosive and abrasive downhole fluids. The material of the valve portion of the
plunger assembly may be high strength non-magnetic material, such as hardened steel,
diamond, tungsten carbide, carbon nitride, or boron nitride or alternative hard and/or
less corrosive material. The valve portion may as well be coated by a hard material,
such a diamond coating.
[0021] Set forth below are some embodiments of the foregoing disclosure:
Embodiment 1: A control valve assembly for a downhole wellbore comprising: a body
including a first fluid passage defining a fluid inlet and a second fluid passage
defining a fluid outlet, wherein the body is formed partially from a magnetic material;
a plunger moveably mounted within the body, the plunger including a third fluid passage
including a plunger fluid inlet and a plunger fluid outlet, the plunger fluid outlet
configured to selectively align and misalign with the second fluid passage , wherein
a portion of the plunger is formed from a magnetic material; a magnetic circuit having
a gap arranged within the control valve assembly, wherein the portion of the body
formed from a magnetic material defines a first portion of the magnetic circuit and
the portion of the plunger formed from magnetic material forms another portion of
the magnetic circuit; and a solenoid mounted at the body about at least a part of
the magnetic material in at least one of the body and the plunger, the solenoid being
selectively activated to create a magnetic field across the gap in the magnetic circuit,
the magnetic field causing the plunger to move thereby narrowing the gap to produce
a pressure pulse in the wellbore.
Embodiment 2: The control valve assembly according to any previous embodiment, wherein
the body includes a first body portion mechanically linked to a second body portion
by a sleeve member, the first body portion including a central passage receptive of
the plunger.
Embodiment 3: The control valve assembly according to any previous embodiment, further
comprising: a fluid sleeve arranged in the central passage, the third fluid passage
being formed in the fluid sleeve.
Embodiment 4: The control valve assembly according to any previous embodiment, wherein
the first body portion includes a fourth fluid passage fluidically connected to the
second fluid passage.
Embodiment 5: The control valve assembly according to any previous embodiment, wherein
the central passage includes an increased diameter portion defining a fluid outlet
chamber fluidically connected to the second fluid passage.
Embodiment 6: The control valve assembly according to any previous embodiment, wherein
the portion of the plunger is formed from soft magnetic material.
Embodiment 7: The control valve assembly according to any previous embodiment, wherein
the second body portion includes a solenoid support and a solenoid carrier mounted
to the solenoid support, the solenoid being carried by the solenoid carrier.
Embodiment 8: The control valve assembly according to any previous embodiment, wherein
the plunger includes an actuator shaft formed from soft magnetic material, the actuator
shaft being movable towards the solenoid support when the solenoid is activated.
Embodiment 9: The control valve assembly according to any previous embodiment, further
comprising: a spring acting upon the plunger arranged between the actuator shaft and
the solenoid support.
Embodiment 10: The control valve assembly according to any previous embodiment, wherein
the second fluid passage includes at least two second fluid passages and the third
fluid passage includes at least two plunger fluid outlets.
Embodiment 11: The control valve assembly according to any previous embodiment, further
comprising: a housing extending about the solenoid, the housing being formed from
a soft magnetic material.
Embodiment 12: A resource exploration system comprising: an uphole system; and a downhole
system including a downhole tool in a wellbore operatively connected to the uphole
system, the downhole tool including a pulser having a control valve assembly comprising:
a body including a first fluid passage defining a fluid inlet and a second fluid passage
defining a fluid outlet, wherein the body is formed partially from a magnetic material;
a plunger moveably mounted within the body, the plunger including a third fluid passage
including a plunger fluid inlet and a plunger fluid outlet, the plunger fluid outlet
configured to selectively align and misalign with the second fluid passage, wherein
a portion of the plunger is formed from a magnetic material; a magnetic circuit having
a gap arranged within the control valve assembly, wherein the portion of the body
formed from a magnetic material defines a first portion of the magnetic circuit and
the portion of the plunger formed from magnetic material forms another portion of
the magnetic circuit; and a solenoid mounted at the body about at least a part of
the magnetic material in at least one of the body and the plunger, the solenoid being
selectively activated to create a magnetic field across the gap in the magnetic circuit,
the magnetic field causing the plunger to move thereby narrowing the gap to produce
a pressure pulse in the wellbore.
Embodiment 13: The resource exploration system according to any previous embodiment,
wherein the body includes a first body portion mechanically linked to a second body
portion by a sleeve member, the first body portion including a central passage receptive
of the plunger.
Embodiment 14: The resource exploration system according to any previous embodiment,
wherein the second fluid passage includes at least two second fluid passages and the
third fluid passage includes at least two plunger fluid outlets.
Embodiment 15: The resource exploration system according to any previous embodiment,
further comprising: a fluid sleeve arranged in the central passage, the third fluid
passage being formed in the fluid sleeve.
Embodiment 16: The resource exploration system according to any previous embodiment,
wherein the first body portion includes a fourth fluid passage fluidically connected
to the second fluid passage.
Embodiment 17: The resource exploration system according to any previous embodiment,
wherein the central passage includes an increased diameter portion defining a fluid
outlet chamber fluidically connected to the second fluid passage.
Embodiment 18: The resource exploration system according to any previous embodiment,
wherein the portion of the plunger is formed from a soft magnetic material.
Embodiment 19: The resource exploration system according to any previous embodiment,
wherein the second body portion includes a solenoid support and a solenoid carrier
mounted to the solenoid support, the solenoid being carried by the solenoid carrier.
Embodiment 20: The resource exploration system according to any previous embodiment,
further comprising: a housing extending about the solenoid, the housing being formed
from a soft magnetic material.
Embodiment 21: The resource exploration system according to any previous embodiment,
wherein the plunger includes an actuator shaft formed from a soft magnetic material,
the actuator shaft being moveable toward the solenoid support when the solenoid is
activated.
Embodiment 22: The resource exploration system according to any previous embodiment,
further comprising: a spring acting upon the plunger arranged between the actuator
shaft and the solenoid support.
[0022] The teachings of the present disclosure may be used in a variety of well operations.
These operations may involve using one or more treatment agents to treat a formation,
the fluids resident in a formation, a wellbore, and/or equipment in the wellbore,
such as production tubing. The treatment agents may be in the form of liquids, gases,
solids, semi-solids, and mixtures thereof. Illustrative treatment agents include,
but are not limited to, fracturing fluids, acids, steam, water, brine, anticorrosion
agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers,
tracers, flow improvers etc.
[0023] The term "about" is intended to include the degree of error associated with measurement
of the particular quantity based upon the equipment available at the time of filing
the application. For example, "about" can include a range of ± 8% or 5%, or 2% of
a given value.
[0024] While one or more embodiments have been shown and described, modifications and substitutions
may be made thereto without departing from the spirit and scope of the invention.
Accordingly, it is to be understood that the present invention has been described
by way of illustrations and not limitation.
1. A control valve assembly for a downhole wellbore comprising:
a body including a first fluid passage defining a fluid inlet and a second fluid passage
defining a fluid outlet, wherein a portion of the body is formed from magnetic material;
a plunger moveably mounted within the body, the plunger including a third fluid passage
including a plunger fluid inlet and a plunger fluid outlet, the plunger fluid outlet
configured to selectively align and misalign with the second fluid passage, wherein
a portion of the plunger is formed from magnetic material;
a magnetic circuit having a gap arranged within the control valve assembly, wherein
the portion of the body formed from magnetic material defines a first portion of the
magnetic circuit and the portion of the plunger formed from magnetic material forms
another portion of the magnetic circuit; and
a solenoid mounted at the body about at least a part of the magnetic material in at
least one of the body and the plunger, the solenoid being selectively activated to
create a magnetic field across the gap in the magnetic circuit, the magnetic field
causing the plunger to move thereby narrowing the gap to produce a pressure pulse
in the wellbore.
2. The control valve assembly according to claim 1, wherein the body includes a first
body portion mechanically linked to a second body portion by a sleeve member, the
first body portion including a central passage receptive of the plunger.
3. The control valve assembly according to claim 1 or 2, further comprising a fluid sleeve
arranged in the central passage, the third fluid passage being formed in the fluid
sleeve.
4. The control valve assembly according to claim 1, 2 or 3, wherein the first body portion
includes a fourth fluid passage fluidically connected to the second fluid passage.
5. The control valve assembly according to any preceding claim, wherein the central passage
includes an increased diameter portion defining a fluid outlet chamber fluidically
connected to the second fluid passage.
6. The control valve assembly according to any preceding claim, wherein the portion of
the plunger is formed from soft magnetic material.
7. The control valve assembly according to any preceding claim, wherein the second body
portion includes a solenoid support and a solenoid carrier mounted to the solenoid
support, the solenoid being carried by the solenoid carrier.
8. The control valve assembly according to claim 7, wherein the plunger includes an actuator
shaft formed from soft magnetic material, the actuator shaft being movable towards
the solenoid support when the solenoid is activated.
9. The control valve assembly according to claim 8, further comprising a spring acting
upon the plunger arranged between the actuator shaft and the solenoid support.
10. The control valve assembly according to any preceding claim, wherein the second fluid
passage includes at least two second fluid passages and the third fluid passage includes
at least two plunger fluid outlets.
11. The control valve assembly according to any preceding claim, further comprising a
housing extending about the solenoid, the housing being formed from soft magnetic
material.
12. A resource exploration system comprising:
an uphole system; and
a downhole system including a downhole tool in a wellbore operatively connected to
the uphole system, the downhole tool including a pulser having the control valve assembly
of any preceding claim.