(19)
(11)EP 3 294 977 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.04.2020 Bulletin 2020/18

(21)Application number: 16793410.8

(22)Date of filing:  11.05.2016
(51)International Patent Classification (IPC): 
E21B 7/06(2006.01)
E21B 7/18(2006.01)
E21B 47/024(2006.01)
E21B 23/00(2006.01)
E21B 7/08(2006.01)
E21B 47/00(2012.01)
E21B 17/20(2006.01)
(86)International application number:
PCT/US2016/031778
(87)International publication number:
WO 2016/183149 (17.11.2016 Gazette  2016/46)

(54)

REAL-TIME STEERABLE ACID TUNNELING SYSTEM

SYSTEM FÜR LENKBARE ECHTZEITSÄUREDURCHTUNNELUNG

SYSTÈME DE FORAGE EN TUNNEL PAR ACIDE, ORIENTABLE EN TEMPS RÉEL


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 13.05.2015 US 201514710926

(43)Date of publication of application:
21.03.2018 Bulletin 2018/12

(73)Proprietor: Baker Hughes, a GE company, LLC
Houston, TX 77073 (US)

(72)Inventors:
  • LIVESCU, Silviu
    Calgary, Alberta T2S 3G4 (CA)
  • WATKINS, Thomas J.
    Calgary, Alberta T2W 3G3 (CA)

(74)Representative: BRP Renaud & Partner mbB Rechtsanwälte Patentanwälte Steuerberater 
Königstraße 28
70173 Stuttgart
70173 Stuttgart (DE)


(56)References cited: : 
US-A1- 2003 234 106
US-A1- 2008 271 925
US-A1- 2012 138 301
US-B1- 6 272 434
US-A1- 2006 278 393
US-A1- 2012 061 079
US-B1- 6 263 984
  
  • A. E. AKHKUBEKOV ET AL: "SPE 135989 Acid Tunneling Technology: Application Potential in Timan-Pechora Carbonates", SPE ANNUAL TECHNICAL CONFERENCE AND EXHIBITION, 26 October 2010 (2010-10-26), pages 26-28, XP055525829, DOI: 10.2118/135989-RU ISBN: 978-1-55563-313-4
  • RICK STANLEY ET AL: "Global Application of Coiled-Tubing Acid Tunneling Yields Effective Carbonate Stimulation", SPE ANNUAL TECHNICAL CONFERENCE AND EXHIBITION, 19 September 2010 (2010-09-19), XP055525868, DOI: 10.2118/135604-MS
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

BACKGROUND OF THE INVENTION


1. Field of the Invention



[0001] The invention relates generally to systems and methods for creating steerable lateral subterranean tunnels and for monitoring formation of tunnels in real-time at surface.

2. Description of the Related Art



[0002] Sidetracking operations create lateral tunnels that extend outwardly from a central wellbore, which is typically substantially vertically-oriented, but might also be horizontally-oriented or inclined. A number of tools and techniques can be used to create lateral tunnels. Included among these tools and techniques are devices that inject acid into the wellbore and surrounding formation in order to dissolve rock. Devices of this type are used, for example, in the StimTunnelTM targeted acid placement service which is available commercially from Baker Hughes Incorporated of Houston, Texas. These acid stimulation devices typically use a bottom hole assembly with a pivotable wand with a nozzle through which acid is dispensed under high pressure. The acid helps dissolve portions of the formation around the nozzle. The wand is typically provided with one or more knuckle joints that help angle the nozzle in a desired direction. Features of this type of tool are discussed in U.S. Patent Publication No. 2008/0271925 ("Acid Tunneling Bottom Hole Assembly") by Misselbrook et al. [the '925 reference].. A.E:Akhkubekov et al. "SPE 135989 Acid Tunneling Technology: Application Potential in Timan-Pechora Carbonates" refers to the application potential of an Acid Tunneling Technology which uses a tool having one or two knuckle joints and a special nozzle and wherein the deviation angle is controlled by coiled tubing pressure.

SUMMARY OF THE INVENTION



[0003] Disclosed is a steerable acid tunneling system for creating lateral tunnels in a subterranean formation surrounding a wellbore as set forth in independent claim 1 and a method of steering an acid tunneling system in real time within a wellbore to create a lateral tunnel from the wellbore as set forth in independent claim 7.

[0004] The present invention relates to devices and techniques for forming lateral tunnels from a subterranean wellbore using acid injection. Devices and methods of the present invention allow greater control of the direction and length of lateral tunnels being created than has been possible with conventional systems. Devices and methods of the present invention allow multiple lateral tunnels to be created radiating in different directions from a central, substantially vertical wellbore at a single depth or location along the wellbore. Devices and methods of the present invention allow for real-time monitoring, at surface, of details relating to the creation of lateral tunnels.

[0005] In accordance with particular embodiments, an acid tunneling system includes an acid-dispensing bottom hole assembly secured to a running arrangement for running into a wellbore. The bottom hole assembly includes a tunneling tool having a wand with a nozzle for injection of acid at desired locations to create lateral tunnels.

[0006] In preferred embodiments, the bottom hole assembly is provided with one or more downhole parameter sensors. The sensors are able to detect downhole parameters including pressure and temperature. In certain embodiments, the sensors are capable of detecting fluid flow parameters, such as density and viscosity. In a described embodiment, the sensors are retained within a sensor module that is incorporated into the bottom hole assembly.

[0007] In accordance with particular embodiments, a data/power cable is used to provide power to downhole components as well as a real-time data transmission system. Downhole parameters detected by the sensors is sent uphole by the cable to a controller. In accordance with preferred embodiments, the data/power cable is disposed within the central flowbore of the running string and may comprise a tube-wire type cable.

[0008] In a described embodiment, the acid tunneling system incorporates a casing collar locator ("CCL") which is useful for determining the position of the bottom hole assembly within a cased wellbore. When the acid tunneling system is run into a wellbore having portions that are lined with casing having collared connection, the casing collar locator provides an indication of the bottom hole assembly's depth or location within the wellbore. Casing collar locator data is transmitted to the controller at surface using the data/power cable.

[0009] In particular embodiments, the acid tunneling system includes an inclinometer which can determine the angular departure from vertical of the bottom hole assembly at any given point within the wellbore. This data is transmitted to the controller at surface. Together with data from the casing collar locator, if used, the inclinometer can be used to locate the bottom hole assembly at a particular desired location in the wellbore.

[0010] In accordance with particular embodiments, an indexing tool is incorporated into the bottom hole assembly and is useful to rotate the tunneling tool portion of the bottom hole assembly within the wellbore. Preferably, the indexing tool can rotate the tunneling tool up to 180 degrees in either radial direction, allowing the tunneling tool to form lateral tunnels in any radial direction outwardly from the central wellbore.

[0011] In certain embodiments, a pulsating tool, such as a lower frequency EasyReach extended reach tool, is connected between the tunneling tool and upper portions of the bottom hole assembly. The pulsating tool creates pressure waves that are transmitted to the tunneling tool and, in response to each pulse, the wand and nozzle of the tunneling tool are flexed radially outwardly to permit acid to be dispensed toward the surrounding formation.

[0012] In accordance with particular embodiments, the pulsating tool is designed to provide pressure waves having a pre-set pressure profile for bending the tunneling too! in a prescribed manner to form enlarged diameter lateral tunnels. The pulsating tool is designed to provide pressure pulses or waves which will activate flexure or bending of the tunneling tool in a periodic manner. In a particular embodiment, radial flexure of the tunneling tool occurs when the pulse is applied (pressure wave increasing) and the tool unflexes when the pulse is stopped (pressure wave decreasing). This flexing and unflexing will alternatively bend and straighten the tunneling tool so that wider tunnels are created. The inventors have determined that creating wider tunnels will advantageously reduce friction between the bottom hole assembly and the formation rock.

[0013] In operation, the acid tunneling system of the present invention can be operated to form lateral tunnels which extends outwardly from the central wellbore into which the acid tunneling system is run. In accordance with an exemplary method of operation, the acid tunneling system is run into a wellbore down to a formation into which it is desired to create lateral tunnels. The approximate location of the bottom hole assembly within the wellbore is determined using a data from a casing collar locator, inclinometer, sensors and/or by other means known in the art. Acid is flowed down through the flowbore of the running string, and the fluid pressure of the acid actuates the pulsating tool. The pulsating tool, in turn, actuates the tunneling tool to flex and unflex as acid is injected into the wellbore and creates lateral tunnels. The pulsating tool is also instrumental in creating lateral tunnels having larger diameters and which provide less frictional resistance with the tunneling tool, thereby facilitating the tunneling process.

[0014] The acid tunneling system of the present invention is steerable since it can be used to create tunnels in particular directions and at particular depths or locations in the wellbore. In certain embodiments, the acid tunneling system is steered by raising and lowering the running string within the wellbore based upon data provided by a casing collar locator or sensors. Further, the tunneling tool can be radially oriented by the indexing tool to direct the nozzle of the tunneling tool in a particular radial direction.

[0015] In a further described embodiment, a steerable acid tunneling system is used in conjunction with a milling tool to form one or more lateral tunnels from a cased wellbore. In this embodiment, a milling tool is first run into the wellbore and cuts one or more windows in the wellbore casing at locations wherein it is desired to create lateral tunnels using acid tunneling. Thereafter, the acid tunneling system is run into the wellbore and the acid tunneling tool is steered to form one or more lateral tunnels through the one or more lateral windows.

BRIEF DESCRIPTION OF THE DRAWINGS



[0016] For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein:

Figure 1 is a side, cross-sectional view of an exemplary wellbore containing an acid tunneling system in accordance with the present invention.

Figure 2 is a side, cross-sectional view of a section of running string used with the acid tunneling system of Figure 1.

Figure 3 is a side, cross-sectional view of the wellbore and acid tunneling system of Figure 1, now with the acid tunneling tool having been flexed to engage the wellbore wall.

Figure 4 is a side, cross-sectional view of the wellbore and acid tunneling system of Figures 1 and 3, now with the acid tunneling tool creating a lateral tunnel in the wellbore wall.

Figure 5 is a side, cross-sectional view of the wellbore and acid tunneling system of Figures 1, 3 and 4, now with the acid tunneling tool having been rotated to create a second lateral tunnel.

Figure 6 is a side, cross-sectional view of the acid tunneling system forming an enlarged diameter lateral tunnel.

Figure 7 is a flow diagram depicting steps in an exemplary acid tunneling system steering operation.

Figure 8 is a side, cross-sectional view of an exemplary wellbore depicting a milling tool cutting a window in a cased wellbore.

Figure 9 is a side, cross-sectional view of the wellbore shown in Figure 8 now with an acid tunneling system disposed within the wellbore to create a lateral tunnel.


DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS



[0017] Figure 1 illustrates an exemplary wellbore 10 that has been drilled through the earth 12 from the surface 14 down to a hydrocarbon-bearing formation 16 into which it is desired to create lateral tunnels. The wellbore 10 has a portion that is lined with metallic casing 17, of a type known in the art. An acid tunneling system, generally indicated at 18 is disposed within the wellbore 10 from the surface 14. The acid tunneling system 18 includes a running string 20, which is preferably coiled tubing of a type known in the art.

[0018] As Figure 2 illustrates, a central axial flowbore 22 is defined along the length of the running string 20. A cable 24 for transmission of electrical power and/or data extends along the length of the flowbore 22. According to preferred embodiments, the cable 24 is tube-wire. Tube-wire is a tube that contains an insulated cable that is used to provide electrical power and/or data to a bottom hole assembly or to transmit data from the bottom hole assembly to the surface 14. Tube-wire is available commercially from manufacturers such as Canada Tech Corporation of Calgary, Canada. Telecoil is coiled tubing which incorporates tube-wire that can transmit power and data.

[0019] At surface 14, a controller 26 receives data from the cable 24. The controller 26 is preferably a programmable data processor having suitable amounts of memory and storage for processing data received from a bottom hole assembly as well as means for displaying such data. In currently preferred embodiments, the controller 26 comprises a computer. In preferred embodiments, the controller 26 is programmed with a suitable geosteering software which is capable of using data collected from downhole sensors and providing guidance to an operator in real time to permit on the fly changes or the position and orientation of the tunneling tool 40. Suitable software for use by the controller 26 includes Reservoir Navigation Services (RNS) software which is available commercially from Baker Hughes Incorporated of Houston, Texas.

[0020] The acid tunneling system 18 includes a bottom hole assembly 28 that is secured to the running string 20 by a coiled tubing connector 30. The bottom hole assembly 28 is designed for the injection of acid and preferably includes a sensor module 32 and a casing collar locator 34. In the described embodiment, the bottom hole assembly 28 also includes an indexing tool 36 and a pulsating tool 38. Additionally, the bottom hole assembly 28 includes an acid tunneling tool 40.

[0021] In many respects, the acid tunneling tool 40 is constructed and operates in the same manner as the acid tunneling bottom hole assembly 100 described in U.S. Patent Publication 2008/0271925 by Misselbrook et al. The acid tunneling tool 40 includes a wand 42 and intermediate sub 44 which are affixed to the pulsating tool 38 by articulable knuckle joint 46. A second articulable knuckle joint 48 interconnects the wand 42 and the intermediate sub 44 together. The wand 42 has a nozzle 50 at its distal end. A suitable device for use as the acid tunneling tool 40 is the StimTunnel™ targeted acid placement tool which is available commercially from Baker Hughes Incorporated of Houston, Texas.

[0022] The indexing tool 36 is disposed axially between the hydraulic disconnect 34 and the pulsating tool 38. A suitable device for use as the indexing tool 36 is the coiled tubing Hi-Torque Indexing Tool which is available commercially from National Oilwell Varco. The indexing tool 36 is capable of rotating the pulsating tool 38 and acid tunneling tool 40 with respect to the running string 20 within the wellbore 10.

[0023] The bottom hole assembly 28 also includes a pulsating tool 38. A suitable device for use as the pulsating tool 38 is the EasyReach™ fluid hammer tool,which is available commercially from Baker Hughes Incorporated of Houston, Texas. A fluid pulsing tool of this type is described in greater detail in U.S. Patent Publication No. 2012/0312156 by Standen et al. entitled "Fluidic Impulse Generator." In operation, fluid, such as acid, is flowed down through the flowbore 22 of the running string, and through the pulsating tool 38 toward the acid tunneling tool 40. The pulsating tool 38 creates pressure pulses within the fluid flowing to the acid tunneling tool 40, and these pulses will cause the wand 42 and intermediate sub 44 to be flexed or bent upon the first and second knuckle joints 46, 48. In currently preferred embodiments, the tunneling tool 40 will flex (flexed position shown in Fig. 3) upon receipt of a pulse and unflex (unflexed position shown in Fig. 1). Flexing of the tunneling tool 40 allows acid to be injected at an angle toward the wellbore 10 wall, as illustrated by Figures 3-4. Lateral tunnel 52 is shown in Figure 4 being created by the injection of acid from nozzle 50.

[0024] Figure 6 illustrates the use of the pulsating tool 38 to help in creating an enlarged diameter lateral tunnel 52. In operation, the pulsating tool 38 generates a series of fluid pulses transmitted toward the tunneling tool 40. As each pulse is transmitted, the wand 42 and intermediate sub 44 flex to the first position shown by the solid lines in Figure 6. When the pulse passes, the wand 42 and intermediate sub 44 unflex to the second position indicated by the broken lines in Figure 6. As a result, the surface area of the formation 16 over which acid is distributed in increased, thereby enlarging the lateral tunnel. In particular, the lateral tunnel 52 will have acid distributed onto an upper portion 54 and a lower portion 56. Periodic flexing and unflexing, together with injection of acid, will create a lateral tunnel 52 having an enlarged diameter or wider portions as compared to acid tunneling tools which do not incorporate a pulsating tool. In addition, the enlargement of the lateral tunnel will result in reduced friction between the tunneling tool 40 and the formation 16 which will aid the process of forming the lateral tunnel 52.

[0025] In certain embodiments, an inclinometer 58 is incorporated into the tunneling tool 40. The inclinometer 58 is capable of determining the angular inclination of the tunneling tool 40, or portions thereof, with respect to a vertical axis or relative to the inclination or angle of the wellbore 10. The inclinometer 58 is electrically connected to the data/power cable 24 so that inclinometer data is sent to the controller 26 at surface 14 in real time. In addition, the sensor module 32 and casing collar locator 34 are electrically connected to the data/power cable 24 so that data obtained by them is provided to the controller 26 in real time.

[0026] The sensor module 32 includes sensors that are capable of detecting at least one downhole parameter. Preferably, the sensor module 32 includes sensors that are capable of detecting a variety of downhole parameters. Exemplary downhole parameters that are sensed by the sensor module 32 include temperature, pressure, gamma, acoustics and pH (acidity/alkalinity). These parameters can be used by the controller 26 or a user to identify the location and orientation of the bottom hole assembly 28 within the wellbore 10 in real time. For example, detected wellbore pressure or temperature can be correlated to a particular depth within the wellbore 10. In particular embodiments, real time bulk and azimuthal gamma measurements provided to the controller 26 from the sensor module 32 are used by the controller 26 in a manner similar to geosteering drilling techniques for determining in real time if the lateral tunnel 52 being formed is being created in the desired direction from the wellbore 10. In certain embodiments, sensed acoustics data is provided to the controller 26 from the sensor module 32 are used by the controller 26 for the same purpose. A pH sensor would be useful to provide information to the controller 26 which will help determine if acid is being spent effectively (i.e., reacting with formation rock) in forming lateral tunnel 52. A user can, in response, adjust acid volume, pumping rate, temperature and/or pressure.

[0027] The controller 26 will provide a user with the information needed to steer the tunneling tool 40 in real time in response to information provided to the controller 26 by the sensor module 32, inclinometer 58 and casing collar locator 34 used with the bottom hole assembly 28. The casing collar locator 34 is capable of providing location data as a result of detection of axial spacing from a casing collar (i.e., connecting collars used with the cased portion 17 of the wellbore 10. In the acid tunneling system 18 of the present invention, data from the casing collar locator 34 is provided to the controller in real time via data/power cable 24.

[0028] In response to the information collected by the controller 26, a user can steer the bottom hole assembly 28 in order to create lateral tunnels at desired locations and in desired directions. With reference to Figure 5, it can be seen that the tunneling tool 40 has been rotated in the wellbore 10 from the creation of first lateral tunnel 52 so that a second lateral tunnel 60 is being created by acid from the nozzle 50. The tunneling tool 40 has been rotated by the indexing tool 36 within the wellbore 10. In certain embodiments, the indexing tool 36 is capable of rotating the tunneling tool 40 up to 180 degrees in either radial direction within the wellbore 10, thereby providing the ability to orient the nozzle 50 of the tunneling tool 40 in any radial direction within the wellbore 10. Such real-time steering of the tunneling tool 40 can also be used to guide and orient the nozzle 50 of the tunneling tool 40 initially for the creation of lateral tunnel 52.

[0029] The invention provides systems and methods for steering a tunneling tool 40 in order to create lateral tunnels, such as tunnels 52, 60. In accordance with particular embodiments, data from downhole sensors and devices is transmitted to the surface in real time and, in response thereto, the tunneling tool 40 is moved axially within the wellbore 10 and/or angularly rotated within the wellbore 10 to steer and orient the nozzle 50 of that acid is injected in a desired direction for creation of one or more lateral tunnels. Figure 7 provides an exemplary flow diagram depicting steps in an exemplary operation to steer the tunneling tool 40 to create lateral tunnels. In step 70, the bottom hole assembly 28 is run into wellbore 10 on running string 20 to a first desired location within the wellbore 10. In step 72, acid is flowed to the bottom hole assembly 28 where the pulsating tool 38 is activated to flex and unflex the tunneling tool 40 as described above. Acid creates a first lateral tunnel at a first location within the wellbore 10.

[0030] In step 74, data from sensor module 32, inclinometer 58, and casing collar locator 34 is transmitted to controller 26. It is noted that step 74 occurs during each of the steps 70 and 72. In step 76, the tunneling tool 40 is steered to orient the nozzle 50 to create a second lateral tunnel at a second location. A user steers the tunneling tool 40 in response to and based upon real-time downhole parameter data collected by the controller 26. In steering the tunneling tool 40, the bottom hole assembly 28 may be moved axially within the wellbore 10. Also, the indexing tool 36 can steer the tunneling tool 40 by rotating it within the wellbore 10. In step 78, the tunneling tool 40 creates a second lateral tunnel in a second location within the wellbore 10. In step 80, acid is flowed to the bottom hole assembly 28. The pulsating tool 38 flexes the tunneling tool 40 and directs the nozzle 50 radially outwardly so that a second lateral tunnel may be formed.

[0031] Figures 8-9 depict an embodiment wherein an acid tunneling system is used to create one or more lateral tunnels from within a wellbore 90 which is lined with metallic casing 92. Figure 8 illustrates a window mill 94 having been run into the wellbore 90 on running string 96. A whipstock 98 has been placed within the wellbore 90 deflects the mill 94 so that a window 100 is cut into the casing 92. The window 100 is cut at a location within the wellbore 90 wherein it is desired to create a lateral tunnel. Although only a single window 100 is shown being cut, it should be understood that more than one window may be cut, allowing lateral tunnels to be created at multiple locations from wellbore 90.

[0032] After the cutting of window 100 (or multiple windows, if applicable), the mill 94 and whipstock 98 are removed from the wellbore 90. Thereafter, an acid tunneling, system 18 is disposed into the wellbore 90 (Figure 9). The tunneling tool 40 of the acid tunneling system 18 is then steered, using the techniques described previously, to direct the nozzle 50 of the tunneling tool 40 toward the window 100 and surrounding formation 16. Steering in this instance will preferably utilize at least data provided to the controller 26 by the casing collar locator 34 in order to assist in properly locating the tunneling tool 40 at the same depth or location in the wellbore 90 as the window 100. Data from the inclinometer 58 is useful for directing the nozzle 50 through the window 100. If there are multiple windows that have been cut in the casing, the tunneling tool 40 is steered to each of them using the techniques described previously. At each location, the acid tunneling tool is used to create a lateral tunnel through the window, such as window 100.

[0033] Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow.


Claims

1. A steerable acid tunneling system (18) for creating lateral tunnels (52, 60) in a subterranean formation (16) surrounding a wellbore (10), the steerable acid tunneling system (18) comprising a bottom hole assembly (28), the bottom hole assembly (28) comprising:

an acid tunneling tool (40) having a wand (42) with a nozzle (50) for injecting acid into the formation and at least one articulable joint (46, 48) for angularly orienting the wand (42) within the wellbore (10);

one or more sensors for detection of at least one downhole parameter and transmission of a signal indicative of the at least one downhole parameter to surface; and

a pulsating tool (38);

wherein the acid tunneling tool (18) is steered by the pulsating tool (38) which creates pressure pulses that are transmitted to the acid tunneling tool (40) to activate flexure of the wand in real time response to the at least one downhole parameter detected in order to inject acid in a particular direction.


 
2. The steerable acid tunneling system (18) of claim 1 being further characterized by:

an indexing tool (36) operably associated with the acid tunneling tool (40) and operable to rotate the acid tunneling tool (40) within the wellbore (10); and

wherein the acid tunneling tool (40) is further steered by rotating the acid tunneling tool (40) within the wellbore (10) with the indexing tool (36).


 
3. The steerable acid tunneling system (18) of claim 1 wherein the at least one downhole parameter is at least one of a group consisting of pressure, temperature, tool inclination, axial spacing from a casing collar, alkalinity/acidity, gamma, and acoustics.
 
4. The steerable acid tunneling system (18) of claim 1 further characterized by:

an inclinometer (58) operably associated with acid tunneling tool (40); and

wherein the inclinometer (58) provides a real time signal indicative of angular inclination of the tunneling tool within the wellbore (10) to surface.


 
5. The steerable acid tunneling system (18) of claim 1 further comprising a controller (26) to receive a signal indicative of the at least one downhole parameter.
 
6. The steerable acid tunneling system (18) of claim 1 further comprising:

a running string (20) for running a bottom hole assembly including the acid tunneling tool (40) and one or more sensors into the wellbore (10), the running string (20) having an axial flowbore (22) for flowing of acid; and

a power/data cable (24) located within the flowbore for transmission of a signal indicative of the at least one downhole parameter to surface.


 
7. A method of steering an acid tunneling system (18) in real time within a wellbore (10) to create a lateral tunnel (52, 60) from the wellbore (10), the method being characterized by the steps of:

running an acid tunneling system (18) into a wellbore (10), the acid tunneling system (18) having an acid tunneling tool (40) with a wand (42) having a nozzle (50) for injecting acid into a formation (16) radially surrounding the wellbore (10) and at least one articulable joint (46, 48) for angularly orienting the wand (42) within the wellbore (10);

detecting at least one downhole parameter with one or more sensors and transmitting a signal indicative of the at least one downhole parameter to surface in real time;

steering the acid tunneling tool (40) of the acid tunneling system (18) to a desired location for forming a lateral tunnel (52, 60) by transmitting pressure pulses from a downhole pulsating tool (38) to the acid tunneling tool (40) to activate flexure of the wand (42); and

flowing acid to the acid tunneling tool (40) to inject the acid into a formation at the desired location to form the lateral tunnel.


 
8. The method of claim 7 wherein the step of steering the acid tunneling tool (40) to a desired location further comprises steering the acid tunneling tool (40) from a first location within the wellbore (10) to a second location within the wellbore (10).
 
9. The method of claim 7 further characterized by the step of:

while flowing the acid to the acid tunneling tool (40), generating a plurality of fluid pulses within acid flowing to the acid tunneling tool (40), and

wherein the plurality of fluid pulses causes the wand (42) to flex about the articulable joint between first and second positions so that the nozzle (50) injects acid at the first and second positions, thereby enlarging the lateral tunnel formed.


 
10. The method of claim 7 wherein the step of steering the acid tunneling tool (40) to a desired location is further characterized by rotating the acid tunneling tool (40) within the wellbore (10).
 
11. The method of claim 7 wherein the step of steering the acid tunneling tool (40) to a desired location is further characterized by moving the acid tunneling tool (40) axially within the wellbore (10).
 
12. The method of claim 7 wherein:

the wellbore (10) is lined with a metallic casing (17); and

prior to running the acid tunneling system (18) into the wellbore (10), a window is cut into the metallic casing (17), and thereafter, the acid tunneling tool (40) is steered within the wellbore (10) to the desired location.


 


Ansprüche

1. Lenkbares Säuretunnelsystem (18) zum Erzeugen von seitlichen Tunneln (52, 60) in einer unterirdischen Formation (16), die ein Bohrloch (10) umgibt, wobei das lenkbare Säuretunnelsystem (18) eine Bohrgarnitur (28) umfasst, wobei die Bohrgarnitur (28) umfasst:

ein Säuretunnelwerkzeug (40), das einen Stab (42) mit einer Düse (50) zum Einspritzen von Säure in die Formation und mindestens eine Gelenkverbindung (46, 48) zur winkligen Ausrichtung des Stabs (42) innerhalb des Bohrlochs (10) aufweist;

einen oder mehrere Sensoren zur Erfassung mindestens eines Bohrlochparameters und zur Übertragung eines Signals zur Oberfläche, das den mindestens einen Bohrlochparameter anzeigt;

und

ein pulsierendes Werkzeug (38);

wobei das Säuretunnelwerkzeug (18) durch das pulsierende Werkzeug (38) gelenkt wird, das Druckimpulse erzeugt, die zum Säuretunnelwerkzeug (40) übertragen werden, um eine Biegung des Stabs in Echtzeit als Reaktion auf den mindestens einen Bohrlochparameter zu aktivieren, der erfasst wird, um Säure in eine bestimmte Richtung einzuspritzen.


 
2. Lenkbares Säuretunnelsystem (18) nach Anspruch 1, ferner gekennzeichnet durch:

ein Indexierungswerkzeug (36), das mit dem Säuretunnelwerkzeug (40) wirkverbunden und betriebsfähig ist, um das Säuretunnelwerkzeug (40) innerhalb des Bohrlochs (10) zu drehen; und

wobei das Säuretunnelwerkzeug (40) ferner gelenkt wird, indem das Säuretunnelwerkzeug (40) innerhalb des Bohrlochs (10) mit dem Indexierungswerkzeug (36) gedreht wird.


 
3. Lenkbares Säuretunnelsystem (18) nach Anspruch 1, wobei der mindestens eine Bohrlochparameter mindestens eines ist aus der Gruppe, bestehend aus Druck, Temperatur, Werkzeugneigung, axialem Abstand von einem Futterrohrrand, Alkalität/Azidität, Gammastrahlung und Akustik.
 
4. Lenkbares Säuretunnelsystem (18) nach Anspruch 1, ferner gekennzeichnet durch:

einen Neigungsmesser (58), der mit dem Säuretunnelwerkzeug (40) wirkverbunden ist; und

wobei der Neigungsmesser (58) ein Echtzeitsignal bereitstellt, das eine Winkelneigung des Tunnelwerkzeugs innerhalb des Bohrlochs (10) zur Oberfläche anzeigt.


 
5. Lenkbares Säuretunnelsystem (18) nach Anspruch 1, ferner umfassend eine Steuereinheit (26) zum Empfang eines Signals, das den mindestens einen Bohrlochparameter anzeigt.
 
6. Lenkbares Säuretunnelsystem (18) nach Anspruch 1, ferner umfassend:

einen Einführstrang (20) zum Einführen einer Bohrgarnitur, die das Säuretunnelwerkzeug (40) und einen oder mehrere Sensoren einschließt, in das Bohrloch (10), wobei der Einführstrang (20) eine axiale Strömungsbohrung (22) zum Strömenlassen von Säure aufweist; und

ein in der Strömungsbohrung angeordnetes Strom-/Datenkabel (24) zur Übertragung eines Signals zur Oberfläche, das den mindestens einen Bohrlochparameter anzeigt.


 
7. Verfahren zum Lenken eines Säuretunnelsystems (18) in Echtzeit innerhalb eines Bohrlochs (10), um einen seitlichen Tunnel (52, 60) aus dem Bohrloch (10) zu erzeugen, wobei das Verfahren gekennzeichnet ist durch die Schritte:

Einführen eines Säuretunnelsystems (18) in ein Bohrloch (10), wobei das Säuretunnelsystem (18) ein Säuretunnelwerkzeug (40) mit einem Stab (42), der eine Düse (50) zum Einspritzen von Säure in die Formation (16) aufweist, die das Bohrloch (10) umgibt, und mindestens eine Gelenkverbindung (46, 48) zur winkligen Ausrichtung des Stabs (42) innerhalb des Bohrlochs (10) aufweist;

Erfassen mindestens eines Bohrlochparameters mit einem oder mehreren Sensoren und Übertragen eines Signals, das den mindestens einen Bohrlochparameter anzeigt, in Echtzeit zur Oberfläche;

Lenken des Säuretunnelwerkzeugs (40) des Säuretunnelsystems (18) an eine gewünschte Stelle zum Bilden eines seitlichen Tunnels (52, 60) durch Übertragen von Druckimpulsen von einem pulsierenden Bohrlochwerkzeug (38) auf das Säuretunnelwerkzeug (40), um die Biegung des Stabs (42) zu aktivieren; und Strömenlassen von Säure zum Säuretunnelwerkzeug (40), um die Säure an der gewünschten Stelle in eine Formation zu einzuspritzen, um den seitlichen Tunnel zu bilden.


 
8. Verfahren nach Anspruch 7, wobei der Schritt des Lenkens des Säuretunnelwerkzeugs (40) an eine gewünschte Stelle ferner ein Lenken des Säuretunnelwerkzeugs (40) von einer ersten Stelle innerhalb des Bohrlochs (10) zu einer zweiten Stelle innerhalb des Bohrlochs (10) umfasst.
 
9. Verfahren nach Anspruch 7, ferner gekennzeichnet durch den Schritt:

während des Strömenlassens der Säure in das Säuretunnelwerkzeug (40) ein Erzeugen einer Vielzahl von Impulsen in Säure, die zum Säuretunnelwerkzeug (40) strömt, und

wobei die Vielzahl von Fluidimpulsen bewirkt, dass sich der Stab (42) um die Gelenkverbindung zwischen einer ersten und zweiten Position biegt, sodass die Düse (50) Säure an der ersten und zweiten Position einspritzt, wodurch der gebildete seitliche Tunnel vergrößert wird.


 
10. Verfahren nach Anspruch 7, wobei der Schritt des Lenkens des Säuretunnelwerkzeugs (40) an eine gewünschte Stelle ferner gekennzeichnet ist durch ein Drehen des Säuretunnelwerkzeugs (40) innerhalb des Bohrlochs (10).
 
11. Verfahren nach Anspruch 7, wobei der Schritt des Lenkens des Säuretunnelwerkzeugs (40) an eine gewünschte Stelle ferner gekennzeichnet ist durch ein axiales Bewegen des Säuretunnelwerkzeugs (40) innerhalb des Bohrlochs (10).
 
12. Verfahren nach Anspruch 7, wobei:

das Bohrloch (10) mit einem metallischen Futterrohr (17) ausgekleidet wird; und

vordem Einführen des Säuretunnelsystems (18) in das Bohrloch (10) ein Fenster in das metallische Futterrohr (17) geschnitten wird und das Säuretunnelwerkzeug (40) anschließend innerhalb des Bohrlochs (10) an die gewünschte Stelle gelenkt wird.


 


Revendications

1. Système de forage en tunnel par acide orientable (18) destiné à créer des tunnels latéraux (52, 60) dans une formation souterraine (16) entourant un puits de forage (10), le système de forage en tunnel par acide orientable (18) comprenant un ensemble de fond de trou (28), l'ensemble de fond de trou (28) comprenant :

un outil de forage en tunnel par acide (40) ayant une baguette (42) avec une buse (50) pour injecter de l'acide dans la formation et au moins un joint articulable (46, 48) pour orienter angulairement la baguette (42) à l'intérieur du puits de forage (10) ;

un ou plusieurs capteurs pour la détection d'au moins un paramètre de fond de trou et la transmission d'un signal indicatif de l'au moins un paramètre de fond de trou à la surface ;

et

un outil à pulsations (38) ;

dans lequel l'outil de forage en tunnel par acide (18) est orienté par l'outil à pulsations (38) qui crée des impulsions de pression qui sont transmises à l'outil de forage en tunnel par acide (40) pour activer la flexion de la baguette en réponse en temps réel à l'au moins un paramètre de fond de trou détecté afin d'injecter de l'acide dans une direction particulière.


 
2. Système de forage en tunnel par acide orientable (18) selon la revendication 1 étant caractérisé en outre par :

un outil d'indexation (36) associé de manière opérationnelle à l'outil de forage en tunnel par acide (40) et pouvant fonctionner pour faire tourner l'outil de forage en tunnel par acide (40) à l'intérieur du puits de forage (10) ; et

dans lequel l'outil de forage en tunnel par acide (40) est orienté en outre par rotation de l'outil de forage en tunnel par acide (40) à l'intérieur du puits de forage (10) avec l'outil d'indexation (36).


 
3. Système de forage en tunnel par acide orientable (18) selon la revendication 1 dans lequel l'au moins un paramètre de fond de trou est au moins l'un parmi un groupe constitué de pression, température, inclinaison d'outil, espacement axial à partir d'un collier de coffrage, acidité/alcalinité, gamma, et acoustique.
 
4. Système de forage en tunnel par acide orientable (18) selon la revendication 1 caractérisé en outre par :

un inclinomètre (58) associé de manière opérationnelle à outil de forage en tunnel par acide (40) ; et

dans lequel l'inclinomètre (58) fournit un signal en temps réel indiquant une inclinaison angulaire de l'outil de forage en tunnel à l'intérieur du puits de forage (10) à la surface.


 
5. Système de forage en tunnel par acide orientable (18) selon la revendication 1 comprenant en outre un contrôleur (26) pour recevoir un signal indicatif de l'au moins un paramètre de fond de trou.
 
6. Système de forage en tunnel par acide orientable (18) selon la revendication 1 comprenant en outre :

un train de tiges de descente (20) pour descendre un ensemble de fond de trou incluant l'outil de forage en tunnel par acide (40) et un ou plusieurs capteurs dans le puits de forage (10), le train de tiges de descente (20) ayant un alésage d'écoulement axial (22) pour l'écoulement de l'acide ; et

un câble d'alimentation/de données (24) situé dans l'alésage d'écoulement pour la transmission d'un signal indicatif de l'au moins un paramètre de fond de trou à la surface.


 
7. Procédé d'orientation d'un système de forage en tunnel par acide (18) en temps réel à l'intérieur d'un puits de forage (10) pour créer un tunnel latéral (52, 60) à partir du puits de forage (10), le procédé étant caractérisé par les étapes consistant à :

descendre un système de forage en tunnel par acide (18) dans un puits de forage (10), le système de forage en tunnel par acide (18) ayant un outil de forage en tunnel par acide (40) avec une baguette (42) ayant une buse (50) pour injecter de l'acide dans une formation (16) entourant le puits de forage (10) au plan radial et au moins un joint articulable (46, 48) destiné à orienter de manière angulaire la baguette (42) à l'intérieur du puits de forage (10) ;

détecter au moins un paramètre de fond de trou avec un ou plusieurs capteurs et transmettre un signal indicatif de l'au moins un paramètre de fond de trou à la surface en temps réel ;

orienter l'outil de forage en tunnel par acide (40) du système de forage en tunnel par acide (18) vers un emplacement souhaité afin de former un tunnel latéral (52, 60) par transmission d'impulsions de pression depuis un outil de pulsations en fond de trou (38) vers l'outil de forage en tunnel par acide (40) pour activer la flexion de la baguette (42) ; et

laisser l'acide s'écouler vers l'outil de forage en tunnel par acide (40) pour injecter l'acide dans une formation à l'emplacement souhaité pour former le tunnel latéral.


 
8. Procédé selon la revendication 7 dans lequel l'étape d'orientation de l'outil de forage en tunnel par acide (40) vers un emplacement souhaité comprend en outre l'orientation de l'outil de forage en tunnel par acide (40) d'un premier emplacement au sein du puits de forage (10) vers un deuxième emplacement au sein du puits de forage (10).
 
9. Procédé selon la revendication 7 caractérisé en outre par l'étape consistant à :

tandis que l'acide s'écoule vers l'outil de forage en tunnel par acide (40), générer une pluralité d'impulsions de fluide au sein de l'acide circulant vers l'outil de forage en tunnel par acide (40), et

dans lequel la pluralité d'impulsions de fluide amène la baguette (42) à fléchir autour du joint articulable entre des première et seconde positions de sorte que la buse (50) injecte de l'acide aux première et deuxième positions, agrandissant ainsi le tunnel latéral formé.


 
10. Procédé selon la revendication 7 dans lequel l'étape d'orientation de l'outil de forage en tunnel par acide (40) vers un emplacement souhaité est caractérisé en outre par la rotation de l'outil de forage en tunnel par acide (40) à l'intérieur du puits de forage (10).
 
11. Procédé selon la revendication 7 dans lequel l'étape d'orientation de l'outil de forage en tunnel par acide (40) vers un emplacement souhaité est caractérisé en outre par le déplacement de l'outil de forage en tunnel par acide (40) au plan axial à l'intérieur du puits de forage (10).
 
12. Procédé selon la revendication 7 dans lequel :

le puits de forage (10) est revêtu d'un coffrage métallique (17) ; et

avant descente du système de forage en tunnel par acide (18) dans le puits de forage (10), une fenêtre est coupée dans le coffrage métallique (17), et par la suite, l'outil de forage en tunnel par acide (40) est orienté à l'intérieur du puits de forage (10) vers l'emplacement souhaité.


 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description




Non-patent literature cited in the description