US20130327519A1

US20130327519A1 - Tubing test system

Info

Publication number: US20130327519A1
Application number: US13/491,286
Authority: US
Inventors: Vismar Ibarra; Shivam Kumar Singh
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 2012-06-07
Filing date: 2012-06-07
Publication date: 2013-12-12
Also published as: WO2013184432A1

Abstract

A technique facilitates preparation of a tubing string, such as a tubing string located in a well. For example, a ball seat member may be mounted in a tubular of a tubing string. A system is coupled to the ball seat member to enable rotation of the ball seat member between cycles. Additionally, a cycle control system is employed in cooperation with the system coupled to the ball seat member to provide control over the number of cycles. Multiple tubing integrity tests may be performed while the system ball seat member is run in hole. Additionally, the system may be used to set a hydraulic packer.

Description

BACKGROUND

Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Various types of tubing strings comprising completions and other downhole equipment may be deployed into the well to facilitate production of the hydrocarbon fluids. In preparing the well, several types of tests may be performed prior to initiation of fluid production. For example, pressure tests may be performed on the tubing string to ensure the equipment is in proper, functional condition. Many types of devices have been employed to facilitate the testing and production preparation procedures.

SUMMARY

In general, the present disclosure pro), ides a system and method for use in preparing, e.g. testing, a tubing string, such as a tubing string located in a well. For example, a ball seat member may be mounted in a tubular of a tubing string, e.g. a tubing string deployed in a wellbore. A system is coupled to the ball seat member to enable rotation of the ball seat member between test cycles or other actuation cycles. Additionally, a cycle control system is employed in cooperation with the system coupled to the ball seat member to provide control over the number of cycles, e.g. test cycles.
However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:

FIG. 1 is an illustration of an example of a well system deployed in a wellbore, according to an embodiment of the disclosure;

FIG. 2 is a schematic illustration of an example of a system designed to enable pressure testing of a tubing string, according to an embodiment of the disclosure;

FIG. 3 is an illustration similar to that of FIG. 2 but showing the system in a different operational position, according to an embodiment of the disclosure;

FIG. 4 is an illustration similar to that of FIG. 2 but showing the system in a different operational position, according to an embodiment of the disclosure;

FIG. 5 is an illustration similar to that of FIG. 2 but showing the system in a different operational position, according to an embodiment of the disclosure;

FIG. 6 is a schematic illustration of another example of a system designed to enable pressure testing, of a tubing string, according to an embodiment of the disclosure;

FIG. 7 is an illustration similar to that of FIG. 6 but showing the system in a different operational position, according to an embodiment of the disclosure;

FIG. 8 is an illustration similar to that of FIG. 6 but showing the system in a different operational position, according to an embodiment of the disclosure;

FIG. 9 is an illustration similar to that of FIG. 6 but showing the system in a different operational position, according to an embodiment of the disclosure; and

FIG. 10 is an illustration similar to that of FIG. 6 but showing the system in a different operational position, according to an embodiment of the disclosure.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The disclosure herein generally involves a system and methodology related to testing tubing strings. In some applications, the system and methodology are applied to preparing well related tubing strings for production of downhole fluids, such as hydrocarbon-based fluids. For example, the system and methodology may comprise mounting a ball seat member in a tubular, such as a well tubular. A rotation system, such as a ratchet system, is coupled to the ball seat member to enable rotation of the ball seat member between subsequent cycles, e.g. test cycles. Additionally, a cycle control system may be used in cooperation with the ball seat member rotation system to control the number of cycles. The cycle control system also may be used to place the ball seat member into a final production position.
Depending on the application, the system may be used as an interventionless valve/plug to test tubing. In well applications, the system also may be used to facilitate setting of a packer, such as a tubing set packer deployed in a well completion. The system is useful in holding pressure from above in a tubing string to facilitate a variety of test procedures and other types of tubing related procedures. In many applications, the design of the system enables repeated tubing tests to be performed.
In a specific example, the system utilizes a ball drop arrangement for tubing testing and packer setting in a well environment. The technique may utilize a variety of mechanisms, such as a ball, a rotatable ball seat member, a J-slot mechanism, a resilient device, e.g. a nitrogen chamber, a ratchet mechanism, and/or a variety of other components to facilitate the desired testing and/or setting actions. It should be noted that the term “ball” is used to represent a variety of members which may be moved downhole for engagement with the ball seat member. For example, the ball may be spherical or the ball may have an arcuate portion designed for seating against a corresponding surface/seat in the ball seat member. Additionally, the ball may be constructed as a dart having an elongated form or as a variety of other types of members having a variety of shapes and configurations which allow the member to travel downhole through the tubing string for engagement with the ball seat member. In some applications, the ball also may be made from a dissolvable material.
Referring generally to FIG. 1, an example of a well system is illustrated as comprising a tubing string deployed in a well. The well system can be used in a variety of well applications, including onshore applications and offshore applications. In this example, the tubing string is illustrated as deployed in a generally vertical wellbore, however the tubing, string may be deployed in a variety of wells including various vertical and deviated wells. The embodiments described below may be employed to facilitate, for example, production and/or servicing operations in well applications and in other types of tubing strings.
In the example illustrated in FIG. 1, a well system 20 is deployed in a wellbore 22 and comprises a tubing string 24. The wellbore 22 may comprise a generally vertical or deviated wellbore deployed in an open hole wellborn or a case wellbore lined with a casing 26. Depending on the application, the tubing string 24 may comprise a variety of components including a ball seat system 28 designed to selectively block or allow flow along the tubing string 24. The ball seat system 28 may be actuated for a variety of tubing string related procedures, such as testing procedures, e.g. pressure testing procedures. In the example illustrated, the ball seat system 28 is deployed in a tubular member 30, e.g. a sub, of the tubing string 24.
However, the tubing, string 24 may comprise many other types of components to facilitate a variety of production and/or other well related operations. For example, the tubing string 24 may comprise a completion 32 having a packer 34, such as a hydraulic packer actuated by pressure in the tubing string. Additionally, the tubing, string 24 may comprise or be deployed beneath a tubing hanger 36. Other examples of tubing string components include a mule shoe guide 38, a landing nipple 40, a sliding sleeve 42, and a safety valve 44. These are just a few examples of the types of components that may be incorporated into the tubing string 24 to accommodate a given well application or other type of application.
Referring generally to FIGS. 2-5, an example of the ball seat system 28 is illustrated. In this embodiment, the ball seat system 28 comprises a ball seat member 46 designed to receive a ball 48 which may be spherical or some other suitable shape. By way of example, the ball seat member 46 may be rotatable within a flow passage 50 that extends through ball seat system 28, tubular member 30, and tubing string 24. When the ball 48 is seated in the ball seat member 46 as illustrated in FIG. 2, flow along the flow passage 50 down through tubing, string 24 is blocked. This enables performance of a variety of pressure tests or other testing on the tubing string 24. The structure of the various embodiments described herein facilitates performance of repeated tubing testing, e.g., repeated pressure tests. The pressure build-up in flow passage 50 of tubing string 24 also may be used to perform other tasks, such as setting of packer 34.
In the example illustrated, the ball seat system 28 also comprises a rotation control system 52, e.g. a ratchet system, to control rotation of ball seat member 46 so as to release and retain sequentially dropped balls 48. The ball seat system 28 also may comprise a test cycle control system 54. By way of example, the test cycle control system 54 may be designed with a J-slot system 56 to control the number and implementation of cycles, e.g. test cycles, on tubing string 24. In this latter example, pressuring up flow passage 50 above ball seat member 46 and then releasing the pressure causes a follower 58 to cycle along a J-slot 60 of the J-slot system 56 (see J-slot 60 in diagram form on right side of each of the FIGS. 2-5). Actuation along the J-slot 60 may be resisted by a suitable resistance system 62, such as a piston 64 acting against a resilient device 66. In some applications, the resilient device 66 comprises a was chamber 68, such as a nitrogen chamber. However, the resilient device 66 may comprise a variety of other resilient devices, such as mechanical springs or other biasing devices.
In an operational example, the follower 58 is initially positioned at a starting position 70 along the J-slot 60, as illustrated in FIG. 2. Once the ball 48 is seated in ball seat member 46, pressure is applied in flow passage 50 which actuates the J-slot system 56 and shifts the follower 58 along the J-slot 60 to a second position 72, as illustrated in FIG. 3. At this stage, a pressure test or other action, e.g. setting of a packer or other tool, may be performed. When the test cycle or other cycle is completed, pressure in flow passage 50 is released and resistance system 62 moves the follower 58 along the J-slot 62 a subsequent position 74, as illustrated in FIG. 4. By way of example, the rotation control system 52 may be designed to rotate the ball seat member 46 and to release the ball 48 after each test cycle. Another ball 48 would then be dropped, e.g. delivered to the valve seat member 46, to provide pressure integrity prior to performance of the next test procedure or other tubing string related action.
The J-slot 60 may be designed with a plurality of cycle segments 76 to enable repetition of this testing/actuation cycle for the desired number of pressure tests or other actions) taken with respect to tubing string 24. Upon completion of the testing/actuation cycles controlled by the number of cycle segments 76, the follower 58 may be shifted to a production position 78, as illustrated in FIG. 5. In this position, no additional balls 48 are dropped and the ball seat member 46 is held at a rotational position which allows the flow of production fluids or other appropriate fluids along the flow passage 50. In other words, the final cycling of the ball seat system 28 may be used as a lockout cycle.
Referring generally to FIGS. 6-10, another embodiment of the ball seat system 28 is illustrated, in this embodiment, the ball seat member 46 comprises a plurality of ball receiving openings 80 sized to receive balls 48 at a variety of rotational angles. By way of example, the embodiment illustrated comprises four of the ball receiving openings 80 arranged in a manner which allows the ball seat member 46 to simply be rotated for release of a ball 48 to a location below the ball seat system 28. In some embodiments, the balls 48 are formed from a degradable material which allows the balls to dissolve or otherwise degrade when exposed to the wellbore environment over a sufficient length of time.
In the example illustrated, the rotation control system 52 is in the form of a ratchet system 82 coupled to the ball seat member 46 to selectively rotate the ball seat member 46 about an axis 84. Although the ratchet system 82 may be constructed in a variety of forms, the illustrated example is a rack and pinion system having a rack 86 which engages a pinion 88 mounted to ball seat member 46. The rack 86 is slidably received in a corresponding opening 90 formed in a ball seat system housing 92.
Linear movement of the rack 86, and thus rotational movement of ball seat member 46, is controlled by test cycle control system 54. In this example, the test cycle control system 54 comprises a piston 64 which acts against gas, e.g. nitrogen, disposed in gas chamber 68, e.g. a nitrogen gas chamber. The piston 64 also is connected to follower 58 by a mechanism 94, such as a rod. Application of pressure in the tubing string causes the follower 58 to move along J-slot 60 of the J-slot mechanism 56, and this movement causes corresponding movement of piston 64 via mechanism 94, in this example, mechanism 94 engages rack 86 by a suitable engagement feature 96. In some embodiments, engagement feature 96 may be spring biased toward rack 86 and designed to permit relative sliding motion between rack 86 and engagement feature 96 in one direction but not in the opposite direction. A similar engagement feature 98 may be mounted in housing 92 for biased engagement with rack 86, as illustrated.
In an operational example, follower 58 is initially at position 70 and a ball 48 is dropped, e.g. deployed, downhole through tubing string 24, as illustrated in FIG. 6. The ball 48 travels downwardly until moving through the upwardly facing opening 80 and into engagement with a seat 100 of ball seat member 46. The ball 48 is used to create a seal in the tubing string 24 which enables building up of pressure for desired procedures, such as tubing testing and setting of the packer. As illustrated in FIG. 7, pressuring up the tubing string 24 (while ball 48 is seated against ball seat 100) causes follower 56 to transition to position 72. The movement of the follower 58 causes corresponding movement of mechanism 94 and piston 64 against the resistance of nitrogen chamber 68. The transition of follower 58 to position 72 occurs as soon as the counter force exerted on piston 64 by the nitrogen in nitrogen chamber 68 is overcome. Additionally, engagement feature 96 slides down along rack 86 without causing, linear movement of rack. 86. During this stage of the cycle, the pressure buildup in tubing string 24 can be used for pressure testing and/or other desired actions related to the specific well application. By way of example, the pressure applied in tubing string 24 may be held for a predetermined test time, and the tubing string 24 may be monitored for leaks.
Following completion of the tubing string procedure, the pressure in tubing string 24 is released. The release of pressure allows the nitrogen in nitrogen chamber 68 (or other suitable resilient device) to move piston 64 in an opposite direction, e.g. upwardly in the illustrated example. During this motion, the piston 64 also moves mechanism 94 and drives follower 58 to position 74, as illustrated in FIG. 8. The movement of mechanism 94 also causes a corresponding movement of rack 86 via engagement feature 96. The engagement feature 96 is designed to prevent relative sliding motion between mechanism 94 and rack 86 when moving in this direction. Consequently, movement of mechanism 94 forces the rack 86 to move along pinion 88 and to thus rotate ball seat member 46 until the ball 48 drops downwardly, as illustrated in FIG. 8.
If another procedure, e.g. a pressure test procedure, is to be performed, a subsequent ball 48 is dropped down through the currently, upwardly facing opening 80 of ball seat member 46, as represented by the upper ball illustrated in FIG. 8. The subsequently dropped ball 48 again forms a seal against seat 100 to enable performance of the next pressure cycle. For example, pressure may again be applied within tubing string 24 to drive follower 58, mechanism 94, and piston 64 to the position illustrated in FIG. 9. During this stage of the cycle, the pressure buildup in tubing string 24 can again be used for pressure testing and/or other desired actions related to the specific well application. Following completion of the tubing string pressure cycle, the pressure in tubing string 24 is again released which allows the nitrogen in nitrogen chamber 68 (or other suitable resilient device) to move piston 64 in an opposite direction. As with the previous cycle, the piston 64 also moves mechanism 94 and drives follower 58 to a return position, as illustrated in FIG. 10. The movement of mechanism 94 again causes corresponding movement of rack 86 via engagement feature 96. The movement of mechanism 94 forces the rack 86 to move along pinion 88 which again rotates ball seat member 46 until the ball 48 drops downwardly, as illustrated in FIG. 10.
After completing the desired number of pressure cycles for which J-slot 60 has been designed, the follower 58 is shifted to a production position 78. Effectively, movement of follower 58 to position 78 locks the ball seat member 46 in a production position. The final, cycle serves as a lock out cycle which locks mechanism 94, piston 64, and ball seat member 46 in a position allowing fluid flow, e.g. production fluid flow, through ball seat member 46 and tubing string 24. It should be noted that a variety of lock out cycles or mechanisms may be used to lock the system in a production configuration.
In wellbore applications, the well system 20 may be constructed in a variety of configurations to facilitate a variety of downhole procedures. For example, well system 20 and ball seat system 28 may be used to enable multiple tubing tests while running in hole. The ball seat system also enables simultaneous packer setting and tubing testing while providing auto fill capability. The overall well system 20 and hall seat system 28 also can be used to reduce rig time by reducing or eliminating slickline operations. Use of the ball seat system 28 also reduces or removes the potential for accidental setting or presetting of the packer while running in hole. Furthermore, the system may be constructed in modular configurations that allow different numbers of cycles to be selected for particular applications. For example, different J-slots having different numbers of cycles may be combined/interchanged with the ball seat system to accommodate the parameters of a given application.
Depending on the well application or other type of tubing string application, and on the desired function of the overall well system, various embodiments described herein may be used to facilitate a variety of production and/or servicing operations. Accordingly, the overall well system may comprise many types of components and arrangements of components. Additionally, the ball seat system described herein may be used with a variety of devices and systems, including a variety of subs, sensors, valves, gauges, control systems, and other components designed to facilitate a given production or servicing operation. The specific components and arrangements of components in the ball seat system also may be changed. For example, the rotation control system may utilize a ratchet system or another type of system for rotating the ball seat member. Similarly, the test cycle control system may utilize combinations of pistons, gas chambers, and J-slots; or the test cycle control system may utilize other types of cycle control mechanisms constructed in various designs and configurations depending on the parameters of a specific application.
Although a few embodiments of the system and methodology have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

Claims

What is claimed is:

1. A method of testing, comprising:

dropping a ball to a ball seat member located in a tubing string;

pressuring up the tubing string to perform a test on the tubing string;

releasing the ball from the ball seat member by rotating the ball seat member via release of the pressure;

dropping a second ball to the ball seat member;

pressuring up the tubing string to perform a subsequent test on the tubing string; and

releasing the second ball from the ball seat member by rotating the ball seat member via release of the pressure.

2. The method as recited in claim 1, further comprising setting a packer by pressuring up the tubing string.

3. The method as recited in claim 1, wherein releasing comprises controlling the ball seat member with a ratchet system to selectively release the ball and the second ball upon release of the pressure in the tubing string.

4. The method as recited in claim 1, further comprising controlling the number of tests on the tubing string with a J-slot system.

5. The method as recited in claim 4, wherein controlling comprises utilizing a piston and a nitrogen chamber in cooperation with a J-slot of the J-slot system.

6. The method as recited in claim 1, further comprising performing a plurality of additional tests on a tubing string by pressuring up the tubing string.

7. The method as recited in claim 1, further comprising locking the ball seat member in an open flow, production position after completing testing of the tubing string.

8. The method as recited in claim 1, wherein dropping comprises dropping a spherically shaped ball.

9. The method as recited in claim 1, wherein dropping comprises dropping a dissolvable ball.

10. A system for use in a well, comprising:

a ball seat member mounted in a well tubular;

a ratchet system coupled to the ball seat member to enable rotation of the ball seat member between test cycles; and

a test cycle control system coupled to the ratchet system, the test cycle control system controlling the number of test cycles.

11. The system as recited in claim 10, wherein the ratchet mechanism comprises a rack and pinion.

12. The system as recited in claim 10, wherein the test cycle control system comprises a J-slot.

13. The system as recited in claim 12, wherein the test cycle control system further comprises a piston coupled to a follower engaged with the J-slot.

14. The system as recited in claim 13, wherein the test cycle control system further comprises a resilient device to return the piston after being actuated by pressure applied in the well tubular.

15. The system as recited in claim 14, wherein the resilient device comprises a nitrogen chamber.

16. The system as recited in claim 10, wherein the ball seat member comprises a plurality of openings, each opening being sized to receive a ball dropped down through a tubing string.

17. A method of performing actions in a wellbore, comprising:

rotatably mounting a ball seat member in a tubing string;

coupling a cycle control system to the tubing string to enable selective rotation of the ball seat member by applying and releasing pressure in the tubing string; and

rotating the ball seat member between cycles to release and capture balls used to enable application of the pressure in the tubing string.

18. The method as recited in claim 17, wherein coupling comprises coupling a ratchet system to the ball seat member.

19. The method as recited in claim 18, wherein rotating comprises cycling the ratchet system via a J-slot.

20. The method as recited in claim 17, further comprising locking the ball seat member in a production position after completing a desired number of test cycles.