MX2013015041A

MX2013015041A - Well tool actuator and isolation valve for use in drilling operations.

Info

Publication number: MX2013015041A
Application number: MX2013015041A
Authority: MX
Inventors: Michael L Fripp; Neal G Skinner
Original assignee: Halliburton Energy Serv Inc
Priority date: 2011-07-01
Filing date: 2011-07-01
Publication date: 2014-02-17
Also published as: CA2837180A1; EP2726700A4; AU2011372531A1; WO2013006159A1; EP2726700A1; AU2011372531B2; SA112330667B1

Abstract

A well tool actuator can include a series of chambers which, when opened in succession, cause the well tool to be alternately actuated. A method of operating a well tool actuator can include manipulating an object in a wellbore; a sensor of the actuator detecting the object manipulation; and the actuator actuating in response to the sensor detecting the object manipulation. A drilling isolation valve can comprise an actuator including a series of chambers which, when opened in succession, cause the isolation valve to be alternately opened and closed. A method of operating a drilling isolation valve can include manipulating an object in a wellbore, a sensor of the drilling isolation valve detecting the object manipulation, and the drilling isolation valve operating between open and closed configurations in response to the sensor detecting the object manipulation.

Description

WELL TOOL ACTUATOR AND ISOLATION VALVE FOR USE IN DRILL OPERATIONS FIELD OF THE INVENTION This disclosure generally refers to equipment used and operations performed in conjunction with an underground well and, in a manner described herein, more particularly provides an isolation valve for use in drilling operations.

BACKGROUND OF THE INVENTION An isolation valve can be used in a drilling operation for various purposes such as preventing a formation from being exposed to pressures in a borehole above the valve, allowing a drill string to be fired into and out of the borehole. Well drilling in a conventional manner, prevent the escape of fluids (eg, gas, etc.) from the formation during the perforation of the drill string, and so on. Therefore, it will be appreciated that improvements are needed in the technique of the operation of isolation valves in drilling operations. These improvements could be used in other types of well tools as well.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a partially cross-sectional view representative of a well system and associated method that may incorporate the principles of this disclosure.

Figure 2 is a quarter-sectional view of a piercing isolation valve that can be used in the system and method of Figure 1, and which may incorporate principles of this disclosure.

Figure 3 is a sectional view of a section of the perforation isolation valve actuated to a closed configuration.

Figure 4 is a fourth cross-sectional view of the perforation isolation valve driven to an open configuration.

Figure 4A is a quarter-section view representative of another example of the perforation isolation valve.

Figures 5A and B are quarter-section views representative of another example of the perforation isolation valve in the open and closed configurations thereof.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates, representatively, a well system 10 and associated method that may incorporate principles of this disclosure. In this example, a borehole 12 is lined with a string of casing 14 and cement 15. A drill string 18 having a drill 20 at one end thereof is used to drill an uncoated section 22 of the well 12 below the casing string 14.

A perforation isolation valve 24 is interconnected in the casing string 14. The isolation valve 24 includes a closure 26, which is selectively used to allow and prevent the flow of fluid through a passage 28 that it extends through the casing string 14 and into the uncoated section 22.

By closing the isolation valve 24, a ground formation 30 which is crossed by the uncoated section 22 can be insulated against the pressure and fluid in. the borehole 12 above the closure 26. However, when the drill string 18 is being used to further perforate the uncoated section 22, the closure 26 is opened, thus allowing the drill string to pass through the isolation valve 24.

In the example of Figure 1, the closure 26 comprises a deflecting plate type pivot element that engages a seat 32 to seal the passage 28. However, in other examples, the closure 26 could comprise a rotating ball, or other type. closing.

In addition, it should clearly be understood that the scope of this disclosure is not limited to any of the other details of the well 10 system or isolation valve 24 as herein described or shown in the drawings. For example, the borehole 12 could be horizontal or inclined near the isolation valve 24 (instead of being vertical as shown in figure 1), the isolation valve could be interconnected in a string of conductive tube that hangs on the casing string 14, it is not necessary for the casing string to be cemented in the borehole in the isolation valve, and so on. Therefore, it will be appreciated that the well system 10 and the isolation valve 24 are provided simply as examples of how the principles of this disclosure can be used, and these examples will not be considered as a limitation of the scope of the invention. this disclosure.

Referring now further to Figure 2, a fourth quarter view is representatively illustrated. enlarged scale section of an example of the isolation valve 24. The isolation valve 24 of Figure 12 can be used in the well system 10 of Figure 1, or it can be used in other well systems adhering to the principles of this disclosure.

The isolation valve 24 is in an open configuration as shown in Figure 2. In this configuration, the drill cake 18 can be extended through the isolation valve 24, for example, to further perforate the section. uncoated 22. Of course, the isolation valve 24 can be opened for other purposes (such as, to install a conductive tube in the uncoated section 22, to perform a formation test, etc.) by adhering to the scope of this disclosure.

In a novel feature of the isolation valve 24, a valve actuator 33 includes a sensor 24 which is used to detect acoustic signals produced by the movement of the drill string 18 (or other object in the borehole 12, such like a string of conductive tube, etc.). The movement that produces the acoustic signals can include the oscillation or axial displacement of the drill string 18, the rotation of the drill string, other manipulations of the string of 'perforation, combinations of different manipulations, etcetera.

Preferably, a predetermined pattern of manipulations of the drill string 18 will produce a corresponding predetermined pattern of acoustic signals, which are detected by the sensor 34. In response, the electronic circy 36 operates one of a series of valves 38a-f .

Each of the valves 38a-f can be selectively opened to provide fluid communication between a passage 40 and one of the multiple chambers 42a-f. The chambers 42a-f are preferably initially at a relatively low pressure (such as atmospheric pressure) compared to the well pressure at the location of the installation of the isolation valve 24 in a well. Chambers 42a-f are preferably also initially filled with air, nitrogen or other inert gas and so on.

A piston 44 separates two chambers filled with fluid 46, 48. The chamber 46 is in communication with the passage 40.

At the time of installation, the chamber 48 is in communication with the well pressure in the passage 28 through an opening 50a, which is aligned with an opening 52 in a tubular mandrel 54. Therefore, the chamber 48 is pressurized to the well pressure when the valve 24 insulation is installed in the well.

Chamber 48 is in communication with another chamber 56. This chamber 56 is separated from another chamber 58 by a piston 60. Chamber 58 is preferably at a relatively low pressure (such as atmospheric pressure), and is preferably initially filled with air,. nitrogen or other inert gas, etcetera.

The piston 60 is attached to a sleeve 62 which, in its position as shown in Figure 2, holds the closure 26 in its open position. However, if the sleeve 62 is displaced to the left as seen in Figure 2, the closure 26 can rotate to its closed position (and preferably does so with the aid of a deflection device, such as a spring (which it is not shown)).

In order to move sleeve 62 to the left, the piston 60 is displaced to the left by reducing the pressure in the chamber 56. The pressure in the chamber 56 does not have to be reduced below the relatively low pressure in the chamber 58, since preferably the area of the piston 60 exposed to the chamber 56 is greater than the piston area exposed to the chamber 58, as shown in Figure 2, and thus the pressure of the well will assist in the deflection of the sleeve 62 to the left when the pressure in the chamber 56 is reduce enough.

To reduce the pressure in the chamber 56, the piston 44 is displaced to the left as seen in Figure 2, thus also displacing a sleeve 64 attached to the piston 44. The sleeve 64 has the opening 50a (as well as additional openings 50b, c) formed in it. Together, the piston 44, the sleeve 64 and the opening 52 in the mandrel 54 comprise a control valve 65 that selectively allows and prevents fluid communication between the passage 28 and the chamber 48.

The initial displacement of the sleeve 64 on the left will block fluid communication between the openings 50a, 52, thus isolating the chamber 48 against the pressure of the well in the passage 28. An additional displacement of the 'piston 44 and sleeve 64 on the left the pressure in the chamber 48 will decrease due to an increase in the volume of the chamber.

To cause the piston 44 to move to the left as seen in Figure 2, the valve 38a is opened by the electronic circuitry 36. The opening of the valve 38a provides fluid communication between the chambers 42a, 46, thereby reducing the pressure in the chamber 46. A pressure differential from the chamber 48 to the chamber 46 will cause the piston 44 to move to the left by a distance that is determined by the volumes and pressures in the various chambers.

Valves 38a-f can preferably be opened in response to the application of a relatively small amount of electrical energy. The electric power to open the valves 38a-f and operate the sensor 34 and the electronic circuitry 36 can be provided by a battery 66, and / or by a downhole electric power generator, and so on.

Valves suitable for use as valves 38a-f are described in U.S. Patent Application No. 12 / 353,664 filed January 14, 2009, the entirety of which is incorporated herein by reference. Of course, other types of valves (such as solenoid-operated valves, spool valves, etc.) may be used if desired, a preferred type of valve uses termite to degrade a rupture disk or other relatively thin pressure barrier .

Referring now further to Figure 3, the isolation valve 24 is representatively illustrated after the valve 38a has been opened in response to the acoustic sensor 34 which detects the predetermined pattern of acoustic signals resulting from the manipulation of the string. perforation 18. Note that piston 44 and sleeve 64 have moved to the left because the pressure in chamber 46 is reduced, and piston 60 and sleeve 62 have moved to the left because the pressure in chamber 56 is reduced, it is reduced.

The closure 26 is no longer held in its open position of Figure 2, and is turned inward, so that it now seals the passage 28. In this configuration, the formation 30 is insulated against the borehole 12 above. the isolation valve 24.

The isolation valve 24 can be reopened by once again producing a predetermined pattern of acoustic signals by manipulating the drill string 18, thereby causing the electronic circuitry 36 to open the next valve 38b. A resulting reduction in the pressure of the chamber 46 will cause the piston 44 and the sleeve 64 to shift to the left as seen in Figure 3. The predetermined pattern of acoustic signals used to open the isolation valve 24 may be different of, or the same as the. default pattern of acoustic signals used to close the isolation valve.

Referring now further to Figure 4, the isolation valve 24 is representatively illustrated after the valve 38b has been opened in response to the acoustic sensor 34 detecting the predetermined pattern of acoustic signals resulting from the manipulation of the string. of drilling 18. Observe that the piston 44 and sleeve 64 have moved to the left because the pressure in chamber 46 is reduced, and piston 60 and sleeve 62 have shifted to the right because the pressure in chamber 56 is increased. The pressure in the chamber 56 is increased because the opening 50b is aligned with the opening 52 in the mandrel 54, thereby admitting well pressure in the chamber 48, which is in communication with the chamber 56.

The displacement to the right of the sleeve 62 rotates the closure 26 outward, so that it now allows flow through the passage 28. In this configuration, the drill string 18 or other assembly can be transmitted through the valve of insulation 24, for example, to further perforate the uncoated section 22.

Valve 38c can now be opened, in order to close once more the isolation valve 24. Then, valve 38d can be. open to open the isolation valve 24, the valve 38e can be opened to close the isolation valve, and the valve 38f can be opened to open the isolation valve.

Therefore, three complete opening and closing cycles can be achieved with the isolation valve 24 as shown in Figures 2-4. Of course, any number of valves and cameras can be used to provide any number of opening and closing cycles, as desired. The sleeve 64 can also be configured to provide any desired number of opening and closing cycles.

Note that, in the example of FIGS. 2-4, it is not necessary for the valves 38a-f to be opened in some particular order. Therefore, the valve 38a does not have to be opened first, and the valve 38f does not have to be open to the latter to activate the isolation valve 24. Each of the valves 38a-f is in communication with the passage 40, and in this way the opening of any of the valves in any order will cause a decrease in the pressure of the chamber 46.

However, in FIG. 4A, another example of the isolation valve 24 is representatively illustrated, in which the valves 38a-f are opened in series, in the order that goes from the valve 38a to the valve 38 f for activate the isolation valve. Each of the. valves 38b-f is only placed in communication with passage 40 when all its predecessor valves have been opened. Only the valve 38a is initially in communication with the passage 40.

In a method for operating the isolation valve 24 in the well system 10 of Figure 1, the drill string 18 itself is used to transmit signals to the isolation valve, in order to activate the isolation valve. The drill string 18 can be displaced axially, rotationally, or in any combination of manipulations so as to transmit acoustic signals to an actuator 33 of the isolation valve 24.

For example, when the drill string 18 is fired into the borehole 12, the isolation valve 24 would typically be closed, in order to isolate the formation 30 against the borehole above the isolation valve. When the drill string 18 is within a certain distance of the isolation valve 24, the drill string is manipulated in a manner in which a predetermined pattern of acoustic signals is produced.

The sensor 34 detects acoustic signals in the downhole environment. If the predetermined pattern of acoustic signals is detected by the sensor 34, the electronic circuitry 36 causes one of the valves 38a-f to open. The valves 38a-f are opened in succession, with a valve being opened each time the predetermined pattern of acoustic signals is detected.

Of course, different techniques for the use of acoustic signal patterns in order to communicate in a well environment are known to those skilled in the art. technique. For example, acoustic signaling techniques known as HALSONICS (TM), SURFCOM (TM) and PICO SHORT HOP (TM) are used by Halliburton Energy Services, Inc.

When the drill string 18 is manipulated in a manner in which the predetermined pattern of acoustic signals is produced, the valve 24 is opened. The drill string 18 can now extend through the passage 28 in the valve 24, and the perforation of the uncoated section 22 can proceed.

When it is time to fire the drill string 18 out of the borehole 12, the drill string is raised within a certain distance above the isolation valve 24. Then, the drill string 18 is manipulated in a that the default pattern of acoustic signals is again produced.

When the acoustic signals are detected by the sensor 34, the isolation valve 24 is closed (eg, by opening another of the valves 38a-f). The drill string 18 can now be fired out of the well, with the closed isolation valve 24 insulating the formation 30 against the borehole 12 above the isolation valve.

However, it should be understood that other methods for operating the isolation valve 24 are within range of this disclosure. For example, it is not necessary that the same predetermined pattern of acoustic signals be used to open and close the isolation valve 24. On the contrary, a pattern of acoustic signals could be used to open the isolation valve 24, and I could use another pattern to close the isolation valve.

Nor is it necessary for the pattern of acoustic signals to be produced by manipulation of the drill string 18. For example, the pattern of acoustic signals could be produced by flowing and stopping the flow of fluid in an alternate manner, altering the circulation , by using a remote acoustic generator, and so on.

Furthermore, it is not necessary for the actuator 33 to respond to acoustic signals. On the other hand, other types of signals (such as electromagnetic signals, pressure pulses, changes in pressure of the ring or passage 28, etc.) could be used to operate the isolation valve 24.

Therefore, the sensor 34 is not necessarily an acoustic sensor. In other examples, the sensor 34 could be a pressure sensor, an accelerometer, a flow meter, an antenna or any other type of sensor.

Referring now further to FIGS. 5A and B, another example of a representative embodiment is illustrated. the isolation valve 24. The isolation valve 24 is shown in an open configuration in Figure 5A, and in a closed configuration in Figure 5B.

For illustrative clarity, in Figures 5A and B only a lower section of the. isolation valve 24. An upper section of the isolation valve 2 is similar to that shown in Figures 3-4, with the upper section including the sensor 34, the electronic circuitry '36, the valves 38a-f, the cameras 42a-f, etcetera.

In the example of Figures 5A and B, the chamber 58 is exposed to the well pressure in the passage 28 through a port 70 in the sleeve 62. In addition, a. deflection device 72 (Lal as a spring, etc.) deflects piston 60 to its open position as shown in Figure 5A.

Therefore, when any of the openings 50A-C is aligned with the opening 52, and the pressure of the well in the passage 28 is thus communicated to the chambers 48, 56, the piston 60 has a balanced pressure. The device 72 can move the piston 60 and the sleeve 62 to its open position, with the closure 26 turned outward, so that flow through the passage 28 is allowed as shown in Figure 5A.

When the piston 44 and the sleeve 64 move to the left (as seen in Figures 5A and B), and the chambers 48, 56 are insulated against the passage 28, a resulting pressure differential through the piston 60 will cause it to move left to its closed position. This will allow the closure '26 to turn inward and prevent it from flowing through the passage 28 as shown in Figure 5B.

It can now be appreciated in its entirety that the above disclosure provides significant advances in the art for operating an isolation valve in a well. The isolation valve 24 described above can be operated by manipulating the drill string 18 in the borehole 12, thus transmitting predetermined patterns of acoustic signals, which are detected by the sensor 34. The isolation valve 24 can be opened and closed multiple times in response to the sensor 34 detecting said acoustic signal patterns. Other methods for operating the isolation valve 24 were also described above.

The above disclosure provides the technique with a piercing isolation valve 24, which may comprise an actuator 33 including a series of chambers 42a-f which, when opened in succession, cause the isolation valve 24 to be alternately open and closed.

The piercing isolation valve 24 may also include a control valve 65 which alternatively exposes a piston 60 to the well pressure and isolates the piston 60 against the well pressure in response to the chambers 42a-f being opened in succession. (that is, each following another, but not necessarily in a particular order). The control valve 65. may comprise a sleeve 64 that moves incrementally in response to the chambers 42a-f being opened in succession. The actuator 33 may include a sensor 34. The cameras 42a-f may be opened in succession in response to the detection of acoustic signals predetermined by the sensor 34. The cameras 42a-f may be opened in succession in response to motion detection of the drill string 18 by the sensor 34. The sensor 34 may comprise an acoustic sensor.

A method for operating a perforation isolation valve 24 was also described above. The method may include. manipulating an object (such as the drill string 18) in a borehole 12, a sensor 34 of the drill isolation valve 24 that detects the handling of the object, and the drill isolation valve 24 operating between the configurations open and closed in response to the sensor 34 detecting the manipulation of the object.

The manipulation may comprise the axial displacement of the object and / or the rotation of the object.

A series of chambers 42a-f of the piercing isolation valve 24 can be 'opened in succession (ie, each following one another, but not necessarily' in a particular order) in response to the sensor 34 sensing respective predetermined patterns of object manipulation. The piercing isolation valve 24 can alternatively be opened and closed in response to the fact that the chambers 42a-f are being opened in succession.

A control valve 65 can alternatively expose a piston 60 to the well head and isolate the piston 60 against the pressure of the well in response to the chambers 42a-f being opened in succession.

The sensor 34 may comprise an acoustic sensor. The manipulation of the object may include that a predetermined acoustic signal is transmitted to the sensor 34. The object may comprise the drill string 18.

The above disclosure also provides the technique for a well system 10. The well system 10 can include a drill string 18 placed in a borehole 12 and a perforation isolation valve 24 that selectively allows and prevents flow of fluid through a passage 28 extending through a tubular casing string 14, the isolation valve 24 includes a sensor 34 which detects the manipulation of the drill string 18 in the tubular string 14, wherewith the isolation valve 24 'is activated in response to the sensor 34 detecting a predetermined pattern of manipulation of the drill string 18.

The isolation valve 24 may include a series of chambers 42a-f which, when opened in succession (i.e., each following the other, but not necessarily in a particular order), cause the isolation valve 24 to open and close alternately. The isolation valve 24 may further include a control valve 65 that alternately exposes a piston 60 to the well pressure and isolates the piston 60 against the well pressure, in. answer to that the cameras 42a-f are being opened in succession.

The cameras 42a-f may be opened in succession in response to the detection of acoustic signals predetermined by the sensor 34, and / or in response to the detection of the predetermined pattern of manipulation of the l string 18.

Although the above description provides several examples of an isolation valve 24 which is activated in response to the opening of the chambers 42a-f. However, it will readily be appreciated that the actuator 33 could be used to activate other types of valves and other types of well tools (eg, tamping rollers, shock coils, etc.). Therefore, it should clearly be understood that the scope of this disclosure is not limited to isolation valves, but instead covers the operation of different types of well tools.

The above description provides the technique with a well tool actuator 33 which may include a series of beds 42a-f which, when opened in succession, cause the well tool (such as the isolation valve 24, a tamping roller , a shock coil, or other flow control device, etc.) is operated alternately.

The above disclosure also provides the art with a method for operating a well tool actuator 33. The method may include manipulating an object (such as l string 18, etc.) into a borehole 12, a sensor 34. of the actuator ..33 detecting the manipulation of the object, and the actuator 33 being actuated in response to the sensor 34 detecting the manipulation of the object.

It will be understood that the various modalities of this Disclosure described herein may be used in various orientations such as inclined, inverted, horizontal, vertical, etc. and in various configurations without departing from the principles of this disclosure. The modalities are described simply as examples of useful applications of the principles of disclosure, which is not limited to any specific detail of these modalities.

In the above description of the representative examples, address terms (such as "above", "below", "upper", "lower", etc.) are used for convenience to refer to the accompanying drawings. In general, "above", "above", "up" and similar terms refer to a direction towards the surface of the earth along a borehole, and "below", "below", "downwards" "and similar terms refer to a direction away from the surface of the earth along the borehole, whether the borehole is horizontal, vertical, inclined, offset, and so on. However, it should clearly be understood that the scope of this disclosure is not limited to any particular address described herein.

Of course, one skilled in the art, at the time of careful consideration of the above description of the representative modalities of the disclosure, it would be easy to appreciate that many modifications, additions, substitutions, deletions and other changes can be made to the specific modalities, and said changes are contemplated by the principles of this disclosure. Accordingly, the above detailed description clearly is. will understand as being provided by way of illustration and example only, the spirit and scope of the invention is limited only by the appended claims and their equivalents.

Claims

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. - A well tool actuator, comprising: a series of chambers that, when opened in succession, cause the well tool to be actuated alternately.

2. - The well tool actuator according to claim 1, further comprising a control valve that alternately exposes a piston to the well pressure and isolates the piston against the pressure of the well in response to the chambers being being opened in succession.

3. - The well tool actuator according to claim 2, characterized in that the control valve comprises a sleeve that moves incrementally in response to the chambers being opened in succession.

4. - The well tool actuator according to claim 1, further comprising a sensor.

5. - The well tool actuator in compliance with claim 4, characterized in that the chambers are opened in succession in response to the detection of acoustic signals predetermined by the sensor.

6. - The well tool actuator according to claim 4, characterized in that the chambers are opened in succession n response to the detection of the movement of the drill string by the sensor.

7. - The well tool actuator according to claim 4, characterized in that the sensor comprises an acoustic sensor.

8. - A method to operate a well tool actuator, the method comprises: manipulate an object in a borehole; an actuator sensor that detects the manipulation of the object; Y the actuator acting in response to the sensor sensing the manipulation of the object.

9. - The method according to claim 8, characterized in that the manipulation comprises moving the object axially.

10. - The method according to claim 8, characterized in that the manipulation comprises rotating the object.

11. - The method according to claim 8, characterized in that a series of actuator chambers are opened in succession in response to the sensor detecting respective predetermined patterns of object manipulation.

12. - The method according to claim 11, characterized in that the actuator alternately opens and closes a valve in response to the chambers being opened in succession.

13. The method according to claim 11, characterized in that a control valve alternately exposes a piston to the well pressure and isolates the piston against the well pressure in response to the chambers being opened in succession.

14. - The method according to claim 8, characterized in that the sensor comprises an acoustic sensor, and wherein the manipulation of the object comprises transmitting a predetermined acoustic signal to the sensor.

15. - The method according to claim 8, characterized in that the object comprises a drilling string.

16. - A perforation isolation valve, comprising: an actuator that includes a series of cameras which, when opened in succession, cause the Isolation valve is open and closed alternately.

17. - The perforation isolation valve according to claim 16, further comprising a control valve that alternately exposes a piston to the pressure of the well and isolates the piston against the pressure of the well in response to the chambers being open in succession.

18. The perforation isolation valve according to claim 17, characterized in that the control valve comprises a sleeve that moves incrementally in response to the chambers being opened in succession.

19. - The perforation isolation valve according to claim 16, characterized in that the actuator includes a sensor.

20. The perforation isolation valve according to claim 19, characterized in that the chambers are opened in succession in response to the detection of acoustic signals predetermined by the sensor.

21. - The perforation isolation valve according to claim 19, characterized in that the chambers are opened in succession in response to the detection of the movement of the drill string by of the sensor.

22. - The perforation isolation valve according to claim 19, characterized in that the sensor comprises an acoustic sensor.

23. - A method to operate a perforation isolation valve, the method comprises: manipulate an object in a borehole; a sensor of the perforation isolation valve that detects the manipulation of the object; Y the perforation isolation valve operating between the open and closed configurations in response to the sensor sensing the manipulation of the object.

24. - The method according to claim 23, characterized in that the manipulation comprises moving the object axially.

25. - The method according to claim 23, characterized in that the manipulation comprises rotating the object.

26. The method according to claim 23, characterized in that a series of perforation isolation valve chambers are opened in succession in response to the sensor detecting respective predetermined patterns of manipulation of the object.

27. - The method according to claim 26, characterized in that the perforation isolation valve alternately opens and closes in response to the chambers being opened in succession.

28. The method according to claim 26, characterized in that a control valve alternately exposes a piston to the pressure of the well and isolates the piston against the pressure of the well in response to the chambers being opened in succession.

29. - The method according to claim 23, characterized in that the sensor comprises an acoustic sensor, and wherein the manipulation of the object comprises transmitting a predetermined acoustic signal to the sensor.

30. - The method according to claim 23, characterized in that the object comprises a drill string.

31. - A well system, comprising: a drill string placed in a borehole; Y a perforation isolation valve that selectively allows and prevents the flow of fluid through a passage that extends through a tubular string, the isolation valve including a sensor that detects the manipulation of the drill string in The tubular string, where the isolation valve is activated in response to that the sensor detects a predetermined pattern of drill string manipulation.

| 32. The well system according to claim 31, characterized in that the sensor comprises an acoustic sensor.

33. - The well system according to claim 31, characterized in that the isolation valve includes a series of chambers which, when opened in succession, cause the isolation valve to be open and closed alternately.

34. - The well system according to claim 33, characterized in that the isolation valve also includes a control valve that alternately exposes a piston to the pressure of the well and isolates the piston against the pressure of the well, in response to which the cameras are being opened in succession.

35. - The well system according to claim 33, characterized in that the chambers are opened in succession in response to the detection of predetermined acoustic signals by the sensor.

36. - The well system according to claim 33, characterized in that the chambers are opened in succession in response to the detection of the predetermined pattern of manipulation of the drill string.