A multi-valve well testing system adapted to be disposed downhole in a borehole, includes a plurality of valves and a plurality of well tool control systems connected, respectively, to the plurality of valves and further includes an automatic control mode feature. The well testing system includes a controller board which comprises a microprocessor and a read only memory (ROM). The ROM has encoded therein a set of microcode which, when executed by the microprocessor, causes the various plurality of valves in the well testing system to be opened and closed automatically, without intervention from the operator at the well surface. A kickoff stimulus is required in order to begin execution of the microcode by the microprocessor. This kickoff stimulus could include a sensing, by a pressure transducer, of a predetermined bottom hole pressure, or a sensing, by a strain gauge, of a predetermined set down weight of the well testing system. As a result, in response to a predetermined kickoff stimulus, the well testing system automatically begins a test which includes the automatic opening and closing of a plurality of valves a predetermined number of times, and in a predetermined sequence.

Patent
   RE39583
Priority
May 26 1988
Filed
Oct 06 1997
Issued
Apr 24 2007
Expiry
May 26 2008
Assg.orig
Entity
unknown
37
11
EXPIRED
1. A well testing system adapted to be disposed in a borehole, comprising:
stimulus generating means for generating an initial kickoff stimulus;
a plurality of valves;
a plurality of control system means connected respectively to the plurality of valves for operating said valves; and
control means interconnected between said plurality of control system means and said stimulus generating means for automatically controlling the operation of one or more of said plurality of control system means and thereby one or more of said plurality of valves in a predetermined manner in response to said initial kickoff stimulus.
0. 25. A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions,
wherein automatic controlling step comprises the step of: operating a plurality of control system means connected respectively to said plurality of valves for operating said valves during the execution of said set of instructions.
0. 40. A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions,
wherein the generating step comprises the steps of:
(a) recognizing pulses of predetermined signature transmitted into said borehole via a borehole fluid, wherein each of the pulses of predetermined signature comprises a predetermined magnitude and a predetermined duration, and wherein the predetermined magnitude and the predetermined duration define the predetermined signature; and
(b) producing said initial kickoff stimulus signal for control of one of said plurality of valves based on said pulses of predetermined signature when the pulses of predetermined signature are detected.
2. The well testing system of claim 1, wherein said control means comprises a memory means for storing a set of instructions and a processor means connected to said memory means for executing said set of instructions in response to said initial kickoff stimulus and automatically controlling the operation of said one or more of said plurality of control system means during the execution of said instructions.
3. The well testing system of claim 2, wherein said set of instructions comprises a special instruction set, said plurality of valves include a first valve and a second valve, the processor means alternately opening and closing said first valve until a predetermined time is reached, said processor means opening said second valve after said predetermined time in response to execution of said special instruction set.
0. 4. A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions.
0. 5. The method of claim 4, wherein the generating step comprises the step of:
sensing an annulus pressure around a tubing string and generating said initial kickoff stimulus signal when the sensed annulus pressure matches a predetermined criterion.
0. 6. The method of claim 4, wherein the generating step comprises the step of:
sensing a bottom hole pressure inside a tubing string and generating said initial kickoff stimulus signal when the sensed bottom hole pressure matches a predetermined criterion.
7. The method of claim 4, A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions,
wherein the generating step comprises the steps of:
sensing a set down weight of said multi-valve well testing system when said system is disposed in said borehole and generating said initial kickoff stimulus signal when the sensed set down weight matches a predetermined criterion.
8. The well testing system of claim 1 wherein said stimulus generating means comprises a pressure transducer.
9. The well testing system of claim 8, wherein the pressure transducer senses annulus pressure around tubing string in said borehole.
10. The well testing system of claim 8, wherein the pressure transducer senses bottom hole pressure inside a tubing string in said borehole.
11. The well testing system of claim 1, wherein said stimulus generating means comprises a strain gauge for sensing a set down weight of said well testing system when disposed in said borehole.
12. The method of claim 4, A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions,
wherein said plurality of valves includes a first valve and a second valve, and wherein the executing step comprises the steps of:
further executing a special instruction set, the further execution of the special instruction set including the steps of,
opening and closing said first valve in an alternating manner until a predetermined time is reached, and
opening said second valve after said predetermined time.
13. The method of claim 4, A method of automatically controlling a plurality of valves disposed in a multi-valve well testing system when said system is disposed in a borehole, comprising:
generating an initial kickoff stimulus signal;
receiving said initial kickoff stimulus signal in a processor means disposed in said system;
executing in said processor means a set of instructions stored in a memory disposed in said system in response to said initial kickoff stimulus signal; and
automatically controlling one or more of said plurality of valves during the execution of said set of instructions,
wherein said plurality of valves includes a first valve and a second valve, and wherein the executing step comprises the steps of:
(a) opening said first valve;
(b) closing said first valve and determining if a measured bottom hole pressure matches a predetermined criterion;
(c) if said measured bottom hole pressure matches said predetermined criterion, opening one of said first valve and said second valve;
(d) if said measured bottom hole pressure does not match said predetermined criterion, determining if a predetermined time has elapsed;
(e) if said predetermined time has elapsed, opening one of said first valve and said second valve; and
(f) if said predetermined time has not elapsed, returning to step (a).
0. 14. The well testing system of claim 1, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 15. The well testing system of claim 2, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 16. The well testing system of claim 3, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 17. The well testing system of claim 8, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 18. The well testing system of claim 9, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 19. The well testing system of claim 10, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 20. The well testing system of claim 11, wherein at least one of said plurality of control system means comprises a solenoid valve.
0. 21. The well testing system of claim 1, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole.
0. 22. The well testing system of claim 2, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole.
0. 23. The well testing system of claim 3, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole.
0. 24. The well testing system of claim 8, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole.
0. 26. The method of claim 25, wherein the generating step comprises the steps of: sensing an annulus pressure around a tubing string and generating said initial kickoff stimulus signal when the sensed annulus pressure matches a predetermined criterion.
0. 27. The method of claim 25, wherein the generating step comprises the steps of: sensing an bottom hole pressure inside a tubing string and generating said initial kickoff stimulus signal when the sensed bottom hole pressure matches a predetermined criterion.
0. 28. The method of claim 7, wherein automatic controlling step comprises the step of:
operating a plurality of control system means connected respectively to said plurality of valves for operating said valves during the execution of said set of instructions.
0. 29. The method of claim 12, wherein automatic controlling step comprises the step of:
operating a plurality of control system means connected respectively to said plurality of valves for operating said valves during the execution of said set of instructions.
0. 30. The method of claim 13, wherein automatic controlling step comprises the step of:
operating a plurality of control system means connected respectively to said plurality of valves for operating said valves during the execution of said set of instructions.
0. 31. The method of claim 25, wherein the generating step comprises the steps of:
(a) recognizing pulses of predetermined signature transmitted into said borehole, wherein each of the pulses of predetermined signature comprises a predetermined magnitude and a predetermined duration, and wherein the predetermined magnitude and the predetermined duration define the predetermined signature; and
(b) producing said initial kickoff stimulus signal for control of one of said plurality of valves based on said pulses of predetermined signature.
0. 32. The method of claim 29, wherein the generating step comprises the steps of:
(a) recognizing pulses of predetermined signature transmitted into said borehole, wherein each of the pulses of predetermined signature comprises a predetermined magnitude and a predetermined duration, and wherein the predetermined magnitude and the predetermined duration define the predetermined signature; and
(b) producing said initial kickoff stimulus signal for control of one of said plurality of valves based on said pulses of predetermined signature.
0. 33. The well testing system of claim 9, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole.
0. 34. The method of claim 26, wherein the generating step comprises the steps of:
(a) recognizing pulses of predetermined signature transmitted into said borehole, wherein each of the pulses of predetermined signature comprises a predetermined magnitude and a predetermined duration, and wherein the predetermined magnitude and the predetermined duration define the predetermined signature; and
(b) producing said initial kickoff stimulus signal for control of one of said plurality of valves based on said pulses of predetermined signature.
0. 35. The well testing system of claim 1, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole, wherein said pulses are propagated in a borehole fluid.
0. 36. The well testing system of claim 2, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole, wherein said pulses are propagated in a borehole fluid.
0. 37. The well testing system of claim 3, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole, wherein said pulses are propagated in a borehole fluid.
0. 38. The well testing system of claim 8, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole, wherein said pulses are propagated in a borehole fluid.
0. 39. The well testing system of claim 9, wherein said stimulus generating means comprises: means for recognition of pulses of predetermined signature transmitted into said borehole, wherein said pulses are propagated in a borehole fluid.
0. 41. The method of claim 40, wherein the recognizing pulses of predetermined signature step comprises detecting the pulses of predetermined signature in an annulus pressure around a tubing string.
0. 42. The method of claim 40, wherein the recognizing pulses of predetermined signature step comprises detecting the pulses of predetermined signature in a bottom hole pressure inside a tubing string.
0. 43. The method of claim 40, wherein the pulses of predetermined signature comprise two or more pulses in a series to form a command signal.
0. 44. The method of claim 41, wherein the pulses of predetermined signature comprise two or more pulses in a series to form a command signal.
0. 45. The method of claim 42, wherein the pulses of predetermined signature comprise two or more pulses in a series to form a command signal.

This application is a continuation-in-part of application Ser. No. 295,614 entitled “Multiple Well Tool Control Systems in a Multi-valve Well Testing System”, filed 1/10/89, which application is a continuation in part of application Ser. No. 243,565 filed Sept. 12, 1988, now U.S. Pat. No. 4,856,595, which is a divisional application of application Ser. No. 198,968 filed May 26, 1988, U.S. Pat. No. 4,796,699.

The subject matter of the present invention pertains to an automatic well tool control system, and, more particularly, to multiple well tool control systems in a multi-valve well testing system including a means for automatically controlling the well tool control systems in response to kickoff stimulus which may include a sensing of bottom hole pressure or a sensing of the output of a strain gauge responsive to a set down weight of the well tool apparatus.

Multi-valve well testing tools of the prior art such as the well testing tools disclosed in U.S. Pat. No. 4,553,589 entitled “Full Bore Sampler Valve Apparatus”, and in U.S. Pat. No. 4,576,234 entitled “Full Bore Sampler Valve”, are typically mechanical in nature in that one valve disposed in the tool is mechanically linked to another valve disposed in the tool. If it is desired to open the one valve, an operator at the well surface, upon opening the one valve, must expect the other valve to be opened or closed as well since the two valves are mechanically linked together. Therefore, the operation of one valve is not independent of the operation of the other valve, and when one valve in the tool is opened, other valves disposed in the tool must be opened or closed in a specific predetermined sequence. A more recent and innovative apparatus for performing such well service operations, embodying pressure controlled valve devices, is shown in application Ser. No. 198,968, filed May 26, 1988, now U.S. Pat. No. 4,796,699, entitled “Well Tool Control System”, assigned to the assignee of this invention, the disclosure of which is incorporated by reference into the specification of this application. In application Ser. No. 198,968 referenced hereinabove, a well testing tool is disclosed which is not totally mechanical in nature, rather, it embodies a microelectronics package and a set of solenoids responsive to the microelectronics package for opening or closing valve disposed in the tool. A set of solenoids embodied in the well tool of application Ser. No. 198,968 are energized by a microcontroller also embodied in the well tool, which microcontroller is responsive to an output signal from any type of sensor, such as a pressure transducer embodied in the tool that further responds to changes in downhole pressure created and initiated by an operator at the well surface. It is understood that the sensor may be responsive to other stimuli than downhole pressure. The solenoids, when energized in a first predetermined manner, open and close a set of pilot valves that permit a hydraulic fluid under pressure, stored in a high pressure chamber, to flow to another section of the tool housing where an axially movable mandrel is positioned. The fluid moves the mandrel from a first position to a second position thereby opening another valve in the tool (for example, a test valve or a reversing valve). When the set of solenoids are energized in a second predetermined manner, the hydraulic fluid, stored in the other section of the tool housing, where the movable mandrel is positioned, is allowed to drain from the housing to a separate dump chamber; as a result, the mandrel moves from the second position to the first position, thereby closing the other valve. In each case, the solenoids are responsive to an output signal from the microcontroller, which is, in turn, responsive to an output signal from the sensor, which is, in turn, responsive to changes in other input stimuli, such as changes in pressure in the well annulus. The change in input stimuli is created and initiated, each time, by the operator at the well surface. Therefore, an opening or closing of the other valve in the tool is responsive, each time, to a stimulus change signal (such as changes in downhole pressure) transmitted into the borehole by the operator at the well surface. However, application Ser. No. 198,968 discloses a well testing tool which includes one well tool control system for controlling the closure state of one valve. The above referenced well testing tool could also contain a plurality of well tool control systems for opening and closing a plurality of valves. In this case, two or more of the above well tool control systems and two or more corresponding valves would be embodied in a well testing tool. The two or more of such well tool control systems would open and close the two or more valves in response to predetermined input signals. An operator need only transmit into a borehole the two or more unique input signals corresponding to the two or more separate valves. As a result, the operation of one valve disposed in the tool would be performed totally independently of the operation of any other valve disposed in the tool. In the application Ser. No. 295,614, referenced above, a well testing system is disclosed including two or more well tool control systems interconnected respectively between two or more valves and a microcontroller. Whenever a valve must be opened or closed, the operator must transmit an input stimulus into the borehole, such as a pressure signal; the microcontroller generates its output signal in response to the input stimulus for energizing one of the control systems which then operates a particular valve. However, when it is desired to operate two or more valves in sequence, a separate input stimulus must be generated in the well testing system for each of the two or more valves. If suitable microcode were provided in the microcontroller, a plurality of openings and closings of the two or more valves in the tool could be accomplished automatically by the microcontroller upon execution of its own microcode in response to an initial kickoff stimulus generated in the well testing system, such as a sensing of a bottom hole pressure or a sensing of a strain gauge output sensitive to a set down weight of the well testing tool in the borehole.

Accordingly, it is a primary object of the present invention to automatically control the operation of multiple well tool control systems disposed in a well testing system by providing such control systems with a microcontroller including a processor and a memory, the memory storing a set of microcode which, when executed by the processor, automatically opens and closes a set of valves in the tool a predetermined number of times, in a predetermined sequence, in response to a predetermined initial kickoff stimulus.

It is a further object of the present invention to initiate execution of the microcontroller microcode in response to an output signal from a pressure transducer, which transducer senses a bottom hole pressure of the well fluids present in the well annulus below a packer.

It is a further object of the present invention to initiate execution of the microcontroller microcode in response to an output signal from a strain gauge, which strain gauge senses, for example, the set down weight of the well testing tool when situated in the borehole of an oil well.

It is a further object of the present invention to initiate execution of the microcontroller microcode in response to an output signal from a pressure transducer which senses annulus pressure above the packer, or in response to an output signal from a timer which counts down a predetermined time delay.

These and other objects of the present invention are accomplished be designing a set of microcode for incorporation in a memory chip resident on a microcontroller chip of multiple well tool control systems disposed in a well testing system. The microcontroller chip includes a processor portion and a memory chip, the novel microcode of the present invention being stored in the memory chip, such as a Read Only Memory (ROM). When an initial kickoff stimulus is received by the microcontroller chip, the processor portion of the chip executes the microcode stored in the memory chip. During execution of the microcode, the processor portion of the chip generates certain output signals which cause other valves in the well testing tool to open or close. The kickoff stimulus may be either an output signal from a pressure transducer indicative of a bottom hole pressure, in the well annulus below the packer in the borehole, or indicative of annulus pressure above a packer, or an output signal from a strain gauge indicative of a set down weight or a torque of the tool when the tool is disposed in a particular position in the borehole. When the processor portion generates the output signals in response to execution of its resident microcode of the present invention, a typical flow/shut-in test may be performed, or a test valve and reversing valve may be opened and closed in an exact preprogrammed sequence. As a result, the results of a test may be based on direct measurements of existing downhole conditions, the measurements being made directly due to the automatic execution of a set of microcode resident in the memory chip of a downhole microcontroller. Using this approach, there is no need to transmit signals from the surface, through the manipulation of pipe or annulus pressure to control the downhole tool, each time an operation is performed downhole. The changes for misrun caused by manipulation of the pipe or annulus pressure to control the test valve is greatly reduced. Furthermore, an exact preset test sequence may be completed and the chances for the commission of human error are greatly reduced (a distinct advantage in open-hole situations where approximately 80% of the test sequences are preset and inflexibly carried out).

Further scope of applicability of the present invention will become apparent from the detailed description presented hereinafter. It should be understood, however, that the detailed description and the specific examples, while representing a preferred embodiment of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to one skilled in the art from a reading of the following detailed description.

A full understanding of the present invention will be obtained from the detailed description of the preferred embodiment presented hereinbelow, and the accompanying drawings, which are given by way of illustration only and are not intended to be limitative of the present invention, and wherein:

FIG. 1 is a schematic view of a string of drill stem testing tools positioned in a well being tested;

FIG. 2 is a schematic drawing of the hydraulic components of the present invention;

FIG. 3 is a block diagram of the control components used to operate the hydraulic system of FIG. 2;

FIG. 4 is a pressure time diagram to illustrate a command signal comprising a sequence of low level pressure pulses;

FIGS. 5A-5F are longitudinal sectional views, with some portions in side elevations, of a circulating valve component of a drill stem testing string (the upper portion of FIG. 5D being rotated with respect to the lower portion thereof to show pressure passages in section);

FIGS. 6 and 7 are transverse cross-sectional views taken on lines 66 and 77, respectively, of FIG. 5D;

FIG. 8 is a sectional view of a tool string component including a ball valve element which can be used to control formation fluid flow through a central passage of a housing in response to operation of the control system of FIG. 3;

FIG. 9 illustrates the schematic view of a string of drill stem testing tools, of FIG. 1, modified to include a test valve and a reversing valve;

FIGS. 10-11 illustrate two respective well tool control systems for controlling two corresponding valves shown in FIG. 9, each control system comprising the hydraulic components of FIG. 2;

FIG. 12 illustrates the block diagram of the control components of FIG. 3, modified to energize the solenoids associated with one set of valves as well as the solenoids associated with another set of valves of the well testing tool;

FIG. 13a illustrates a typical pressure time diagram associated with one of the well tool control systems disposed in the well testing tool of FIGS. 9-14; and

FIG. 14 including FIGS. 14a through 14d illustrates a well testing tool which embodies two valves that are connected to two corresponding well tool control systems.

FIG. 15 illustrates a more detailed construction of the controller board 93 shown in FIG. 12;

FIG. 16 illustrates a sketch of a typical bottom hole pressure vs time plot; and

FIG. 17 illustrates a view of a pressure transducer which senses an input stimulus comprising bottom hole pressure below a packer;

FIG. 18 illustrates a view of a strain gauge which senses an input stimulus comprising a set down weight or torque of the tool when disposed in a particular position in a borehole; and

FIG. 19 illustrates a flow chart of the microcode resident in the memory chip shown in FIG. 15.

The following detailed description is divided into three parts: (1) part A entitled “Well Tool Control System” which describes the well tool control system as set forth in prior pending application Ser. No. 243,565, filed Sept. 12, 1988, now U.S. Pat. No. 4,856,595; assigned to the same assignee as that of the present invention, which application Ser. No. 243,565 is incorporated herein by reference, application Ser. No. 243,565 being a divisional application of application Ser. No. 198,968, filed May 26, 1988, now U.S. Pat. No. 4,796,699, assigned to the same assignee as that of the present invention, which application Ser. No. 198,968 is also incorporated herein by reference; (2) part B which represents a continuation-in-part of prior pending application Ser. No. 243,565 referenced hereinabove in part A, and describes “multiple well tool control systems in a multi-valve well testing system” as set forth in prior pending application Ser. No. 295,614 filed 1/10/89, assigned to the same assignee as that of the present invention, which application is incorporated herein by reference; and (3) part C which represents a continuation-in-part of prior pending application Ser. No. 295,614 referenced hereinabove in part B, and describes “multiple well tool control systems in a multi-valve well testing system having automatic control modes”, in accordance with the present invention.

Referring initially to FIG. 1, a string of drill stem testing tools is shown suspended in well bore 10 on drill pipe or tubing 11. The testing tools comprise a typical packer 12 that acts to isolate the well interval being tested from the hydrostatic head of fluids standing in the annulus space 13 thereabove, and a main test valve assembly 14 that serves to permit or to prevent the flow of formation fluids from the isolated interval into the pipe string 11. The main valve 14 is closed while the tools are being lowered, so that the interior of the tubing provides a low pressure region into which formation fluids can flow. After the packer 12 is set, the valve 14 is opened for a relatively short flow period of time during which pressures in the well bore are reduced. Then the valve 14 is closed for a longer flow period of time during which pressure build-up in the shut-in well bore is recorded. Other equipment components such as a jar and a safety joint can be coupled between the test valve 14 and the packer 12, but are not illustrated in the drawing because they are notoriously well known. A perforated tail pipe 15 is connected to the lower end of the mandrel of the packer 12 to enable fluids in the well bore to enter the tool string, and typical inside and outside pressure recorders 16, 17 are provided for the acquisition of pressure data as the test proceeds.

A circulating valve 20 that has been chosen to illustrate the principles of the present invention is connected in the tool string above the main test valve assembly 14. As shown schematically in FIG. 2, the valve assembly 20 includes an elongated tubular housing 21 having a central flow passage 22. A valve actuator 23 is slidably mounted in the housing 21, and includes a mandrel 24 having a central passage 25 and an outwardly directed annular piston 26 that is sealed by a seal ring 28 with respect to a cylinder 27 in the housing 21. Additional seal rings 29, 30 are used to prevent leakage between the cylinder 27 and the passage 22. The seal rings 29, 30 preferably engage on the same diameter so that the mandrel 24 is balanced with respect to fluid pressures within the passageway 22. A coil spring 32 located in the housing below the piston 26 reacts between an upwardly facing surface 33 at the lower end of the cylinder 27 and a downwardly facing surface 34 of the piston 26. The spring 32 provides upward force tending to shift the mandrel 24 upwardly relative to the housing 21. The annular area 35 in which the spring 32 is positioned contains air at atmospheric or other low pressure The cylinder area 36 above the piston 26 is communicated by a port 37 to a hydraulic line 38 through which oil or other hydraulic fluid is supplied under pressure. A sufficient pressure acting on the upper face 40 of the piston 26 will cause the mandrel 24 to shift downward against the resistance afforded by the coil spring 32, and a release of such pressure will enable the spring to shift the mandrel upward to its initial position. The reciprocating movement of the mandrel 24 is employed, as will be described subsequently, to actuate any one of a number of different types of valve elements which control the flow of fluids either through the central passage 22 of the housing 21, or through one or more side ports through the walls of the housing 21.

The source of hydraulic fluid under pressure is a chamber 42 that is filled with hydraulic oil. As will be explained below, the chamber 42 is pressurized by the hydrostatic pressure of well fluids in the well annulus 13 acting on a floating piston which transmits such pressure to the oil. A line 43 from the chamber 42 leads to a first solenoid valve 44 which has a spring loaded, normally closed valve element 45 that engages a seat 46. Another line 47 leads from the seat 46 to a line 48 which communicates with a first pilot valve 50 that functions to control communication between a hydraulic line 51 that connects with the actuator line 38 and a line 52 that also leads from the high pressure chamber 42. A second solenoid valve 53 which also includes a spring loaded, normally closed valve element 54 engageable with a seat 55 is located in a line 56 that communicates between the lines 47, 48 and a dump chamber 57 that initially is empty of liquids, and thus contains air at atmosphere 99 94, whereby selected pairs of the solenoid valves are supplied with current. Thus the actuator mandrel 24 is moved upward or downward on command from the surface. With pair 53, 65 energized, low pressure in the dump chamber 57 is communicated to the rear of the pilot valve shuttle 60, which causes it to shift open, whereby hydrostatic pressure of the oil in chamber 42 is applied to the upper face 40 of the actuator piston 26. Energization of the solenoid valve 65 ensures that pressures are balanced across the shuttle 70 so that its spring 74 retains it closed across the line 73. The difference between hydrostatic fluid pressure and atmospheric pressure thus is applied to the actuator piston 26 which produces downward force to drive the actuator mandrel 24 downward against the bias of the return spring 32. Such movement positions the valve seal assembly 221 below the side ports 102 in the housing 21 and after a suitable time delay to insure complete travel of the mandrel 24, the solenoid valves 53 and 65 are de-energized by the driver 94 in response to signals from the controller 93. Pressure then can be applied to the annulus 13 at the surface cause any fluids in the pipe string 11 to be reverse circulated to the surface where they can be piped to a suitable container for inspection and analysis, or disposed of if desired. If the test is to be terminated at this point, the packer 12 is unseated and the tool string withdrawn from the well so that the pressure recorder charts also can be inspected and analyzed

If further testing or other service work is to be done without removing the equipment from the well, the circulating valve 20 is reclosed. To accomplish this, another series of low level pressure pulses is applied at the surface to the fluids in the well annulus. Such pulses activate the controller 93 as described above, which causes the driver 94 to energize the other pair of solenoid valves 44, 76. Opening of the solenoid valve 44 equalizes pressures across the pilot valve shuttle 60, so that its spring 63 forces the shuttle closed across the line 51. The solenoid valve 53, when no longer energized, moves to its normally closed position against the seat 55. Opening of the solenoid valve 76 reduces the pressure on the spring side of the pilot shuttle 70, whereby pressure in the line 82 shifts the shuttle to open position where communication is established between line 82 and dump line 73. Of course the solenoid valve 65, when not energized, moves to its normally closed position. The return spring 32 forces the actuator mandrel 24 upward, displacing that volume of oil in the chamber region 36 into the dump chamber 57. By repeated applications of command signals to the fluids in the annulus 13, the circulating valve 20 can be repeatedly opened and closed.

Cycles of downward and upward movement of the actuator mandrel 24 also can be used to rotate the ball element 228 shown in FIG. 8 between its open and closed positions with respect to the flow passage 22. Thus a ball valve in combination with the control system of the present invention can be used as the main test valve 14, or as a sampler safety valve apparatus. Each valve component is the test string can have its own control system, which is operated in response to a command signal having a different signature. Also, one control system can be used to operate a number of different valve components with the driver 94 arranged to control the energization of a plurality of pairs of solenoid valves associated with respective valve components.

Referring to FIG. 9, a borehole 10 is illustrated, as in FIG. 1, and a well testing tool 11 is disposed in the borehole. For purposes of this discussion, the tool includes a test valve section 20 and a reversing valve section 14. All other numerals shown in FIG. 9 are identical to the numerals shown in FIG. 1. It should be understood that a test valve and a reversing valve were indicated in the drawing for purposes of illustration only. The present invention would work equally well in conjunction with other valves, such as safety valves, samplers, safety joints, etc. In addition, the multiple well tool control system can be used for controlling more than two valves.

For purposes of this discussion, the well testing tool 11 of the preferred embodiment includes an electronics section, a first well tool control system connected to the electronics section, the test valve connected to the first well tool control system, a second well tool control system connected to the electronics section, and the reversing valve connected to the second well tool control system.

Referring to FIG. 10, the first well tool control system 14a disposed in the well testing tool of FIG. 9 includes the reversing valve 14 to which is connected a first set of solenoids SV1, and a second set of solenoids SV2 in the manner as described in part A above entitled “WELL TOOL CONTROL SYSTEM”.

Referring to FIG. 11, the second well tool control system 20a disposed in the well testing tool of FIG. 9 includes a test valve 20 to which is connected a third set of solenoids SV3 and a fourth set of solenoids SV4 in the manner as described in part A above.

Referring to FIG. 12, the solenoids SV1, SV2, SV3 and SV4 are connected to the electronics section also disposed in the well testing tool of FIG. 9. The electronics section comprises a command sensor 95, a command receiver board 92, a controller board 93 which contains an Intel 8088 microprocessor, a power supply 91 connected to the controller board 93, a battery 90 connected to the power supply, and a solenoid driver board 94 connected to the output of the controller board 93.

The solenoid driver board 94 is energized by a controller board 93. The controller board comprises a processor portion and a memory portion in which a set of microcode may be encoded. The controller board is powered by power supply board 91 and receives unique signature input signals from the command receiver board 92. The command receiver board 92 receives an input stimulus from a command sensor 95, which input stimulus may be an output signal from an annulus pressure transducer, a strain gauge or a bottom hole pressure transducer. The command sensor 95 may sense various types of input stimuli, such as changes in pressure within the annulus around the tool. The preferred embodiment will utilize changes in pressure within the annulus as the input stimulus to the command sensor 95, but only for purposes of illustration, since any type of input stimulus to command sensor 95 will suffice for purposes of the present invention. A first pressure change signal, having a first predetermined signature, transmitted into a borehole by an operator would be sensed by the command sensor 95 and interpreted by the controller board 93 as an intent to control the test valve 20, whereas a second pressure change signal, having a second predetermined signature, transmitted into the borehole by an operator, would be sensed by the command sensor 95 and interpreted by the controller board 93 as an intent to control the reversing valve 14.

Referring to FIG. 13a, a typical input stimulus for command sensor 95 is illustrated, the stimulus being a pressure change signal transmitted into the borehole by an operator at the well surface for purposes of energizing one of the solenoid sets SV1/SV2 or SV3/SV4. In FIG. 13a, two pressure signals are shown, P-1 and P-2, each having the same predetermined signature. The first pressure signal P-1 has a pulse width of T-1 and has an indicated pressure P. The second pressure signal P-2 has a pulse width T-2 and has the same indicated pressure P. The second pressure signal P-2 is transmitted into the borehole only for purposes of ensuring that the command sensor 95 accurately recognizes the pressure signal P-1 as being associated with the one solenoid set (either SV1/SV2 or SV3/SV4) and that a random pressure change in the borehole annuls is not recognized. When the pressure signal P-1 is transmitted into the borehole, followed by pressure signal P-2, the command sensor 95 recognizes the P-1 pulse as applying to one of solenoid sets SV1/SV2 or SV3/SV4 and energizes the microprocessor within the controller board 93. If pressure signal P-2 does not follow immediately after pressure signal P-1, the command sensor 95 will not energize controller board 93. As a result, random pressure changes in the borehole annulus will not activate the command sensor 95 and inadvertently open a valve. When the controller board 93 is energized, the controller board 93, via solenoid driver board 94, selects and energizes a particular solenoid set (either SV1/SV2 or SV3/SV4), as identified by pressure signal P-1 (or P-2), and would either open normally closed solenoid 44, and open normally closed solenoid 76, or would open normally closed solenoid valve 53 and open normally closed solenoid valve 65 of the selected solenoid set. As a result, the mandrel 24 of well tool control system 14a or 20a would move up or down in FIG. 9, thereby opening or closing its corresponding valve.

The functional operation of the multiple well too tool control systems of the present invention is set forth in the following paragraphs with reference to FIGS. 9 through 13a of the drawings.

Each individual well tool control system, shown in FIG. 10 and FIG. 11, functions in the manner described in part A of this specification entitled WELL TOOL CONTROL SYSTEM. An operator at the well surface decides that the reversing valve 14 must be opened. He transmits a pressure signal downhole, similar to the pressure signal illustrated in FIG. 13a. The pressure signal has a unique, predetermined signature, uniquely associated with the reversing valve 14. The command sensor 95 detects the first pulse of the pressure signal. The command receiver board 92 transforms the pressure signal detected by the command sensor 95 into a signal uniquely recognizable by the microprocessor in the controller board 93. The microprocessor used in the preferred embodiment is an Intel 8088 microprocessor, which microprocessor interprets the signal from the command receiver board 92 as one uniquely associated with the well tool control system 14a of FIG. 10. As a result, the microprocessor in the controller board 93 instructs the solenoid driver board 94 to energize the solenoid sets SV1 and SV2 of well tool control system 14a in a manner which will move mandrel 24 of reversing valve 14 downwardly in FIG. 9 and open the reversing valve 14. This action has no effect on the test valve 20, the operation of the reversing valve 14 being totally independent of the operation of the test valve. In fact, the operator need only know which pressure signal to transmit downhole in order to open or close the reversing valve 14; he need not be concerned about the test valve 20; he need not know whether there is one or more than one well testing tool disposed downhole and he need not know in which well testing tool the reversing valve 14 is disposed. When the operator desires to open the test valve 20, he transmits another pressure signal downhole, similar to the pressure signal illustrated in FIG. 13a, but different than the pressure signal transmitted downhole associated with the reversing valve 14. The test valve 20 pressure signal pulse width and/or amplitude is changed relative to the reversing valve 14 pressure signal pulse width and/or amplitude. Again, the command sensor 95 senses the existance existence of the new test valve 20 pressure signal and the command receiver board 92 converts this new pressure signal into another signal which is uniquely recognizable by the controller board 93 as being associated with the test valve 20, and not the reversing valve 14. As a result, the solenoid driver board 94 energizes solenoid set sets SV3 and SV4 associated with well tool control system 20a, causing mandrel 24 of test valve 20 to move downwardly in FIG. 9 thereby opening the test valve 20. Again, the opening of the test valve 20 is done totally independently of the reversing valve 14; and the operator need only know the identity of the particular pressure signal which opens the test valve 20; he need not know in which well testing tool the test valve 20 is disposed or even if there is more than one such tool disposed downhole.

Referring to FIG. 14, a well testing tool is illustrated including, for purposes of this discussion, two valves, and a well tool control system connected to each valve.

In FIG. 14a, a top part of the well testing tool is illustrated and includes a threaded portion for connection to the tubing string disposed in the borehole.

In FIG. 14b, a first valve (valve 1) 14 is illustrated, this valve representing the reversing valve 14 shown in FIGS. 9 and 10. The valve 14 includes circulating ports 102 which open or close depending upon the position of mandrel 24 in the tool. If mandrel 24 is moved upwardly in the figure, ports 102 close, whereas if mandrel 24 moves downwardly, ports 102 open. Mandrel 24 moves up and down depending upon the pressure of fluid on the top and bottom surface of the piston 26 portion of the mandrel 24. Fluid is conducted to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37. Oil passage 37 is connected to pilot valves 50 and 68 via lines 38, 51, and 82 of well tool control system 14a of FIG. 10. Fluid is conducted to the bottom surface of piston 26 via another oil passage 125. The other oil passage 125 conducts fluid under pressure to the bottom surface of piston 26 and represents spring 32 shown in FIG. 10. The bias force of spring 32 in FIG. 10 provides the same pressure to the bottom surface of piston 26 as does the pressure of the fluid in oil passage 125 in FIG. 14b.

In operation, referring to FIG. 14b, when fluid under pressure is provided to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37, from well tool control system 14a shown in FIG. 10, such pressure is greater than the pressure provided to the bottom surface of piston 26 via oil passage 125; therefore, piston 26 moves downwardly in FIG. 14b, causing mandrel 24 to move out from between circulating ports 102, opening said ports. Fluid under pressure is provided to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37 in the following manner: an operator at the well surface transmits an input stimulus into the borehole, such as a pressure signal as shown in FIG. 13a; command sensor 95 detects the input stimulus, and command receiver board 92 converts the stimulus into a signal recognizable by the microprocessor in the controller board 93 as uniquely associated with valve 14 of FIG. 14b; controller board 93, via solenoid driver board 94, energizes solenoid sets SV1 and SV2 of the well tool control system 14a in FIG. 10 in a first predetermined manner as described in PART A of this specification thereby permitting oil in the hydro chamber 42 of FIG. 10 to be transmitted to the top surface of piston 26 in FIG. 14b. When solenoid sets SV1 and SV2 of the well tool control system 14a in FIG. 10 are energized in a second predetermined manner as set forth in PART A of this specification in response to another input stimulus transmitted into the borehole by an operator, the oil above piston 26 in FIG. 14b is permitted to drain to dump chamber 57 of FIG. 10.

In FIG. 14c, a second valve (valve 2) 20 is illustrated, this valve representing the test valve 20 shown in FIGS. 9 and 11. The valve 20 includes ball valve 228 which opens or closes depending upon the position of mandrel 24 in the tool of FIG. 14c. If mandrel 24 is moved upwardly in the figure, ball valve 228 opens, whereas if mandrel 24 moves downwardly, ball valve 228 closes (see the description in this specification associated with FIG. 8 of the drawings). Mandrel 24 moves up and down depending upon the pressure of fluid on the top and bottom surface of the piston 26 portion of the mandrel 24. Fluid is conducted to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37. Oil passage 37 is connected to pilot valves 50 and 68 via lines 38, 51, and 82 of well tool control system 20a of FIG. 11. Fluid is conducted to the bottom surface of piston 26 via another oil passage 125. The other oil passage 125 conducts fluid under pressure to the bottom surface of piston 26 and represents spring 32 shown in FIG. 11. The bias force of spring 32 in FIG. 11 provides the same pressure to the bottom surface of piston 26 as does the pressure of the fluid in oil passage 125 in FIG. 14c.

In operation, referring to FIG. 14c, when fluid under pressure is provided to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37, from well tool control system 20a shown in FIG. 11, such pressure is greater than the pressure provided to the bottom surface of piston 26 via oil passage 125; therefore, piston 26 moves downwardly in FIG. 14c, causing mandrel 24 to rotate ball valve 228 thereby closing valve 20 of FIG. 14c. Fluid under pressure is provided to the top surface of piston 26 via cylinder region 36, port 122, and oil passage 37 in the following manner: an operator at the well surface transmits another input stimulus into the borehole, such as a pressure signal as shown in FIG. 13a, which input stimulus or pressure signal is different than the input stimulus transmitted previously into the borehole when it was desired to open valve 14 of FIG. 14b. Command sensor 95 detects the input stimulus, and command receiver board 92 converts the stimulus into a signal recognizable by the microprocessor in the controller board 93 as uniquely associated with valve 20 of FIG. 14c; controller board 93, via solenoid driver board 94, energizes solenoid sets SV3 and SV4 of the well tool control system 20a in FIG. 11 in a first predetermined manner, as set forth in PART A of this specification, thereby permitting oil in the hydro chamber 42 of FIG. 11 to be transmitted to the top surface of piston 26 in FIG. 14c. When solenoid sets SV3 and SV4 are energized in a second predetermined manner as set forth in PART A of this specification in response to transmission of another input stimulus into the bor hole by an operator, the oil above piston 26 in FIG. 14c is permitted to drain to dump chamber 57 in FIG. 11.

FIG. 14d represents the bottom portion of the well testing tool shown in FIGS. 14a through 14c.

By incorporating suitable microcode into the controller board 93, the well tool control system of part B presented hereinabove may operate automatically, opening and closing various valves in the tool a predetermined number of times and in a predetermined sequence, in response to a single input kickoff stimulus. The input stimulus may, for example, be a sensing of a predetermined bottom hole pressure, in the borehole below the packer, and a generation of the proper input stimulus when the bottom hole pressure exceeds a predetermined level. When the input stimulus is generated, the pre-programmed series of instructions generated by the controller board 93 microcode may, for example, require that the well be flowed for 5 minutes, followed by a shut-in until stabilized pressure is reached, followed by flowing the well until the well appears to be killing itself, followed by shut-in until the Horner straight line is reached, followed by opening a reversing valve. The input stimulus may also be a sensing of a specific set down weight of the tool in the borehole when the tool reaches bottom, via a strain gauge placed on the tool, and a generation of an input stimulus when the set down weight reaches a predetermined amount. In response to the input stimulus representative of the specific set down weight of the tool, a specific action would be taken, such as opening a test valve for 5 minutes, then closing the valve for 1 hour, then opening the valve for 1 hour, then closing the valve for 2 hours, after which a reversing valve would open.

The exact sequence of valve openings and closings, and the exact number of times the valves are opened and closed per hour, is determined by the specific instructions encoded into the controller board memory chip. A flow chart of the microcode instructions is presented hereinbelow.

Referring to FIG. 15, a construction of the controller board 93 of FIG. 12 is illustrated.

In FIG. 15, the controller board 93 includes a microprocessor 93a connected to a system bus and a read only memory (ROM) 93b also connected to the system bus. The microprocessor may be any typical microprocessor chip, such as the Intel 8088 microprocessor chip used in conjunction with this preferred embodiment of the present invention. The ROM 93b is pre-programmed (encoded) with certain specific microcode instructions. These instructions determine the exact sequence by which the valves in the well testing tool of part A are opened and closed, and determine the number of times such valves are opened and closed per hour.

Referring to FIG. 16, a plot of typical bottom hole pressure vs time is illustrated. This plot identifies and defines the times To, T1, T2, T3, and T4 used below during the discussion of the microcode instruction flow chart of FIG. 19.

Referring to FIG. 17, a pressure transducer section 95a includes pressure transducer 95 to which an electrical cable 95b is connected, for further connection to the command receiver board 92. The pressure transducer 95 is ported to the inside of the tubing string, below the packer, via channels 210 and 210a, so that the bottom hole pressure, below the packer, may be sensed by the pressure transducer 95. When the bottom hole pressure is sensed by pressure transducer 95, the transducer 95 generates an output signal which energizes the command receiver board 92 thereby acting as an input stimulus to controller board 93 for initiating the execution of the controller board 93 microcode, stored in ROM 93b of FIG. 15.

Referring to FIG. 18, in lieu of the pressure transducer section 95a shown in FIG. 17, a strain gauge section 95c may be substituted for the pressure transducer section. The strain gauge section of the tool shown in FIG. includes a strain gauge 95d integrally connected to the body of the well testing tool. An electrical cable 95e is connected to the strain gauge for further connection to the command receiver board 92. The strain gauge 95d senses the set down weight of the well testing system of part B of this application, when such system sets down in the borehole. In response to the sensing of the set down weight, the strain gauge 95d generates an output signal which energizes the command receiver board 92, thereby acting as an input stimulus to controller board 93 for initiating the execution of the controller board 93 microcode, stored in ROM 93b of FIG. 15.

Referring to FIG. 19, a flowchart of the microcode encoded in the ROM 93b of the controller board 93 is illustrated. A complete discussion of the flowchart of figure 19 will be presented hereinbelow. This discussion will identify and ear plain each block of the flowchart and will set forth a functional description of the present invention.

The invention of this application is a system which includes a processor portion (e.g., the Intel 8088 microprocessor) and a memory portion (ROM 93b), the memory storing certain instructions therein. When the instructions stored in the memory portion are executed by the processor portion, certain specific functions are performed by the system. In FIG. 19, the microcode stored in ROM 93b begins with START (block b1), and, as indicated in block b2, asks the question “Is T>T sleep?”. T sleep is defined as being the length of time, from initialization of the microprocessor clock at the surface, during which no input stimulus is received by the microprocessor and certain control components are temporarily shut down to conserve battery energy and reduce the chance for inadvertent tool or system operation. In other words, Tsleep is the length of time during which the well testing tool or system is being disposed down the borehole of an oil well for eventual testing operations. If not, return to the beginning of block b2 and begin again. Otherwise, if yes, ask “Is override received?” (block b3). Override is a signal transmitted to the tool by the operator at the surface and would act as an interrupt to halt any further operations by the multiple well tool control systems of PART B in accordance with the present invention. Note that all the microcoded operations set forth in FIG. 19 eventually loop back to the top of the flowchart, where the question “Is override received” is asked once again. Override is important since it may be necessary to revert to manual operation, as set forth in PART A of this specification, for manually transmitting an input stimulus into the borehole, or it may be necessary to manually change the set down weight which would trigger an output signal from the strain gauge 95d. Furthermore, the time T is always incremented, as the microcode of FIG. 19 is executed; as a result, override may be selected at any time by an operator thereby interrupting any further execution of the microcode in ROM 93b by the processor 93a. If override is received by the processor 93a of the controller board 93, ask “is stop override received?” (block b4). If yes, stop operations immediately. If no, “perform the override function” (block b5) and return to block b3 and ask, once again, “is override received”. If not, the microcode asks “is kickoff received?” (block b6). If not, return to the beginning of block b3. “kickoff” is defined as the input stimulus mentioned above, such as the output signal from the strain gauge or the output signal from the pressure sensor sensing the bottom hole pressure. If the kickoff signal (input stimulus) is received, the microcode asks “is automode 1 set?” (block b7). Automode 1 is a preprogrammed test wherein a certain time sequence of openings and closings of a test valve and a reversing valve is preprogrammed into the ROM as a part of the ROM microcode. For example, the processor 93a, in response to execution of the automode 1 test microcode stored in ROM, will alternately open and close the test valve until a predetermined time is reached; when the predetermined time has elapsed, the processor 93a will open the reversing valve.

The following is a description of the automode 1 test.

If automode 1 is set, a series of questions are asked by the ROM microcode (block b8): “is it time for first shut-in?; is it time for second shut-in?; is it time for first flow or second flow?; is it time for reverse?”; referring also to FIG. 10, if the time T is (greater than or equal to time T1 or greater than or equal to time T3) and (less than time T2 or less than time T4), close the test valve (block b9) and return to the top of the block b3; if the time T is greater than or equal to time T4, open the reversing valve (block b10) and return to the top of block b3; if the time T is (greater than or equal to time To or greater than or equal to time T2) and (less than time T1 or less than time T3), open the test valve (block b11) and return to the top of block b3.

If automode 1 is not set, the ROM microcode asks “is automode 2 set?” (block b12). Automode 2 is a test whose sequence is automatically controlled based on a combination of time and measured bottom hole pressure. For example, if the measured bottom hole pressure falls on a certain curve (Horner straight line) or value, the processor 93a opens and/or closes the test valve and/or the reversing valve; otherwise, if the bottom hole pressure does not fall on such curve or value, the test valves and/or reversing valves are opened and/or closed in accordance with a predetermined elapsed time.

The following is a description of the automode 2 test.

The first question asked by the ROM microcode is: “what is the test type, impulse or conventional?” (block b13). An impulse test is a 1 flow test whereas a conventional test is a 2 flow test. If the test is the impulse type: open the test valve (block b14); ask “is the well killing itself?” (is the hydrostatic head pressure the=formation pressure?) (block b15); if yes, close the test valve (block b16), if no, ask “is the flow time exceeded (T is greater than or equal to T1)?” (block b17); if no, return to the top of block b3, if yes, close the test valve (block b16), then ask “is the Horner straight line reached?” (has the bottom hole pressure reached a predetermined criterion, the criterion in this case being the Horner straight line?) (block b18); if yes, open the reversing valve (block b19), if no, ask “is shut-in time exceeded (T greater than or equal to time T2)?” (block b20); if no, return to the top of the block b3, if yes, open the reversing valve (block b19) and return to the top of block b3, which asks “is override received?”. If the test is the conventional type: open the test valve (block b21), and ask “is the well killing itself?” (block b22); if yes, close the test valve (block b23) and return to the top of block b3, if no, ask “is it time for shut-in (is T less than T1 or is T greater than or equal to T1)?” (block b24); if T is less than T1, it is not time for shut-in and return to the top of block b3; if T is greater than or equal to time T1, it is time for shut-in and close the test valve (block b25); ask “has the bottom hole pressure (BHP or Pbh) stabilized (i.e., is the current bottom hole pressure the previous bottom hole pressure)?” (bottom b26); if yes, open the test valve (block b27), if no, ask “is shut-in time exceeded (is T greater than or equal to T2)?” (block b28), if no, return to the top of block b3, if yes, open the test valve (block b27); the ROM microcode, as executed by the processor, asks “is the well killing itself?” (block b29), if yes, shut the test valve (block b30), if no, ask “is flow time exceeded (T greater than or equal to time T3?” (block b31); if no, return to top of block b3, if yes, shut the test valve (block b30); the ROM microcode (as interrogated by the processor portion) asks “is the Horner straight line reached?” (block b32), if yes, open the reversing valve (block b33) and return to the top of block b3, if no, ask “is shut-in time exceeded (is T greater than or equal to time T4)?” (block b34); if yes, open the reversing valve (block b33) and return to the top of block b3, if no, return to the top of block b3.

In the above functional and structural description of the ROM microcode, where the question is asked “is the Horner straight line reached” other criteria could be used, such as Log-Log straight line, or type curve matching. Where the question is asked “is the well killing itself”, other criteria could be used or a feedback from a downhole flowmeter could be used to control the flowrate (e.g., constant Q) through a downhole variable choke. Blocks b10 and b33 are optional; reversing could be controlled only by override. In block b8, this is a preprogrammed test where T1, T2, T3, T4 are preset. In block b13, for the conventional test, the times T1-T4 maximums are preset; for the impulse test, the times T1, T2 maximums are preset.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Upchurch, James M.

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9163750, Mar 31 2010 Safoco, Inc. Safety valve and method of use
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9488046, Aug 21 2009 Wells Fargo Bank, National Association Apparatus and method for downhole communication
9540911, Jun 24 2010 Schlumberger Technology Corporation; CHEVRON U S A INC Control of multiple tubing string well systems
9631458, Mar 07 2008 Wells Fargo Bank, National Association Switching device for, and a method of switching, a downhole tool
9890609, Aug 04 2010 Safoco, Inc. Safety valve control system and method of use
Patent Priority Assignee Title
3254531,
3665955,
3964556, Jul 10 1974 SCHERBATSKOY FAMILY TRUST, THE, P O BOX 653, KNICKERBOCKER STATION, NEW YORK, NEW YORK 10002 Downhole signaling system
4078620, Mar 10 1975 Eastman Christensen Company Method of and apparatus for telemetering information from a point in a well borehole to the earth's surface
4292842, May 25 1979 GEARHART INDUSTRIES, INC A CORP OF TX Tool for testing earth formations in boreholes
4489786, Sep 19 1983 HALLIBURTON COMPANY A DE CORP Low pressure responsive downhole tool with differential pressure holding means
4553589, Jul 12 1984 VETCO GRAY INC , Fire-safe surface-controlled subsurface safety valve control line/wellhead connector and blowout preventer
4635717, May 21 1982 Amoco Corporation Method and apparatus for obtaining selected samples of formation fluids
4712613, Jun 12 1985 PEDER SMEDVIG AKSJESELSKAP, VERKSGT 13, STAVANGER, NORWAY Down-hole blow-out preventers
5113379, Dec 05 1977 Method and apparatus for communicating between spaced locations in a borehole
ZA780466,
/
Executed onAssignorAssigneeConveyanceFrameReelDoc
Oct 06 1997Schlumberger Technology Corporation(assignment on the face of the patent)
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