Valve control system

• US 4,880,060 A
• Filed: 08/31/1988
• Issued: 11/14/1989
• Est. Priority Date: 08/31/1988
• Status: Expired due to Term

• Current Assignee: Power Well Services, L.P.
• Original Assignee: Halliburton Company
• Inventors: Schwendemann, Kenneth L., Noack, Timothy J.
• Primary Examiner(s): Novosad, Stephen J.
• Assistant Examiner(s): MELIUS, TERRY L
• Application Number:
  US07/238,741
• Time in Patent Office: 440 Days
• Field of Search: 166/336, 166/338, 166/340, 166/363, 166/365, 166/368, 166/319, 166/322, 166/323
• US Class Current: 166/336
• CPC Class Codes: E21B 2200/04 Ball valves
• CPC Class Codes: E21B 34/045 adapted to be lowered on a tubular string into position within a blow-out preventer stack, e.g. so-called test trees

Abstract

A hydraulic control system for controlling a retainer valve in an underwater well test system. The control system is contained in a housing in the test string above the retainer valve. The control system and valve are operated by a surface control manifold via control conduits extending between the manifold and control system housing. The system provides opening and closing and very quick closure of the retainer valve by eliminating the requirement for closing pressure to be conducted through a long conduit from surface and by utilizing well pressure to close the valve and lock the valve closed. One embodiment of the control system requires a pressure pulse from surface to start quick retainer valve closure. Another embodiment of the control system monitors control conduits for loss of pressure while the retainer valve is open and automatically closes the valve on loss of control pressure. This control system permits killing fluid to be pumped through the retainer valve into the well after automatic closure or control system operation to reopen the valve and monitor.

Claims

1. A system for testing an underwater well, said system comprising:

(a) a test pipe string in said underwater well, said string having an upper section and a lower section;

(b) a hydraulically operated retainer valve in said upper section;

(c) a control system housing in said upper section;

(d) control manifold means for operating said control system and said retainer valve, said control manifold means comprising;

(a) a source of pressure;

(b) a gas charged accumulator;

(c) a directional control valve; and

(d) conduits conducting pressurized fluid from said pressure source to said accumulator and from said accumulator to said shut-off valve;

(e) hydraulic control system means in said housing for controlling said retainer valve, said hydraulic control system means conducting well pressure from said test pipe string to said retainer valve for quickly closing said retainer valve and locking said retainer valve closed, said hydraulic control system means comprising;

(a) a normally closed pilot valve;

(b) a flow passage for conducting a pressure pulse from the accumulator to the pilot valve for opening the pilot valve;

(c) a flow passage for conducting fluid from the inside of the test pipe to said pilot valve; and

(d) a flow passage for conducting fluid from said pilot valve to said retainer valve for closing said retainer valve and locking said retainer valve closed; and

(f) control conduit means for conducting control fluid between said control manifold and said housing and between said housing and said valve.

2. The system of claim 1 further including test tree means in the test pipe string below the retainer valve for disconnecting the upper pipe section from the lower pipe section and a conduit extending between the control manifold and housing and extending between said housing and said tree.

3. The system of claim 1 wherein the pilot valve is a three-way two-position valve.

4. The system of claim 1 wherein the control conduit means comprise:

(a) a conduit for control fluid extending between the control manifold means and the control system housing and between said system housing and the valve, for opening the valve; and

(b) a conduit for control fluid extending between said manifold means and said housing and between said housing and said valve, for closing said valve and locking said valve closed.

5. A system for testing an underwater well, said system comprising:

(a) a test pipe string in said underwater well, said string having an upper section and lower section;

(b) a hydraulically operated retainer valve in said upper section;

(c) a control system housing in said upper section;

(d) control manifold means for operating said control system and said retainer valve, said control manifold means including;

(a) a pressure source; and

(b) conduits in conjunction with a plurality of valves therein for conducting control fluid to the control system housing;

(e) hydraulic control system means in said housing for controlling said retainer valve, said hydraulic control system means conducting well pressure from said test pipe string to said valve for quickly closing said retainer valve and locking said retainer valve closed, said hydraulic control system means including means for sensing reduced pressure in the upper test pipe section above a closed and locked retainer valve and for unlocking the retainer valve to permit fluids to be pumped through the retainer valve and test pipe into said underwater well, said hydraulic control system means comprising;

(a) a first normally closed pilot valve having a pilot portion associated therewith;

(b) a second normally open pilot valve having a pilot portion associated therewith;

(c) a first pressure source flow passage means for conducting fluid between said first pilot valve and the pressure source;

(d) a first check valve in said first pressure source flow passage means, permitting flow from said first pilot valve to said pressure source;

(e) second retainer valve closing and locking flow passage means for communicating between said first pilot valve and said retainer valve for closing said retainer valve and locking said retainer valve closed;

(f) a first second pilot valve flow passage between said first pilot valve and the pilot portion of said second pilot valve for closing said second pilot valve;

(g) an accumulator;

(h) a second first pilot valve flow passage between said accumulator and said first pilot valve for opening said first pilot valve;

(i) a third first pilot valve flow passage between the interior of upper test pipe section and said first pilot valve, said second first pilot passage and said first pressure source flow passage means for opening said first pilot valve and charging said accumulator;

(j) a second check valve in said third first pilot valve flow passage between said first pilot valve and the pilot portion of said first pilot valve for allowing flow from the pilot portion of said first pilot valve;

(k) a third check valve in said third first pilot valve flow passage between said remote pressure source and said second check valve for allowing flow from said remote pressure source through said first pressure source flow passage means to said second first pilot valve flow passage;

(l) a third multi-flow passage means for communicating between said remote pressure source and the pilot portion of said first pilot valve, said second pilot valve and the pilot portion of said second pilot valve;

(m) fourth retainer valve closing flow passage means for communicating between said second pilot valve and said retainer valve for closing said retainer valve; and

(n) a fifth flow passage between said second pilot valve and the exterior of the control system housing; and

(f) control conduit means for conducting control fluid between said control manifold and said housing and between said housing and said valve.

6. The system of claim 5 wherein the control system means pilot valves are three-way two-position valves.

7. The system of claim 5 further including test tree means in the test pipe string below the retainer valve for disconnecting the upper pipe section from the lower pipe section and a conduit extending between the control manifold and housing and extending between said housing and said tree.

8. The system of claim 5 wherein the control conduit means comprise:

(a) a conduit for control fluid extending between the control manifold means and the control system housing and between said system housing and the valve, for opening the valve; and

(b) a conduit for control fluid extending between said manifold means and said housing and between said housing and said valve, for closing said valve and locking said valve closed.

9. The system of claim 5 wherein the first flow passage means is a flow passage in the control system housing communicating with the first pilot valve and a conduit extending between said housing and the control manifold means.

10. The system of claim 5 wherein the second flow passage means is a flow passage in the housing communicating with the first pilot valve and a conduit extending between said housing and the retainer valve.

11. The system of claim 5 wherein the third flow passage means is a flow passage in the housing communicating with the first and second pilot valve pilots and the second pilot valve and a conduit extending between said flow passage and the control manifold means.

12. The system of claim 5 wherein the fourth flow passage means is a flow passage in the housing communicating with the second pilot valve and a conduit extending between the housing and the retainer valve.

13. The system of claim 5 wherein the control system means further includes an isolator in the third flow passage between the inside of the upper test string section and the second check valve.

14. A hydraulic control system for controlling a retainer valve in a test pipe string having an upper section and lower section in a well, said hydraulic control system comprising:

(a) a control system housing in said test pipe string; and

(b) control system means in said housing for conducting pressure from said test pipe string to said valve for quickly closing said retainer valve, said control system means including means for sensing reduced pressure in said test pipe string above a said retainer valve when closed and locked and for locking said retainer valve to allow fluids to be pumped through said retainer valve and said test pipe string into said well, said control system means comprising;

(a) a first normally closed pilot valve having a pilot portion associated therewith;

(b) a second normally open pilot valve having a pilot portion associated therewith;

(c) a remote pressure source;

(d) first remote pressure source flow passage means for conducting fluid between said first pilot valve and said remote pressure source;

(e) a first pressure source check valve in said first flow passage means, allowing flow from said first pilot valve to said pressure source;

(f) second retainer valve closing and locking flow passage means from said first pilot valve to said retainer valve for closing said retainer valve and locking said retainer valve closed;

(g) a first second pilot valve closing flow passage between said pilot valve and the pilot portion of said second pilot valve for closing said second pilot valve;

(h) an accumulator;

(i) a second first pilot valve opening flow passage between said accumulator and the pilot portion of said first pilot valve for opening said first pilot valve;

(j) a third first pilot valve flow passage between the interior of the upper section of said test pipe string in said well and said first pilot valve, said second flow passage and said first flow passage means for opening said first pilot valve and charging said accumulator;

(k) a second sick valve in said third first pilot valve flow passage located between said first pilot valve and the pilot portion of said first pilot valve, allowing flow from the pilot portion of said first pilot valve;

(l) a third check valve in said third first pilot valve flow passage located between said remote pressure source and said second check valve, allowing flow from said pressure source through said first flow passage means to said second flow passage;

(m) a third multi-flow passage means located between said pressure source and the pilot portion of said first pilot valve, said second pilot valve and the pilot portion of said second pilot valve;

(n) fourth retainer valve closing flow passage means located between said second pilot valve and said retainer valve for closing said retainer valve; and

(o) a fifth flow passage located between said second pilot valve and the exterior of the control system housing.

15. The control system of claim 14 the pilot valves are three-way, two-position valves.

16. The control system of claim 14 further including an isolator in the third flow passage between the inside of the upper test string section and the second check valve.

17. The control system of claim 14 wherein the first flow passage means is a flow passage in the control system housing communicating with the first pilot valve and a conduit extending between said housing in the control manifold means.

18. The control system of claim 14 wherein the second flow passage means is a flow passage in the housing communicating with the first pilot valve and a conduit extending between said housing and the retainer valve.

19. The control system of claim 14 wherein the third flow passage means is a flow passage in the housing communicating with the first and second pilot valve pilots and the second pilot valve and a conduit extending between said flow passage and the control manifold means.

20. The control system of claim 14 wherein the fourth flow passage means is a flow passage in the housing communicating with the second pilot valve and a conduit extending between the housing and the retainer valve.