Automated method and system for recognizing well control events

• US 6,820,702 B2
• Filed: 08/27/2002
• Issued: 11/23/2004
• Est. Priority Date: 08/27/2002
• Status: Active Grant

• Current Assignee: TDE Petroleum Data Solutions Incorporated
• Original Assignee: Noble Drilling Services Incorporated (Noble Corporation plc)
• Inventors: Niedermayr, Michael, Glaser, Gerhard P., Pinckard, Mitchell D., Vidal de Sousa, Joao Tadeu
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): BOMAR, THOMAS S
• Application Number:
  US10/229,470
• Publication Number:
  US 20040040746A1
• Time in Patent Office: 819 Days
• Field of Search: 175/26, 175/27, 175/38, 175/7, 175/40, 175/48, 175/50, 175/24, 175/72, 175/57, 731/521.9, 731/522.1, 731/522.9, 731/523.1
• US Class Current: 175/57
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 47/10 Locating fluid leaks, intrusions or movements

Abstract

An automated method and system for recognizing a well control event includes determining a state of drilling operations. When drilling operations are in a circulating state, a benchmark for a relative flow value. The relative flow value is based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore. A limit on variation of the relative flow value is determined from the benchmark. A cumulative sum for the relative flow value is determined over time in response to the relative flow value exceeding the limit. A well control event is recognized based on the cumulative sum.

Claims

1. An automated method for recognizing a well control event, comprising:

determining a state of drilling operations; and

when drilling operations are in a circulating state;

determining a benchmark for a relative flow value, the relative flow value based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore;

determining a limit on variation of the relative flow value from the benchmark;

determining a cumulative sum for the relative flow value over time in response to at least the relative flow value exceeding the limit; and

recognizing a well control event based on the cumulative sum.

2. The method of claim 1, wherein the relative flow value is based on a ratio of the flow of drilling fluid out of the well bore and the flow of drilling fluid into the well bore.

3. The method of claim 1, further comprising:

determining whether drilling fluid flow conditions are stabilized; and

determining the benchmark in response to at least stable flow conditions.

4. The method of claim 3, wherein the stable flow conditions are determined when variations in the relative flow value fall below a selected threshold.

5. The method of claim 1, further comprising determining the flow of drilling fluid into the well bore based on a flow of drilling fluid pumped from a mud tank.

6. The method of claim 1, further comprising determining the flow of drilling fluid from the well bore based on a flow of drilling fluid into at least one mud tank.

7. The method of claim 1, further comprising determining the limit on variation based on variation of the relative flow value during stable flow conditions.

8. The method of claim 1, where the cumulative sum is based on cumulative deviations from the benchmark of the relative flow value.

9. The method of claim 1, wherein the well control event comprises a well inflow event, further comprising generating an alarm in response to at least the well inflow event.

10. The method of claim 1, wherein the well control event comprises a well outflow event, further comprising generating an alarm in response to at least the well outflow event.

11. The method of claim 1, further comprising recognizing the well control event based on the cumulative sum exceeding a volume-based limit.

12. The method of claim 11, wherein the volume-based limit is dynamically calculated based on real-time operational parameters.

13. The method of claim 12, wherein the real-time operational parameters comprise at least one of stand pipe pressure, weight on bit, strokes per minute of a mud pump, the cumulative sum, and the mud tank level.

14. The method of claim 1, further comprising recognizing the well control event based on a deviation of the cumulative sum over a period of time.

15. The method of claim 1, further comprising:

when drilling operations are in the circulating state, further repetitively determining the relative flow value in real-time and comparing the relative flow value to the limit on variation.

16. The method of claim 15, further comprising:

when drilling operations are in a non-circulating, constant bit position state, repetitively determining whether there is substantial flow from the well bore.

17. The method of claim 15, further comprising, when drilling operations are in a non-circulating, non-constant bit position state, repetitively determining whether the displacement of drilling fluid in at least one of the well bore and a mud tank is within a limit of displacement caused by the movement of a drill string used for the drilling operations.

18. The method of claim 1, further comprising, in determining the benchmark for the relative flow, compensating for movement of the drilling platform.

19. The method of claim 1, wherein the limit on variation comprises a selected number of standard deviations of the relative flow value from the benchmark.

20. The method of claim 1, further comprising resetting the cumulative sum to zero when the relative flow value falls below the limit on variation for a predetermined time interval.

21. An automated system for recognizing a well control event, comprising:

means for determining a state of drilling operations; and

when drilling operations are in the circulating state;

determining a benchmark for a relative flow value, the relative flow value based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore;

determining a limit on variation of the relative flow value from the benchmark;

determining a cumulative sum for the relative flow value over time in response to the relative flow value exceeding the limit; and

recognizing a well control event based on the cumulative sum.

22. The system of claim 21, wherein the relative flow value is based on a ratio of the flow of drilling fluid out of the well bore and the flow of drilling fluid into the well bore.

23. The system of claim 21, further comprising:

means for determining whether drilling fluid flow conditions are stabilized; and

means for determining the benchmark in response to at least stable flow conditions.

24. The system of claim 23, wherein the stable flow conditions are determined when variations in the relative flow value fall below a selected threshold.

25. The system of claim 21, further comprising means for determining the flow of drilling fluid into the well bore based on a flow of drilling fluid pumped from a mud tank.

26. The system of claim 21, further comprising means for determining the flow of drilling fluid from the well bore based on a flow of drilling fluid into at least one mud tank.

27. The system of claim 24, further comprising means for determining the limit on variation based on variation of the relative flow value during stable flow conditions.

28. The system of claim 24, wherein the cumulative sum is based on cumulative deviations from the benchmark of the relative flow value.

29. The system of claim 24, further comprising means for recognizing the well control event based on the cumulative sum exceeding a volume-based limit.

30. The system of claim 31, further comprising means for dynamically calculating the volume-based limit based on real-time operational parameters.

31. The system of claim 32, wherein the real-time operational parameters comprise at least one of stand pipe pressure, weight on bit, strokes per minute of a mud pump, and the cumulative sum.

32. The system of claim 24, further comprising means for recognizing the well control event based on a continued deviation of the cumulative sum over a period of time.

33. The system of claim 24, further comprising:

means for, when drilling operations are in the circulating state, further repetitively determining the relative flow value in real-time and comparing the relative flow value to the limit on variation.

34. The system of claim 35, further comprising means for, when drilling operations are in a non-circulating, constant bit position state, repetitively determining whether there is substantial inflow.

35. The system of claim 33, further comprising, means for, when drilling operations are in a non-circulating, non-constant bit position state, repetitively determining whether the displacement of drilling fluid in at least one of the well bore and a mud tank is within a limit of displacement caused by the movement of a drill string.

36. The system of claim 21, further comprising means for, in determining the benchmark for the relative flow value, compensating for movement of the drilling platform.

37. The system of claim 21, wherein the limit on variation comprises a selected number of standard deviations of the relative flow value from the benchmark.

38. The system of claim 21, further comprising means for resetting the cumulative sum to zero when the relative flow value falls below the limit on variation for a predetermined time interval.

39. An automated system for recognizing a well control event, comprising:

logic encoded in media; and

logic operable to;

determine a state of drilling operations; and

when drilling operations are in a circulating state;

determine a benchmark for a relative flow value, the relative flow value based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore;

determine a limit on variation of the relative flow value from the benchmark;

determine a cumulative sum for the relative flow value over time in response to the relative flow value exceeding the limit; and

recognize a well control event based on the cumulative sum.

40. The system of claim 39, wherein the relative flow value is based on a ratio of the flow of drilling fluid out of the well bore and the flow of drilling fluid into the well bore.

41. The system of claim 39, the logic further operable to:

determine whether drilling fluid flow conditions are stabilized; and

determine the benchmark in response to at least stable flow conditions.

42. The system of claim 41, wherein flow conditions are stabilized when variations in the relative flow value fall below a selected threshold.

43. The system of claim 39, the logic further operable to determine the flow of drilling fluid into the well bore based on a flow of drilling fluid pumped from a mud tank.

44. The system of claim 39, the logic further operable to determine the flow of drilling fluid from the well bore based on a flow of drilling fluid into at least one mud tank.

45. The system of claim 39, the logic operable to determine the limit a variation based on variation of the relative flow value during stable flow conditions.

46. The system of claim 39, the logic operable to determine the cumulative sum based on cumulative deviations from the benchmark of the relative flow value.

47. The system of claim 39, the logic operable to recognize the well control event based on the cumulative sum exceeding a volume-based limit.

48. The system of claim 47, wherein the volume-based limit is dynamically calculated based on real-time operational parameters.

49. The system of claim 48, wherein the real-time operational parameters comprise at least one of stand pipe pressure, weight on bit, strokes per minute of a mud pump, and the cumulative sum.

50. The system of claim 39, the logic further operable to recognize the well control event based on a continued deviation of the cumulative sum over a period of time.

51. The system of claim 39, the logic further operable to, when the drilling operations are in a circulating state, adjust the relative flow value to account for changes in a total circulating volume of the well bore and a drilling fluid circulating system.

52. The system of claim 39, wherein the limit on variation comprises a selected number of standard deviations of the relative flow value from the benchmark.

53. The system of claim 39, the logic operable to recognize the well control event when the cumulative sum exceeds a first selected threshold.

54. The system of claim 53, wherein the first selected threshold comprises a selected fluid volume.

55. The system of claim 54, the logic further operable to generate first alarm when the cumulative sum exceeds the first selected threshold.

56. The system of claim 53, the logic further operable to determine a value of a warning indicator when the cumulative sum exceeds the first selected threshold.

57. The system of claim 56, wherein the value of the warning indicator comprises a preselected second threshold for the cumulative sum, the second threshold larger than the first selected threshold.

58. The system of claim 57, the logic further operable to recalculate the second selected threshold based on at least one real-time drilling parameter.

59. The system of claim 58, wherein the at least one real-time drilling parameter comprises at least one of stand pipe pressure, weight on bit, strokes per minute of a mud pump, the cumulative sum, and the mud tank level.

60. The system of claim 57, the logic further operable to generate a second alarm when the cumulative sum exceeds the second threshold.

61. The system of claim 39, the logic further operable to reset the cumulative sum to zero when the relative flow falls below the variation limit for a predetermined time interval.

62. The system of claim 39, the logic operable to, when drilling operations are in the circulating state, repetitively determine the relative flow value in real-time and to compare the relative flow value to the limits on variation.

63. The system of claim 62, the logic operable to, when drilling operations are in a non-circulating, constant bit position state, determine whether there is substantial flow from the wellbore.

64. The system of claim 62, the logic operable to, when drilling operations are in a non-circulating, non-constant bit position state, repetitively determine whether the displacement of drilling fluid in at least one of the well bore and a mud tank is within a limit of displacement caused by the movement of a drill string used for the drilling operation.

65. The system of claim 39, further comprising, in determining the benchmark for the relative flow value, compensating for movement of the drilling platform.

66. The system of claim 39, the logic further operable to reset the cumulative sum to zero when the relative flow value falls below the limit on variation for a predetermined time interval.