Sucker rod apparatus and method

• US 9,045,951 B2
• Filed: 12/18/2013
• Issued: 06/02/2015
• Est. Priority Date: 08/09/2011
• Status: Active Grant

• Current Assignee: Finalrod IP, LLC
• Original Assignee: Russell P. Rutledge, Russell P. Rutledge Jr, Ryan B. Rutledge
• Inventors: Rutledge, Russell P., Rutledge, Russell P. Jr., Rutledge, Ryan B.
• Primary Examiner(s): WRIGHT, GIOVANNA COLLINS
• Application Number:
  US14/132,807
• Publication Number:
  US 20140102715A1
• Time in Patent Office: 531 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: E21B 17/04 between rod or the like and bit or between rod and rod or the like
• CPC Class Codes: E21B 17/1071 specially adapted for pump rods, e.g. sucker rods
• CPC Class Codes: E21B 43/127 Adaptations of walking-beam pump systems
• CPC Class Codes: Y10T 403/7064 by wedge or cam

Abstract

Sucker rods include end fittings having an outer wedge portion proximate to an open end, an inner wedge portion proximate to a closed end, and an intermediate wedge portion between the outer and inner wedges. Each wedge includes a leading edge, a trailing edge, and an angle between the leading and trailing edges. The triangular configuration, length of the leading edge, the length of the trailing edge, and size of the angle in each wedge portion cause distribution of force, such that compressive forces distributed to the rod proximate the closed end exceed compressive forces distributed to the rod proximate the open end.

Claims

1. An end fitting for a sucker rod, the end fitting comprising:

a body having an interior, a closed end, an open end, and a wedge system formed in the interior, wherein the wedge system comprises;

an outer wedge portion formed in the interior proximate to the open end, wherein the outer wedge portion comprises a first leading edge, a first trailing edge, and a first angle between the first leading edge and the first trailing edge, wherein the first leading edge faces the open end and the first trailing edge faces the closed end, and wherein an intermediate wedge portion formed in the interior between the outer wedge portion and the closed end, wherein the intermediate wedge portion comprises a second leading edge, a second trailing edge, and a second angle between the second leading edge and the second trailing edge, wherein the second leading edge faces the open end and the second trailing edge faces the closed end, and wherein the length of the second leading edge, the length of the second trailing edge, and the size of the second angle define a second distribution of force in the intermediate wedge portion; and

an inner wedge portion formed in the interior between the intermediate wedge portion and the closed end, proximate to the closed end, wherein the inner wedge portion comprises a third leading edge, a third trailing edge, and a third angle first angle between the third leading edge and the third trailing edge, wherein the third leading edge faces the open end and the third trailing edge faces the closed end, and wherein the length of the third leading edge, the length of the third trailing edge, and the size of the third angle define a third distribution of force in the inner wedge portion,

wherein at least two of the first leading edge, the second leading edge, and the third leading edge differ in length such that during use a compressive load applied to the inner wedge portion is greater than a compressive load applied to the outer wedge portion, such that compressive forces at the closed end of the body exceed compressive forces at the open end of the body, and wherein the length of the second leading edge is equal to the length of the first leading edge or the third leading edge.

2. The end fitting of claim 1, wherein the third leading edge is longer than the first leading edge.

3. The end fitting of claim 1, wherein the first leading edge is longer than the third leading edge.

64. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 1;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.

4. An end fitting for a sucker rod, the end fitting comprising:

a body having an interior, a closed end, an open end, and a wedge system formed in the interior, wherein the wedge system comprises;

an outer wedge portion formed in the interior proximate to the open end, wherein the outer wedge portion comprises a first leading edge, a first trailing edge, and a first angle between the first leading edge and the first trailing edge, wherein the first leading edge faces the open end and the first trailing edge faces the closed end, and wherein the length of the first leading edge, the length of the first trailing edge, and the size of the first angle define a first distribution of force in the outer wedge portion;

an intermediate wedge portion formed in the interior between the outer wedge portion and the closed end, wherein the intermediate wedge portion comprises a second leading edge, a second trailing edge, and a second angle between the second leading edge and the second trailing edge, wherein the second leading edge faces the open end and the second trailing edge faces the closed end, and wherein the length of the second leading edge, the length of the second trailing edge, and the size of the second angle define a second distribution of force in the intermediate wedge portion; and

an inner wedge portion formed in the interior between the intermediate wedge portion and the closed end, proximate to the closed end, wherein the inner wedge portion comprises a third leading edge, a third trailing edge, and a third angle first angle between the third leading edge and the second third edge, wherein the third leading edge faces the open end and the third trailing edge faces the closed end, and wherein the length of the third leading edge, the length of the third trailing edge, and the size of the third angle define a third distribution of force in the inner wedge portion,

wherein at least two of the first angle, the second angle, and the third angle differ in size such that during use a compressive load applied to the sucker rod at the inner wedge portion is greater than a compressive load applied to the sucker rod at the outer wedge portion, such that compressive forces applied to the sucker rod at the closed end of the body exceed compressive forces at the open end of the body, and wherein the second angle is equal to one of the first angle or the third angle.

5. The end fitting of claim 4, wherein the first angle is larger than the third angle.

6. The end fitting of claim 4, wherein the third angle is larger than the first angle.

65. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 4;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.

7. An end fitting for a sucker rod, the end fitting comprising:

a body having an interior, a closed end, an open end, and a wedge system formed in the interior, wherein the wedge system comprises;

an outer wedge portion formed in the interior proximate to the open end, wherein the outer wedge portion comprises a first leading edge, a first trailing edge, and a first angle between the first leading edge and the first trailing edge, wherein the first leading edge faces the open end and the first trailing edge faces the closed end, and wherein the length of the first leading edge, the length of the first trailing edge, and the size of the first angle define a first distribution of force in the outer wedge portion;

an intermediate wedge portion formed in the interior between the outer wedge portion and the closed end, wherein the intermediate wedge portion comprises a second leading edge, a second trailing edge, and a second angle between the second leading edge and the second trailing edge, wherein the second leading edge faces the open end and the second trailing edge faces the closed end, and wherein the length of the second leading edge, the length of the second trailing edge, and the size of the second angle define a second distribution of force in the intermediate wedge portion; and

an inner wedge portion formed in the interior between the intermediate wedge portion and the closed end, proximate to the closed end, wherein the inner wedge portion comprises a third leading edge, a third trailing edge, and a third angle first angle between the third leading edge and the third trailing edge, wherein the third leading edge faces the open end and the third trailing edge faces the closed end, and wherein the length of the third leading edge, the length of the third trailing edge, and the size of the third angle define a third distribution of force in the inner wedge portion,

wherein the first trailing edge, the second trailing edge, and the third trailing edge differ in length such that during use a compressive load applied to the sucker rod at the inner wedge portion is greater than a compressive load applied to the sucker rod at the intermediate wedge portion, and the compressive load applied to the sucker rod at the intermediate wedge portion is greater than a compressive load applied to the sucker rod at the outer wedge portion, such that compressive forces applied to the sucker rod at the closed end of the body exceed compressive forces at the open end of the body.

8. The end fitting of claim 7, wherein the first trailing edge is longer than the second trailing edge, and wherein the second trailing edge is longer than the third trailing edge.

9. The end fitting of claim 7, wherein the third trailing edge is longer than the second trailing edge, and wherein the second trailing edge is longer than the first trailing edge.

10. The end fitting of claim 7, wherein the first trailing edge and the second trailing edge are substantially equal in length, and wherein third trailing edge is longer than the first trailing edge and the second trailing edge.

11. The end fitting of claim 7, wherein the first trailing edge and the second trailing edge are substantially equal in length, and wherein third trailing edge is shorter than the first trailing edge and the second trailing edge.

12. The end fitting of claim 7, wherein the second trailing edge and the third trailing edge are substantially equal in length, and wherein first trailing edge is shorter than the second trailing edge and the third trailing edge.

13. The end fitting of claim 7, wherein the second trailing edge and the third trailing edge are substantially equal in length, and wherein first trailing edge is longer than the second trailing edge and the third trailing edge.

66. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 7;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.

14. An end fitting for a sucker rod, the end fitting comprising:

a body having an interior, a closed end, and an open end;

a first wedge portion formed in the interior proximate the open end, wherein the first wedge portion comprises a first leading edge, a first trailing edge, and a first angle between the first leading edge and the first trailing edge, wherein the first leading edge faces the open end and the first trailing edge faces the closed end, and wherein the length of the first leading edge, the length of the first trailing edge, and the size of the first angle define a first distribution of force in the first wedge portion; and

a second wedge portion formed in the interior proximate the closed end, between the first wedge portion and the closed end, wherein the second wedge portion comprises a second leading edge, a second trailing edge, and a second angle between the second leading edge and the second trailing edge, wherein the second leading edge faces the open end and the second trailing edge faces the closed end, and wherein the length of the second leading edge, the length of the second trailing edge, and the size of the second angle define a second distribution of force in the second wedge portion,

wherein the length of the first trailing edge and the length of the second trailing edge differ, and wherein the first distribution of force and the second distribution of force vary such that during use a compressive load applied to the sucker rod at second wedge portion is greater than a compressive load applied to the sucker rod at first wedge portion, such that compressive forces in the sucker rod at the closed end of the body exceed compressive forces in the sucker rod at the open end of the body.

15. The end fitting of claim 14, wherein the length of the first leading edge and the length of the second leading edge differ such that the compressive load applied to the sucker rod at the second wedge portion is greater than the compressive load applied to the sucker rod at the first wedge portion.

16. The end fitting of claim 15, wherein the size of the first angle and the size of the second angle are substantially equal.

17. The end fitting of claim 15, wherein the size of the first angle and the size of the second angle differ.

18. The end fitting of claim 14, wherein the length of the first leading edge and the length of the second leading edge are substantially equal.

19. The end fitting of claim 18, wherein the size of the first angle and the size of the second angle are substantially equal.

20. The end fitting of claim 18, wherein the size of the first angle and the size of the second angle differ.

67. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 14;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.

21. An end fitting for a sucker rod, the end fitting comprising:

a body having an interior, a closed end, an open end, and a wedge system formed in the interior, wherein the wedge system comprises;

an outer wedge portion formed in the interior proximate to the open end, wherein the outer wedge portion comprises a first leading edge, a first trailing edge, and a first angle between the first leading edge and the first trailing edge, wherein the first leading edge faces the open end and the first trailing edge faces the closed end, and wherein the length of the first leading edge, the length of the first trailing edge, and the size of the first angle define a first distribution of force in the outer wedge portion;

an intermediate wedge portion formed in the interior between the outer wedge portion and the closed end, wherein the intermediate wedge portion comprises a second leading edge, a second trailing edge, and a second angle between the second leading edge and the second trailing edge, wherein the second leading edge faces the open end and the second trailing edge faces the closed end, and wherein the length of the second leading edge, the length of the second trailing edge, and the size of the second angle define a second distribution of force in the intermediate wedge portion; and

an inner wedge portion formed in the interior between the intermediate wedge portion and the closed end, proximate to the closed end, wherein the inner wedge portion comprises a third leading edge, a third trailing edge, and a third angle first angle between the third leading edge and the second third edge, wherein the third leading edge faces the open end and the third trailing edge faces the closed end, and wherein the length of the third leading edge, the length of the third trailing edge, and the size of the third angle define a third distribution of force in the inner wedge portion,

wherein the length of at least two of the first trailing edge, the second trailing edge, and the third trailing edge vary, and wherein the first distribution of force, the second distribution of force, and the third distribution of force vary such that during use a compressive load applied to the sucker rod at the inner wedge portion is greater than a compressive load applied to the sucker rod at the intermediate wedge portion, and the compressive load applied to the sucker rod at the intermediate wedge portion is greater than a compressive load applied to the sucker rod at the outer wedge portion, such that compressive forces applied to the sucker rod at the closed end of the body exceed compressive forces at the open end of the body.

22. The end fitting of claim 21, wherein the first leading edge is longer than the second leading edge, and wherein the second leading edge is longer than the third leading edge.

23. The end fitting of claim 21, wherein the first leading edge and the second leading edge are substantially equal in length, and wherein the third leading edge is shorter than the first leading edge and the second leading edge.

24. The end fitting of claim 21, wherein the second leading edge and the third leading edge are substantially equal in length, and wherein the first leading edge is longer than the second leading edge and the third leading edge.

25. The end fitting of claim 21, wherein the third leading edge is longer than the second leading edge, and wherein the second leading edge is longer than the first leading edge.

26. The end fitting of claim 21, wherein the first leading edge and the second leading edge are substantially equal in length, and wherein the third leading edge is longer than the first leading edge and the second leading edge.

27. The end fitting of claim 21, wherein the second leading edge and the third leading edge are substantially equal in length, and wherein the first leading edge is shorter than the second leading edge and the third leading edge.

28. The end fitting of claim 21, wherein the first leading edge, the second leading edge, and the third leading edge are substantially equal in length.

29. The end fitting of claim 21, wherein the first leading edge is longer than the third leading edge, and wherein the second leading edge is shorter than the third leading edge.

30. The end fitting of claim 21, wherein the third leading edge is longer than the first leading edge, and wherein the second leading edge is shorter than the first leading edge.

31. The end fitting of claim 21, wherein the first leading edge is longer than the third leading edge, and wherein the second leading edge is longer than the first leading edge.

32. The end fitting of claim 21, wherein the third leading edge is longer than the first leading edge, and wherein the second leading edge is longer than the third leading edge.

33. The end fitting of claim 21, wherein the first leading edge and the third leading edge are substantially equal in length, and wherein the second leading edge is shorter than the first leading edge and the third leading edge.

34. The end fitting of claim 21, wherein the first leading edge and the third leading edge are substantially equal in length, and wherein the second leading edge is longer than the first leading edge and the third leading edge.

35. The end fitting of claim 21, wherein the first trailing edge is longer than the second trailing edge, and wherein the second trailing edge is longer than the third trailing edge.

36. The end fitting of claim 21, wherein the first trailing edge and the second trailing edge are substantially equal in length, and wherein the third trailing edge is shorter than the first trailing edge and the second trailing edge.

37. The end fitting of claim 21, wherein the second trailing edge and the third trailing edge are substantially equal in length, and wherein the first trailing edge is longer than the second trailing edge and the third trailing edge.

38. The end fitting of claim 21, wherein the third trailing edge is longer than the second trailing edge, and wherein the second trailing edge is longer than the first trailing edge.

39. The end fitting of claim 21, wherein the first trailing edge and the second trailing edge are substantially equal in length, and wherein the third trailing edge is longer than the first trailing edge and the second trailing edge.

40. The end fitting of claim 21, wherein the second trailing edge and the third trailing edge are substantially equal in length, and wherein the first trailing edge is shorter than the second trailing edge and the third trailing edge.

41. The end fitting of claim 21, wherein the first trailing edge is longer than the third trailing edge, and wherein the second trailing edge is shorter than the third trailing edge.

42. The end fitting of claim 21, wherein the third trailing edge is longer than the first trailing edge, and wherein the second trailing edge is shorter than the first trailing edge.

43. The end fitting of claim 21, wherein the first trailing edge is longer than the third trailing edge, and wherein the second trailing edge is longer than the first trailing edge.

44. The end fitting of claim 21, wherein the third trailing edge is longer than the first trailing edge, and wherein the second trailing edge is longer than the third trailing edge.

45. The end fitting of claim 21, wherein the first trailing edge and the third trailing edge are substantially equal in length, and wherein the second trailing edge is shorter than the first trailing edge and the third trailing edge.

46. The end fitting of claim 21, wherein the first trailing edge and the third trailing edge are substantially equal in length, and wherein the second trailing edge is longer than the first trailing edge and the third trailing edge.

47. The end fitting of claim 21, wherein the first angle is larger than the second angle, and wherein the second angle is larger than the third angle.

48. The end fitting of claim 21, wherein the first angle and the second angle are substantially equal, and wherein the third angle is smaller than the first angle and the second angle.

49. The end fitting of claim 21, wherein the second angle and the third angle are substantially equal, and wherein the first angle is larger than the second angle and the third angle.

50. The end fitting of claim 21, wherein the third angle is larger than the second angle, and wherein the second angle is larger than the first angle.

51. The end fitting of claim 21, wherein the first angle and the second angle are substantially equal, and wherein the third angle is larger than the first angle and the second angle.

52. The end fitting of claim 21, wherein the second angle and the third angle are substantially equal, and wherein the first angle is smaller than the second angle and the third angle.

53. The end fitting of claim 21, wherein the first angle, the second angle, and the third angle are substantially equal.

54. The end fitting of claim 21, wherein the first angle is larger than the third angle, and wherein the second angle is smaller than the third angle.

55. The end fitting of claim 21, wherein the third angle is larger than the first angle, and wherein the second angle is smaller than the first angle.

56. The end fitting of claim 21, wherein the first angle is larger than the third angle, and wherein the second angle is larger than the first angle.

57. The end fitting of claim 21, wherein the third angle is larger than the first angle, and wherein the second angle is larger than the third angle.

58. The end fitting of claim 21, wherein the first angle and the third angle are substantially equal, and wherein the second angle is smaller than the first angle and the third angle.

59. The end fitting of claim 21, wherein the first angle and the third angle are substantially equal, and wherein the second angle is larger than the first angle and the third angle.

68. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 21;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.

60. An end fitting for a fiber composite sucker rod, the end fitting comprising:

a body having an interior, a closed end, an open end, and a wedge system formed in the interior;

the wedge system comprising an outer wedge portion formed in the interior proximate the open end, the outer wedge portion configured to distribute compressive force in the sucker rod proximate the open end, the outer wedge portion in cross-section having a respective outer wedge triangular configuration, the outer wedge triangular configuration comprising an outer leading edge extending between the open end and an outer trailing edge, the outer leading edge intersecting the outer trailing edge at a respective outer vertex characterized by a respective outer vertex angle, the outer wedge triangular configuration comprising an imaginary outer triangle base opposite the outer vertex, the outer wedge triangular configuration determining distribution by the outer wedge portion of compressive force in the sucker rod proximate the open end;

the wedge system comprising an inner wedge portion formed in the interior proximate the closed end, the inner wedge portion configured to distribute compressive force in the sucker rod proximate the closed end, the inner wedge portion in cross-section having a respective inner wedge triangular configuration, the inner wedge triangular configuration comprising an inner leading edge extending between the closed end and an inner trailing edge, the inner leading edge intersecting the inner trailing edge at a respective inner vertex characterized by a respective inner vertex angle, the inner wedge triangular configuration comprising an imaginary inner triangle base opposite the inner vertex, the inner wedge triangular configuration determining distribution by the inner wedge portion of compressive force in the sucker rod proximate the closed end; and

the inner wedge triangular configuration differing from the outer wedge triangular configuration to bias distribution of compressive force in the sucker rod at the end fitting during use, the outer wedge triangular configuration confining the outer wedge portion to distribute relatively less compressive force in the sucker rod proximate the open end than distributed by the inner wedge portion in the sucker rod proximate the closed end, the inner wedge geometric configuration confining the inner wedge portion to distribute relatively more compressive force in the sucker rod proximate the closed end than distributed by the outer wedge portion in the sucker rod proximate the open end.

61. The end fitting of claim 60, further comprising:

the inner wedge triangular configuration differing from the outer wedge triangular configuration to bias distribution of compressive force in the sucker rod at the end fitting during use, the outer wedge triangular configuration confining the outer wedge portion to distribute less compressive force in the sucker rod proximate the open end than distributed by the inner wedge portion in the sucker rod proximate the closed end, the inner wedge geometric configuration confining the inner wedge portion to distribute more compressive force in the sucker rod proximate the closed end than distributed by the outer wedge portion in the sucker rod proximate the open end.

62. The end fitting of claim 61, further comprising:

the inner wedge triangular configuration differing from the outer wedge triangular configuration to bias distribution of compressive force in the sucker rod at the end fitting during use, the outer wedge triangular configuration confining the outer wedge portion to reduce compressive force in the sucker rod proximate the open end below compressive force in the sucker rod proximate the closed end, the inner wedge geometric configuration confining the inner wedge portion to maintain compressive force in the sucker rod proximate the closed end above compressive force in the sucker rod proximate the open end.

63. The end fitting of claim 60, further comprising:

the wedge system comprising an intermediate wedge portion formed in the interior between the inner wedge portion and outer wedge portion, the intermediate wedge portion configured to distribute compressive force in the sucker rod intermediate the inner wedge portion and outer wedge portion, the intermediate wedge portion in cross-section having a respective intermediate wedge triangular configuration, the intermediate wedge triangular configuration comprising an intermediate leading edge extending between the outer wedge portion and an intermediate trailing edge, the intermediate leading edge intersecting the intermediate trailing edge at a respective intermediate vertex characterized by a respective intermediate vertex angle, the intermediate wedge triangular configuration comprising an imaginary intermediate triangle base opposite the intermediate vertex, the intermediate wedge triangular configuration determining distribution by the intermediate wedge portion of compressive force in the sucker rod proximate the intermediate wedge portion between the inner wedge portion and outer wedge portion; and

the intermediate wedge triangular configuration differing from the inner wedge triangular configuration to bias distribution of compressive force in the sucker rod at the end fitting during use, the intermediate wedge triangular configuration confining the intermediate wedge portion to distribute relatively less compressive force in the sucker rod proximate the intermediate portion between the closed end and open end than distributed by the inner wedge portion in the sucker rod proximate the closed end, the intermediate wedge triangular configuration confining the intermediate wedge portion to distribute relatively more compressive force in the sucker rod proximate the intermediate portion between the closed end and open end than distributed by the outer wedge portion in the sucker rod proximate the open end.

69. A method for artificial lift of fluid from a wellbore, said method comprising the steps of:

providing a sucker rod with an end fitting according to claim 60;

bottom connecting the sucker rod in driving relationship with a down hole pump in the wellbore;

top connecting the sucker rod in driven relationship with a pump drive; and

reciprocating the sucker rod by operation of the pump drive to cause pumping motion of the down hole pump to lift fluid from the wellbore.