Claims
- 1. An elongated drive string assembly comprising a plurality of hollow sucker rods and a connecting elements with an axis, connected together and between a drive head located at the surface of an oil well and a rotary pump located deep down hole in an oil well, wherein each hollow sucker rod has at least a first end comprising an internal female threaded surface engaging an external male threaded surface on a connecting element, wherein said threads are frustro-conical, non-symmetrical but differential in diametral taper to each other; the free first ends of each hollow sucker rod further comprising an annular torque shoulder engaging an annular torque shoulder on a connecting element, and being characterized in that, for an outside diameter of the connecting element (DEN), the internal diameter (DIN) of the connecting element, and the starting diameter of the torque shoulder (DHT) the following ratios are maintained:
- 2. An elongated drive string assembly according to claim 1, wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; the thread is complete on the connecting element and incomplete on the first end of the hollow rod; the torque shoulder makes an angle with the axis of the rod which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of the connecting element (DEVU) to the outside diameter of the hollow rod (DEV) is maintained within the following range:
- 3. An elongated drive string assembly according to claim 2, wherein the ratio between the starting diameter of the torque shoulder on the connecting element (DHT) and the internal diameter of the hollow rod at the thread free end (DIFR), is maintained within the following range:
- 4. An elongated drive string assembly according to claim 1, wherein each connecting element is a separate nipple connector element having male threads on each end separated by a central section defining a pair of torque shoulders wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; the thread is complete on the nipple and incomplete on the first end of each hollow rod; each torque shoulder makes an angle with the axis of the rod which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of the connecting element (DEVU) to the outside diameter of the hollow rod (DEV) is maintained within the following range:
- 5. An elongated drive string assembly according to claim 4, wherein the ratio between the starting diameter of the torque shoulder on the nipple connector element (DHT) and the internal diameter of the hollow rod at the thread free end (DIFR), is maintained within the following range:
- 6. An elongated drive string assembly according to claim 1, wherein each connecting element is an integral male thread on the second end of each hollow rod wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; the thread is complete on the second end and incomplete on the first end of each hollow rod; each torque shoulder makes an angle with the axis of the rod which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of the connecting element (DEVU) to the outside diameter of the hollow rod (DEV) is maintained within the following range:
- 7. An elongated drive string assembly according to claim 6, wherein the ratio between the starting diameter of the torque shoulder on the hollow rod second end (DHT) and the internal diameter of the hollow rod at the thread free first end (DIFR), is maintained within the following range:
- 8. An elongated drive string assembly according to claim 1, wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; each torque shoulder makes an angle with the axis of the rod which is substantially 83°; and the connector element is a separate nipple connector element having substantially conical threads with male threads on each end separated by a central section defining a pair of torque shoulders, an internal cylindrical bore within the central section communicating with a conical inner bore proximate the length of each threaded end that defines an increasing cross-section of the nipple from each free end of the nipple towards the central section, and the torque shoulder locations.
- 9. An elongated drive string assembly according to claim 8, wherein the differential threads are modified buttress threads, have a pitch of substantially eight threads per inch, and the nipple connector element male threads have a diametral taper in inches per inch of diameter of substantially 0.0976, and the hollow rod female threads have a diametral taper in inches per inch of diameter of substantially 0.1.
- 10. A hollow sucker rod adapted to engage a connecting element along an axis, wherein each hollow sucker rod has at least a first end comprising an internal female threaded surface adapted to engage an external male threaded surface on a connecting element, which is complementary but differential in diametral taper to the female threaded surface; the free first end of the hollow sucker rod further comprising an annular torque shoulder adapted to engage an annular torque shoulder on said connecting element, and being characterized in that, for an outside diameter of the connecting element (DEN), the internal diameter (DIN) of the connecting element, and the starting diameter of the torque shoulder (DHT) the following ratios are maintained:
- 11. A hollow sucker rod adapted to engage a connecting element according to claim 10, wherein the differential thread is a non-symmetrical truncated trapezoid in thread shape; the thread is incomplete on the first end of the hollow rod; the torque shoulder makes an angle with the axis which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of a connecting element (DEVU) to the outside diameter of the hollow rod (DEV) is maintained within the following range:
- 12. A hollow sucker rod adapted to engage a connecting element according to claim 11, wherein the ratio between the starting diameter of the torque shoulder on a connecting element (DHT) and the internal diameter of the hollow rod at the thread free end (DIFR), is maintained within the following range:
- 13. A hollow sucker rod adapted to engage a connecting element according to claim 12, wherein the differential thread is a modified buttress thread, has a pitch of substantially eight threads per inch, and the hollow rod female thread has a diametral taper in inches per inch of diameter of substantially 0.1 that is adapted to engage a connecting element with a diametral taper in inches per inch of diameter of substantially 0.0976.
- 14. A connecting element adapted to engage a hollow sucker rod along an axis, wherein an external male threaded surface on the connecting element is adapted to engage a hollow sucker rod first end comprising an internal female threaded surface which is complementary but differential in diametral taper to the male threaded surface; the connecting element further comprising an annular torque shoulder adapted to engage an annular torque shoulder on a free first end of a hollow sucker rod, and being characterized in that, for an outside diameter of the connecting element (DEN), the internal diameter (DIN) of the connecting element, and the starting diameter of the torque shoulder (DHT) the following ratios are maintained:
- 15. A connecting element adapted to engage a hollow sucker rod according to claim 14, wherein the connecting element is a separate nipple connector element having male threads on each end separated by a central section defining a pair of torque shoulders wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; the thread is complete on the nipple; each torque shoulder makes an angle with the axis which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of the connecting element (DEVU) to the outside diameter of a hollow rod (DEV) is maintained within the following range:
- 16. A connecting element adapted to engage a hollow sucker rod according to claim 15, wherein the ratio between the starting diameter of the torque shoulder on the connecting element (DHT) and the internal diameter of a hollow rod at the thread free end (DIFR), is maintained within the following range:
- 17. A connecting element adapted to engage a hollow sucker rod according to claim 14, wherein the connecting element is an integral male thread on the second end of a hollow rod wherein the differential threads are each non-symmetrical truncated trapezoids in thread shape; the thread is complete on the second end and incomplete on the first end of the hollow rod; each torque shoulder makes an angle with the axis of the rod which is between 75° and 90°, and being characterized in that the ratio of the outside diameter of the connecting element (DEVU) to the outside diameter of the hollow rod (DEV) is maintained within the following range:
- 18. A connecting element adapted to engage a hollow sucker rod according to claim 17, wherein the ratio between the starting diameter of the torque shoulder on the connecting element (DHT) and the internal diameter of a hollow rod at the thread free end (DIFR), is maintained within the following range:
- 19. A connecting element adapted to engage a hollow sucker rod according to claim 14, wherein the differential thread is a non-symmetrical truncated trapezoid in thread shape; the torque shoulder makes an angle with the axis of which is substantially 83°; and the connecting element is a separate nipple connector element having substantially conical threads with male threads on each end separated by a central section defining a pair of torque shoulders, an internal cylindrical bore within the central section communicating with a conical inner bore proximate the length of each threaded end that defines an increasing cross-section of the nipple from each free end of the nipple towards the central section, and the torque shoulder locations.
- 20. A connecting element adapted to engage a hollow sucker rod according to claim 19, wherein the differential thread is a modified buttress thread, has a pitch of substantially eight threads per inch, and each of the nipple connector element male threads have a diametral taper in inches per inch of diameter of substantially 0.0976 and are adapted to engage a hollow rod female thread with a diametral taper in inches per inch of diameter of substantially 0.1.
- 21. An elongated drive string assembly according to claim 1, wherein the connector element is a separate nipple connector element having substantially conical threads with male threads on each end separated by a central section defining a pair of torque shoulders, and the nipple further comprises complete threads and free ends adapted to engage against a shoulder of a rod, so as to define a seal between the inner bore and the threads.
- 22. An elongated drive string assembly according to claim 21, wherein the bore of the nipple is conical and opening towards each end, there is an external cylindrical zone between each free end and the beginning of the threads and each free end contacts a shoulder of a rod so as to define said seal between the inner bore and the threads.
- 23. An elongated drive string assembly according to claim 1, wherein the rod sections located proximate to each extreme end of the string each have a plurality of holes extending through the rod wall of said sections, to enable fluid flowing outside of the rod to also flow within said bore and between the extreme ends.
- 24. An elongated drive string assembly according to claim 23, wherein the plurality of holes are drilled radially through the rod wall, proximate to each extreme end of the string.
- 25. An elongated drive string assembly according to claim 23, wherein the plurality of holes through the rod wall and are arranged in a symmetrical fashion about the centerline of the rod, proximate to each extreme end of the string.
- 26. An elongated drive string assembly according to claim 23, wherein the plurality of holes comprise between about 62 and 162 holes which are arranged in sets of one to three holes at specific tranverse sections spaced along the centerline of the rod, proximate to each extreme end of the string.
- 27. An elongated drive string assembly according to claim 23, wherein the plurality of holes comprise between about 62 and 162 holes which are arranged in a helicoidal path about the centerline of the rod, proximate to each extreme end of the string.
- 28. A connecting element according to claim 14, further having substantially conical threads with male threads on each end separated by a central section defining a pair of torque shoulders, and the nipple further comprises complete threads and free ends adapted to engage against a shoulder of a rod, so as to define a seal between the inner bore and the threads.
- 29. A connecting element according to claim 28, wherein the bore of the nipple is conical and opening towards each end, there is an external cylindrical zone between each free end and the beginning of the threads and each free end is adapted to contact a shoulder of a rod so as to define a seal between the inner bore and the threads.
- 30. A hollow rod according to claim 10, wherein a rod section to be located proximate to each extreme end of a string has a plurality of holes through the rod wall of that section, to enable fluid flowing outside of the rod to also flow within said bore.
- 31. A hollow rod according to claim 30, wherein the plurality of holes are drilled radially through the rod wall.
- 32. A hollow rod according to claim 30, wherein the plurality of holes through the rod wall are arranged in a symmetrical fashion about the centerline of the rod.
- 33. A hollow rod according to claim 30, wherein the plurality of holes comprise between about 62 and 162 holes which are arranged in sets of one to three holes at specific tranverse sections spaced along the centerline of the rod.
- 34. A hollow rod according to claim 30, wherein the plurality of holes comprise between about 62 and 162 holes which are arranged in a helicoidal path about the centerline of the rod.
Priority Claims (1)
Number |
Date |
Country |
Kind |
P99 01 06162 |
Dec 1999 |
AR |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] A Continuation-In-Part of U.S. application Ser. No. 10/254,500, filed Sep. 26, 2002, which is a Continuation-In-Part of U.S. application Ser. No. 09/679,359, filed Oct. 5, 2000, now abandoned, which claims priority of Argentina P99 01 06162, filed Dec. 3, 1999
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
10254500 |
Sep 2002 |
US |
Child |
10668503 |
Sep 2003 |
US |
Parent |
09679359 |
Oct 2000 |
US |
Child |
10254500 |
Sep 2002 |
US |