Filter for subterranean use

• US 6,382,318 B1
• Filed: 09/24/1999
• Issued: 05/07/2002
• Est. Priority Date: 04/04/1997
• Status: Expired due to Term

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Whitlock, Michael B.
• Primary Examiner(s): TSAY, FRANK
• Application Number:
  US09/405,173
• Time in Patent Office: 956 Days
• Field of Search: 166/278, 166/227, 166/229, 166/228, 166/51, 166/369, 166/230, 166/235
• US Class Current: 166/278
• CPC Class Codes: B01D 2201/0407 Perforated supports on both sides of the filtering element
• CPC Class Codes: B01D 29/111 Making filtering elements
• CPC Class Codes: B01D 29/15 arranged for inward flow filtration
• CPC Class Codes: B01D 29/58 arranged concentrically or coaxially
• CPC Class Codes: E21B 43/082 Screens comprising porous materials, e.g. prepacked screens
• CPC Class Codes: E21B 43/084 Screens comprising woven materials, e.g. mesh or cloth

Abstract

A filter for subterranean use includes a filter body containing a filter medium, and a restraining member disposed around the filter body. The inner periphery of the restraining member is sufficiently close to the outer periphery of the filter body to prevent the filter body from being damaged by radially outward forces encountered during operation of the filter within a well.

Claims

1. A filter for subterranean use comprising:

a hollow filter body including a filter medium; and

a perforated cage which surrounds the filter body and is plastically deformed radially inwards towards an outer periphery of the filter body so that an outer periphery of the filter body can contact an inner periphery of the cage around an entire circumference of the filter body without exceeding a maximum allowable elongation of the filter body.

2. A filter as claimed in claim 1 including an inner support member surrounded by the filter body.

3. A filter as claimed in claim 1 wherein the cage comprises a perforated steel tube.

4. A filter as claimed in claim 3 wherein the tube has perforations elongated in a lengthwise direction of the tube by the plastic deformation.

5. A filter as claimed in claim 1 wherein the cage is deformed over an entire length of the filter body.

6. A filter as claimed in claim 5 wherein the cage is uniformly deformed over the entire length of the filter body.

7. A filter as claimed in claim 1 wherein the cage is uniformly deformed around its periphery.

8. A filter as claimed in claim 1 wherein the inner periphery of the cage contacts the outer periphery of the filter body when there is no differential pressure between an interior and an exterior of the filter.

9. A filter as claimed in claim 8 wherein the inner periphery of the cage is compressed against the outer periphery of the filter body when there is no differential pressure between an interior and an exterior of the filter.

10. A filter as claimed in claim 1 wherein the outer periphery of the filter body is spaced from the inner periphery of the cage when there is no differential pressure between an interior and an exterior of the filter.

11. A filter as claimed in claim 1 wherein an inner diameter of the cage increases towards its lengthwise ends.

12. A filter as claimed in claim 1 including end connectors surrounding the inner support member and secured to lengthwise ends of the cage, the cage having a minimum inner diameter smaller than a maximum outer diameter of each end connector.

39. A filter arrangement for subterranean use comprising:

a filter according to claim 1, 20, 25 or 30 disposed in a well; and

a fluid transporting member in fluid communication with the filter for transporting a fluid between an interior of the filter and an exterior of a well.

40. A filter arrangement as claimed in claim 39 wherein the fluid transporting member comprises a pipe string.

41. A filter arrangement as claimed in claim 39 wherein the fluid transporting member comprises coiled tubing.

42. A filter arrangement as claimed in claim 39 wherein the fluid transporting member comprises a downhole pump.

43. A filter arrangement as claimed in claim 39 wherein the fluid transporting member comprises another filter.

13. A method of forming a filter for subterranean use comprising:

disposing a perforated cage around a filter body including a filter medium; and

plastically deforming the cage radially inwards to reduce an inner diameter thereof.

14. A method as claimed in claim 13 including reducing the inner diameter of the cage to a value such that an outer periphery of the filter body can contact an inner periphery of the cage around an entire circumference of the filter body without exceeding a maximum allowable elongation of the filter body.

15. A method as claimed in claim 13 wherein the cage comprises a perforated steel tube.

16. A method as claimed in claim 13 including restraining lengthwise ends of the cage against axial elongation while deforming the cage.

17. A method as claimed in claim 13 comprising plastically deforming the cage with a swaging mechanism.

18. A method as claimed in claim 13 including disposing the cage around the filter body with a radial clearance.

19. A method as claimed in claim 13 including reducing the inner diameter of a midportion of the cage more than the inner diameter of lengthwise ends of the cage.

20. A filter for subterranean use comprising:

a hollow filter body containing a filter medium; and

a wrap member helically wrapped around the filter body in a plurality of turns, the wrap member having a non-circular transverse cross section and being twisted around a longitudinal axis thereof.

21. A filter as claimed in claim 20 wherein adjoining turns of the wrap member contact each other.

22. A filter as claimed in claim 20 including spaces through the wrap member through which particles measuring approximately 0.015 inches in diameter can pass to reach the filter body.

23. A filter as claimed in claim 20 wherein the wrap member has a rectangular transverse cross section.

24. A filter as claimed in claim 20 wherein the wrap member comprises steel.

25. A filter for subterranean use comprising:

a hollow filter body containing a metallic filter medium; and

a wrap member helically wrapped around the filter body and defining openings for fluid through which particles measuring approximately 0.015 inches in diameter can pass to reach the filter body.

26. A filter as claimed in claim 25 wherein the wrap member radially compresses the filter body.

27. A filter as claimed in claim 25 wherein the wrap member is not secured to the filter body.

28. A filter as claimed in claim 25 wherein the filter medium comprises a porous metal.

29. A filter as claimed in claim 28 wherein the filter medium comprises a porous sintered metal.

30. A filter for subterranean use comprising:

a hollow filter body containing a metallic filter medium capable of resisting tension in a circumferential direction of the filter body; and

a perforated cage surrounding the filter body, an outer periphery of the filter body being able to contact an inner periphery of the cage around an entire circumference of the filter body without exceeding a maximum allowable elongation of the filter body, wherein an inner diameter of the cage increases towards lengthwise ends of the cage.

31. A filter as claimed in claim 30 wherein the inner periphery of the cage is radially spaced from the outer periphery of the filter body when there is no differential pressure between an interior and an exterior of the filter.

32. A filter as claimed in claim 30 wherein the cage comprises a steel tube.

33. A filter as claimed in claim 30 wherein the cage can withstand a pressure within the filter which is at least approximately 200 psi greater than a pressure on the outside of the filter without the filter body exceeding its maximum allowable elongation.

34. A filter as claimed in claim 30 wherein the cage can withstand a pressure within the filter which is at least approximately 1000 psi greater than a pressure on the outside of the filter without the filter body exceeding its maximum allowable elongation.

35. A filter as claimed in claim 30 wherein the cage can withstand a pressure within the filter which is at least approximately 2000 psi greater than a pressure on the outside of the filter without the filter body exceeding its maximum allowable elongation.

36. A filter as claimed in claim 30 wherein the filter medium comprises a porous metal.

37. A filter as claimed in claim 30 wherein the filter medium comprises a porous sintered metal.

38. A filter as claimed in claim 30 wherein the filter medium comprises a sintered metal supported porous medium.