SHALE SHAKER

• US 20100270216A1
• Filed: 04/30/2010
• Published: 10/28/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: National Oilwell Varco LP (NOV, Inc.)
• Original Assignee: National Oilwell Varco LP (NOV, Inc.)
• Inventors: Burnett, George Alexander, Larson, Thomas Robert
• Granted Patent: US 9,079,222 B2
• Time in Patent Office: Days
• US Class Current: 209/606
• CPC Class Codes: B01D 33/0376 supported
• CPC Class Codes: B01D 33/41 in series connection
• CPC Class Codes: B07B 1/46 Constructional details of screens in general; Cleaning or heating of screens
• CPC Class Codes: B07B 13/16 Feed or discharge arrangements
• CPC Class Codes: B07B 2201/04 Multiple deck screening devices comprising one or more superimposed screens
• CPC Class Codes: B07B 2230/01 Wet separation

Abstract

A shale shaker for separating solids from solids laden drilling fluid is disclosed as having a basket with a scalping screen deck, at least one first screen deck and at least one second screen deck. The basket further may have a flow tray arranged between said scalping screen deck and at least one first screen deck, and a plurality of first ducts and a plurality of second ducts, the plurality of first ducts for directing solids laden drilling fluid to the at least one first screen deck. The second plurality of second ducts are for directing solids laden drilling fluid to said second screen deck.

Claims

1. A shale shaker for separating solids from solids laden drilling fluid, said shale shaker comprising a basket having at least one first screen deck and at least one second screen deck and at least one first duct and at least one second duct, wherein said basket further comprises a flow tray having at least one first duct opening for said at least one first duct and at least one second duct opening for said at least one second duct, said at least one first duct for directing solids laden drilling fluid to said at least one first screen deck and said at least one second duct for directing solids laden drilling fluid to said at least one second screen deck.

2. A shale shaker as claimed in claim 1, wherein said solids laden drilling fluid flows along said flow tray in a flow direction the flow tray having a flow tray width substantially transverse to said flow direction, said at least one first duct opening arranged across a first portion of said flow tray width and said second duct opening arranged across a second portion of said flow tray width, said first portion not overlapping said second portion.

3. A shale shaker as claimed in claim 1, wherein said at least one first duct opening is a plurality of first duct openings, and said at least second duct opening is a plurality of second duct openings.

4. A shale shaker as claimed in claim 3, wherein said solids laden drilling fluid flows along said flow tray in a flow direction, said plurality of first duct openings interleaved with said plurality of second duct openings, said plurality of first and second duct openings arranged substantially perpendicularly to said flow direction.

5. A shale shaker as claimed in claim 1, wherein said flow tray has a feed end and a discharge end, the first and second duct openings arranged at said discharge end of said flow tray.

6. A shale shaker as claimed in claim 1, wherein said flow tray has a floor and at least one of said first and second duct openings is planar with said floor of said flow tray.

7. A shale shaker as claimed in claim 6, wherein the other of the first and second ducts has a duct opening planar with a floor of said flow tray.

8. A shale shaker as claimed in claim 1, wherein said flow tray further comprises a valve for directing said solids laden drilling fluid to one of said at least one first screen deck and said at least first and second duct openings.

9. A shale shaker as claimed in claim 8, wherein said flow tray has at least one gate opening therein and said valve is a gate valve comprising a gate tray slideable from closed position closing off said gate opening to a position closing said gate opening.

10. A shale shaker as claimed in claim 1, further comprising a scalping screen for removing large solids from said solids laden drilling fluid, said solids laden drilling fluid flowing therefrom on to said flow tray and said large solids passing over said scalping screen.

11. A shale shaker as claimed in claim 10, wherein said large solids pass over said scalping screen into one of a:

skip; and

ditch.

12. A shale shaker as claimed in claim 1, wherein said at least one first screen deck has a screened fluid flow tray thereunder for collecting and guiding said screened drilling fluid.

13. A shale shaker as claimed in claim 1, wherein said at least one second screen deck has a screened fluid flow tray thereunder for collecting and guiding said screened drilling fluid.

14. A shale shaker as claimed in claim 12, wherein said basket further comprises at least one discharge duct for directing said screened drilling fluid from said screened fluid flow tray to a sump arranged beneath said basket.

15. A shale shaker as claimed in claim 1, wherein said at least one first screen deck is an upper screen deck and said at least one second screen deck is a lower screen deck, the lower screen deck at least part of which is arranged beneath said upper screen deck.

16. A shale shaker as claimed in claim 1, wherein said at least one first screen deck is an upper screen deck and said at least one second screen deck is a lower screen deck, the lower screen deck wholly arranged beneath said upper screen deck.

17. A shale shaker as claimed in claim 1, wherein said basket further comprises a trough, wherein said at least one first screen deck has a solids discharge end and said trough is arranged thereunder to receive solids.

18. A shale shaker as claimed in claim 17, further comprising a sump arranged below said basket, said tough arranged to feed solids into said sump.

19. A shale shaker as claimed in claim 17, said basket further comprising a jetting nozzle arranged to jet screened drilling fluid into said trough to facilitate flow of solids therethrough.

20. A shale shaker as claimed in claim 18, wherein the basket further comprises a flexible duct, solids flowing through said trough into said flexible duct and into said sump.

21. A shale shaker as claimed in claim 1, wherein said basket further comprises a trough and a diverter plate, wherein said at least one first screen deck has a solids discharge end and said trough is arranged thereunder, said diverter plate to guide solids into said trough.

22. A shale shaker as claimed in claim 1, wherein said basket further comprises a trough and a diverter cap, wherein said at least one first screen deck has a solids discharge end and said trough is arranged thereunder, said diverter cap to inhibit solids flowing into said trough.

23. A shale shaker as claimed in claim 22, further comprising one of a skip and ditch, wherein said diverter cap guides solids into said one of said skip and said ditch.

24. A shale shaker as claimed in claim 1, wherein said at least one first screen deck comprises a left-hand first screen deck and a right-hand first screen deck.

25. A shale shaker as claimed in claim 24, wherein said at least one second screen deck comprises a left-hand and a right-hand screen deck.

26. A shale shaker as claimed in claim 1, wherein said basket has a feed end and a solids discharge end, said at least one first screen deck arranged at an uphill angle from horizontal from said feed end of said basket to said solids discharge end.

27. A shale shaker as claimed in claim 1, further comprising at least one first screen assembly in said at least one first screen deck and at least one second screen assembly in said second screen deck.

28. A shale shaker as claimed in claim 27, wherein said first screen assembly has screening material thereon and said second screen assembly has screening material thereon, wherein the screening material of said first screen assembly is the same as the screening material of the second screen assembly to provide the same cut point.

29. A shale shaker as claimed in claim 27, wherein said first screen assembly has screening material thereon and said second screen assembly has screening material thereon, wherein the screening material of said second screen assembly is finer than the screening material of the first screen assembly to provide the different cut points.

30. A shale shaker as claimed in claim 1, further comprising a fixed base, said basket suspended from the base on at least one spring, said basket further comprising a vibrating apparatus for vibrating said basket and the at least one first and second screen decks arranged therein.

31. A method for separating solids from solids laden drilling fluid using a shale shaker comprising a basket having a flow tray with at least first and second duct openings, at least first and second ducts, at least one first screen deck and at least one second screen deck, the method comprising the steps of flowing solids laden drilling fluid over said flow tray, through said at least first and second duct openings into said at least first and second ducts, said at least one first duct directing solids laden drilling fluid to said at least one first screen deck and said at least one second duct directing solids laden drilling fluid to said second screen deck.

32. A shale shaker for separating solids from solids laden drilling fluid, said shale shaker comprising a basket having a scalping screen deck, at least one first screen deck and at least one second screen deck, wherein said basket further comprises a flow tray arranged between said scalping screen deck and said at least one first screen deck, and a plurality of first ducts and a plurality of second ducts, said plurality of first ducts for directing solids laden drilling fluid to said at least one first screen deck and said second plurality of second ducts for directing solids laden drilling fluid to said second screen deck.

33. A shale shaker as claimed in claim 32, wherein said flow tray has at least one gate opening therein and a gate valve comprising a gate tray slideable from a closed position closing off said gate opening to an open position opening said gate opening allowing solids laden drilling mud to flow therethrough.

34. A shale shaker as claimed in claim 33, wherein said basket further comprises a screened fluid flow tray arranged under said at least one first screen deck, said screened fluid flow tray having a selector opening therein and a selector gate valve for selectively opening and closing said selector opening to selectively allow screened drilling fluid to flow therethrough on to said at least one second screen deck.

35. A shale shaker for separating solids from solids laden drilling fluid, the shale shaker comprising a base, a basket isolated from the base, the basket comprising a scalping deck, at least one first deck and at least one second deck, the at least one first deck having a feed end and a solids discharge end, a trough arranged in the basket at said discharge end of said at least one first deck and a diverter plate for selectively inhibiting and allowing solids discharged from the discharge end of the at least one first deck into said trough.

36. A shale shaker as claimed in claim 35, further comprising a flexible duct leading from said trough into a sump arranged beneath the basket for collecting screened drilling fluid.

37. A method for separating solids laden drilling fluid with a shale shaker, the shale shaker comprising a base, a basket isolated from the base, the basket comprising a scalping deck having a scalping screen, at least one first deck having a screen assembly and at least one second deck having a fine screen screen assembly, the at least one first deck having a feed end and a solids discharge end, a trough arranged in the basket at said discharge end of said at least one first deck and a diverter plate the method comprising the steps of flowing solids laden drilling mud on to the scalping screen large solids passing over said scalping screen and solids laden drilling fluid passing through the scalping deck to said screen assembly of said at least one first screen deck sized solids passing over said screen assembly into said trough guided by said diverter plate into said trough.

38. A method in accordance with claim 37, further comprising the step of flowing the sized solids from said trough into a sump under said basket, said sump also collecting screened drilling fluid screened by said fine mesh screens of said at least one second screen deck.

39. A method in accordance with claim 38, flowing the sized solids through the trough is facilitated by a jet of drilling fluid.