Device for removal and filtration of drilling fluid

1. An apparatus for removal and filtration of drilling fluid during top hole drilling, wherein a suction module ( 10 ) comprises an elongated pipe-formed body ( 30 ), which is open at the top and is arranged to an ocean-bottom penetrating pipe, through which is led a drill stem for drilling of the top hole, and

the pipe-formed body ( 30 ) comprises a filtration device with through openings, where said openings are arranged to let through to at least one outlet passage ( 32 ) in the pipe wall, filtered return drilling fluid containing dispersed material, such as swelling clay or stones,

wherein filtered return drilling fluid from the bore hole is exported to a pump module ( 12 ) through the at least one outlet passage ( 32 ) in the pipe wall, the material in the drilling fluid being of a size less than the diameter of a inlet pipe of the pump or openings of the pump,

the upper part of the pipe-formed body ( 30 ) is arranged to contain return drilling fluid, which is not fed to the pump module ( 12 ), and where a volume of said drilling fluid stands as a “plug” above the outlet ( 32 ) of the suction pipe ( 22 ) of the pump and is sealed against the drill stem (l 6 ), and

the level of return drilling fluid in the pipe-formed body ( 30 ) being adjusted by regulation of the capacity of the pump ( 12 ).

2. The apparatus according to claim 1 , wherein the suction module ( 10 ) comprises a camera ( 38 ) and/or a sonar for monitoring of the level of the drilling fluid, including the “plug” of return drilling fluid, in the pipe-formed body ( 30 ), and that monitoring signals are sent to an operator for regulation of the capacity of the pump ( 12 ).

3. The apparatus according to claim 1 , wherein the suction module ( 10 ) comprises measuring equipment for monitoring of the level of drilling fluid, including the “plug” of return drilling fluid, in the pipe-formed body ( 30 ), and that monitoring signals are sent to an operator, or directly to the pump ( 12 ) for regulation of the capacity of the pump.

4. The apparatus according to claim 1 , wherein the filtration device comprises an inner, elongated and arched, perforated filtration plate ( 40 ) where at least one annular space, or parts of an annular space that is closed at the top and/or at the bottom, is provided between the inner pipe wall of the pipe-formed body ( 30 ) and the inner perforated filtration plate ( 40 ).

5. The apparatus according to claim 4 , wherein the annular space extends in the whole, or parts, of the longitudinal direction of the pipe-formed body ( 30 ) and/or its circumference.

6. The apparatus according to claim 4 , wherein the elongated, perforated filtration plate ( 40 ) is formed in the shape of a pipe.

7. The apparatus according to claim 1 , wherein the pipe wall of the pipe-formed body ( 30 ) comprises a number of outlet passages ( 32 ) arranged spaced apart radially around the pipe wall, where the outlet passages ( 32 ) are connected to the suction pipe ( 22 ) of the pump ( 12 ).

8. The apparatus according to claim 7 , wherein at least one of the outlet passages ( 32 ) in said pipe wall is connected to a suction manifold ( 34 ), and that the suction pipe ( 22 ) of the pump is connected to the suction manifold ( 34 ).

9. The apparatus according to claim 8 , wherein the suction manifold ( 34 ) comprises a number of outlets with suction connection for the pump ( 12 ).

10. The apparatus according to claim 1 , wherein the suction module ( 10 ) comprises a lifting loop ( 42 ), or another appliance for connection of a lifting tool.

11. The apparatus according to claim 1 , wherein the suction module ( 10 ) and the pump module ( 12 ) are integrated with each other.

12. The apparatus according to claim 2 , wherein the suction module ( 10 ) comprises measuring equipment for monitoring of the level of drilling fluid, including the “plug” of return drilling fluid, in the pipe-formed body ( 30 ), and that monitoring signals are sent to an operator, or directly to the pump ( 12 ) for regulation of the capacity of the pump.

13. The apparatus according to claim 3 , wherein the filtration device comprises an inner, elongated and arched, perforated filtration plate ( 40 ) where at least one annular space, or parts of an annular space that is closed at the top and/or at the bottom, is provided between the inner pipe wall of the pipe-formed body ( 30 ) and the inner perforated filtration plate ( 40 ).

14. The apparatus according to claim 5 , wherein the elongated, perforated filtration plate ( 40 ) is formed in the shape of a pipe.

15. The apparatus according to claim 5 , wherein the pipe wall of the pipe-formed body ( 30 ) comprises a number of outlet passages ( 32 ) arranged spaced apart radially around the pipe wall, where the outlet passages ( 32 ) are connected to the suction pipe ( 22 ) of the pump ( 12 ).

16. The apparatus according to claim 6 , wherein the pipe wall of the pipe-formed body ( 30 ) comprises a number of outlet passages ( 32 ) arranged spaced apart radially around the pipe wall, where the outlet passages ( 32 ) are connected to the suction pipe ( 22 ) of the pump ( 12 ).

17. The apparatus according to claim 4 , wherein the suction module ( 10 ) comprises a lifting loop ( 42 ), or another appliance for connection of a lifting tool.

18. The apparatus according to claim 7 , wherein the suction module ( 10 ) comprises a lifting loop ( 42 ), or another appliance for connection of a lifting tool.

19. The apparatus according to claim 10 , wherein the suction module ( 10 ) and the pump module ( 12 ) are integrated with each other.