ROV retrievable sea floor pump

• US 7,150,325 B2
• Filed: 07/25/2003
• Issued: 12/19/2006
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Rivera, Robert J., Ratterman, Eugene E., Ireland, Floyd D., Ferreira, Janislene S.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): WRIGHT, GIOVANNA COLLINS
• Application Number:
  US10/627,859
• Publication Number:
  US 20050016735A1
• Time in Patent Office: 1,243 Days
• Field of Search: 166/366, 166/352, 166/69, 166107-109, 166/358
• US Class Current: 166/366
• CPC Class Codes: E21B 43/01 specially adapted for obtaining from underwater installations
• CPC Class Codes: E21B 43/128 Adaptation of pump systems with down-hole electric drives
• CPC Class Codes: F04D 29/607 means for positioning from outside

Abstract

A subsea pumping assembly locates on a seafloor for pumping well fluid from subsea wells to the level. The pumping assembly has a tubular outer housing that is at least partially embedded in the seafloor. A tubular primary housing locates in the outer housing and has a lower end with a receptacle. An annular space surrounds the primary housing within the outer housing for delivering fluid to a receptacle at the lower end of the primary housing. A capsule is lowered in and retrieved from the primary housing. The capsule sealingly engages the receptacle for receiving well fluid from the annular space. A submersible pump is located inside the capsule. The pump has an intake that receives well fluid and a discharge that discharges the well fluid exterior of this capsule. The capsule has a valve in its inlet that when closed prevents leakage of well fluid from the capsule. The capsule may be retrieved through open sea without a riser.

Claims

1. A subsea pumping assembly, comprising:

a primary housing adapted to be located subsea, the primary housing having an open first end and a second end containing a receptacle of smaller inner diameter than an inner diameter of the open first end;

an intake conduit in fluid communication with the receptacle for supplying well fluid;

a capsule that is installed through the open first end and lands in the primary housing, the capsule having an inlet that sealingly engages the receptacle as the capsule lands for receiving well fluid flowing through the intake conduit into the receptacle and the inlet of the capsule;

a submersible pump assembly located in the capsule, the pump assembly having an intake for receiving well fluid flowing into the capsule and a discharge for discharging the well fluid from the capsule; and

wherein the capsule while containing the pump assembly therein is retrievable from the primary housing.

2. The pumping assembly according to claim 1, wherein the inlet of the capsule comprises a tail pipe that stabs sealingly into the receptacle as the capsule lands in the primary housing.

3. The pumping assembly according to claim 1, further comprising a capsule valve at the inlet of the capsule that prevents well fluid in the capsule from leaking out the capsule when the capsule is removed from the primary housing.

4. The pumping assembly according to claim 1, wherein the pump assembly comprises a rotary pump and an electrical motor, and wherein the intake of the pump is spaced from the inlet of the capsule to cause the well fluid to flow over the motor as it flows from the inlet of the capsule to the intake of the pump.

5. The pumping assembly according to claim 1, wherein the intake conduit comprises an outer housing that encloses the primary housing, defining a space between the outer housing and the primary housing for the flow of well fluid from the intake conduit to the receptacle.

6. The pumping assembly according to claim 1, wherein:

the intake conduit comprises a tubular outer housing at least partially embedded in a sea floor; and

the primary housing is a tubular member concentrically located in the outer housing, defining an annular space between the primary housing and the outer housing for the flow of well fluid.

7. The pumping assembly according to claim 1, further comprising:

a removable cap mounted to an upper end of the primary housing; and

a lifting profile on the capsule for engagement by a lift line lowered from a vessel at the surface.

8. The pumping assembly according to claim 1, wherein the sealing engagement of the inlet of the capsule with the receptacle prevents the entry of well fluid into the primary housing.

9. The pumping assembly according to claim 1, wherein the intake conduit for the receptacle is located above the receptacle.

10. A subsea pumping assembly, comprising:

a primary housing adapted to be located subsea, the primary housing having a lower end with a receptacle;

an intake conduit connected with the receptacle for supplying well fluid from a well;

a capsule that lands in the primary housing, the capsule having an inlet that sealingly engages the receptacle for receiving well fluid;

a submersible pump assembly located in the capsule, the pump assembly having an intake for receiving well fluid flowing into the capsule and a discharge for discharging the well fluid from the capsule; and

wherein the capsule while containing the pump assembly therein is retrievable from the primary housing; and

a receptacle valve at the receptacle for blocking the flow of well fluid from the intake conduit into the receptacle when the capsule is removed from the primary housing.

11. A subsea pumping assembly, comprising:

a tubular outer housing at least partially embedded in a sea floor;

a tubular primary housing located in the outer housing and having a lower end with a receptacle, the primary housing having an outer diameter smaller than an inner diameter of the outer housing, defining an annular space that is adapted to receive well fluid flowing from a well;

a capsule that lands in and is retrievable from the primary housing, the capsule having an inlet on a lower end that sealingly engages the receptacle for flowing well fluid from the annular space into the capsule, the exterior of the capsule being sealed from exposure to the well fluid by the primary housing;

a submersible pump assembly located in the capsule, the pump assembly having an intake for receiving well fluid flowing into the capsule and a discharge for discharging the well fluid exterior of the capsule; and

a capsule valve in the inlet of the capsule that when closed prevents leakage of well fluid from the capsule, enabling the capsule to be retrieved through the sea without a riser.

12. The pumping assembly according to claim 11, further comprising a receptacle valve at the receptacle for blocking the flow of well fluid from the outer housing into the receptacle when the capsule is removed from the primary housing.

13. The pumping assembly according to claim 11, wherein the inlet of the capsule comprises a tail pipe that extends slidingly into the receptacle.

14. The pumping assembly according to claim 11, wherein the pump assembly comprises a rotary pump and an electrical motor, and wherein the pump intake is spaced from the inlet of the capsule to cause the well fluid to flow over the motor as it flows from the inlet of the capsule to the intake of the pump.

15. A method of pumping well fluid from a sea floor to a surface platform, comprising:

(a) installing a primary housing at the sea floor at a location remote from a producing well;

(b) placing a submersible pump assembly in a capsule;

then

(c) lowering the capsule from the surface into the primary housing while the pump assembly is contained therein and sealingly engaging an inlet of the capsule with a receptacle of the primary housing;

then

(d) flowing well fluid from the producing well into the receptacle, through the inlet and into the capsule and pumping the well fluid from the capsule with the pump assembly.

16. The method according to claim 15, wherein:

step (a) further comprises at least partially embedding a tubular outer housing in the sea floor and landing the primary housing in the sea floor; and

step (d) further comprises;

flowing the well fluid down an annular space between the primary housing and the outer housing to the receptacle.

17. The method according to claim 15, wherein step (b) comprises connecting a rotary pump to an electrical motor and positioning the pump and motor such that well fluid in the capsule flows over the motor for cooling the motor as it flows from the inlet of the capsule to an intake of the pump.

18. The method according to claim 15, wherein the sealing engagement of the inlet of the capsule with the receptacle prevents the entry of well fluid into the primary housing.

19. A method of pumping well fluid from a sea floor to a surface platform, comprising:

(a) installing a primary housing at the sea floor;

(b) placing a submersible pump assembly in a capsule;

then

(c) lowering the capsule from the surface into the primary housing while the pump assembly is contained therein and sealingly engaging an inlet of the capsule with a receptacle of the primary housing;

then

(d) flowing well fluid into the receptacle, through the inlet and into the capsule and pumping the well fluid from the capsule with the pump assembly; and

retrieving the capsule for maintenance to the pump assembly by closing a valve at the inlet of the capsule, and retrieving the capsule on a lift line through the open sea, the primary housing preventing exposure of well fluid to the exterior of the capsule.