Reverse Moineau motor and pump assembly for producing fluids from a well

• US 5,417,281 A
• Filed: 02/14/1994
• Issued: 05/23/1995
• Est. Priority Date: 02/14/1994
• Status: Expired due to Term

• Current Assignee: BICO Drilling Tools Incorporated
• Original Assignee: Steven M. Wood
• Inventors: Craig, Gordon W., Wood, Steven M.
• Primary Examiner(s): Dang, Hoang C.
• Application Number:
  US08/194,835
• Time in Patent Office: 463 Days
• Field of Search: 166/105, 166/68, 166/68.5, 166/369, 418/48, 417/405, 417/406
• US Class Current: 166/68
• CPC Class Codes: B29C 53/58 helically
• CPC Class Codes: B29C 53/60 using internal forming surfaces, e.g. mandrels
• CPC Class Codes: B29L 2031/7498 Rotors with blades B29L2031/08
• CPC Class Codes: B29L 2031/75 Shafts
• CPC Class Codes: E21B 43/129 Adaptations of down-hole pump systems powered by fluid supplied from outside the borehole gas-lift E21B43/122; jet pumps E21B43/124
• CPC Class Codes: F03C 2/08 of intermeshing-engagement type, i.e. with engagement of co- operating members similar to that of toothed gearing
• CPC Class Codes: F04C 13/008 Pumps for submersible use, i.e. down-hole pumping
• CPC Class Codes: F04C 2/084 Toothed wheels
• CPC Class Codes: F04C 2/1071 the inner and outer member having a different number of threads and one of the two being made of elastic materials, e.g. Moineau type
• CPC Class Codes: F04C 2/1073 where one member is stationary while the other member rotates and orbits
• CPC Class Codes: F05C 2253/04 Composite, e.g. fibre-reinforced

Abstract

A downhole submersible fluid pump having a progressive cavity motor section and a progressive cavity pump section. In each section the rotor is fixed and the pumping action occurs by forcing power fluid into the motor chamber around the rotor which action causes the normally fixed stator to rotate around relative to the fixed rotor. This rotary motion is transmitted via the housing to the pump stator formed internally thereof which rotates relative to another fixed rotor drawing fluids from the subterranean formation upwardly as produced fluids.

Claims

1. A downhole pump apparatus for producing fluids from a formation within a well bore to the surface, said apparatus comprising:

progressive cavity motor means within a motor-pump housing to rotate said motor-pump housing by passing fluid under pressure into said cavity; and

progressive cavity pump means within said rotatable motor-pump housing in communication with said formation fluids to pump said fluid by said rotation of said motor-pump housing relative to a fixed internal helical rotor.

2. A downhole pump apparatus as set forth in claim 1 including:

a. production tubing affixed within said well bore with means adjacent said formation to receive produced fluids therefrom;

b. a fixed inlet power fluid tubing positioned within said production tubing; and

c. a fixed return power fluid tubing positioned between said production tubing and said inlet power fluid tubing, wherein said motor-pump housing is rotatably connected to said inlet and said return fluid tubing.

3. A downhole pump apparatus as set forth in claim 1 wherein said progressive cavity motor means includes said rotatable housing with internal helical threads, a substantially fixed helical rotor and a hollow flexible shaft attached to said rotor for communicating said fluid under pressure into said cavity.

4. A downhole pump apparatus as set forth in claim 1 wherein said progressive cavity pump means includes a pump chamber formed by an internal helical stator on said rotatable housing, said pump chamber in communication with said formation fluids, and wherein said internal helical rotor is substantially affixed, via a flexible shaft, to production tubing to receive said formation fluids.

5. A downhole pump apparatus for producing fluids from a formation with a well bore to the surface, said apparatus comprising:

a motor-pump housing rotatably connected to power fluid tubing capable of supplying and returning power fluid to the surface; and

means to rotate said motor-pump housing by passing fluid under pressure through a flexible shaft, that includes a helical rotor, affixed to said power fluid tubing, said helical rotor being operative within a rotatable stator having helical threads, and means within said threads for returning said fluid under pressure to said surface.

6. A downhole pump apparatus as set forth in claim 5 including production tubing affixed within said well bore and wherein said power fluid tubing supplying said power fluid is positioned within said production tubing and said power fluid tubing returning said power fluid is positioned between said production tubing and said power fluid tubing.

7. A downhole pump apparatus as set forth in claim 5 wherein said motor-pump housing is divided into a progressive cavity motor section and a progressive cavity pump section.

8. A downhole pump apparatus as set forth in claim 7 wherein said progressive cavity motor section includes a chamber formed by a helical stator relative to said helical rotor and wherein said flexible shaft is hollow and communicates said fluid under pressure into said chamber.

9. A downhole pump apparatus as set forth in claim 7 wherein said progressive cavity pump section includes a pump chamber formed by an internal helical stator in said motor-pump housing, said pump chamber in communication with said fluids within said formation, and an internal helical rotor affixed via a flexible shaft to said production tubing so that rotation of said motor pump housing rotates said helical stator.

10. A downhole pump apparatus for producing fluids from a formation within a well bore to the surface, said apparatus comprising:

production tubing affixed within said well bore;

a fixed inlet power fluid tubing concentrically positioned within said production tubing;

a fixed outlet power fluid tubing concentrically positioned between said production tubing and said inlet power fluid tubing; and

a motor-pump housing rotatably connected to said inlet and outlet power fluid tubing, said housing divided into a progressive cavity motor section and a progressive cavity pump section, said motor section including a chamber formed by an internal helical stator, within which is an internal helical rotor affixed to said power fluid tubing, a hollow flexible shaft attached to said rotor for communicating inlet power fluid into said chamber and thereby effect the rotation of said motor-pump housing, said helical stator including a chamber for receiving and returning power fluid to said outlet power fluid tubing,

said progressive cavity pump section including a pump chamber formed by an internal helical stator in said motor-pump housing and an internal helical rotor within which is affixed, via a flexible shaft, to said production tubing so that rotation of said motor-pump housing rotates said internal helical stator of said pump section, and

means to communicate said pump chamber with said formation fluids.

11. A downhole pump apparatus as set forth in claim 10 including a cross-over bypass above said pump chamber for channeling produced fluids into said production tubing.

12. A downhole pump apparatus for producing fluids from a formation within a well bore to the surface, said apparatus comprising:

a rotatable housing, said housing divided into a motor chamber and a pump chamber;

internal helical threads in each said motor and said pump chambers;

a first substantially fixed rotor, substantially matching said internal threads in said motor chamber,

a second substantially fixed rotor substantially matching said internal threads in said pump chamber;

means to communicate said pump chamber with said formation fluids;

means to supply power fluid to said motor chamber and to return said power fluid to said surface, whereby said housing is rotated and said formation fluids are pumped to said surface.

13. A downhole pump apparatus for producing fluids from a formation within a well bore to the surface, said apparatus comprising:

a progressive cavity motor with a fixed internal helical rotor within a housing;

means to rotate said housing by passing fluid under pressure into said cavity; and

a pump having a rotatable member connected to said housing, said pump in communication with said formation fluids to pump said formation fluid by said rotation of said housing.

14. A downhole pump apparatus for producing fluids from a formation within a well bore to the surface, said apparatus comprising:

production tubing affixed within said well bore;

a fixed inlet power fluid tubing concentrically positioned within said production tubing;

a fixed outlet power fluid tubing concentrically positioned between said production tubing and said inlet power fluid tubing; and

a motor housing rotatably connected to said inlet and outlet power fluid tubing, said housing having a progressive cavity motor section, said motor section including a chamber formed by an internal helical stator, within which is an internal helical rotor affixed to said power fluid tubing, a hollow flexible shaft attached to said rotor for communicating inlet power fluid into said chamber and thereby effect the rotation of said motor housing, said helical stator including a chamber for receiving and returning power fluid to said outlet power fluid tubing;

a pump section having a rotatable member, said rotatable member being affixed to said motor housing; and

means to communicate said pump chamber with said formation fluids and with said production tubing.