Jet pump

Abstract

A jet pump including a housing having a central longitudinal bore and at least one longitudinal return bore, the central bore is in fluid communication with the return bore. A nozzle is disposed in the central bore in fluid communication with a mixing section. A chamber is formed within the central bore proximate the nozzle and the mixing section. A production inlet port is formed radially through the housing between the chamber and the exterior of the housing. The top of the housing is adapted for connecting a conduit for providing the motive or power fluid to the central bore and the carried nozzle and for returning the mixed motive and production fluid from the return bore to the surface. The jet pump may further include a check valve mechanism positioned in the production inlet ports. The check valve mechanism allowing fluid flow through the port from the exterior of the housing into the central bore and substantially blocking flow through the port directed from the central bore to the exterior of the housing.

Description

FIELD OF THE INVENTION

The present invention relates to jet pumps.

BACKGROUND

Jet pumps in general include a power fluid conduit and a produced fluid return line connected from the surface to the pump. Pressurized power fluid is forced by a pump at the surface down through the jet pump drawing a production fluid into the pump and intermixing with the power fluid. The intermixed power and production fluid are then returned to the surface through the return line. In a common installation, the jet pump is run into a wellbore on a tubing for de-watering hydrocarbon bearing wells and/or producing hydrocarbons.

Typically these prior art jet pumps draw the production fluid through a standing valve positioned at the base of the pump. These bottom draw jet pumps often fail due to sludge or particulate in the fluid. Additionally, many of these prior art jet pumps include torturous production and mixed fluid paths and multiple valve assemblies increasing points of failures and increasing the cost of constructing and repairing the pumps. Further, many of these prior art pumps are difficult to start up as the flow of motive fluid is stabilized drawing production fluid into the pump.

Therefore, it is a desire to provide an improved jet pump that addresses shortcomings of prior art jet pumps. It is a still further desire to provide a jet pump having radial production inlet ports.

SUMMARY OF THE INVENTION

Accordingly, a jet pump is provided. The jet pump including a housing having a central longitudinal bore and at least one longitudinal return bore, the central bore is in fluid communication with the return bore. A nozzle is disposed in the central bore in fluid communication with a mixing section. A chamber is formed within the central bore proximate the nozzle and the mixing section. A production inlet port is formed radially through the housing between the chamber and the exterior of the housing. The top of the housing is adapted for connecting a conduit for providing the motive or power fluid to the central bore and the carried nozzle and for returning the mixed motive and production fluid from the return bore to the surface. The central bore and the return bores are in fluid connection proximate the bottom of the housing. The fluid connection may be provided by a bull plug further closing the bottom end of the housing from fluid communication with the exterior of the housing.

It may further be desired for the jet pump to include a check valve mechanism positioned in the production inlet ports. The check valve mechanism allowing fluid flow through the port from the exterior of the housing into the central bore and substantially blocking flow through the port directed from the central bore to the exterior of the housing.

The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of an embodiment of a jet pump assembly of the present invention,

FIG. 2 is a cross sectional view of the housing along the line 2-2 of FIG. 1; and

FIG. 3 is a cross-sectional side view of an embodiment of a housing of the present invention.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.

As used herein, the terms “up” and “down”; “upper” and “lower”, and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements of the embodiments of the invention. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth of the well being the lowest point.

FIG. 1 is a cross-sectional view of a jet pump assembly of the present invention generally denoted by the numeral 10. Jet pump assembly 10 includes a housing 12 having a central bore 14 and a plurality of mixed fluid return bores 16 formed substantially parallel to the longitudinal axis of housing 12. Housing 10 may be constructed of any material suitable for the fluids produced and well conditions. For example, the housing may be constructed of steel, stainless steel, polypropylene, polyvinyl chloride, acrylic, or polytetrafluorethylene.

Housing 12 further includes at least one production inlet port 18 in fluid communication between central bore 14 and the exterior of housing 12. Production inlet port 18 is formed radially through housing 12 and is not located at the bottom of housing 12.

Housing 10 includes a first end 20 adapted for connecting to a motive fluid conduit 11 and a mixed fluid return line conduit 13, such as a string of tubing. The second end 22 of housing 22 is adapted for carrying a bull plug 24 for creating fluid communication between return bores 16 and central bore 14.

Jet pump 10 further includes a nozzle assembly 26 and a mixing tube assembly 28 disposed within central bore 14 of housing 12. Nozzle assembly 26 includes a power fluid channel 30 connected to a nozzle 32. Nozzle assembly 26 may be pumped to the surface for repair or replacement by reversing fluid flow through pump 10.

Mixing tube assembly 28 includes a mixing section 34 and a mixed fluid conduit 36. Mixing tube assembly 28 is disposed in central bore 14 with mixing section 34 position below and in fluid communication with nozzle 32.

A vacuum chamber 38 is formed within central bore 14 proximate nozzle 32 and mixing section 34. Production inlet ports 18 are formed radially through housing 12 proximate chamber 38. Fluid communication between chamber 38 and the exterior of housing 12 is provided through ports 18. As power or motive fluid 40 is discharged from nozzle 32 into mixing section 34, a low pressure or vacuum is created in chamber 38. Formation or production fluid 42 is drawn through production inlet ports 18 into mixing section 34 and mixes with motive fluid 40 to form a mixed fluid stream 44.

As shown in FIG. 1, production inlet ports 18 are shown as being substantially parallel to central bore 14. However, it should be recognized that ports 18 may be at any desired angle in relation to central bore 14. Production ports 18 are substantially cylindrical bores and in the present embodiment include a check valve mechanism 46 connected therein. Radial check valve mechanisms 46 may be fixedly or removably connected within port 18 as described further in relation to FIGS. 2 and 3.

FIG. 2 is a cross-sectional view of housing 12 of the present invention along line 2-2 of FIG. 1. The Figure illustrates a plurality of mixed fluid return bores 16 formed longitudinally through housing 12. The size and number of return bores 16 are determined as a design choice.

Check valve mechanism 46 may take numerous forms. For example, radial check valve mechanism 46 includes at least a check valve member 58 operable within port 18 to substantially prevent fluid flow from bore 14 through port 18 to the exterior of housing 12. As shown, in the illustrated embodiments check valve mechanism 18 is a ball, however, it may comprise other elements such as, but not limited to, flappers. In a preferred embodiment, ball 58 is moveable within port 18 between interior port end 18a, proximate bore 14, and exterior port end 18b, open to the exterior of housing 12. Desirably, interior port end 18a is either adapted, or includes a blocking member, to prevent ball 58 from passing through without sealing fluid flow. Exterior port end 18b is adapted to prevent ball 58 from passing there through and is adapted for being sealed to prevent fluid flow toward the exterior of housing 12.

In the illustrated embodiments, the check valve mechanism is a check valve insert 46 shown removably disposed within production inlet port 18. Check valve inserts 46 include a substantially circular tube 48 having a first open end 50 and a second open seating end 52. Tube 48 includes external threads 54 for threadably engaging threads 56 formed by production inlet port 18. In this manner, check valve insert 46 can be removed or replaced when desired. In an embodiment not illustrated, check valve mechanism 46 may comprise a single open seating cap, similar to seating end 52 entrapping ball 58 within port 18. In a still further embodiment, a check valve insert 46 or similar check valve assembly may be fixedly connected within port 18 by welding or adhesive or other attaching mechanisms known in the art.

A check ball 58 is movably disposed within tube 48 between first open end 50 and second seating end 52. First open end 50 may have a smaller inside diameter than the outside diameter of ball 58 to prevent ball 58 from passing there through. In the embodiment illustrated, a blocking mechanism 60, illustrated as a pin, is connected to tubing 48 proximate first open end 50 to prevent ball 58 from passing through first open end 50 and from sealing first open end 50. Second sealing end 52 includes a seating surface 62 adapted for mating with ball 58 to substantially block fluid flowing from central bore 14 through port 18 to the exterior of housing 12. As is shown, and will be understood in the description of the operation of the system, first open end 50 is oriented toward central bore 14 and second seating end 52 is oriented toward the exterior of housing 12.

FIG. 3 is cross-sectional side view of an embodiment of housing 12 of the present invention. This Figure illustrates a production inlet port 18 without a check valve 46 installed. Port 18 further illustrates the internal threads 56 adapted to mate with threads 54 of tube 48. As should be understood in operation of the current invention, it may be desired from time to time to operate jet pump 10 without check valve inserts 46.

With reference to FIGS. 1 through 3, an embodiment of a method of producing a fluid and operating jet pump 10 of the present invention is provided. Jet pump 10 is disposed within a fluid to be produced. Commonly, jet pump 10 will be disposed in a wellbore for producing water and/or hydrocarbons. Jet pump 10 comprises a housing having a central longitudinal bore 14 and at least one longitudinal return bore 16. A production inlet port 18 is formed radially through housing 12 in fluid communication between central bore 14 and the exterior of housing 12. Disposed within central bore 14 is a nozzle 32 and a mixing section 34 positioned proximate each other and production inlet port 18 to define a vacuum chamber 38. A bull plug or fluid diverter 24 is connected to the second or bottom end 22 of housing 12 to fluidly connect mixing section 34 through central bore 14 to return bores 16. A motive fluid conduit 11 is connected to the first or top end 20 of housing 12 in fluid communication with central bore 14 and nozzle 32. A produced fluid conduit 13 is connected to first end 20 of housing 12 in fluid communication with return bores 16.

In operation, a motive or power fluid 40 is pumped through motive fluid conduit 11, nozzle assembly 26 and out of nozzle 32 into mixing section 34 of mixing tube assembly 28. When motive fluid 40 is discharged from nozzle 32 into mixing section 34, a low-pressure or vacuum is created in vacuum chamber 38 drawing production fluid 42 through production inlet bore 18 into chamber 38 and mixing section 34.

With check valve mechanism 46 disposed in production inlet port 18, ball 58 is unseated permitting production fluid 42 to enter housing 12. Check valve 46 provides a mechanism to aide in a quicker and more economical means of start-up. When motive fluid 40 is initially pumped into pump 10, ball 58 will seat against seating end 52 allowing the flow of motive fluid 40 to stabilize and a low-pressure to be created in chamber 38.

Production fluid 42 mixes with motive fluid 40 in mixing section 34 and mixed fluid conduit 36. The mixed fluid stream 44 is rerouted at bull plug 24 into return bores 16 and into produced fluid conduit 13.

As can be seen from the disclosure of the present invention, an improved jet pump 10 is provided. The present invention eliminates intake of the production or formation fluid from the bottom of the pump eliminating standing valves and the associated limitations and failures. For example, in bottom intake jet pumps solids are often encountered which can plug the production intake, typically a standing valve, causing a failure in sealing fluid from passing out of the pump and preventing the intake of fluid. The addition of a radial check valve mechanism facilitates a quicker, more efficient and economical start-up of the jet pump.

From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a jet pump that is novel has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including, but not limited to, those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow.

Claims

1. A jet pump comprising:

a housing having a central longitudinal bore and at least one longitudinal return bore, the central bore in fluid communication with the return bore;

a nozzle disposed in the central bore in fluid communication with a mixing section;

a chamber formed within the central bore proximate the nozzle and the mixing section; and

a production inlet port formed radially through the housing between the chamber and the exterior of the housing.

2. The jet pump of claim 1, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

3. The jet pump of claim 1, further including:

a check valve mechanism disposed within the radial production inlet port; and

wherein the check valve mechanism substantially blocks fluid flow through the production inlet port from the central bore to the exterior of the housing and permits fluid flow through the production inlet port from exterior of the housing to the central bore.

4. The jet pump of claim 3, wherein the check valve mechanism comprises a ball.

5. The jet pump of claim 3, wherein the check valve mechanism comprises:

a ball movably disposed within the radial production inlet port between an interior bore end and an exterior bore end; and

a seating end connected proximate the exterior bore end having a seating surface adapted for mating with the ball.

6. The jet pump of claim 5, further including a blocking member disposed within the radial production inlet port proximate the interior bore end adapted to prevent the ball from passing through the interior bore end.

7. The jet pump of claim 5, wherein the seating end is removably connected proximate the exterior bore end.

8. The jet pump of claim 3, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

9. The jet pump of claim 4, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

10. The jet pump of claim 5, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

11. The jet pump of claim 6, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

12. The jet pump of claim 7, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

13. The jet pump of claim 1, wherein the housing does not comprise a standing valve.

14. A jet pump comprising:

a housing having a central longitudinal bore and at least one longitudinal return bore, the central bore in fluid communication with the return bore;

a nozzle disposed in the central bore in fluid communication with a mixing section;

a chamber formed within the central bore proximate the nozzle and the mixing section;

a production inlet port formed radially through the housing between the chamber and the exterior of the housing; and

a check valve insert disposed within the radial production inlet port, the check valve insert comprising a ball movably disposed in a tube between a first open end and a second seating end;

wherein the check valve insert substantially blocks fluid flow through the production inlet port from the central bore to the exterior of the housing and permits fluid flow through the production inlet port from exterior of the housing to the central bore.

15. The jet pump of claim 14, wherein a bottom end of the housing is closed to fluid communication to the exterior of the housing.

16. The jet pump of claim 14, wherein the check valve insert is fixedly connected within the radial production inlet bore.

17. The jet pump of claim 15, wherein the check valve insert is fixedly connected within the radial production inlet bore.

18. The jet pump of claim 14, wherein the check valve insert is removably connected within the radial production inlet bore.

19. The jet pump of claim 15, wherein the check valve insert is removably connected within the radial production inlet bore.

20. The jet pump of claim 14, wherein the housing does not comprise a standing valve.