Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
NOVEL VALVE HAVING SPHERICAL SEALING SURFACE
Document Type and Number:
WIPO Patent Application WO/2019/169365
Kind Code:
A1
Abstract:
A valve assembly for a hydraulic frac pump includes a valve body having a spherical sealing surface, a valve seat having a circular concave sealing surface that receives and accommodates the spherical sealing surface of the valve body. The valve seat forms a fluid passageway, where the fluid passageway is completely closed when the valve body is received and accommodated in the valve seat in a closed position. The valve assembly further includes a stopper disposed above the valve body to restrict movement of the valve body when it is lifted off of the valve seat in an open position.

Inventors:
SPENCER, Gideon Nathanael (101 N. Roaring Springs Rd, #8205Westworth Village, Texas, 76114, US)
POEHLS, Justin Lane (1043 County Road 321, Glen Rose, Texas, 76043, US)
CORTES, Adalberto (8824 Prairie Dawn Drive, Fort Worth, Texas, 76131, US)
MYERS, Jeff (900 Matisse Drive, Apt. 5009Fort Worth, Texas, 76107, US)
PEER, Richard David (11625 Turkey Creek Drive, Fort Worth, Texas, 76244, US)
Application Number:
US2019/020445
Publication Date:
September 06, 2019
Filing Date:
March 01, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
S.P.M. FLOW CONTROL, INC. (601 Weir Way, Fort Worth, Texas, 76102, US)
International Classes:
F16K5/06; E21B34/00; E21B34/06; E21B34/14; E21B43/26; F04B53/10; F16K1/42
Foreign References:
US5226445A1993-07-13
US20090044949A12009-02-19
US20030024502A12003-02-06
US20150144826A12015-05-28
Attorney, Agent or Firm:
JEANG, Wei Wei (Grable Martin Fulton PLLC, 2709 Dublin RoadPlano, Texas, 75094, US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A valve assembly for a hydraulic frac pump, comprising:

a valve body having a spherical sealing surface;

a valve seat having a circular concave sealing surface that receives and accommodates the spherical sealing surface of the valve body, the valve seat forming a fluid passageway, where the fluid passageway is completely closed when the valve body is received and accommodated in the valve seat in a closed position; and

a stopper disposed above the valve body to restrict movement of the valve body when it is lifted off of the valve seat in an open position.

2. The valve assembly of claim 1 , wherein the valve body is ball-shaped.

3. The valve assembly of claim 1, wherein the valve body is pear-shaped.

4. The valve assembly of claim 1 , wherein the valve body is tear drop-shaped.

5. The valve assembly of claim 1, wherein the valve body comprises:

a lower portion having a spherical sealing surface;

a narrow upper portion coupled to the lower portion; and

a valve stem coupled to the narrow upper portion in alignment with a longitudinal central axis of the valve body.

6. The valve assembly of claim 1, further comprising a biasing member disposed above the valve body and below the stopper.

7. The valve assembly of claim 1, wherein the valve body is constructed of at least one material selected from the group consisting of plastic, rubber, steel, and ceramic.

8. The valve assembly of claim 1, wherein the valve seat is constructed of at least one material selected from the group consisting of steel, metal, polyurethane, plastic, ceramic, and rubber.

9. The valve assembly of claim 1, wherein the valve seat has a shape selected from the group consisting of spherical concave and frusto-conical.

10. A valve assembly for a hydraulic frac pump, comprising:

a valve body having a spherical sealing surface; and

a valve seat having a spherical concave sealing surface that receives and accommodates the spherical sealing surface of the valve body, the valve seat forming a fluid passageway, where the fluid passageway is completely closed when the valve body is received and accommodated in the valve seat in a closed position; and

a biasing member disposed above the valve body to apply a downward force on the valve body and restrict movement of the valve body when it is lifted off of the valve seat in an open position.

11. The valve assembly of claim 10, wherein the valve body has a shape selected from the group consisting of spherical, pear-shaped, and tear drop-shaped.

12. The valve assembly of claim 10, wherein the valve body comprises:

a lower portion having a spherical sealing surface;

a narrow upper portion coupled to the lower portion; and

a valve stem coupled to the narrow upper portion in alignment with a longitudinal central axis of the valve body.

13. The valve assembly of claim 10, further comprising a stopper disposed above the valve body to restrict movement of the valve body when it is lifted off of the valve seat in an open position.

14. The valve assembly of claim 10, wherein the valve body is constructed of at least one material selected from the group consisting of plastic, rubber, steel, and ceramic.

15. The valve assembly of claim 10, wherein the valve seat is constructed of at least one material selected from the group consisting of steel, metal, polyurethane, plastic, ceramic, and rubber.

16. A valve assembly for a hydraulic frac pump, comprising:

a valve body having a spherical sealing surface; and

a valve seat having a concave sealing surface that receives and accommodates the spherical sealing surface of the valve body, the valve seat forming a fluid passageway, where the fluid passageway is completely closed when the valve body is received and accommodated in the valve seat in a closed position.

17. The valve assembly of claim 16, wherein the valve body has a shape selected from the group consisting of spherical, pear-shaped, and tear drop-shaped.

18. The valve assembly of claim 16, wherein the valve body comprises:

a lower portion having a spherical sealing surface;

a narrow upper portion coupled to the lower portion; and

a valve stem coupled to the narrow upper portion in alignment with a longitudinal central axis of the valve body.

19. The valve assembly of claim 16, further comprising a biasing member disposed above the valve body and below the stopper.

20. The valve assembly of claim 16, further comprising a stopper disposed above the valve body to restrict movement of the valve body when it is lifted off of the valve seat in an open position.

Description:
NOVEL VALVE HAVING SPHERICAL SEALING SURFACE

FIELD

The present disclosure relates to hydraulic fracturing pumps, and in particular, to a novel valve having a spherical sealing surface.

BACKGROUND

Hydraulic fracturing (a.k.a. fracking) is a process to obtain hydrocarbons such as natural gas and petroleum by injecting a fracking fluid or slurry at high pressure into a wellbore to create cracks in deep rock formations. The hydraulic fracturing process employs a variety of different types of equipment at the site of the well, including one or more positive displacement pumps, slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), wellhead, valves, charge pumps, and trailers upon which some equipment are carried.

Positive displacement pumps are commonly used in oil fields for high pressure hydrocarbon recovery applications, such as injecting the fracking fluid down the wellbore. A positive displacement pump may include one or more plungers driven by a crankshaft to create a high or low pressure in a fluid chamber. A positive displacement pump typically has two sections, a power end and a fluid end. The power end includes a crankshaft powered by an engine that drives the plungers. The fluid end of the pump includes cylinders into which the plungers operate to draw fluid into the fluid chamber and then forcibly push out at a high pressure to a discharge manifold, which is in fluid communication with a well head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a positive displacement pump according to the teachings of the present disclosure;

FIG. 2 is a cross-sectional view of a fluid end of a positive displacement pump including an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure;

FIG. 3 is a more detailed partial cross-sectional view of an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure;

FIG. 4 is a more detailed view of an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure; FIG. 5 is a more detailed partial cross-sectional view of a second exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure; and

FIG. 6 is a more detailed view of a second exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure.

DETAILED DESCRIPTION

The positive displacement pump commonly deployed at a frac site includes seals on its pony rods in the power end, or flow valves, suction valves, discharge valves, etc. in the fluid end. Such seals operate in harsh conditions, including high pressure (up to 15000 psi), continuous-duty (e.g., full rod load at 120 RPM), and in corrosive (e.g., up to 18% HC1) and high abrasive liquids. The valves must remain in service for a long life without leakage and other failure and be cost-effective to replace. Suction covers are used to provide closure and seal valve access ports. They are typically sealed with pressure energized seals, O-rings, or D-ring seals.

FIG. 1 is a perspective view of an exemplary embodiment of a positive displacement pump 10, and FIG. 2 is a partial cross-sectional view of a fluid end 14 of a positive displacement pump including an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure. Referring to both figures, the positive displacement pump 10 has two sections, a power end 12 and a fluid end 14 connected by a stay rod tube section 13. The power end 12 includes a crankshaft powered by an engine, transmission, electric motor, hydraulic motor, etc. that rotationally drive a crankshaft. A connecting rod, attached to a pin located eccentrically from the crankshaft centerline, converts rotational motion into linear motion and terminates at a wrist pin and a series of plungers 16. The plunger piston slides coaxially inside a fluid chamber, alternately increasing and decreasing chamber volume. The plungers 16 operate to draw fluid from a suction manifold 17 into the fluid chamber through an intake or suction valve 18, and then discharge the fluid at a high pressure through a discharge valve 20 to a discharge manifold 22. The discharged liquid is then injected at high pressure into an encased wellbore. The injected fracturing fluid is also commonly called a slurry, which is a mixture of water, proppants (silica sand or ceramic), and chemical additives. The novel suction cover and seal concept described herein can be employed for a suction valve, a discharge valve, and any valve and seal present in the frac pump, as well as other types of equipment that may be present at an exemplary hydraulic fracturing site and elsewhere in other applications. An exemplary hydraulic fracturing site employs positive displacement pumps, a slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), trailers upon which some equipment are carried, valves, wellhead, charge pump (typically a centrifugal pump), conveyers, and other equipment at the site of a hydraulic fracturing operation or other types of hydrocarbon recovery operations.

FIG. 3 is a more detailed partial cross-sectional view of an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure. Specifically, the fluid end 14 includes an inlet suction chamber 32 and an outlet discharge chamber 36 through which frac fluid is drawn in and dispelled, respectively. Ball-type valve assemblies are positioned at each of the chambers 32 and 36. Each ball-type valve assembly includes a ball that freely rests inside a ball seat. Ball 18 sits in a valve seat 30 that has a circular or spherical concave in the suction chamber 32, and ball 20 sits in a valve seat 34 that has a circular or spherical concave in the discharge chamber 36. In operation, frac fluid drawn into the suction chamber 32 pushes the ball 18 out of contact with the ball seat 30 to allow the frac fluid to fill up the suction chamber 32, thereby opening the ball-type valve in the suction chamber 32. The frac fluid is may then be pumped-or otherwise drawn-into the discharge chamber 36 by applying enough pressure to push the ball 20 out of contact with the ball seat 34, thereby opening the ball-type valve in the discharge chamber 36. When the pressure of the frac fluid against either ball 18 or 20 falls below the pressure needed to lift the ball, the ball falls back into contact with its corresponding ball seat 30, 34 and closes the path for the frac fluid. In this manner, balls and ball seats function as ball-type valves to open and close the suction and discharge chambers 32, 36 (respectively) and control passage of frac fluid therethrough in the fluid end 28. The ball may be partially or wholly made of steel, metal, polyurethane, plastic, ceramic, rubber, or a combination thereof.

FIG. 4 is a more detailed view of an exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure. The ball-type valve assembly includes a ball 42 that may be moved into and out of contact with a ball-type valve seat 44 by frac fluid. For example, when pressure exerted by the frac fluid exceeds provides enough force to push the ball 42 out of the ball-type valve seat 44, the ball 42 is thereby moved allowing the frac fluid to flow into the (suction or discharge) chamber 48. A ball stop 46 is positioned above the ball 42 to prevent the ball from moving out of the chamber 48. The ball stop 46 together with the fluid chamber 48 forms a ball cage for the ball 42. Once the frac fluid pressure on the ball 42 diminishes below the amount of force needed to lift or hold the ball 42 out of the ball-type valve seat 44, the ball falls back into contact with the ball-type valve seat 44, thereby shutting passage for the frac fluid into the chamber 48. The ball-type valve seat 44 may manufactured from steel, metal, polyurethane, plastic, ceramic, rubber, or a combination thereof.

FIG. 5 is a more detailed partial cross-sectional view of a second exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure. The valve body of this embodiment is preferably shaped like a pear or teardrop, with a wider radius of curvature at the bottom and a narrower top. A valve stem extending along the center longitudinal axis of the valve body may be included on the top of the pear/tear-shaped valve body, to guide movement of the valve body in a straight line. As shown in FIG. 5, the fluid end 68 includes an inlet suction chamber 78 and an outlet discharge chamber 88 through which frac fluid is drawn in and dispelled, respectively. The pear/tear-shaped valve assemblies are positioned at each of the chambers. Each valve assembly includes a pear/tear-shaped valve that freely rests inside a concave seat. Referring to each one separately shown in FIG. 5, a pear-shaped valve 70 includes a smaller upper spherical portion 74 coupled to a larger lower spherical portion 72 that directly surfaces with a spherical concave seat 76 in the suction chamber 78. Further for the discharge valve, a pear-shaped valve 80 includes a smaller upper spherical portion 84 coupled to a larger lower spherical portion 82 that directly surfaces with a spherical concave seat 86 in the discharge chamber 88. In operation, frac fluid drawn into the suction chamber 78 pushes the pear-shaped valve 70 out of contact with the concave seat 76 to allow the frac fluid to fill up the suction chamber 78, thereby opening the ball-type valve assembly at the suction chamber 78. The frac fluid is may then be pumped-or otherwise drawn-into the discharge chamber 88 by applying enough pressure to push the valve 80 out of contact with the spherical concave seat 86, thereby opening the valve in the discharge chamber 88. When the pressure of the frac fluid against a pear-shaped valve falls below the pressure needed to lift the valve, it falls back into contact with its corresponding spherical concave seat, and closes the fluid path for the frac fluid. In this manner, the pear-shaped valves open and close the suction and discharge chambers and control the passage of frac fluid therethrough in the fluid end. The pear-shaped valve may be partially or wholly made of steel, metal, polyurethane, plastic, ceramic, rubber, or a combination thereof.

FIG. 6 is a more detailed view of a second exemplary embodiment of a novel valve having a spherical sealing surface according to the teachings of the present disclosure. The pear/tear-shaped valve assembly includes a valve with an upper portion 104 coupled to a lower portion 102 that may be moved into and out of contact with a valve seat 106 by the frac fluid in the (suction or discharge) fluid chamber 108. For example, when pressure exerted by the frac fluid exceeds provides enough force to push the lower portion 102 of the valve out of the spherical concave seat 106, the frac fluid is permitted to flow into the (suction or discharge) chamber 108. A stop 101 is positioned above the valve to prevent it from moving out of the chamber 108. The stop 101 together with the fluid chamber 108 forms a cage for the pear/tear-shaped valve. Once the frac fluid pressure on the valve diminishes below the amount of force needed to lift or hold the lower portion 102 of the valve out of the seat 106, it falls back into contact with the valve seat 106, thereby shutting passage for the frac fluid into the chamber 108. The valve seat 106 may manufactured from steel, metal, polyurethane, plastic, ceramic, rubber, or a combination thereof.

The valve bodies described in the present disclosure includes a spherical sealing surface or surface that intimately meets with the spherical concave surface of the valve seat. A biasing member such as a coiled spring can optionally be coaxially aligned with the valve stem and/or upper portion of the valve body. The sealing surface of the valve is a portion of the spherical surface of the ball or the bottom, larger end of the pear/tear-shaped valve body. When the valve is closed, the spherical sealing surface of the ball-valve or the larger spherical bottom end of the pear/tear-shaped valve is forced against the valve seat the fluid path is completely shut off. The valve seat may have the same spherical concave surface with a radius of curvature as the valve body sealing surface, possibly defining a circular, oval, or elliptical arc. When the valve is open, the valve is lifted out of the seat, and permitting the frac fluid to pass into the fluid chamber. As the fluid flow passes around the valve body into the chamber, there will be more space to accommodate the fluid as the fluid passes around the pear/tear-shaped valve body, because the circumference of the upper portion of the valve body narrows. This geometry can reduce the friction between the fluid and the valve body and thus reduce wear.

It should be noted that the valve body may have a spherical sealing surface but have shapes other than spherical and pear/tear drop. For example, the valve body may be an ellipsoid, which also has a spherical sealing surface (crosss-section).

Replacing existing valves and valve seats with the disclosed valve body with a spherical sealing surface improves the life of the valve assemblies used in the fluid end of hydraulic pumps and is significantly cheaper to manufacture. Moreover, part reduction also reduces the cost of the valve assemblies, as the simple geometries of the valve bodies disclosed herein can replace valves with more complex geometries.

Additionally, the ball-shaped valve assembly can last longer than conventional valves and valve seats because the ball valve rotates when lifted from the valve seat, which in turn rotates the face of the ball that strikes the ball-type valve seat. This leads to less time and cost for maintenance of the fluid end due to the valve assemblies on the suction and discharge chambers, and also provides a valve solution with no restrictions on flow angle. In some embodiments, the ball-type seat includes an internal semi-spherical portion that curves to receive the ball valve body. Alternatively, the ball-type seat may include in a frusto-conical portion to receive the ball valve body. Other shapes may alternatively be used.

A list of non-limiting features of the ball-type valve assemblies discussed herein are: 1. Different strike face angles to accommodate the ball; 2. Ball cage to retain the ball; and 3. A ball-type valve that may be constructed of plastic, rubber, steel, ceramic, or any other material (or combinations thereof) disclosed herein.

The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the novel valve having a spherical sealing surface described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.