TRAVELING VALVE ASSEMBLY FOR RECIPROCATING ROD PUMPS

A traveling valve assembly for a downhole pump includes a traveling valve housing comprising a shouldered lower section; a valve seat within the traveling valve housing and adjacent to the shouldered lower section; a traveling valve cage insert within the traveling valve housing and adjacent to the valve seat; and a valve ball adjacent to the valve seat and within the traveling valve cage insert.

BACKGROUND

The present disclosure relates to reciprocating rod pumps, and more specifically to a traveling valve assembly therefor.

Oil wells are often equipped with reciprocating pump systems to bring oil to the surface. Reciprocating pump systems, such as sucker rod pump systems, extract fluids from the well and employ a downhole pump connected to a driving source at the surface. A sucker rod string connects the surface driving force to the downhole pump in the well. When operated, the driving source cyclically raises and lowers the downhole pump, and with each stroke, the downhole pump lifts well fluids toward the surface.

While reciprocating pump systems have proven to be economical and reliable, they may still experience certain shortcomings typically associated with the valves which are generally of the ball and seat variety.

SUMMARY

A traveling valve assembly for a downhole pump according to one disclosed non-limiting embodiment of the present disclosure includes a traveling valve housing comprising a shouldered lower section; a valve seat within the traveling valve housing and adjacent to the shouldered lower section; a traveling valve cage insert within the traveling valve housing and adjacent to the valve seat; and a valve ball adjacent to the valve seat and within the traveling valve cage insert.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the traveling valve housing comprises an internally threaded upper section.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the internally threaded upper section threads onto a plunger of a downhole pump.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the shouldered lower section forms an inner diameter that is 70%-75% of an inner diameter of the traveling valve housing.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the shouldered lower section forms an inner diameter that is 71% of an inner diameter of the traveling valve housing.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the traveling valve cage insert comprises a cylindrical open lower section and an arched open upper section opposite thereto.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the arched open upper section comprises three (3) axial arched rails.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the three (3) axial arched rails form an arched dome that operate to stop the ball yet permit fluid to be communicated therethrough.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the traveling valve cage insert is monolithic.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the traveling valve housing is monolithic.

A downhole pump according to one disclosed non-limiting embodiment of the present disclosure includes a pump barrel; a standing valve assembly attached to the pump barrel; and a traveling valve assembly located in the pump barrel above the standing valve assembly, the traveling valve assembly comprises a traveling valve housing within which a valve seat is located adjacent to a shouldered lower section of the traveling valve housing, a traveling valve cage insert is within the traveling valve housing adjacent to a valve seat, and a valve ball is adjacent to the valve seat and within the traveling valve cage insert.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the traveling valve housing comprises an internally threaded upper section.

A further embodiment of any of the foregoing embodiments of the present disclosure includes that the internally threaded upper section threads onto a plunger of the downhole pump.

DETAILED DESCRIPTION

FIG.1schematically illustrates a downhole rod pump system10that is used to produce fluid from a well. The downhole rod pump system10generally includes a surface unit12that is connected by a rod string14to a downhole pump16. The surface unit12cycles the rod string14and thereby the downhole pump16.

The downhole pump16includes a pump barrel18. The pump barrel18of the downhole pump16supports a standing valve assembly26located in a lower portion thereof. The standing valve assembly26typically includes a cage, a ball, and a seat, to allow the fluid to enter the downhole pump16from a wellbore. The pump barrel18of the downhole pump16also houses a traveling valve assembly40above the standing valve assembly26. The traveling valve assembly40allows fluid communication from the pump barrel18of the downhole pump16into a production tube50for communication of the fluid to the surface but prevents fluid return from the production tube50into the pump barrel18.

With reference toFIG.2, the traveling valve assembly40includes a traveling valve housing70that contains a traveling valve cage insert72(FIG.3A-3E), which in turn, contains, a ball74, and a seat76(FIG.4A-4B). The seat76is assembled into the traveling valve housing70, the ball74is inserted within the traveling valve cage insert72, then the traveling valve cage insert72with the ball74therein is assembled into the traveling valve housing70such that the ball74rests on the seat76(FIG.5).

During the upstroke, the traveling valve assembly40is closed (FIG.5), and any fluid above the seal between the ball74, and the seat76is lifted towards the surface. Meanwhile, the standing valve assembly26opens and allows fluid to enter the pump barrel18from the wellbore. During the downstroke, the traveling valve assembly40is opened (FIG.6) by the ball74being displaced from the seat76, and the standing valve assembly26is closed. Previously drawn fluid within the pump barrel18can then enter into the production tubing50for communication to the surface.

With continued reference toFIG.2, the traveling valve housing70is generally cylindrical and includes an internally threaded upper section80and a shouldered lower section82. The internally threaded upper section80threads to the rod string14at a plunger60(FIG.1). The traveling valve assembly40eliminates the need for a traveling valve plug by utilizing the lower shouldered section and the connection between the traveling valve housing70and the plunger60to secure the cage components and generate a seal surface that provides valve function integrity.

The shouldered lower section82supports the seat76which supports the traveling valve cage insert72within which the ball74is movable along axis A. That is, the shouldered lower section82provides a reduced inner diameter that operates as a stop and a support for the seat76to be assembled into the traveling valve housing70and thereby be supported within the traveling valve housing70. In one embodiment, the shouldered lower section82forms an inner diameter that is 70%-75% of an inner diameter of the traveling valve housing70. In another embodiment, the shouldered lower section82forms an inner diameter that is 71% of an inner diameter of the traveling valve housing70.

With reference toFIG.3A-3E, the traveling valve cage insert72is generally cylindrical and includes a cylindrical open lower section90and an arched open upper section92opposite thereto. The arched open upper section92in the disclosed non-limiting embodiment includes three (3) axial arched rails99A,99B,99C along the axis A. The axial arched rails99A,99B,99C provide an effective guide for the ball74to facilitate a more direct hit on the seat76which reduces wear.

The axial arched rails99A,99B,99C together form an arched dome96(best seen inFIGS.3A,3B and3C) that operate to stop the ball74(FIG.6) yet permits fluid to be communicated around the ball74and through the traveling valve cage insert72when the ball74is off the seat76. The arched dome96also provides greater axial clearance to increase fluid flow.

The axial arched rails99A,99B,99C that form the arched dome96may each be chamfered98(FIG.3E) to facilitate flow of the fluid thereby. That is, the chamfered98axial arched rails99A,99B,99C that form the arched dome96minimizes turbulence of the fluid flow.

The assembly torque of threading the internally threaded upper section80to the plunger60retains the internal components of the valve cage insert72, ball74and seat76, which were previously inserted into the traveling valve housing70from the internally threaded upper section80to achieve a metal-to-metal seal for proper operation of the traveling valve assembly40. That is, a top surface100(FIG.3D) of the traveling valve cage insert72may be machined to facilitate a seal with the plunger60. The monolithic traveling valve cage insert72also eliminates the heretofore required bottom traveling valve plug.

With reference toFIG.7, in another embodiment of traveling valve assembly40A, the traveling valve housing70A includes an externally threaded lower section200. The externally threaded lower section200facilitates the threaded attachment of a primary traveling valve assembly40to the traveling valve assembly40A as a secondary which also threads to the plunger60. The primary and secondary traveling valve assembly thereby increases the throughput as well as maintains a seal surface that provides valve function integrity. Although a primary and a secondary are disclosed in the illustrated embodiment, it should be appreciated that any number of traveling valve assemblies may be so configured.

The traveling valve assembly40provides for increased valve life, reduced connections, more efficient fluid flow, and durability.