Method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump

A method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump. A first step involves mechanically displacing and disabling, without removing, a ball from a ball seat on the travelling ball valve. A second step involves mechanically displacing and disabling, without removing, a ball from a ball seat on the standing valve assembly. A third step involves inserting coil tubing through the travelling ball valve and the standing ball valve to cleanout the entire workstring and pump.

FIELD OF THE INVENTION

The present invention relates to a method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump.

BACKGROUND OF THE INVENTION

Canadian Patent Application 2,431,604, describes a method of circulating fluids through a reciprocating downhole tubing pump. In accordance with the teachings of that method, the following steps are taken. A first step involves providing first means for mechanically displacing and disabling, without removing, a ball from a ball seat on the travelling ball valve. A second step involves providing second means for mechanically displacing and disabling, without removing, a ball from a ball seat on the standing valve assembly. A third step involves activating the first means to prevent the ball from engaging the ball seat on the travelling ball valve and the second means to prevent the ball from engaging the ball seat on the standing ball valve assembly and circulating fluids through both the travelling ball valve and the standing ball valve assembly.

The circulation of fluids through the downhole tubing pump is usually sufficient to remove any sand build up which is causing a blockage and restore circulation. Unfortunately, there are blockages that are so severe that circulation cannot be restored using this method.

SUMMARY OF THE INVENTION

What is required is a method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump, without having to pull the tubing string and the downhole tubing pump from the well.

According to the present invention there is provided a method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump which has a standing ball valve and a travelling ball valve positioned downhole. A first step involves mechanically displacing and disabling, without removing, a ball from a ball seat on the travelling ball valve. A second step involves mechanically displacing and disabling, without removing, a ball from a ball seat on the standing valve assembly. A third step involves inserting coil tubing through the travelling ball valve and the standing ball valve to cleanout the entire workstring and pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred method of cleaning out blockages which prevent operation of a reciprocating downhole tubing pump will now be described with reference toFIGS. 1 and 2.

Referring toFIG. 1, a pump with workstring10is provided. A first step involves providing means for mechanically displacing and disabling, without removing, a first ball12from a first ball seat14on a travelling ball valve16. In the illustrated embodiment, an upstanding displacement member18is positioned in a first position on top of a piston assembly20in axial alignment with first ball seat14such that first ball12is displaced when piston assembly20is in a second position as illustrated inFIG. 2.

Referring toFIG. 1, a second step involves providing means for mechanically displacing and disabling, without removing, a second ball22from a second ball seat24on a standing ball valve assembly26. In the illustrated embodiment, a linkage28is positioned in a first position in valve assembly26. Second ball22is contained within a ball cage30which is pivotally linked to linkage28such that when pump barrel32is lowered onto standing ball valve assembly26, ball cage30is moved to a circulating position when piston assembly20is in a second position as illustrated inFIG. 2.

Referring toFIG. 2, a third step involves inserting coil tubing34through travelling ball valve16and standing ball valve assembly26such that pump with workstring10is cleaned out.

The remaining aspects of pump with workstring10which are not part of the inventive concept will now be described. Referring toFIG. 1, pump with workstring10has a drive collar36and a kelly38.

A person skilled in the art will note that the pumping unit has been illustrated in an inverted condition. This inverted condition has proven to be slightly more convenient for the teachings of this method. The pumping unit need not be inverted for the invention to work.