RU2313696C2 - Borehole sucker-rod pump - Google Patents

Abstract

FIELD: fluid production, particularly pumping facilities for highly-viscous liquid production from wells.

SUBSTANCE: sucker-rod pump comprises upper piston, upper cylinder, rod string connected to pressure valve, lower cylinder, pusher and sucking valve. Upper cylinder is fixed. Pressure valve is connected to lower sealed piston through pusher. Lower cylinder may move for distance equal to travel of sucking valve having annular locking means installed at upper end of lower cylinder. Annular seat is arranged at lower end of upper cylinder. Sucking valve travel is limited by stop.

EFFECT: increased operational efficiency.

1 dwg

Description

The invention relates to the field of oil production from reservoirs by sucker rod pumps and can be used in oil and gas industries during well operation.

A device for a sucker rod pump is known that prevents the rod string from hanging in a highly viscous fluid by creating load tension [Oilfield machines and mechanisms, M., Nedra, 1976, p. 60].

However, it is not effective enough, since it leads to an additional load on the rods during the plunger upward movement, to their rapid fatigue breakage and excessive energy consumption.

The closest technical solution that we have chosen as a prototype is a well sucker-rod pump with controlled suction and discharge valves, which prevents them from freezing in high-viscosity oil. The pump contains a plunger with a controlled column of rods discharge valve. The plunger moves in the upper movable cylinder connected to the pusher, made with the possibility of interaction and forced closure of the suction valve [RF Patent No. 2201530].

The disadvantage of the pump is the possibility of a hang of the rod string during the down stroke. Another disadvantage is the small bore in the push rod, which makes it difficult to use a pump for the production of highly viscous fluids, as well as the lack of control of the suction valve during the upward stroke.

The objective of the invention is to increase the efficiency of the sucker rod pump.

To successfully solve the problem in a borehole sucker rod pump containing an upper cylinder, an upper plunger, a rod string connected to a discharge valve, a lower cylinder, a pusher and a suction valve, according to the invention, the upper cylinder is fixed and the upper plunger is connected to the lower muffled plunger this lower cylinder is made with the possibility of movement by the stroke of the suction valve, the annular locking element of which is mounted on the lower cylinder, and the annular seat on the upper cylinder e.

These signs can eliminate the disadvantages inherent in the prototype, due to the application of the difference between the pressure in the tubing and in the well to the lower plunger during the down stroke, a significant flow area of the suction valve and the application of the friction force of the pair of lower plunger - lower cylinder to the latter during the up stroke and down, contributing, respectively, to the opening and closing of the suction valve.

We are not aware of well sucker-rod pumps possessing a combination of the abovementioned features, which means that the proposed pump meets the requirements for inventions.

The drawing schematically shows a borehole sucker rod pump.

The downhole sucker rod pump comprises an upper plunger 1 with a seat 2 of the discharge valve 3, the locking element 4 of which is controlled by a column of rods 5 provided with an upper stop 6. The upper plunger 1 moves in the upper stationary cylinder 7. The locking element 4 of the pressure valve 3 is connected to the lower muffled plunger 8 pusher 9. The lower plunger 8 is moved in the lower cylinder 10, made with the possibility of movement by the stroke of the suction valve 11, an annular locking element 12 which is installed in the upper part of the lower cylinder core 10, and the annular seat 13 in the lower part of the upper cylinder 7. The stroke of the suction valve 11 is limited by the stop 14.

The sucker rod pump operates as follows. When moving upward, the rod string 5 closes the discharge valve 3, moving the upper plunger 1 with the valve seat 2 in the upper stationary cylinder 7 all the way into the locking element 4, as well as the lower muffled plunger 8 - in the lower cylinder 10 by means of the pusher 9. In the cavity under the plunger 1, a vacuum is formed, as a result of which, as well as the friction force of the pair of plunger 8 — cylinder 10, the lower movable cylinder 10 moves up to the stop 14, opening the shut-off element 12 of the suction valve 11.

During the downward movement, the rod string 5 moves the shut-off element 4, opening the discharge valve 3, and by means of the upper stop 6 moves the upper plunger 1 and the lower plunger 8 in the lower cylinder 10 in the lower cylinder 10 by means of the pusher 9. The lower movable cylinder 10 under the action of the friction force created by the moving lower plunger 8, and its own weight moves down to the contact of the locking element 12 with the seat 13 of the suction valve 11, closing the latter. The difference between the pressure in the tubing and the hydrostatic pressure in the well acts on the lower plugged plunger 8, creating an additional load on the rods directed downward and preventing them from hanging, especially in high viscosity fluids. Next, the pump cycle is repeated.

The proposed device of the sucker rod pump allows to increase the filling factor of the pump and to prevent the hanging of valves and rods in highly viscous liquids.

Claims (1)

A downhole sucker rod pump comprising an upper cylinder, an upper plunger, a rod string connected to a discharge valve, a lower cylinder, a lower plunger and a suction valve, characterized in that the upper cylinder is stationary and the upper plunger is connected to the lower muffled plunger, while the lower cylinder made with the possibility of movement by the stroke of the suction valve, the annular locking element of which is mounted on the lower cylinder, and the annular seat on the upper cylinder.