RU2851368C1 - Downhole sucker rod pumping unit - Google Patents

Abstract

FIELD: oil production industry.

SUBSTANCE: invention relates to the oil industry and can be used in oil production from wells with a high fluid flow rate of more than 20 m³/day in conditions complicated by a high gas factor and the presence of mechanical impurities. The downhole sucker rod pumping unit comprises a column of pump-compressor pipes, a column of sucker rods, and a sucker rod pump driven by a drive through the column of sucker rods. Below the sucker rod pump, an upper pipe, a bypass valve, and an inner pipe with external threads on the side surface are installed in sequence. An upper coupling with a central internal threaded hole and radial holes is screwed onto the inner pipe. The upper coupling connects the upper outer pipe of variable diameter with a narrowing at the top and the middle outer pipe, connected via the lower coupling to an assembly consisting of a lower outer pipe with a transfer piece, a container made of pump-compressor pipes and a plug, installed in series. The lower coupling is made with a central internal opening, and the area of the radial openings of the upper coupling and the area of the internal cross-section of the inner pipe are equal. The upper part of the upper outer pipe has an area for the inflow of well fluid into it. The bypass valve is designed to allow well fluid to flow through it into the rod pump when the radial holes of the upper coupling are clogged.

EFFECT: increased reliability for wells with high fluid flow rates in conditions complicated by a high gas factor and the presence of mechanical impurities due to the effective separation of gas and mechanical impurities.

1 cl, 3 dwg

Description

The invention relates to the oil production industry and can be used in the extraction of oil from wells with a high liquid flow rate of more than 20 ^m3 /day under conditions complicated by a high gas factor and the presence of mechanical impurities.

A traditional borehole sucker-rod pumping unit is well known (A.G. Molchanov, V.L. Chicherov. "Oilfield Machines and Mechanisms." Textbook for Technical Schools. 2nd edition, revised and enlarged. Moscow, "Nedra", 1983, pp. 34-37), consisting of a drive, a column of sucker rods, a borehole pump, and a column of tubing. When the borehole pump, driven by the drive through the column of sucker rods, operates, the fluid rises through the column of tubing to the wellhead, from where it enters the collection system.

Currently, due to the optimization measures being carried out to reduce bottomhole pressure, there is a problem of ensuring operability with maximum fluid extraction, therefore, a conventional installation without additional protective equipment (from gas and mechanical impurities) cannot provide the necessary extraction with high reliability.

A well-known downhole sucker-rod pumping unit (I.T. Mishchenko, "Borehole Oil Production," Moscow, "Oil and Gas," Gubkin Russian State University of Oil and Gas, 2003, p. 588) consists of a drive, a string of sucker rods, a downhole pump, a string of tubing, and a gas-sand anchor with a tubing container. When the downhole pump, driven by the drive through the string of sucker rods, operates, fluid enters the gas-sand anchor, where, due to changes in flow velocity, gravitational sedimentation of mechanical impurities and the emergence of gas bubbles occurs.

The disadvantage of this installation is its insufficient efficiency for wells with a high liquid flow rate (more than 20 ^m3 /day) due to the small area of the annular space in which gas separation occurs, i.e., due to the high flow rate, the gas does not have time to float and is carried away into the pump, which leads to a decrease in the filling and delivery coefficient of the pump, and the efficiency of the installation.

The closest to the proposed device is a device for pumping out carbonated liquid (SU Patent Application No. 866133, IPC E21B 43/00, published on September 23, 1981 in Bulletin No. 35), comprising a submersible sucker-rod pump with a separator shank connected to the pump intake, and a casing with a shank and a gas release valve, wherein the casing is located concentrically to the submersible sucker-rod pump, secured in its upper part, and the gas release valve is located at the casing attachment point. The shank-separator is equipped in the lower part with a mesh with a mesh size of 0.1-0.2 mm.

A disadvantage of the device is the low reliability of protection against mechanical impurities due to the rapid clogging of the mesh on the tailpiece, which leads to the need to replace the pump.

The technical objective of the invention is to increase the operational reliability of wells with a high liquid flow rate under conditions complicated by a high gas factor and the presence of mechanical impurities through the effective separation of gas and mechanical impurities.

The technical problem is solved by a borehole sucker rod pumping unit, containing a column of tubing pipes, a column of sucker rods, and a sucker rod pump driven by a drive through the column of sucker rods.

What is new is that below the sucker rod pump there are installed in series an upper branch pipe, a bypass valve, an inner pipe with an external thread on the side surface, an upper coupling with a central internal threaded hole and radial holes is screwed onto the inner pipe, the upper coupling connects the upper outer branch pipe of variable diameter with a narrowing in the upper part and a middle outer branch pipe connected through the lower coupling with an arrangement consisting of a lower outer branch pipe with a sub, a container made of tubing and a plug installed in series, wherein the lower coupling is made with a central inner hole, and the area of the radial holes of the upper coupling and the area of the inner section of the inner pipe are equal, wherein in the upper part of the upper outer branch pipe there is a zone for the flow of well fluid into it, and the bypass valve is made with the possibility of well fluid flowing through it into the sucker rod pump when the radial holes of the upper coupling are clogged.

Fig. 1-3 shows a diagram of the proposed installation, where the tubing string is 1, the sucker rod string is 2, the sucker rod pump is 3, the upper branch pipe is 4, the inner pipe is 5, the upper coupling is 6, the central internal threaded hole is 7, the radial holes are 8, the upper outer branch pipe is 9, the bypass valve is 10, the middle outer branch pipe is 11, the lower coupling is 12, the central hole is 13, the lower outer branch pipe is 14, the container is 15, and the plug is 16.

The essence of the invention.

The borehole sucker rod pumping unit comprises a column of tubing pipes 1, a column of pump rods 2, a sucker rod pump 3, driven by a drive through the column of pump rods 2.

Below pump 3, the upper branch pipe 4, bypass valve 10, and internal pipe 5 with external threads on the side surface are installed in sequence.

An upper coupling 6 with a central internal threaded hole 7 and radial holes 8 is screwed onto the inner pipe 5.

The upper coupling 6 connects the upper outer branch pipe 9 of variable diameter with a narrowing in the upper part and the middle outer branch pipe 11, connected through the lower coupling 12 with an assembly consisting of a sequentially installed lower outer branch pipe 14 with a sub, a container 15 made of tubing pipes and a plug 16.

In this case, the lower coupling 12 is made with a central internal hole 13.

The area of the radial holes 8 of the upper coupling 6 and the area of the internal section of the inner pipe 5 are equal.

The borehole sucker rod pumping unit operates as follows.

When the sucker rod pump 3 is operating, driven by a drive through the column of pump rods 2, the product is lifted along the column of tubing 1.

The rod installation implements the principle of multi-stage separation using the hydrodynamic effects of liquid jet reversal, changing the flow speed with a change in the direction of flow.

When the fluid flow turns in the areas of the variable-diameter upper outer pipe 9 and the lower portion of the inner pipe 5, the difference in gas and liquid density causes the fluid flow to separate. The lighter gas, under the influence of the buoyancy force, rises into the well's annulus, preventing gas from entering the pump and increasing its efficiency. The constriction of the variable-diameter upper outer pipe 9 ensures high gas separation efficiency for wells with high liquid flow rates (over 20 ^m3 /day) by increasing the annular space between the pipe and the production casing, where gas and liquid are separated when the fluid flow direction changes.

Mechanical impurities accumulate in container 15 from pipes and plug 16 due to gravitational sedimentation when the direction of liquid flow changes in the lower part of inner pipe 5. Reducing the annular space due to the presence of lower coupling 12 with a central hole increases the speed of liquid flow and the efficiency of separation of mechanical impurities.

In case of complete clogging of radial holes 8, well fluid at a pressure difference of 0.3-0.4 MPa begins to flow into the pump through bypass valve 10, which increases the operating time of the unit.

Thus, the proposed borehole sucker rod pumping unit has high operational reliability for wells with a large liquid flow rate under conditions complicated by a high gas factor and the presence of mechanical impurities due to the effective separation of gas and mechanical impurities.

Claims (1)

A downhole sucker-rod pumping unit comprising a tubing string, a sucker rod string, a sucker rod pump driven by a drive through the tubing string, characterized in that an upper branch pipe, a bypass valve, an inner pipe with an external thread on the side surface are installed in series below the sucker rod pump, an upper coupling with a central internal threaded hole and radial holes is screwed onto the inner pipe, the upper coupling connects the upper outer branch pipe of variable diameter with a narrowing in the upper part and a middle outer branch pipe connected through the lower coupling with an assembly consisting of a lower outer branch pipe with a sub, a container made of tubing pipes and a plug installed in series, wherein the lower coupling is made with a central inner hole, and the area of the radial holes of the upper coupling and the area of the inner cross-section of the inner pipe are equal, and in the upper part of the upper outer branch pipe a zone for the flow of well fluid into it is made, and The bypass valve is designed to allow well fluid to flow through it into the sucker rod pump when the radial holes of the upper coupling become clogged.