RU2836974C1 - Sucker-rod pump - Google Patents

Abstract

FIELD: oil industry; pumps.

SUBSTANCE: invention relates to oil industry, in particular, to sucker-rod pumps for operation in conditions of high gas factor and presence of mechanical impurities in produced product of wells with small sump. Pump is made with possibility of connection to tubing string and includes cylinder 1 with suction valve 2 and hollow cylindrical casing 6 with metal mesh filters 7, 8, plunger 3 with delivery valve 4. Casing 6 is made with an open upper part. Upper and lower filters 7, 8 are made in the form of a truncated cone of metal wire, the larger base of which is metal ring 10, fixed in casing 6 by limiting screws 11, 11/, smaller base is a sealing rubber ring 9, 9/, coupled with cylinder 1. Ring 9/ of filter 8 is installed on annular limiter 12 connected to cylinder 1 by means of a threaded connection. Truncated cone of filter 7 is directed with its top to the wellhead. Truncated cone of filter 8 has its top to the bottomhole. Filter 7 is made in the form of a coarse filter, and filter 8 is a fine one.

EFFECT: invention is aimed at improvement of efficiency and reliability of sucker-rod pump.

1 cl, 1 dwg

Description

The device is intended for use in the oil production industry, in particular in the extraction of oil by sucker rod pumping units from wells with a small sump (less than 5 m), the operation of which is complicated by a high gas factor and the presence of mechanical impurities in the extracted product.

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

A traditional borehole sucker rod pumping unit is 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 pump rods, a borehole pump, and a column of tubing. When the borehole pump, driven by the drive through the column of pump rods, operates, the liquid rises along the column of tubing to the wellhead, from where it enters the collection system.

Currently, in connection with the optimization measures 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 sucker-rod pumping unit for oil production from wells with a high liquid flow rate under high gas factor conditions (RU patent No. 216467, IPC E21B 43/00, 43/38, published on 02/07/2023 in Bulletin No. 4) consists of a rod pump, a column of sucker rods, a column of production tubing, a liner, and a packer. The rod pump is driven through the column of sucker rods and the column of production tubing. The packer is located above the productive formation. A perforated branch pipe, a plugged coupling, a branch pipe of the production tubing column, and a two-channel coupling with a branch are installed in series between the rod pump and the liner. A bypass valve with forced gas pumping is installed above the inserted sucker rod pump. The branch is made with an internal diameter of 40 mm and a length that ensures a distance between the outlet of the branch and the inlet of the inserted sucker rod pump of at least 2 m.

The disadvantage of this unit is the limitation on use in production columns less than 168 mm due to the presence of a side branch in the design, which increases the dimensions of the device. In addition, due to the possibility of clogging the gas bypass valve with pieces of asphaltene-resin-paraffin deposits (ARPD), there is a possibility of subsequent accumulation of gas in the intertube space and a decrease in the dynamic level up to the failure of the pump feed.

A sucker rod pump is known (I.T. Mishchenko "Borehole Oil Production" M., "Oil and Gas" Gubkin Russian State University of Oil and Gas, 2003, p. 588), which includes a cylinder with a main suction valve, a plunger with a discharge valve, and the sucker rod pump is designed with the possibility of connecting to a column of lifting pipes. A tailpiece is attached to the pump intake. A gas-sand anchor with a container made of tubing is located below the pump. When the borehole pump, driven by the pumping unit drive through the column of pump rods, operates, the liquid enters the gas-sand anchor, in which, due to a change in flow rates, gravitational sedimentation of mechanical impurities and the emergence of gas bubbles occurs.

The disadvantages of this pump are:

- limited functionality of the pump, associated with the impossibility of placing the pump as close as possible to the productive formation, in the absence of or a small sump of the well, since the gas-sand anchor with a container made of tubing is placed below the pump, and lifting the pump higher to be able to place the gas-sand anchor with a container leads to a decrease in the immersion of the pump under the dynamic level and pressure at the pump intake, a decrease in the filling and feed coefficients, and a decrease in the oil flow rate;

- the impossibility of using the gravity method of separating gas and mechanical impurities using a gas-sand anchor installed under the pump, in conditions where it is necessary to lower the pump directly opposite the productive formation and there is a small sump or none.

The closest is a sucker rod pump for oil production from wells with a small sump under high gas factor conditions (RU patent No. 215129, IPC E21B 17/00, F04B 47/02, published on 30.11.2022, bulletin No. 34), including a cylinder with a suction valve, a plunger with a discharge valve, wherein the sucker rod pump is designed with the possibility of connecting to a column of elevator pipes. The cylinder is provided with a hollow cylindrical casing, fixedly fixed in the upper part with the cylinder, while above the main suction valve, the hollow cylindrical casing is made with at least two inlet slotted filter holes covered with a metal mesh and a cup-shaped half-casing, facing the open part to the wellhead, moreover, in the upper part of the cylindrical casing there are gas bypass valves, at least two.

The disadvantage of this pump is its limited technological capabilities; it cannot be used in wells with a production column diameter of less than 168 mm due to the presence of a cylindrical semi-casing on the side surface.

The technical task is to protect against mechanical impurities with maximum gas separation during operation in wells with a production column diameter of less than 168 mm.

The technical result of the invention is an increase in the efficiency and reliability of the operation of a sucker rod pump due to the use of multi-stage filtration and separation of the extracted product using the hydrodynamic effects of reversal of liquid jets, changing the flow rate with a change in the direction of flow, ensuring the operability and maintaining the value of the filling and feed coefficients of the sucker rod pump, as well as expanding the technological capabilities of operation in wells with a production column diameter of less than 168 mm.

The technical result is achieved by a sucker rod deep well pump, designed with the possibility of connection to a column of lift pipes, including a cylinder with a suction valve and a hollow cylindrical casing with metal mesh filters, a plunger with a discharge valve.

What is new is that the cylindrical casing is made with an open upper part, the upper and lower metal mesh filters are made in the form of a truncated cone made of metal wire, the larger base of which is a metal ring fixed in the casing with limiting screws, the smaller base is a sealing rubber ring mated with the cylinder, while the sealing rubber ring of the lower filter is installed on an annular limiter attached to the cylinder using a threaded connection, and the truncated cone of the upper filter is directed with its apex toward the wellhead, the truncated cone of the lower filter is directed with its apex toward the well bottom, the upper filter is made in the form of a coarse filter, and the lower one is a fine filter.

The figure shows a diagram of the proposed installation, where the cylinder is 1, the suction valve is 2, the plunger is 3, the discharge valve is 4, the column of lift pipes is 5, the casing is 6, the upper mesh filter is 7, the lower mesh filter is 8, the sealing rubber ring is 9, 9/, the metal ring is 10, 10/, the limiting screws are 11, 11/, the annular limiter is 12.

The essence of the invention

A sucker rod deep well pump, designed with the possibility of being connected to a column of lift pipes, includes a cylinder 1 with a suction valve 2 and a hollow cylindrical casing 6 with metal mesh filters 7, 8, a plunger 3 with a discharge valve 4.

The cylindrical casing 6 is made with an open upper part.

The upper 7 and lower 8 metal mesh filters are made in the form of a truncated cone made of metal wire, the larger base of which is a metal ring 10, 10/, fixed in the casing by limit screws 11, 11/, the smaller base is a sealing rubber ring 9, 9/, mating with cylinder 1.

In this case, the sealing rubber ring 9/ of the lower filter 8 is installed on the annular limiter 12, connected to the cylinder 1 using a threaded connection (not shown in the figure).

Moreover, the truncated cone of the upper filter 7 is directed with its apex toward the wellhead (not shown in the figure), and the truncated cone of the lower filter 8 is directed with its apex toward the well bottom (not shown in the figure). This increases the filter area, which will extend the service life of the device.

The upper filter 7 is designed as a coarse filter, and the lower filter 8 is designed as a fine filter.

The sucker rod pump operates as follows.

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

The sucker rod pump implements the principle of multi-stage separation using hydrodynamic effects of liquid jet reversal, flow velocity change with flow direction change. When liquid flow turns in the area of the upper mesh filter 7 of the casing 6 and at the pump intake, due to the difference in gas and liquid density, the liquid and gas flow is separated, the gas rises into the annular space, can be released through the wellhead valve into the pipeline or with the help of a compressor (not shown in the diagram).

The extracted product with mechanical impurities undergoes step-by-step filtration, large debris is retained in the coarse filter, small mechanical impurities are retained by the fine filter. The execution of filters in the form of truncated cones also increases the filtration area and the duration of the pump operation with optimal filling.

Thus, the proposal increases the efficiency of the sucker rod pump by means of step-by-step filtration of the extracted product from mechanical impurities with maximum gas separation, maintaining optimal filling and feeding of the sucker rod pump, as well as expanding the technological capabilities of operation in wells with a production column diameter of less than 168 mm.

Claims (1)

A sucker rod pump designed with the possibility of being connected to a column of elevator pipes, comprising a cylinder with a suction valve and a hollow cylindrical casing with metal mesh filters, a plunger with a discharge valve, characterized in that the cylindrical casing is designed with an open upper part, the upper and lower metal mesh filters are designed in the form of a truncated cone made of metal wire, the larger base of which is a metal ring fixed in the casing with limiting screws, the smaller base is a sealing rubber ring mated with the cylinder, wherein the sealing rubber ring of the lower filter is mounted on an annular limiter connected to the cylinder using a threaded connection, wherein the truncated cone of the upper filter is directed with its apex toward the wellhead, the truncated cone of the lower filter is directed with its apex toward the well bottom, the upper filter is designed as a coarse filter, and the lower one is a fine filter.