RU2211372C1 - Sucker-rod well pump - Google Patents

Abstract

FIELD: oil extraction from deep boreholes. SUBSTANCE: pump has barrel with plunger accommodated in casing that forms circular cavity together with barrel. Cavity accommodates diaphragm that covers one of barrel holes. Other hole communicates with circular cavity. Bottom part of pump houses viscoplastic liquid container communicating with circular cavity. EFFECT: reduced wear probability of barrel-and-plunger pair; reduced borehole liquid leakage. 3 cl, 1 dwg

Description

 The invention relates to techniques for oil production, in particular to deep sucker rod pumps, and can be used in the oil industry.

 Known deep sucker-rod pump (AS 539160, IPC F 04 B 47/00, op. 15.12.76) with lubrication of the gap between the plunger and the cylinder produced fluid through inclined channels in the plunger.

 A disadvantage of the known pump is the supply of produced fluid containing mechanical impurities into the gap between the plunger and the cylinder.

 The closest set of essential features is the downhole reagent dispenser (A.S. 1320509, IPC F 04 B 47/02, op. 30.06.87). The known device comprises a borehole pump comprising a cylinder with a plunger and suction and discharge valves. The pump is connected through an intermediate chamber to a container filled with reagent, closed by a lid, in which a channel is made for the passage of reagent from the container into the intermediate chamber. The channel is equipped with an ejector and is connected to a calibrated pipeline, and the suction valve is equipped with a spring-loaded plunger. During pump operation, the reagent from the container enters the intermediate chamber, where it is mixed with the borehole fluid, and then at the pump inlet.

 However, the known device also does not protect against wear a pair of plunger-cylinder when mechanical particles get into the gap between them and does not prevent well fluid leakage, which reduces the durability and reliability of the pump. In addition, in the operation of low-production wells, the operation of such a pump may be ineffective due to the insufficient speed of the jet in the ejector.

 Thus, there was a problem of increasing the reliability and durability of the deep-well pump.

 EFFECT: prevention of wear of a plunger-cylinder pair and leakage of a well fluid by sealing the gap between them with a special process fluid.

 The specified technical result is achieved by the fact that in the known deep sucker rod pump, which includes a cylinder with a plunger and suction and discharge valves, in the lower part of which there is a container with a process fluid, equipped with a check valve and a lid with a channel for the passage of the aforementioned process fluid, a borehole inlet liquids according to the invention, at least two openings are made in the cylinder, one of which is closed by an elastic diaphragm with a stopper covering the lower hour cylinder, and the second is communicated with an annular cavity formed by the cylinder and the casing in which the pump is located, while the channel for the passage of the process fluid is in communication with the aforementioned annular cavity and is equipped with a check valve.

 It is advisable to open the hole for the entry of the borehole fluid into the cylinder cavity in the lid of the container.

 The lid of the container can be made in the form of an sub.

 The presence of holes in the pump cylinder, one of which is closed by an elastic diaphragm with a stop, and the second is communicated with an annular cavity formed by the cylinder and the casing, allows the pump to seal the gap between the plunger and the cylinder with a special process fluid (viscoplastic grease), thereby preventing wear plunger-cylinder pairs and reduce well fluid leakage.

 The attached drawing shows the proposed deep-well sucker rod pump, a longitudinal section.

 The pump consists of a cylinder 1 with a plunger 2 and a suction 3 and discharge 4 valves. A cylinder 1 with a plunger 2 is placed in the casing 5, forming an annular cavity 6 with the cylinder. In the cylinder 1, holes 7 and 8 are made. The lower hole 7 is closed by an elastic diaphragm 9 with a stop 10 located in the annular cavity 6 and covering the lower part of the cylinder 1. The lower hole 7 communicates a sub-plunger cavity with a diaphragm cavity 9. The upper hole 8 communicates an annular cavity 6 with a gap between the cylinder 1 and the plunger 2. A container 11 with process fluid 12 is attached to the pump casing 5 below (in this case, viscoplas grease). The container 11 is equipped with a check valve 13 and a cover 14, made in the form of a sub. In the cover 14, a channel 15 is made for the passage of viscoplastic lubricant into the annular cavity 6. The channel 15 is equipped with a check valve 16. A hole 17 for entering the well fluid is made in the cover 14.

 The pump operates as follows.

 When moving upward, a vacuum is created in the cavity under the plunger 2, which is transmitted to the cavity under the elastic diaphragm 9. Due to the discharge, the diaphragm 9 is reduced, and a vacuum is created in the annular cavity 6. The valve 16 opens, and the visco-plastic grease enters the annular cavity 6 container 11. When the plunger 2 moves down, the discharge valve 4 opens and the pressure in the cavity under the plunger increases sharply, while the diaphragm 9 stretches and displaces the viscoplastic grease from the annular cavity 6 through the upper aperture 8 in the gap between the cylinder 1 and the plunger 2. The stopper 10 of the diaphragm 9 is necessary to prevent the surface of the diaphragm from closing together with the plunger during the plunger downward movement and to create a channel for viscoplastic grease from the container 11 to enter the cavity above the diaphragm.

 Then the cycle repeats.

 By changing the size of the elastic diaphragm 9, it is possible to achieve a certain volume of supply of viscoplastic grease. The required container size is determined by calculation, based on the average overhaul period of the pumps.

 The proposed pump, in comparison with the known one, provides the supply of the process fluid (viscoplastic grease) to the gap between the cylinder and the plunger, which prevents wear of the plunger-cylinder pair and, as a result, reduces the likelihood of jamming of the plunger. In addition, the proposed device can reduce the leakage of well fluid through the gap.

 Thus, the present invention makes it possible to increase the reliability and thereby increase the service life of the deep-well pump.

Claims (3)

 1. A deep-well sucker-rod pump, comprising a cylinder with a plunger and suction and discharge valves, in the lower part of which there is a container with a process fluid, equipped with a check valve and a cover with a channel for the passage of the said process fluid, holes for entering the well fluid, characterized in that at least two openings are made to the cylinder, one of which is closed by an elastic diaphragm with a stopper covering the lower part of the cylinder, and the second is communicated with an annular cavity formed the second cylinder and the casing in which the pump is located, while the channel for the passage of the process fluid is in communication with the said annular cavity and is equipped with a check valve.  2. The deep sucker rod pump according to claim 1, characterized in that the openings for the inlet of the well fluid are made in the lid of the container.  3. The deep sucker rod pump according to claim 1, characterized in that the lid of the container is made in the form of a sub.