Oil well pump anti-corrosion device and method

Abstract

The present invention discloses an anti-corrosion device and method for an oil well pump, wherein the anti-corrosion device comprises an oil outlet nipple, a two-way joint, and a cannula. The lower end of the oil outlet nipple is connected to the two-way joint, and the two-way joint is provided with a produced fluid channel and a lubricating anti-corrosion channel. The lower end of the cannula is connected to the lubricating anti-corrosion channel of the two-way joint, and the upper end of the cannula extends into the oil outlet nipple, and the cannula and the oil outlet nipple form an annulus. The lower end of the produced fluid channel is connected to the internal space of the plunger, and the upper end of the produced fluid channel is connected to the inner cavity of the oil outlet nipple. One end of the lubricating anti-corrosion channel is connected to the lower port of the cannula, and the other end is connected to the outer side of the outer wall of the two-way joint. The oil outlet nipple is provided with a radial production hole, and the upper port of the cannula is higher than the production hole, and at the same time, the upper port of the cannula is lower than the upper port of the oil outlet nipple. The present invention utilizes the principle of crude oil self-enrichment to change the lubricating medium between the sealing pairs, so as to realize that the contact medium of the sealing pairs is changed from water to oil, thereby further improving the anti-corrosion performance of the oil well pump.

Description

Technical Field

[0001] The invention relates to an oil well pump anti-corrosion technology, in particular to an oil well pump anti-corrosion device and method. Background Art

[0002] During the normal operation of the oil pump, an oil film will form in the gap between the plunger and the pump barrel, which plays a role in lubrication and corrosion prevention. However, as the oil field development enters the middle and late stages, the water content of the produced fluid increases, the gap between the plunger and the pump barrel cannot be lubricated by crude oil, and the friction coefficient increases, which intensifies the corrosion and wear of the oil pump and reduces the lifting life of the oil pump.

[0003] Regarding the anti-corrosion of oil well pumps, there are currently two main methods: one is to use surface treatment technologies such as chrome plating, nickel-phosphorus plating, spray welding, and coating to achieve anti-corrosion, but the anti-corrosion cycle is related to the surface treatment process level, plating thickness, coating thickness, etc. In field applications, there are still problems of oil well pump failure caused by corrosion and wear of the pump barrel plunger, and the anti-corrosion effect needs to be strengthened; the other is to use special materials (such as non-metallic materials, copper pump barrels, etc.), but they have high requirements for temperature resistance, corrosion resistance, wear resistance, and tensile strength, high cost, and poor field adaptability.

[0004] Application number: 201520782223.8, for a swirl tube type anti-corrosion and anti-scale oil pump, comprising a pump tube upper coupling, a pump body, and a fixed valve, wherein the pump tube upper coupling, the pump body, and the fixed valve are connected in sequence, an internal thread plunger is installed in the pump body through a pump barrel, the fixed valve comprises a fixed valve cover, a fixed valve joint is installed at the right end of the fixed valve cover, a fixed valve seat and a fixed valve ball are installed between the fixed valve cover and the fixed valve head, the fixed valve ball is located at the left end of the fixed valve seat, and a fixed valve swirl head is also installed on the inner side of the left end of the fixed valve cover. Its beneficial effects are: preventing dirt from crystallizing and solidifying in the liquid retention part, extending the service life of the oil pump, and improving the oil extraction efficiency.

[0005] Application No.: 201410095806.3, discloses a corrosion-resistant, sand-resistant and wear-resistant oil pump, comprising a pump barrel, the upper end of the pump barrel is connected to an upper pump barrel coupling by a thread, and the lower end of the pump barrel is connected to a fixed one-way valve by a lower pump barrel coupling, and the pump barrel has a plunger body whose axis is in the same straight line as the axis of the pump barrel, and the upper and lower ends of the plunger body are respectively connected to upstream and downstream movable one-way valves, the fixed one-way valve comprises a fixed valve seat joint, the fixed valve seat joint is connected to a sand control pipe by a thread, the lower end of the sand control pipe is provided with a sealing plug by a thread, the wall of the sand control pipe is evenly distributed with oil inlet holes, the outer sleeve of the sand control pipe is provided with a sand blocking casing, the wall of the sand blocking casing is staggered with strip-shaped sand blocking holes, and the hole width of the strip-shaped sand blocking holes is smaller than the inner diameter of the oil inlet holes on the wall of the sand control pipe. The anti-corrosion, anti-sand and wear-resistant oil pump with the above structure can effectively prevent fine sand and other hard fine particles from entering the pump barrel, thereby reducing the wear on the matching wall surface of the plunger body and the pump barrel.

[0006] Application number: 200710162753.2, a sacrificial anode protection cathode - oil pump anti-corrosion device, which uses the principle of electrochemical sacrificial anode protection cathode, and uses active metals such as zinc, lead, and magnesium to design the oil pump anode. The manufacturing method is: firstly process the oil pump short section according to the technical specifications of the oil pump, and the short section length is 400-500MM, then put the oil pump short section into a special rod cavity, and heat and melt the magnesium or aluminum or zinc metal block into liquid, and then cast it into the special oil pump short section cavity, and then demould after forming, heat preservation, and slow cooling, and then perform mechanical processing, and process the rough blank into a smooth gyroscope, and then process the threads at both ends of the oil pump short section, and install the coupling to form the oil pump anode assembly. The installation method is to connect the oil pump anode in series with the coupling at the lower end of the oil pump during the process of lowering the oil pump, and tighten the coupling buckle.

[0007] After searching, no disclosed technical solution identical to the present invention was found. Summary of the invention

[0008] The purpose of the present invention is to provide an anti-corrosion device and method for an oil well pump, which utilizes the principle of crude oil self-enrichment to change the lubricating medium between the seal pairs, so that the contact medium of the seal pairs is changed from water to oil, further improving the anti-corrosion performance of the oil well pump, effectively solving the corrosion and wear problems between the plunger and the pump barrel of the oil well pump, and extending the pump inspection cycle.

[0009] In order to achieve the above-mentioned purpose, the present invention provides the following technical scheme: an anti-corrosion device for an oil well pump, comprising an oil outlet nipple, a two-way joint, and a cannula. The lower end of the oil outlet nipple is connected to the two-way joint. The two-way joint has a produced liquid channel and a lubrication and anti-corrosion channel. The lower end of the cannula is connected to the lubrication and anti-corrosion channel of the two-way joint. The upper end of the cannula extends into the oil outlet nipple. The cannula and the oil outlet nipple form an annulus.

[0010] The lower end of the produced fluid channel is connected to the internal space of the plunger, and the upper end of the produced fluid channel is connected to the inner cavity of the oil outlet nipple.

[0011] One end of the lubricating and anti-corrosion channel is connected to the lower port of the insert tube, and the other end is connected to the outer side of the outer wall of the two-way joint.

[0012] The oil outlet sub is provided with a radial outlet hole, the upper port of the insert pipe is higher than the outlet hole, and the upper port of the insert pipe is lower than the upper port of the oil outlet sub.

[0013] The upper end of the oil outlet short joint is connected to the sucker rod through a sucker rod joint, and the lower end of the two-way joint is connected to the plunger.

[0014] The two-way joint has the same outer diameter as the oil pump plunger and forms a gap seal with the pump barrel.

[0015] In order to achieve the above-mentioned another purpose, the present invention provides the following technical scheme, a method for anti-corrosion of an oil pump, wherein the produced fluid of an oil well with high water content enters the produced fluid channel of a two-way joint through a plunger, and then enters the oil outlet nipple upward, and gathers in the annulus between the oil outlet nipple and the cannula. Due to the density difference, oil and water are separated in the produced fluid, and the liquid rich in crude oil is concentrated above the annulus. Since the upper port of the cannula is higher than the production hole and lower than the upper port of the oil outlet nipple, the upper port of the cannula is in a position where the liquid rich in crude oil is concentrated. Then the liquid rich in crude oil enters the cannula, enters the gap formed by the two-way joint and the pump barrel through the lubricating anti-corrosion channel, and enters the gap between the plunger and the pump barrel, thereby playing the role of a lubricating sealing pair.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The produced fluid from high-water-content oil wells enters the oil outlet nipple through the oil outlet flow channel and gathers between the oil outlet nipple and the annulus of the insert. Due to the density difference, the produced fluid is separated into oil and water, and the liquid rich in crude oil is concentrated above the annulus. When it reaches a certain amount, the crude oil enters the sealing pair matching gap through the lubrication flow channel, playing a role of lubrication and anti-corrosion.

[0018] The mechanical design method is used to optimize the structure of the oil well pump, realize the self-enrichment of crude oil in the oil well pump, change the lubricating medium between the seal pairs, and realize the automatic oil lubrication between the pump barrel and the plunger of the oil well pump;

[0019] Only a small amount of crude oil is needed to achieve anti-corrosion lubrication, with a long anti-corrosion cycle and low processing costs.

[0020] The present invention is applied to the lifting of high water-content wells, can effectively solve the corrosion and wear problem between the plunger and the pump barrel of the oil well pump, prolong the pump inspection cycle, and reduce the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of an oil well pump anti-corrosion device of the present invention;

[0022] Figure 2 This is the AA cross-sectional view of the two-way connector.

[0023] In the figure: sucker rod joint 1, oil outlet nipple 2, insert pipe 3, two-way joint 4. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 to Figure 2 The present invention provides a technical solution: an anti-corrosion device for an oil well pump, comprising an oil outlet nipple 2, a two-way joint 4, and a cannula 3. The lower end of the oil outlet nipple 2 is connected to the two-way joint 4. The two-way joint is provided with a produced liquid channel II and a lubricating anti-corrosion channel I. The lower end of the cannula 3 is connected to the lubricating anti-corrosion channel of the two-way joint, and the upper end of the cannula extends into the oil outlet nipple 2. The cannula 3 and the oil outlet nipple 2 form an annulus.

[0026] The lower end of the produced fluid channel is connected to the internal space of the plunger, and the upper end of the produced fluid channel is connected to the inner cavity of the oil outlet nipple.

[0027] One end of the lubricating and anti-corrosion channel is connected to the lower port of the insert tube, and the other end is connected to the outer side of the outer wall of the two-way joint.

[0028] The oil outlet sub is provided with a radial outlet hole, and the upper end of the insert pipe 3 is higher than the outlet hole, and the upper end of the insert pipe 3 is lower than the upper end of the oil outlet sub.

[0029] The upper end of the oil outlet nipple is connected to the sucker rod through a sucker rod joint 1, and the lower end of the two-way joint is connected to the plunger.

[0030] The insert pipe 3 is connected to the two-way joint 4; the upper end of the two-way joint 4 is connected to the oil outlet short section 2, and the lower end is connected to the oil pump plunger; the two-way joint 4 has the same outer diameter as the oil pump plunger, and forms a gap seal with the pump barrel; the two-way joint 4 is provided with a produced fluid channel II and a lubricating and anti-corrosion channel I, wherein the produced fluid channel II is connected to the inside of the plunger, and the lubricating and anti-corrosion channel I is connected to the gap between the oil pump plunger and the pump barrel; the lower part of the oil outlet short section 2 is provided with a production hole, and its upper end is connected to the sucker rod through the sucker rod joint 1.

[0031] The inner space of the plunger, the produced fluid channel II, the oil outlet nipple 2, the oil outlet nipple 2 and the annular space of the pump barrel constitute an oil outlet flow channel.

[0032] The inner space of the insert tube 3, the lubricating anti-corrosion channel I, the gap formed by the two-way joint 4 and the pump barrel, and the matching gap of the plunger pump barrel constitute a lubricating flow channel.

[0033] The oil production process of the present invention is consistent with that of an ordinary oil pump, and the lubrication and anti-corrosion working process is that the produced fluid from the high-water-content oil well enters the produced fluid channel of the two-way joint through the plunger, and then enters the oil outlet pup joint upward, and gathers in the annulus between the oil outlet pup joint and the cannula. Due to the density difference, the produced fluid is separated into oil and water, and the liquid rich in crude oil is concentrated above the annulus. Since the upper port of the cannula is higher than the production hole and the upper port of the cannula is lower than the upper port of the oil outlet pup joint, the upper port of the cannula is in a position where the liquid rich in crude oil is concentrated. Then the liquid rich in crude oil enters the cannula, enters the gap formed by the two-way joint and the pump barrel through the lubrication and anti-corrosion channel, and enters the gap between the plunger and the pump barrel, playing the role of a lubricating sealing pair.

[0034] In the description of the present invention, it is necessary to understand that the orientation indications or positional relationships are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pump anti-corrosion device, characterized in that: It includes an oil outlet nipple, a two-way joint, and a cannula. The lower end of the oil outlet nipple is connected to the two-way joint. The two-way joint is provided with a produced fluid channel and a lubricating and anti-corrosion channel. The lower end of the cannula is connected to the lubricating and anti-corrosion channel of the two-way joint. The upper end of the cannula extends into the oil outlet nipple. The cannula and the oil outlet nipple form an annulus. The lower end of the produced fluid channel is connected to the internal space of the plunger, and the upper end of the produced fluid channel is connected to the inner cavity of the oil outlet nipple; One end of the lubricating and anti-corrosion channel is connected to the lower port of the cannula, and the other end is connected to the outer side of the outer wall of the two-way joint; The oil outlet sub is provided with a radial output hole, the upper port of the plug pipe is higher than the output hole, and the upper port of the plug pipe is lower than the upper port of the oil outlet sub; The upper end of the oil outlet short joint is connected to the sucker rod through a sucker rod joint, and the lower end of the two-way joint is connected to the plunger.

2. The oil well pump anti-corrosion device according to claim 1, characterized in that: The two-way joint has the same outer diameter as the oil pump plunger and forms a gap seal with the pump barrel.

3. A method for anti-corrosion of a wellbore pump, characterized in that: By using the oil pump anti-corrosion device described in claim 1, the produced fluid from the high-water-content oil well enters the produced fluid channel of the two-way joint through the plunger, and then enters the oil outlet nipple upward and gathers in the annulus between the oil outlet nipple and the cannula. Due to the density difference, the produced fluid is separated into oil and water, and the liquid rich in crude oil is concentrated above the annulus. Since the upper port of the cannula is higher than the production hole and lower than the upper port of the oil outlet nipple, the upper port of the cannula is in a position where the liquid rich in crude oil is concentrated. Then the liquid rich in crude oil enters the cannula, enters the gap formed by the two-way joint and the pump barrel through the lubricating anti-corrosion channel, and enters the gap between the plunger and the pump barrel, playing the role of a lubricating sealing pair.

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