Jet flow pump with floating pump core ring and using method

Abstract

The invention relates to the technical field of oil and gas field and coal bed gas field drainage and mining, in particular to a buoyancy lift pump core ring jet flow pump and a using method. According to the technical scheme, a low-density buoyancy lift pump core is installed in an inner cavity of a pump cylinder, an annular gap is formed between the low-density buoyancy lift pump core and the inner wall of the pump cylinder, a formation liquid suction inlet is formed in the lower side of the annular gap, an annular throat pipe is arranged below the formation liquid suction inlet, a diffusion cavity is formed below the annular throat pipe, and a pump core supporting seat is arranged at the bottom of the diffusion cavity; a mixed liquid outlet is formed in the lower side of the diffusion cavity, and the diffusion cavity is communicated with the mixed liquid discharge cavity. The low-density buoyancy lift pump core has the advantages that due to the fact that the overall density of the low-density buoyancy lift pump core is adjusted and reduced, the power hydraulic pressure and the using amount for pulling out the low-density buoyancy lift pump core can be reduced, and operation cost is reduced; in addition, the low-density buoyancy lift pump core is simple in structure, an annular jet flow structure is formed between the low-density buoyancy lift pump core and the pump cylinder, the liquid drainage and production amount is increased, the working condition of the low-density buoyancy lift pump core suitable for pumping media is wider, and the manufacturing cost is lower.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas field and coalbed methane field drainage technology, in particular to a floating pump core ring jet flow pump and a use method thereof. BACKGROUND

[0002] In the oil and gas field and coalbed methane field exploitation, the jet flow drainage pump is a commonly used exploitation technology. When the jet flow pump is working, the power fluid is injected into the downhole through the oil pipe, is accelerated to form a high-speed jet flow through the nozzle, the high-speed jet flow generates a negative pressure zone at the throat pipe, the formation crude oil is sucked into the mixing chamber, the mixed liquid is decelerated and pressurized when passing through the diffuser pipe, is converted into a high-pressure low-speed liquid flow, and is finally lifted to the ground through the oil jacket annulus.

[0003] The existing downhole jet flow drainage pump is mainly composed of a pump barrel and a pump core. The pump core does not need to be replaced by moving the pipe column, which is a significant process advantage of the hydraulic jet flow pump. However, when the pump is checked and the pump core is replaced, the pump core needs to be flushed out by reverse circulation through increasing the displacement of the power fluid on the ground, or the pump core needs to be lifted out by using a wireline fishing method. The former needs a much higher power fluid supply than the normal production of the jet flow pump, which results in that the displacement and power of the power fluid pump on the ground are much higher than those of other drainage equipment, which leads to high power, high energy consumption and high investment of the power fluid pump injection equipment. The latter needs to use a special fishing equipment, which is time-consuming and high in operation cost. Therefore, the jet flow pump drainage has higher energy consumption than other drainage processes. The existing downhole jet flow pump with built-in nozzle and throat pipe type pump core structure and internal flow channel is complex, is easy to be blocked, has high manufacturing precision requirement and high manufacturing cost.

[0004] Chinese patent No. CN201010011438.1 and patent name for "deep well oil production outer flow channel positive and reverse circulation free lifting type jet flow pump oil production method and device" install a pump barrel with an external flow channel in the downhole, install a positive circulation pump core when positive circulation, install a reverse circulation pump core when reverse circulation, and there is no internal flow channel in the positive and reverse circulation pump core. When positive circulation, the power fluid passes through the wellhead to the nozzle in the positive circulation pump core, the formation fluid is sucked into the pump core through the external flow channel on the pump barrel, and the mixed liquid is formed after mixing with the power fluid and reaches the ground. When reverse circulation, the power fluid passes through the wellhead to the nozzle in the reverse circulation pump core, the formation fluid is sucked into the pump core through the external flow channel on the pump barrel, and the mixed liquid is formed after mixing with the power fluid and reaches the ground. Positive and reverse circulation production and hydraulic free lifting pump core are realized. However, the existing problems are as follows: the pump core structure is complex, the pump core needs to be flushed out by reverse circulation through increasing the displacement of the power fluid on the ground when the pump core is lifted out, the ground power fluid pump injection equipment has high power due to the heavy pump core, the energy consumption is large, the investment is high, and the operation cost is increased. SUMMARY

[0005] The present application aims at the above-mentioned defects in the prior art, and provides a floating pump core ring jet flow pump and a use method.

[0006] The present application provides a floating pump core ring jet flow pump, which comprises a pump barrel, a large-diameter oil pipe connected to the outer side of the upper end of the pump barrel, and a small-diameter oil pipe connected to the inner side of the pump barrel.

[0007] Preferably, the floating pump core comprises a fishing head, a pump core body, a pump core plug, and a multi-stage floating cavity.

[0008] Preferably, the multi-stage floating cavity comprises a first gas filling chamber, a second gas filling chamber, and a low-density liquid chamber.

[0009] Preferably, the multi-stage floating cavity comprises a first gas filling chamber, a first partition plate, and a low-density liquid chamber.

[0010] Preferably, a conical auxiliary lifting fin is arranged between the pump core body and the fishing head of the floating pump core.

[0011] Preferably, the above-mentioned float pump core comprises a fishing head, a pump core body, a first inflation chamber, a pump core plug and a bellows section, the top of the pump core body is provided with the fishing head, the bottom of the pump core body is provided with the pump core plug, the pump core body is supported by cooperating with the pump core support seat of the pump barrel, the first inflation chamber is arranged on the upper side of the inner cavity of the pump core body, and the bellows section is arranged on the lower side of the pump core body.

[0012] Preferably, the outer diameter of the bellows section when contracted is greater than the outer diameter of the pump core body, and the outer diameter of the bellows section when expanded is equal to the outer diameter of the pump core body.

[0013] The float pump core ring jet flow pump mentioned in the application has the technical scheme that: a pump barrel is arranged, the outer side of the upper end of the pump barrel is connected with an oil pipe, and the inner cavity of the pump barrel is arranged with a float pump core, an annular gap is formed between the float pump core and the inner wall of the pump barrel, the lower side of the annular gap is arranged with a formation liquid suction inlet, the lower side of the formation liquid suction inlet is an annular throat, the lower side of the annular throat is arranged with a diffusion cavity, the bottom of the diffusion cavity is arranged with a pump core support seat, the lower side of the diffusion cavity is arranged with a mixed liquid outlet, the bottom of the pump barrel is arranged with a formation liquid inlet, the formation liquid inlet is arranged with a fixed valve ball, and the formation liquid suction inlet and the formation liquid inlet are communicated through a formation liquid suction channel in the pump barrel.

[0014] The use method of the float pump core ring jet flow pump mentioned in the application comprises the following processes: I. The pump barrel is lowered into a set position in the well through the large-diameter oil pipe and the small-diameter oil pipe at the wellhead on the ground, the ground flow process and the wellhead control valve group are set according to the positive circulation production, the ground power liquid pump is started to circulate the well, then the fixed valve ball is put into the small-diameter oil pipe, the fixed valve ball is set and sealed to the upper part of the formation liquid inlet, the pipe string is pressure tested by injecting power liquid, after the pressure test is qualified, the float pump core is put into the small-diameter oil pipe, and the float pump core is continuously injected into the power liquid, the float pump core is sent to the pump core support seat in the pump barrel, and is set and sealed in the pump core support seat under the action of the continuous injection of the power liquid and the self weight of the float pump core, because the gas is injected into the first inflation chamber of the float pump core, the air is filled in the second inflation chamber, and the low-density liquid is injected into the low-density liquid chamber, the overall density of the float pump core is greater than the density of water, the center of gravity of the float pump core is kept at the lower position, so as to prevent the pump core body from shaking and being in the central position; then, the pressure of the power liquid is increased, and the double-tube positive circulation production is started; II. When the dual-tube positive circulation production is carried out, the buoyancy pump core is seated on the pump core support seat in the pump barrel under the continuous action of the power fluid from the small-diameter oil pipe and the self weight of the buoyancy pump core; then, the power fluid is accelerated through the annular gap between the buoyancy pump core and the pump barrel, a negative pressure is formed at the formation liquid suction inlet to induce the formation liquid from the formation liquid suction channel, the power fluid and the formation liquid are mixed and downward, the mixed fluid is mixed and converted in the annular throat pipe, is decelerated in the diffusion cavity and then is upward along the mixed fluid outlet into the mixed fluid discharge cavity, and then is upward along the annular cavity between the large-diameter oil pipe and the small-diameter oil pipe to the ground surface; III. When the buoyancy pump core needs to be pulled out in reverse circulation, the power fluid is injected into the annular space between the large-diameter oil pipe and the small-diameter oil pipe at the ground wellhead, the power fluid enters the diffusion cavity through the mixed fluid outlet of the pump barrel, since the overall density of the buoyancy pump core is greater than the density of water, the buoyancy pump core leaves the seated pump core support seat under the action of the power fluid, and then continues to be upward along the inner cavity of the pump barrel to the inner cavity of the small-diameter oil pipe, and then continues to be upward along the inner cavity of the small-diameter oil pipe to the ground wellhead under the action of the power fluid, so that the buoyancy pump core is pulled out.

[0015] Compared with the prior art, the beneficial effects of the present application are as follows: I. The buoyancy pump core adopted in the present application has a multistage buoyancy cavity body, and the overall density of the buoyancy pump core is greater than the density of water, so that when the pump core is pulled out, the displacement and power of the ground power system can be reduced, the energy efficiency of the pump core pulling out is lower than that of the prior art, the configuration power of the ground power system is reduced, and the operation energy consumption is saved; II. The present application adopts an annular gap type downhole jet structure, which eliminates the traditional internal multiple circuitous flow channels, reduces the manufacturing difficulty and cost, improves the sand plugging resistance, prolongs the service life of the pump barrel, reduces the frequency of well repair, is more suitable for wells with large fluctuations in oil-gas ratio and solid content, and prolongs the well inspection pump cycle; III. The buoyancy pump core adopted in the present application adopts a conical auxiliary lifting fin, which can enhance the upward buoyancy when the pump is pulled out in reverse circulation, reduce the liquid flow slip when the pump is pulled out in reverse circulation, and shorten the pump pulling-out time; in addition, the buoyancy pump core further increases a bellows section which can be self-adjusted according to the fluctuation of the well pressure, so as to stabilize the working pressure of the system and maintain the stable operation condition and yield of the downhole system; when the pump is pulled out, the outer diameter of the bellows section is contracted and sealed at the bottom to assist the upward movement of the buoyancy pump core. In summary, the buoyancy pump core of the present application has a simple structure, forms an annular jet flow structure with the pump barrel, increases the production fluid volume, makes the working condition of the suction medium more extensive, has a lower manufacturing cost and a lower operation cost. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the first embodiment of the present invention; Figure 2 This is a structural diagram of a first embodiment of a floating pump core; Figure 3 It is a structural schematic diagram of a second embodiment of a floating pump core; Figure 4 is a schematic diagram of the overall structure of another embodiment of the present invention; Figure 5 1 is a schematic structural diagram of a third embodiment of a floating pump core; In the figure: large diameter oil pipe 1, small diameter oil pipe 2, floating pump core 3, pump barrel 4, formation fluid suction port 5, outer barrel 6, formation fluid suction channel 7, fixed valve ball 8, annular gap 9, annular throat 10, diffusion chamber 11, mixed liquid outlet 12, mixed liquid discharge chamber 13; Fishing head 3.1, pump core body 3.2, first air-filled chamber 3.3, first baffle 3.4, second air-filled chamber 3.5, second baffle 3.6, low-density liquid chamber 3.7, pump core plug 3.8, liquid injection seal 3.9, air injection seal 3.10, auxiliary lift fin 3.11, bellows section 3.12, pump core support base 4.1, formation fluid inlet 4.2. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0018] Example 1, with reference to Figure 1 and Figure 2 The present invention mentions a floating pump core ring jet pump, which is a double-tube structure, including a pump barrel 4, the outer side of the upper end of the pump barrel 4 is connected to the large-diameter oil pipe 1, and the inner side is connected to the small-diameter oil pipe 2, which also includes a floating pump core 3, a formation fluid suction port 5, an outer barrel 6, a formation fluid suction channel 7, a fixed valve ball 8, an annular gap 9, an annular throat 10, a diffusion chamber 11, a mixed liquid outlet 12, and a mixed liquid discharge chamber 13. The outer side of the pump barrel 4 is provided with an outer barrel 6, and the floating pump core 3 is installed in the inner cavity of the pump barrel 4. An annular gap 9 is formed between the floating pump core 3 and the inner wall of the pump barrel 4, which improves the anti- In order to improve the sand plugging performance, a formation fluid suction port 5 is provided at the lower side of the annular gap 9, and an annular throat 10 is provided below the formation fluid suction port 5. A diffusion chamber 11 is provided below the annular throat 10, and a pump core support seat 4.1 is provided at the bottom of the diffusion chamber 11. A mixed liquid outlet 12 is provided at the lower side of the diffusion chamber 11, connecting the diffusion chamber 11 with the mixed liquid discharge chamber 13; a formation fluid inlet 4.2 is provided at the bottom of the pump barrel 4, and a fixed valve ball 8 is installed on the formation fluid inlet 4.2. The formation fluid suction port 5 is connected to the formation fluid inlet 4.2 through a formation fluid suction channel 7 in the pump barrel 4.

[0019] Referring Figure 2 The floating pump core 3 mentioned in the present application comprises a fishing head 3.1, a pump core body 3.2, a pump core plug 3.8 and a multi-stage floating cavity, the pump core body 3.2 is provided with a multi-stage floating cavity, the fishing head 3.1 is arranged at the top of the pump core body 3.2, the pump core plug 3.8 is arranged at the bottom of the pump core body 3.2, and the pump core body 3.2 is supported by cooperating with the pump core support seat 4.1 of the pump barrel 4.

[0020] The multi-stage floating cavity comprises a first gas filling chamber 3.3, a second gas filling chamber 3.5 and a low-density liquid chamber 3.7, the first gas filling chamber 3.3 and the second gas filling chamber 3.5 are provided with a first partition plate 3.4, the second gas filling chamber 3.5 and the low-density liquid chamber 3.7 are provided with a second partition plate 3.6, the outer wall of the first gas filling chamber 3.3 is provided with a gas injection seal 3.10 for filling gas such as nitrogen into the first gas filling chamber 3.3, the bottom of the low-density liquid chamber 3.7 is connected with the hollow pump core plug 3.8, and the bottom of the pump core plug 3.8 is provided with a liquid injection seal 3.9 for filling low-density liquid such as methanol, ethanol or gasoline into the low-density liquid chamber 3.7; the second gas filling chamber 3.5 in the middle is filled with air during preparation and plays a basic buoyancy role, and the first gas filling chamber 3.3 and the low-density liquid chamber 3.7 are filled with a certain amount according to needs and play a function of adjusting the overall density.

[0021] The overall density of the floating pump core 3 is adjusted to be slightly greater than the density of water, which is a preferred scheme, and the density of the floating pump core 3 is low relative to the density of metal materials, so that the pressure required by the prior art is much lower when the power liquid is injected in reverse circulation, so that the energy consumption of the reverse circulation to lift the floating pump core 3 is saved; of course, the overall density of the floating pump core 3 is calculated by weighing and measuring the volume on the ground.

[0022] The use method of the floating pump core ring jet flow pump mentioned in the present application comprises the following processes: I. Through the large-diameter tubing 1 and small-diameter tubing 2 at the ground wellhead, the pump barrel 4 is lowered into the well to set the position, the ground flow and wellhead control valve group are set according to the positive circulation production, the ground power liquid pump is started to circulate the well, then the fixed valve ball 8 is put into the small-diameter tubing 2, the fixed valve ball 8 is set to the upper part of the formation liquid inlet 4.2, the power liquid is injected to test the pressure of the pipe string, after the test is qualified, the floating pump core 3 is put into the small-diameter tubing 2, then the power liquid is continuously injected, the floating pump core 3 is sent to the pump core support seat 4.1 in the pump barrel 4, and is set in the pump core support seat 4.1 under the action of the continuous injection of the power liquid and the self weight of the floating pump core 3, because the gas is injected into the first gas-filled chamber 3.3 of the floating pump core 3, the air is filled in the second gas-filled chamber 3.5, and the low-density liquid is injected into the low-density liquid chamber 3.7, so as to adjust the overall density of the floating pump core 3 to be greater than the density of water, the center of gravity of the floating pump core 3 is kept at the lower position, so as to prevent the pump core main body 3.2 from shaking and being in the central position; then, the pressure of the power liquid is increased to the power liquid, and the double-tube positive circulation production is started; II. During the double-tube positive circulation production, under the continuous action of the power liquid from the small-diameter tubing 2 and the self weight of the floating pump core 3, the floating pump core 3 is set on the pump core support seat 4.1 in the pump barrel 4; then, the power liquid is accelerated through the annular gap 9 between the floating pump core 3 and the pump barrel 4, the negative pressure is formed at the formation liquid suction inlet 5 to suction the formation liquid from the formation liquid suction channel 7, the power liquid and the formation liquid are mixed and downward, after the mixing and energy conversion in the annular throat 10, the power liquid is decelerated in the diffusion chamber 11, and then is upward along the mixed liquid outlet 12 into the mixed liquid discharge chamber 13, and then is upward along the annular cavity between the large-diameter tubing 1 and the small-diameter tubing 2 to the ground; III. When the floating pump core 3 needs to be pulled out in reverse circulation, the power liquid is injected into the annular space between the large-diameter tubing 1 and the small-diameter tubing 2 at the ground wellhead, the power liquid enters the diffusion chamber 11 along the mixed liquid outlet 12 of the pump barrel 4, because the overall density of the floating pump core 3 is greater than the density of water, the floating pump core 3 leaves the set pump core support seat 4.1 under the action of the power liquid, then continues to be upward along the inner cavity of the pump barrel 4 to the inner cavity of the small-diameter tubing 2, then continues to be upward along the inner cavity of the small-diameter tubing 2 to the ground wellhead under the action of the power liquid, so as to pull out the floating pump core 3, the power liquid injected in the reverse circulation is far lower than the pressure required by the prior art, so the energy consumption of the reverse circulation to pull out the floating pump core 3 is saved.

[0023] Embodiment 2, the floating pump core ring jet flow pump mentioned in the application is a double tube structure, comprising a pump barrel 4, the outer side of the upper end of the pump barrel 4 is connected with a large-diameter oil pipe 1, and the inner side is connected with a small-diameter oil pipe 2, wherein, it further comprises a floating pump core 3, a formation fluid suction inlet 5, an outer barrel 6, a formation fluid suction channel 7, a fixed valve ball 8, an annular gap 9, an annular throat 10, a diffusion cavity 11, a mixed liquid outlet 12 and a mixed liquid discharge cavity 13, the outer side of the pump barrel 4 is provided with the outer barrel 6, the floating pump core 3 is installed in the inner cavity of the pump barrel 4, the annular gap 9 is formed between the floating pump core 3 and the inner wall of the pump barrel 4, the lower side of the annular gap 9 is provided with the formation fluid suction inlet 5, the lower side of the formation fluid suction inlet 5 is the annular throat 10, the lower side of the annular throat 10 is provided with the diffusion cavity 11, the bottom of the diffusion cavity 11 is provided with a pump core support seat 4.1, the lower side of the diffusion cavity 11 is provided with the mixed liquid outlet 12, and the diffusion cavity 11 and the mixed liquid discharge cavity 13 are communicated; the bottom of the pump barrel 4 is provided with a formation fluid inlet 4.2, the fixed valve ball 8 is arranged on the formation fluid inlet 4.2, and the formation fluid suction inlet 5 and the formation fluid inlet 4.2 are communicated through the formation fluid suction channel 7 in the pump barrel 4.

[0024] The difference between embodiment 1 and embodiment 2 is that: Referring to Figure 3 , the multi-stage floating cavity comprises a first gas filling chamber 3.3, a first partition plate 3.4 and a low-density liquid chamber 3.7, the first partition plate 3.4 is installed between the first gas filling chamber 3.3 and the low-density liquid chamber 3.7, the first gas filling chamber 3.3 is filled with gas, and the low-density liquid chamber 3.7 is filled with low-density liquid, so that the center of gravity is kept below the pump core body 3.2.

[0025] The pump core body 3.2 of the floating pump core 3 and the fishing head 3.1 are provided with a conical auxiliary lifting fin 3.11, the outer diameter of the lower end of the auxiliary lifting fin 3.11 is greater than the outer diameter of the pump core body 3.2, so that when the floating pump core 3 is pulled out in reverse circulation, the auxiliary lifting fin 3.11 can enhance the lifting force when the pump is pulled out in reverse circulation, reduce the liquid flow slip when the pump is pulled out in reverse circulation, and shorten the pump pulling-out time.

[0026] Embodiment 3, referring to Figure 4The application provides a floating pump core ring jet flow pump, which is a single-pipe structure and comprises a pump barrel 4, an oil pipe connected to the outer side of the upper end of the pump barrel 4, a floating pump core 3, a formation liquid suction inlet 5, a formation liquid suction channel 7, an annular gap 9, an annular throat 10, a diffusion cavity 11 and a mixed liquid outlet 12.

[0027] Referring to Figure 5 The floating pump core 3 comprises a fishing head 3.1, a pump core body 3.2, a first inflation chamber 3.3, a pump core plug 3.8 and a bellows section 3.12. The top of the pump core body 3.2 is provided with the fishing head 3.1, the bottom of the pump core body 3.2 is provided with the pump core plug 3.8, the pump core body 3.2 is supported by cooperating with the pump core support seat 4.1 of the pump barrel 4, the upper side of the inner cavity of the pump core body 3.2 is provided with the first inflation chamber 3.3, and the lower side of the pump core body 3.2 is provided with the bellows section 3.12.

[0028] The outer diameter of the bellows section 3.12 when being contracted is greater than the outer diameter of the pump core body 3.2, and the outer diameter of the bellows section 3.12 when being stretched is equal to the outer diameter of the pump core body 3.2.

[0029] The bellows section 3.12 at the bottom of the floating pump core 3 can be self-adjusted according to the fluctuation of the well pressure, and the bellows section 3.12 plays a self-adjusting and reducing role on the shaking of the floating pump core 3 caused by the fluctuation of the gas and sand content of the formation liquid in the production process, so as to stabilize the working pressure of the system and maintain the stable operation condition and yield of the downhole system. When the pump is started, the outer diameter of the bellows section 3.12 is contracted and plays a sealing and boosting role at the bottom, and helps the floating pump core 3 to go up.

[0030] The bellows structure is more suitable for the application of high-gas-content, medium-shallow-layer wells and wells with non-serious medium corrosion.

[0031] The above description is only some preferred embodiments of the application, and any skilled person in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, the corresponding simple modifications or equivalent transformations according to the technical solutions of the application are within the scope of protection of the application.

Claims

1. A floating pump core ring jet pump, comprising a pump barrel (4), the upper end of the pump barrel (4) being connected to a large-diameter oil pipe (1) on the outside and to a small-diameter oil pipe (2) on the inside, characterized in that: The pump barrel (4) further comprises a floating pump core (3), a formation fluid suction port (5), an outer barrel (6), a formation fluid suction channel (7), a fixed valve ball (8), an annular gap (9), an annular throat (10), a diffusion chamber (11), a mixed liquid outlet (12), and a mixed liquid discharge chamber (13). The outer barrel (6) is provided on the outside of the pump barrel (4), the floating pump core (3) is installed in the inner cavity of the pump barrel (4), an annular gap (9) is formed between the floating pump core (3) and the inner wall of the pump barrel (4), a formation fluid suction port (5) is provided on the lower side of the annular gap (9), and the lower side of the formation fluid suction port (5) is provided. The annular throat pipe (10) is provided with a diffusion chamber (11) below the annular throat pipe (10), a pump core support seat (4.1) is provided at the bottom of the diffusion chamber (11), and a mixed liquid outlet (12) is provided on the lower side of the diffusion chamber (11), connecting the diffusion chamber (11) with the mixed liquid discharge chamber (13); a formation fluid inlet (4.2) is provided at the bottom of the pump barrel (4), a fixed valve ball (8) is installed on the formation fluid inlet (4.2), and the formation fluid suction port (5) is connected with the formation fluid inlet (4.2) through a formation fluid suction channel (7) in the pump barrel (4).

2. The floating pump core ring jet pump according to claim 1, characterized in that: The floating pump core (3) comprises a salvaging head (3.1), a pump core body (3.2), a pump core plug (3.8) and a multi-stage floating cavity. The multi-stage floating cavity is provided in the pump core body (3.2). The salvaging head (3.1) is provided on the top of the pump core body (3.2), and the pump core plug (3.8) is provided at the bottom of the pump core body (3.2). The pump core body (3.2) is supported by cooperating with the pump core support seat (4.1) of the pump barrel (4).

3. The floating pump core ring jet pump according to claim 2, characterized in that: The multi-stage buoyancy chamber comprises a first air-filled chamber (3.3), a second air-filled chamber (3.5) and a low-density liquid chamber (3.7); a first partition (3.4) is provided between the first air-filled chamber (3.3) and the second air-filled chamber (3.5); a second partition (3.6) is provided between the second air-filled chamber (3.5) and the low-density liquid chamber (3.7); an air injection seal (3.10) is provided on the outer wall of the first air-filled chamber (3.3); a hollow pump core plug (3.8) is connected to the bottom of the low-density liquid chamber (3.7); and a liquid injection seal (3.9) is provided at the bottom of the pump core plug (3.8).

4. The floating pump core ring jet pump according to claim 2, characterized in that: The multi-stage buoyancy chamber comprises a first air-filled chamber (3.3), a first partition (3.4) and a low-density liquid chamber (3.7); the first partition (3.4) is installed between the first air-filled chamber (3.3) and the low-density liquid chamber (3.7); the first air-filled chamber (3.3) is filled with gas, and the low-density liquid chamber (3.7) is filled with low-density liquid, so that the center of gravity is kept below the pump core body (3.2).

5. The floating pump core ring jet pump according to claim 3 or 4, characterized in that: A conical auxiliary lift wing (3.11) is provided between the pump core body (3.2) and the salvage head (3.1) of the floating lift pump core (3), and the outer diameter of the lower end of the auxiliary lift wing (3.11) is larger than the outer diameter of the pump core body (3.2).

6. The floating pump core ring jet pump according to claim 1, characterized in that: The floating pump core (3) comprises a salvage head (3.1), a pump core body (3.2), a first air-filled chamber (3.3), a pump core plug (3.8) and a bellows section (3.12). The top of the pump core body (3.2) is provided with a salvage head (3.1), the bottom of the pump core body (3.2) is provided with a pump core plug (3.8), and the pump core body (3.2) is supported by cooperating with a pump core support seat (4.1) of a pump barrel (4). The first air-filled chamber (3.3) is provided on the upper side of the inner cavity of the pump core body (3.2), and the bellows section (3.12) is provided on the lower side of the pump core body (3.2).

7. The floating pump core ring jet pump according to claim 6, characterized in that: The outer diameter of the bellows section (3.12) when contracted is larger than the outer diameter of the pump core body (3.2), and the outer diameter of the bellows section (3.12) when extended is equal to the outer diameter of the pump core body (3.2).

8. A floating pump core ring jet pump, comprising a pump barrel (4), the upper end of the pump barrel (4) being connected to an oil pipe on the outside, characterized in that: The pump barrel (4) further comprises a floating pump core (3), a formation fluid suction port (5), a formation fluid suction channel (7), a fixed valve ball (8), an annular gap (9), an annular throat (10), a diffusion chamber (11), and a mixed liquid outlet (12). The floating pump core (3) is installed in the inner cavity of the pump barrel (4), and an annular gap (9) is formed between the floating pump core (3) and the inner wall of the pump barrel (4). A formation fluid suction port (5) is provided on the lower side of the annular gap (9), and an annular throat is provided below the formation fluid suction port (5). (10), a diffusion chamber (11) is provided below the annular throat (10), a pump core support seat (4.1) is provided at the bottom of the diffusion chamber (11), a mixed liquid outlet (12) is provided on the lower side of the diffusion chamber (11), a formation fluid inlet (4.2) is provided at the bottom of the pump barrel (4), a fixed valve ball (8) is installed on the formation fluid inlet (4.2), and the formation fluid suction port (5) is connected to the formation fluid inlet (4.2) through the formation fluid suction channel (7) in the pump barrel (4).

9. The method for using the floating pump core ring jet pump according to claim 3, characterized in that The following processes are included:

1. At the surface wellhead, a double-layer oil pipe is formed by a large-diameter oil pipe (1) and a small-diameter oil pipe (2), and the pump barrel (4) is lowered into the well to set a position. The surface process and the wellhead control valve group are set according to the positive circulation production. The surface power fluid pump is started to circulate and wash the well. Then, a fixed valve ball (8) is put into the small-diameter oil pipe (2). The fixed valve ball (8) is sealed to the upper part of the formation fluid inlet (4.2). Power fluid is injected to test the pressure of the pipe string. After the pressure test is qualified, a floating pump core (3) is put into the small-diameter oil pipe (2), and the power fluid is continuously injected to send the floating pump core (3) into the pump core support seat (4) in the pump barrel (4). .1), and is sealed in the pump core support seat (4.1) under the action of continuous injection of power fluid and the weight of the floating pump core (3). Since gas is injected into the first air-filled chamber (3.3) of the floating pump core (3), air is filled into the second air-filled chamber (3.5), and low-density liquid is injected into the low-density liquid chamber (3.7), it is convenient to adjust the overall density of the floating pump core (3) to be greater than the density of water, and keep the center of gravity of the floating pump core (3) in the lower position to prevent the pump core body (3.2) from shaking and in the middle position; then, the pressure of the power fluid is increased to start the double-tube positive circulation drainage production; 2. During the double-tube positive circulation drainage production, under the continuous action of the power fluid from the small-diameter oil pipe (2) and the weight of the floating pump core (3), the floating pump core (3) is seated on the pump core support seat (4.1) in the pump barrel (4); then, the power fluid is accelerated through the annular gap (9) between the floating pump core (3) and the pump barrel (4), and a negative pressure is formed at the formation fluid suction port (5) to draw the formation fluid from the formation fluid suction channel (7). The power fluid and the formation fluid are mixed together and move downward. After mixing and energy conversion in the annular throat (10), they are decelerated in the diffusion chamber (11), and then enter the mixed liquid discharge chamber (13) along the mixed liquid outlet (12) and move upward. After that, they move upward along the annular cavity between the large-diameter oil pipe (1) and the small-diameter oil pipe (2) to be drained to the ground.

3. When reverse circulation is required to remove the floating pump core (3), power fluid is injected into the annular space between the large-diameter oil pipe (1) and the small-diameter oil pipe (2) at the surface wellhead. The power fluid enters the diffusion chamber (11) along the mixed liquid outlet (12) of the pump barrel (4). Since the overall density of the floating pump core (3) is greater than the density of water, the floating pump core (3) leaves the pump core support seat (4.1) of the seat under the action of the power fluid, and then continues to ascend along the inner cavity of the pump barrel (4) to the inner cavity of the small-diameter oil pipe (2). Then, under the action of the power fluid, it is discharged along the inner cavity of the small-diameter oil pipe (2) to the surface wellhead, thereby removing the floating pump core (3).

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