CN104533350A - Oil well fluid flooding pumping system - Google Patents

Abstract

The oil well fluid-driving oil pumping system comprises a first two-position four-way reversing valve and a second two-position four-way reversing valve, wherein a third port and a fourth port of the first two-position four-way reversing valve are communicated with the second two-position four-way reversing valve, a second port of the first two-position four-way reversing valve is communicated with the third port and the fourth port alternately, high-pressure power fluid entering from the second port enters the second two-position four-way reversing valve through the third port or the fourth port and pushes a valve core of the second two-position four-way reversing valve to move, so that an eighth port of the second two-position four-way reversing valve is communicated with a fifth port and a sixth port of the second two-position four-way reversing valve alternately, and the high-pressure power fluid entering from the eighth port is guided to enter a third chamber or a fourth chamber through the fifth port and then pushes a piston to move. The invention solves the problem of piston load balance, and solves the problem that the prior art can only pump oil by single stroke, namely upward stroke, so that the production efficiency is greatly improved.

Description

Oil well fluid flooding pumping system

technical field

The invention belongs to the technical field of artificial lift for oil and gas field exploitation, and in particular relates to an oil well fluid flooding pumping system.

Background technique

The existing artificial lift technology can be divided into two categories: rod lift and rodless lift. The hydraulic piston pump used in the oil field belongs to the rodless lifting. The hydraulic piston pump system is a hydraulically driven rodless pumping equipment. It is a kind of equipment used to lift oil from the oil well. After the power fluid is pressurized, it is pumped into the downhole to drive the piston and the main control slide valve in the oil cylinder through the oil pipe or a special channel, so that the fluid motor can reciprocate up and down, thereby lifting the oil well output fluid to the surface.

According to whether the produced fluid is mixed with the anaerobic fluid, the hydraulic piston pump system includes a closed system and an open system. For the closed hydraulic piston pump, the exhaust fluid and the produced fluid are returned to the ground through a separate flow channel. Although the oil-water separation link is avoided, the structure of the downhole string becomes complicated and the cost is lower due to the addition of a flow channel. The high height of the open system has limited its scope of use. Therefore, the hydraulic piston pump system uses more open systems.

See Figure 1. The basic principle of the open hydraulic piston pump is: the high-pressure power fluid enters the lower cylinder 15 through the channel 13, and acts on the annular end surface of the lower end of the piston 11, and then the high-pressure power fluid enters the upper cylinder 19 through the channel 17, and acts on the upper cylinder 11 of the piston. end face. Because the action area of the upper end surface of the piston is larger than the action area of the lower end surface, a pressure difference is generated between the upper and lower end surfaces of the piston 11, and the piston 11 drives the plunger 23 to move downward through the piston rod 21 affixed thereto. The upper and lower parts of the piston rod 21 are respectively provided with a control groove 29 and a control groove 31. When the piston rod 21 moves close to the bottom dead point, the upper control groove 29 communicates with the upper chamber 25 and the lower chamber of the main control slide valve 33. Chamber 27, so that high-pressure power fluid enters the lower chamber 27 of the main control spool valve 33 from the upper chamber 25 through the control groove 29. Because the area of the lower end surface of the main control spool valve 33 is greater than the area of the upper end surface, a pressure difference is generated under the action of the high-pressure power fluid, so that the main control spool valve 33 is pushed to the top dead center, thereby completing the downstroke. Please refer to Fig. 2 for the structural diagram of the hydraulic piston pump after the downstroke is completed.

The main control spool valve 33 is at the top dead center, and the upper cylinder 19 communicates with the lower oil production chamber 39 through the channel 17 and the annular space 37 in the middle of the main control spool valve 33 . Continue to deliver the high-pressure power fluid to the lower cylinder 15 through the channel 13. Since the main control spool valve 33 is at the top dead center position, the channel 35 between the lower cylinder 15 and the channel 17 is blocked by the main control spool valve 33, so that the high-pressure power fluid cannot Entering the upper cylinder 19, the piston 11 drives the plunger 23 to move upward through the piston rod 21 fixed to it, and pumps out the output fluid; at the same time, the rising piston 11 squeezes out the idle power fluid in the upper cylinder 19, and The produced fluids are mixed and lifted to the surface together. When the piston rod 21 is close to the top dead center, the control groove 31 located at the bottom of the piston rod 21 communicates with the lower chamber 27 of the main control spool valve 33 and the oil production chamber 39, and the main control spool valve 33 is pushed to the bottom dead point, and the upstroke ends , and restart the downstroke.

The problems of the above-mentioned open system are: during the upstroke and downstroke, the load on the piston is seriously unbalanced, the power hydraulic pressure of the upstroke is high, and the upward speed is slow; the power hydraulic pressure of the downstroke is low, and the downward speed is fast, resulting in System pressure fluctuations will cause a large impact on the high-pressure power fluid delivery pipeline, and in severe cases, the high-pressure power fluid delivery pipeline will burst. The reason for the unbalanced load is that the upstroke is the process of oil production, and the piston 11 goes up under the action of the high-pressure power fluid in the lower cylinder 25, not only to lift the piston rod 21 and the plunger 23 and other hydraulic piston pump equipment, but also to lift the hydraulic piston pump itself. The pumped output fluid is lifted, so the load on the piston 11 in the upstroke is relatively large; while no oil is produced in the downstroke, the high-pressure power fluid enters the upper cylinder 19 and the lower cylinder 15 of the piston 11 at the same time, and pushes the piston rod in a differential manner Equipment such as 21 and plunger 23 descends, and running speed is accelerated, and these parts self have gravitational potential energy, thereby make piston 11 suffered load very little in the downstroke process.

Contents of the invention

Aiming at the defect of unbalanced upstroke and downstroke loads in the open hydraulic piston pump system of the prior art, the present invention provides an oil well fluid flooding pumping system, and the technical scheme is as follows:

Oil well fluid flooding pumping system, including:

The oil well pump core body has a hollow chamber and can be lowered into a predetermined position in the casing of the oil production well. The hollow chamber is provided with a first piston and a second piston that can move therein. The first piston and the The second piston is connected by a piston rod, the first piston is close to the wellhead of the oil production well, and the second piston is far away from the wellhead, and the end face of the first piston close to the wellhead is connected to the pump The oil pump core body forms an airtight first chamber, and the end face of the second piston away from the wellhead forms an airtight second chamber with the oil pump core body;

The first chamber is communicated with a first pipeline and a second pipeline, and the second chamber is communicated with a third pipeline and a fourth pipeline. When the oil pump core body is lowered into the oil production well, The formation fluid in the formation can flow into the first chamber and the second chamber respectively through the first pipeline and the third pipeline, and enter the first chamber and the second chamber The formation fluid in the chamber can flow out through the second pipeline and the fourth pipeline respectively;

The first pipeline, the second pipeline, the third pipeline and the fourth pipeline are provided with one-way valves, wherein the one-way valves on the first pipeline and the third pipeline can prevent the The formation fluid in the first chamber and the second chamber flows back; the one-way valves on the second pipeline and the fourth pipeline can prevent the fluid from flowing out of the first chamber and the second chamber Formation fluid backflow in the chamber;

A reversing mechanism arranged in the hollow chamber and having a first two-position four-way reversing valve and a second two-position four-way reversing valve, the reversing mechanism is arranged on the first piston and the second piston Between the pistons, the end face of the first piston away from the wellhead forms a closed third chamber with the reversing mechanism and the oil pump core body, and the end face of the second piston close to the wellhead and the reversing mechanism The mechanism and the oil pump core body form a closed fourth chamber;

The first two-position four-way reversing valve includes a first port, a second port, a third port, and a fourth port, and the second port can alternately communicate with the third port and the fourth port, and When the second port communicates with one of the third port and the fourth port, the other of the third port and the fourth port can communicate with the first port;

The spool of the first two-position four-way reversing valve is fixedly connected with a connecting rod, and the two ends of the connecting rod respectively extend into the third chamber and the fourth chamber, so that the first piston and the second The piston can push the connecting rod during the movement, and drive the spool of the first two-position four-way reversing valve to move;

The second two-position four-way reversing valve includes a fifth port, a sixth port, a seventh port, and an eighth port, and the eighth port can alternately communicate with the fifth port and the sixth port, and When the eighth port communicates with one of the fifth port and the sixth port, the other of the fifth port and the sixth port can communicate with the seventh port;

The third port and the fourth port are connected to the second two-position four-way reversing valve, and high-pressure power can flow into the second two-position four-way reversing valve through the third port and the fourth port. liquid to push the spool of the second two-position four-way reversing valve to move, the fifth port communicates with the third chamber, and the sixth port communicates with the fourth chamber.

The above-mentioned oil well fluid flooding pumping system includes a first pipe string, the core body of the oil well pump can be sealed and sleeved in the first pipe string, and the pipe wall of the first pipe string is arranged along its axial direction There are a first channel and a second channel, and the first channel communicates with the first pipeline and the formation, so that the formation fluid in the formation can flow into the first cavity through the first channel and the first pipeline in sequence In the chamber, the formation fluid in the formation enters the second chamber through the third pipeline, the second channel communicates with the second port and the eighth port, and the first pipe string radially A radial channel communicating with the second channel is opened, and the high-pressure power fluid in the first pipe string can enter the second channel through the radial channel.

In the oil well fluid flooding pumping system described above, the oil pump core body can be lowered into the casing of the oil production well through the first pipe string, and the first pipe string and the casing can form a In the first annulus, a packer is connected to the first pipe string below the oil well pump core body, and the packer separates the first annulus from the formation. The first port, the seventh A port, a second line, and a fourth line communicate with the first annulus.

In the oil well fluid flooding pumping system described above, a third passage is arranged in the pipe wall of the first pipe string along its axial direction, and the first port, the seventh port, the second pipeline and the fourth pipeline are communicate with the third channel.

In the above-mentioned oil well fluid flooding pumping system, the second pipe string is sleeved inside the first pipe string, the oil well pump core body can be sealed and sleeved in the second pipe string, and the oil well pump core body A second annulus is formed between the first pipe string between the wellhead and the second pipe string, and the second annulus communicates with the third channel.

The above-mentioned oil well fluid flooding pumping system includes a ground part, and the ground part includes:

a production fluid output pipeline, the production fluid output pipeline communicates with the first annulus/second annulus;

A three-phase separation device, a liquid storage tank, a booster pump, and a high-pressure power fluid delivery pipeline connected in sequence, the three-phase separation device is connected to the output fluid output pipeline, and part of the output fluid in the output fluid output pipeline After the liquid is separated and processed by the three-phase separation device, the obtained liquid enters the liquid storage tank, and the liquid in the liquid storage tank is pressurized by the booster pump, and then transported to the high-pressure power fluid delivery pipeline to the In the first string/second string.

In the above-mentioned oil well fluid flooding pumping system, the high-pressure power fluid delivery pipeline is provided with a one-way valve, and the one-way valve can prevent the high-pressure power fluid from entering the first pipe string/second pipe string reflow.

The above-mentioned oil well fluid flooding pumping system includes a safety valve, and the safety valve is arranged on the pipeline connecting the liquid storage tank and the high-pressure power fluid delivery pipeline upstream of the check valve.

By means of the above technical solution, the beneficial effect of the present invention is that: a reversing mechanism composed of the first two-position four-way reversing valve and the second two-position four-way reversing valve is provided, and the first piston and the second piston are in the process of moving In the middle, push the spool of the first two-two four-way pilot valve, so that the second port of the first two-two four-way pilot valve, that is, the high-pressure power fluid inlet, can alternately communicate with the third port and the fourth port, thereby guiding the high-pressure power The liquid enters the second two-position four-way reversing valve to push the spool of the second two-two four-way reversing valve to move, so that the eighth port of the second two-two four-way reversing valve, that is, the high-pressure power fluid inlet It can alternately communicate with the fifth port and the sixth port, so as to guide the high-pressure power fluid to alternately enter the third chamber and the fourth chamber, and then alternately push the first piston 73 and the second piston 75 to move, and the first chamber and the second chamber The formation fluid in the second chamber is squeezed out, so that no matter it is an upstroke or a downstroke, fluid can be produced. While solving the problem of piston load balance, it also solves the problem that the existing technology only relies on a single stroke, that is, the upstroke to pump. The oil problem greatly improves the production efficiency.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative work.

Fig. 1 is the structural representation of the open hydraulic piston pump of prior art;

Fig. 2 is the structural representation of the open hydraulic piston pump that completes downstroke shown in Fig. 1;

Fig. 3 is a kind of embodiment structural representation of oil well fluid flooding pumping system of the present invention;

Fig. 4 is a partial enlarged view of the oil well pump core body shown in Fig. 3;

Fig. 5 is a structural schematic diagram of the first two-position four-way reversing valve shown in Fig. 4;

Fig. 6 is a structural schematic diagram of another working state of the first two-position four-way reversing valve shown in Fig. 5;

Fig. 7 is a structural schematic diagram of the second two-position four-way reversing valve shown in Fig. 4;

Fig. 8 is a schematic diagram of the connection relationship between the first two-position four-way reversing valve and the second two-position four-way reversing valve;

Fig. 9 is a structural schematic diagram of an embodiment in which the reversing mechanism of the present invention transports high-pressure power fluid and outputs formation fluid;

Fig. 10 is a structural schematic diagram of another embodiment of the oil well fluid flooding pumping system of the present invention;

Fig. 11 is a structural schematic diagram of another embodiment of the reversing mechanism of the oil well fluid flooding pumping system shown in Fig. 10 to deliver high-pressure power fluid and output formation fluid.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Please refer to Figure 3 and Figure 4 together. Oil well fluid flooding pumping system, including:

An oil pump core body 61 having a hollow chamber 59 that can be lowered into a predetermined position in the casing 41 of the oil production well, the hollow chamber 59 is provided with a first piston 73 and a second piston 75 that can move therein, The first piston 73 and the second piston 75 are connected by a piston rod 77, the first piston 73 is close to the wellhead of the oil production well, while the second piston 75 is far away from the wellhead, and the first piston 75 is far away from the wellhead. The end surface of a piston 73 close to the wellhead forms a closed first chamber 79 with the oil pump core body 61, and the end surface of the second piston 75 away from the wellhead forms a closed first chamber 79 with the oil pump core body 61. Two chambers 81; the first chamber 79 communicates with the first pipeline 63 and the second pipeline 65, and the second chamber 81 communicates with the third pipeline 67 and the fourth pipeline 69, when the The oil pump core body 61 is lowered into the oil production well, and the formation fluid in the formation can flow into the first chamber 79 and the second chamber through the first pipeline 63 and the third pipeline 67 respectively 81, the formation fluid entering the first chamber 79 and the second chamber 81 can flow out through the second pipeline 65 and the fourth pipeline 69 respectively; the first pipeline 63. The second pipeline 65, the third pipeline 67 and the fourth pipeline 69 are all provided with one-way valves, wherein the one-way valves on the first pipeline 63 and the third pipeline 67 can prevent the The formation fluid in the first chamber 79 and the second chamber 81 flows back; the one-way valves on the second pipeline 65 and the fourth pipeline 69 can prevent the liquid from flowing out of the first chamber Formation fluid reflux in the chamber 79 and the second chamber 81; the reversing valve that is set in the hollow chamber 59 and has a first two-position four-way reversing valve 83 and a second two-position four-way reversing valve 85 mechanism, the reversing mechanism is arranged between the first piston 73 and the second piston 75, and the end face of the first piston 73 away from the wellhead is formed with the reversing mechanism and the oil pump core body 61 A closed third chamber 87, the end face of the second piston 75 close to the wellhead forms a closed fourth chamber 89 with the reversing mechanism and the oil pump core body 61; the first two-position four-way switch The directional valve 83 includes a first port, a second port, a third port and a fourth port, the second port can alternately communicate with the third port and the fourth port, and when the second port communicates with the fourth port When one of the third port and the fourth port communicates, the other of the third port and the fourth port can communicate with the first port; A connecting rod 91 is fixedly connected to the spool of the valve 83, and the two ends of the connecting rod 91 respectively extend into the third chamber 87 and the fourth chamber 89, so that the first piston 73 and the second piston 75 During the movement, the connecting rod 91 can be pushed to drive the spool of the first two-position four-way reversing valve 83 to move; the second two-position four-way reversing valve 85 includes a fifth port and a sixth port. , the seventh port and the eighth port, the eighth port can alternately communicate with the fifth port and the sixth port, and when the eighth port communicates with the fifth port and the sixth port When communicating with one of the fifth port and the sixth port, the other of the fifth port and the sixth port can communicate with the seventh port; the third port and the fourth port communicate with the second two-position four The reversing valve 85 communicates, and high-pressure power fluid can flow into the second two-position four-way reversing valve 85 through the third port and the fourth port to push the valve of the second two-position four-way reversing valve 85. The core moves, the fifth port communicates with the third chamber 87 , and the sixth port communicates with the fourth chamber 89 .

The beneficial effects of the present invention are: the first piston 73 and the second piston 75 are in the process of moving, through Push the connecting rod 91 to drive the spool of the first two-two four-way reversing valve 83, so that the second port of the first two-two four-way reversing valve 83, that is, the high-pressure power fluid inlet can alternate with the third port and the fourth port Communication, so as to guide the high-pressure power fluid into the second two-two four-way reversing valve 85 to push the spool of the second two-two four-way reversing valve 85 to move, so that the eighth of the second two-two four-way reversing valve 85 port, that is, the high-pressure power fluid inlet can alternately communicate with the fifth port and the sixth port, thereby guiding the high-pressure power fluid to alternately enter the third chamber 87 and the fourth chamber 89, and then alternately push the first piston 73 and the second piston 75 Move to squeeze out the formation fluid in the first chamber 79 and the second chamber 81, so that no matter it is an upstroke or a downstroke, fluid can be produced, and while solving the problem of piston load balance, it also solves the problem of the prior art The problem of only relying on a single stroke, that is, the upstroke to pump oil, greatly improves the production efficiency.

The main train of thought of the present invention is to utilize the principle of two-position four-way reversing valve. Driven by external force, the spool of the two-position four-way reversing valve is in different positions, thereby communicating with different ports. Please refer to Figures 5 and 6 for details. The first two-position four-way reversing valve 83 has four ports, namely a first port 97 , a second port 99 , a third port 93 and a fourth port 95 . Specifically, the first port 97 is the return port of the idle power fluid, the second port 99 is the inlet of the high-pressure power fluid, through which the high-pressure power fluid is delivered to the first two-position four-way reversing valve 83, the third port 93, the first The four ports 95 are working ports, which communicate with the second two-position four-way reversing valve 85 . These four ports can all be communicated with the spool moving channel 98 in the first two-two four-way reversing valve 83, and a spool 90 is arranged in the spool moving channel 98, and three shoulders are arranged on the spool 90; When the moving spool 90 drives the three shoulders on it to be in different positions, the four ports will be in different communication states to realize reversing; and the second port 99 is always connected with the third port 93 and the fourth port 95 One of them communicates, while the other of the third port 93 and the fourth port 95 communicates with the first port 97 . Specifically, please refer to Fig. 5, when the spool 90 is in a relatively upper position, the second port 99 communicates with the fourth port 95, and the first port 97 communicates with the third port 93; when the external force pushes the spool 90 down to When it is in a relatively lower position, please refer to FIG. 6 , at this time, the second port 99 communicates with the third port 93 , and the first port 97 communicates with the fourth port 95 .

See Figure 5 or Figure 6. In the embodiment of the present invention, a connecting rod 91 of a certain length is fixedly connected to the spool 90 of the first two-position four-way reversing valve 83, and the two ends of the connecting rod 91 extend to the third chamber 87 and the fourth chamber respectively. 89, when the first piston 73 and the second piston 75 are moving, the connecting rod 91 can push the spool 90 of the first two-position four-way reversing valve 83 to move, thereby realizing reversing.

Please refer to Figure 4 and Figure 7 together. The structure of the second two-position four-way reversing valve 85 is similar to that of the first two-position four-way reversing valve 83 and the working principle of realizing reversing is similar, the difference is that the spool 100 of the second two-position four-way reversing valve 85 is not fixed. connecting rod. The second two-position four-way reversing valve 85 also has four ports, namely the fifth port 101 , the sixth port 102 , the seventh port 103 and the eighth port 104 . Specifically, the fifth port 101 and the sixth port 102 are working ports, which communicate with the third chamber 87 and the fourth chamber 89 respectively; Power fluid inlet, through which high-pressure power fluid is delivered to the second two-position four-way reversing valve 85, and the spool 100 of the second two-position four-way reversing valve 85 forms upper power chambers 106 at both ends during movement and the lower power chamber 107 , the upper power chamber 106 and the lower power chamber 107 are part of the spool moving channel 105 of the second two-position four-way reversing valve 85 .

Please refer to FIG. 8 for the connection relationship between the first two-position four-way switching valve 83 and the second two-position four-way switching valve 85 . The third port 93 and the fourth port 95 communicate with the second two-position four-way reversing valve 85 through the upper power chamber 106 and the lower power chamber 107 respectively, and the high-pressure power fluid through the second port 99 is transferred from the third port 93 or The fourth port 95 flows out and enters the upper power chamber 106 or the lower power chamber 107, thereby pushing the spool 100 of the second two-position four-way reversing valve 85 to move, so that the eighth port 104 is connected with the fifth port 101 and the sixth port 102 Alternate communication to realize commutation.

Therefore, the first two-position four-way reversing valve 83 and the second two-position four-way reversing valve 85 have different external forces to realize the respective spool movement, and the spool 90 of the first two-position four-way reversing valve 83 is passed through the The first piston 73 or the second piston 75 is pushed, while the spool 100 of the second two-position four-way reversing valve 85 is pushed by high-pressure power fluid.

The embodiment of the present invention to deliver high-pressure power fluid to the reversing mechanism and output formation fluid is:

Please refer to Figure 3, Figure 4, Figure 7 and Figure 9 together.

Including the first pipe string 47, the oil well pump core body 61 can be sealed and sleeved in the first pipe string 47, and the pipe wall of the first pipe string 47 is provided with a first channel 64 and a second channel along its axial direction. Two channels 56, the first channel 64 communicates with the first pipeline 63 and the formation, so that the formation fluid in the formation can flow into the first chamber through the first channel 64 and the first pipeline 63 in sequence 79, the formation fluid in the formation enters the second chamber 81 through the third pipeline 67, the second channel 56 communicates with the second port 99 and the eighth port 104, and the first pipe string 47 A radial passage 58 communicating with the second passage 56 is opened in the radial direction, and the high-pressure power fluid in the first pipe string 47 can enter into the second passage 56 through the radial passage 58 and into the The high-pressure power fluid in the second channel 56 enters the first two-position four-way reversing valve 83 and the first two-position four-way reversing valve 85 through the second port 99 and the eighth port 104 respectively.

The oil well pump core body 61 can be lowered into the casing 41 of the oil production well through the first pipe string 47, and a first annular space 45 can be formed between the first pipe string 47 and the casing 41, A packer 57 is connected to the first pipe string 47 below the oil well pump core body 61, and the packer 57 separates the first annulus 45 from the formation. The first port 97, the second The seven ports 103 , the second pipeline 65 and the fourth pipeline 69 communicate with the first annulus 45 .

The working process of this embodiment is:

When the first piston 73 pushes the connecting rod 91 to the bottom dead center, the second port 99 communicates with the third port 93, the fourth port 95 communicates with the first port 97, and the high-pressure power fluid in the second channel 56 passes through the second port 99 and the third port 93 are guided into the upper power chamber 106 of the second two-two four-way reversing valve 85, pushing the spool 100 of the second two-two four-way reversing valve 85 down, so that the eighth port 104 and the fifth The port 101 communicates, and the sixth port 102 communicates with the seventh port 103, so that the high-pressure power fluid in the second channel 56 is guided into the third chamber 87 through the eighth port 104 and the fifth port 101, thereby pushing the first piston 73 up. The upward first piston 73 drives the second piston 75 upward through the piston rod 77, the liquid in the first chamber 79 is squeezed, enters the first annular space 45 through the second pipeline 65, and the space of the second chamber 81 increases. Large, the formation fluid in the formation enters the second chamber 81 through the third pipeline 67, and the idle power fluid in the fourth chamber 89 enters the first annulus 45 through the sixth port 102 and the seventh port 103, and The liquids discharged from the first chamber 79 are mixed and output together. This process is an upstroke.

During the upstroke, the second piston 75 will touch the connecting rod 91 after moving a certain distance, thereby driving the connecting rod 91 to move upward together. When the second piston 75 pushes the connecting rod 91 to the top dead center At this time, the second port 99 communicates with the fourth port 95, and the high-pressure power fluid in the second channel 56 is guided into the second two-position four-way reversing valve 85 through the second port 99 and the fourth port 95. The lower power chamber 107 pushes the spool 100 of the second two-position four-way reversing valve 85 upward, so that the eighth port 104 communicates with the sixth port 102, and the fifth port 101 communicates with the seventh port 103, thereby connecting the second channel The high-pressure power fluid in 56 is guided into the fourth chamber 89 through the eighth port 104 and the sixth port 102 , and then the second piston 75 is pushed down. The descending second piston 75 drives the first piston 73 to descend through the piston rod 77, the liquid in the second chamber 81 is squeezed, enters the first annular space 45 through the fourth pipeline 69, and the space of the first chamber 81 increases. Large, the formation fluid in the formation enters the first chamber 79 through the first channel 64 and the first pipeline 63, and the idle power fluid in the third chamber 87 enters the first ring through the fifth port 101 and the seventh port 103 In the air 45, it is mixed with the liquid discharged from the second chamber 81 and output together. This process is downstroke.

In addition, when the spool 100 of the second two-position four-way reversing valve 85 is moving, it will guide the upper power chamber into the second two-position four-way reversing valve 85 via the third port 93 or the fourth port 95 . 106 or the dead power fluid in the lower power chamber 107 is squeezed out, and this part of the dead power fluid will enter the first two-position port along the third port 93 or the fourth port 95 communicating with the second two-position four-way reversing valve 85 The four-way reversing valve 83 enters the first annular space 45 through the first port 97 communicating with the third port 93 or the fourth port 95 .

Generally, for the convenience of distinction, the liquid entering the first chamber 79 and the second chamber 81 from the formation is called formation fluid, and the liquid entering the first chamber 79 and the second chamber 81 Liquid Due to the pumping force, the liquid squeezed out from the first chamber 79 and the second chamber 81 into the external output pipeline is called produced liquid.

Therefore, the formation fluid extruded through the second pipeline 65 and the fourth pipeline 69, and the exhausted fluid discharged through the first port 97 and the seventh port 103 are mixed into the first annulus 45, and then passed through the first annulus 45 transported to the ground.

The above-mentioned idle power fluid refers to the high-pressure power fluid that has entered the first two-position four-way reversing valve 83 and the second two-position four-way reversing valve 85 and the third chamber 87 and the fourth chamber 89. The high-pressure power fluid needs to do work externally, so its pressure is reduced, and the high-pressure power fluid that completes the work is called the idle power fluid.

Another embodiment of the present invention for delivering high-pressure power fluid to the reversing mechanism and outputting formation fluid is:

Please refer to Figure 7, Figure 10 and Figure 11 together.

A third passage 62 is also arranged in the pipe wall of the first pipe string 47 along its axial direction, and the first port 97, the seventh port 103, the second pipeline 65 and the fourth pipeline 69 are connected with the first The three channels 62 are connected.

The first pipe string 47 is sleeved with a second pipe string 60, the oil well pump core body 61 can be sealed and sleeved in the second pipe string 60, and the oil well pump core body 61 and the wellhead A second annulus 40 is formed between the first pipe string 47 and the second pipe string 60 , and the second annulus 40 communicates with the third channel 62 .

The working process of this embodiment is:

When the first piston 73 pushes the connecting rod 91 to the bottom dead center, the second port 99 communicates with the third port 93, the fourth port 95 communicates with the first port 97, and the high-pressure power fluid in the second channel 56 passes through the second port 99 and the third port 93 are guided into the upper power chamber 106 of the second two-two four-way reversing valve 85, pushing the spool 100 of the second two-two four-way reversing valve 85 down, so that the eighth port 104 and the fifth The port 101 communicates, and the sixth port 102 communicates with the seventh port 103, so that the high-pressure power fluid in the second channel 56 is guided into the third chamber 87 through the eighth port 104 and the fifth port 101, and then a piston 73 is pushed upward . The upward first piston 73 drives the second piston 75 upward through the piston rod 77, the liquid in the first chamber 79 is squeezed and enters the third channel 62 through the second pipeline 65, and the space of the second chamber 81 increases , the formation fluid in the formation enters the third channel 62 through the sixth port 102 and the seventh port 103 through the third pipeline 67 in the second chamber 81, and the passive fluid in the fourth chamber 89 enters the third channel 62 through the sixth port 102 and the seventh port 103. The liquids discharged from the chamber 79 are mixed and output together. This process is an upstroke.

During the upstroke, the second piston 75 will touch the connecting rod 91 after moving a certain distance, thereby driving the connecting rod 91 to move upward together. When the second piston 75 pushes the connecting rod 91 to the top dead center At this time, the second port 99 communicates with the fourth port 95, and the high-pressure power fluid in the second channel 56 is guided into the second two-position four-way reversing valve 85 through the second port 99 and the fourth port 95. The lower power chamber 107 pushes the spool 100 of the second two-position four-way reversing valve 85 upward, so that the eighth port 104 communicates with the sixth port 102, and the fifth port 101 communicates with the seventh port 103, thereby connecting the second channel The high-pressure power fluid in 56 is guided into the fourth chamber 89 through the eighth port 104 and the sixth port 102 , and then the second piston 75 is pushed down. The descending second piston 75 drives the first piston 73 downward through the piston rod 77, and the liquid in the second chamber 81 is squeezed and enters the third channel 62 through the fourth pipeline 69, and the space of the first chamber 81 increases , the formation fluid in the formation enters the first chamber 79 through the first channel 64 and the first pipeline 63, and the idle power fluid in the third chamber 87 enters the third channel 62 through the fifth port 101 and the seventh port 103 , mixed with the liquid discharged from the second chamber 81 and output together. This process is downstroke.

In addition, when the spool 100 of the second two-position four-way reversing valve 85 is moving, it will guide the upper power chamber into the second two-position four-way reversing valve 85 via the third port 93 or the fourth port 95 . 106 or the dead power fluid in the lower power chamber 107 is squeezed out, and this part of the dead power fluid will enter the first two-position port along the third port 93 or the fourth port 95 communicating with the second two-position four-way reversing valve 85 The four-way reversing valve 83 enters the third channel 62 through the first port 97 communicating with the third port 93 or the fourth port 95 .

Therefore, the formation fluid extruded through the second pipeline 65 and the fourth pipeline 69, and the exhausted fluid discharged through the first port 97 and the seventh port 103 are mixed into the third channel 62, and then communicated with the third channel 62 The second annulus 40 is delivered to the surface.

In this embodiment, the mixed fluid delivery channel of formation fluid and idle power fluid is set in the pipe wall of the first pipe string 47, and is transported to the surface through the second annulus 40, without using a packer to separate the formation from the first annulus. The space 45 is separated, and relevant oil well tests such as dynamic fluid level tests can be carried out through the released first annular space 45 .

It should be pointed out that in the above two implementations, the first passage 64, the second passage 56 and the third passage 62 are closed on the end face of the first pipe string 47 close to the formation, preventing the three passages from Formation fluids, high-pressure power fluids, and produced fluids flow into the formation.

Of course, the embodiment of the present invention for delivering high-pressure power fluid to the reversing mechanism is not limited thereto. For example, on the high-pressure power fluid inlet-second port 99 of the first two-two four-way reversing valve 83, and the high-pressure power fluid inlet-eighth port 104 of the second two-two four-way reversing valve 85, the pipelines are respectively connected. , the pipeline communicates with the first pipe string 47, and the high-pressure power fluid in the first pipe string 47 can enter the second port 99 and the eighth port 104 through the pipeline; or the pipeline is directly output from the ground The equipment connection of high-pressure power fluid is used to deliver high-pressure power fluid to the pipeline through the equipment on the ground that outputs high-pressure power fluid.

See Figure 3 or Figure 10. The oil well fluid flooding pumping system according to the embodiment of the present invention also includes a ground part, and the ground part includes: a production fluid output pipeline 42, and the production fluid output pipeline 42 is connected to the first annular space 45/second annular space 40 is connected, and the mixed solution of formation fluid production fluid and exhaust fluid entering the first annulus 45/second annulus 40 is transported to the ground through the production fluid output pipeline 42; the three-phase separation device 44, storage Liquid tank 46, booster pump 48, high-pressure power fluid delivery pipeline 50, the three-phase separation device 44 is connected to the output fluid output pipeline 42, and part of the output fluid in the output fluid output pipeline 42 passes through the After the three-phase separation device 44 is separated and processed, the obtained liquid enters the liquid storage tank 46, and the rest of the liquid is transported to the metering station through the pipeline. After the liquid in the liquid storage tank 46 is pressurized by the booster pump 48, The high-pressure power fluid is delivered to the first pipe string 47 /second pipe string 60 through the high-pressure power fluid delivery pipeline 50 .

The high-pressure power fluid delivery pipeline 50 is provided with a one-way valve 52, and the one-way valve 52 can prevent the high-pressure power fluid that has entered the first pipe string 47/second pipe string 60 from flowing back.

The preferred solution further includes a safety valve 54 , which is arranged on the pipeline connecting the liquid storage tank 46 and the high-pressure power fluid delivery pipeline 50 upstream of the check valve 52 . The effect of installing the safety valve 54 is: once the downhole equipment breaks down and the liquid cannot be lifted to the ground, then the high-pressure power fluid is sent to the first pipe string 47/second pipe string 60, which will cause pressure to be suppressed, so that the high-pressure power fluid The pressure in the delivery pipeline 50 increases, and if the pressure increases to a certain value, the pipeline may burst. In order to prevent this from happening, the safety valve 54 can increase the pressure in the high-pressure power fluid delivery pipeline 50 to a certain value. At this time, the high-pressure power fluid therein is returned to the liquid storage tank 46 along the branch where the safety valve 50 is located, so as to achieve the purpose of pressure relief.

The beneficial effects of the oil well fluid flooding pumping system of the embodiment of the present invention are: the reversing mechanism consisting of the first two-position four-way reversing valve 83 and the second two-position four-way reversing valve 85 is set, the first piston 73 and the second two-way reversing valve 85 During the movement of the second piston 75, the spool of the first two-position four-way reversing valve 83 is driven by pushing the connecting rod 91, so that the second port of the first two-position four-way reversing valve 83, that is, the high-pressure power fluid inlet can be Alternately communicate with the third port and the fourth port, so as to guide the high-pressure power fluid into the second two-two four-way reversing valve 85 to push the spool of the second two-two four-way reversing valve 85 to move, so that the second two-two The eighth port of the four-way reversing valve 85, that is, the high-pressure power fluid inlet can alternately communicate with the fifth port and the sixth port, thereby guiding the high-pressure power fluid to alternately enter the third chamber 87 and the fourth chamber 89, and then alternately push the The first piston 73 and the second piston 75 move to squeeze out the formation fluid in the first chamber 79 and the second chamber 81, so that no matter whether it is an upstroke or a downstroke, fluid can be produced, and the problem of piston load balance can be solved. At the same time, it also solves the problem that the existing technology only relies on a single stroke, that is, the upstroke to pump oil, so that the production efficiency is greatly improved.

The above are only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims (8)

1. Oil well fluid flooding pumping system, characterized in that it comprises: The oil well pump core body has a hollow chamber and can be lowered into a predetermined position in the casing of the oil production well. The hollow chamber is provided with a first piston and a second piston that can move therein. The first piston and the The second piston is connected by a piston rod, the first piston is close to the wellhead of the oil production well, and the second piston is far away from the wellhead, and the end face of the first piston close to the wellhead is connected to the pump The oil pump core body forms an airtight first chamber, and the end face of the second piston away from the wellhead forms an airtight second chamber with the oil pump core body; The first chamber is communicated with a first pipeline and a second pipeline, and the second chamber is communicated with a third pipeline and a fourth pipeline. When the oil pump core body is lowered into the oil production well, The formation fluid in the formation can flow into the first chamber and the second chamber respectively through the first pipeline and the third pipeline, and enter the first chamber and the second chamber The formation fluid in the chamber can flow out through the second pipeline and the fourth pipeline respectively; The first pipeline, the second pipeline, the third pipeline and the fourth pipeline are provided with one-way valves, wherein the one-way valves on the first pipeline and the third pipeline can prevent the The formation fluid in the first chamber and the second chamber flows back; the one-way valves on the second pipeline and the fourth pipeline can prevent the fluid from flowing out of the first chamber and the second chamber Formation fluid backflow in the chamber; A reversing mechanism arranged in the hollow chamber and having a first two-position four-way reversing valve and a second two-position four-way reversing valve, the reversing mechanism is arranged on the first piston and the second piston Between the pistons, the end face of the first piston away from the wellhead forms a closed third chamber with the reversing mechanism and the oil pump core body, and the end face of the second piston close to the wellhead and the reversing mechanism The mechanism and the oil pump core body form a closed fourth chamber; The first two-position four-way reversing valve includes a first port, a second port, a third port, and a fourth port, and the second port can alternately communicate with the third port and the fourth port, and When the second port communicates with one of the third port and the fourth port, the other of the third port and the fourth port can communicate with the first port; The spool of the first two-position four-way reversing valve is fixedly connected with a connecting rod, and the two ends of the connecting rod respectively extend into the third chamber and the fourth chamber, so that the first piston and the second The piston can push the connecting rod during the movement, and drive the spool of the first two-position four-way reversing valve to move; The second two-position four-way reversing valve includes a fifth port, a sixth port, a seventh port, and an eighth port, and the eighth port can alternately communicate with the fifth port and the sixth port, and When the eighth port communicates with one of the fifth port and the sixth port, the other of the fifth port and the sixth port can communicate with the seventh port; The third port and the fourth port are connected to the second two-position four-way reversing valve, and high-pressure power can flow into the second two-position four-way reversing valve through the third port and the fourth port. liquid to push the spool of the second two-position four-way reversing valve to move, the fifth port communicates with the third chamber, and the sixth port communicates with the fourth chamber. 2. The oil well fluid flooding pumping system according to claim 1, characterized in that: it includes a first pipe string, the core body of the oil well pump can be sealed and sleeved in the first pipe string, and the first pipe string A first channel and a second channel are arranged in the pipe wall along its axial direction, and the first channel communicates with the first pipeline and the formation, so that the formation fluid in the formation can pass through the first channel and the second channel in sequence. A pipeline flows into the first chamber, the formation fluid in the formation enters the second chamber through the third pipeline, and the second channel communicates with the second port and the eighth port, The first pipe string is radially provided with a radial passage communicating with the second passage, and the high-pressure power fluid in the first pipe string can enter the second passage through the radial passage. 3. The oil well fluid flooding pumping system according to claim 2, characterized in that: the oil pump core body can be lowered into the casing of the oil production well through the first pipe string, and the first pipe string A first annulus can be formed with the casing, and a packer is connected to the first pipe string below the oil well pump core body, and the packer separates the first annulus from the formation , the first port, the seventh port, the second pipeline and the fourth pipeline communicate with the first annular space. 4. The oil well fluid flooding pumping system as claimed in claim 2, characterized in that: a third passage is arranged in the pipe wall of the first pipe string along its axial direction, and the first port, the seventh port, The second pipeline and the fourth pipeline communicate with the third channel. 5. The oil well fluid flooding pumping system according to claim 4, wherein a second pipe string is sleeved inside the first pipe string, and the oil well pump core body can be sealed and sleeved on the second pipe string. In the string, a second annulus is formed between the first pipe string and the second pipe string between the oil well pump core body and the wellhead, and the second annulus communicates with the third channel. 6. The oil well fluid flooding pumping system according to any one of claims 2 to 5, characterized in that: it includes a ground part, and the ground part comprises: a production fluid output pipeline, the production fluid output pipeline communicates with the first annulus/second annulus; A three-phase separation device, a liquid storage tank, a booster pump, and a high-pressure power fluid delivery pipeline connected in sequence, the three-phase separation device is connected to the output fluid output pipeline, and part of the output fluid in the output fluid output pipeline After the liquid is separated and processed by the three-phase separation device, the obtained liquid enters the liquid storage tank, and the liquid in the liquid storage tank is pressurized by the booster pump, and then transported to the high-pressure power fluid delivery pipeline to the In the first string/second string. 7. The oil well fluid flooding pumping system according to claim 6, characterized in that: said high-pressure power fluid delivery pipeline is provided with a one-way valve, and said one-way valve can prevent the oil from entering said first pipe string/ The high pressure power fluid in the second pipe string returns. 8. The oil well fluid flooding pumping system according to claim 7, characterized in that: it comprises a safety valve, and the safety valve is arranged on the high-pressure power fluid delivery pipeline upstream of the liquid storage tank and the check valve on the pipeline.