A variable displacement lifting device and method for integrated steam injection and oil production

Abstract

The present invention discloses a variable displacement lifting device and method for integrated steam injection and oil production, comprising: a large pump barrel, the upper end of which is connected to an oil pipe; a large plunger, which is arranged inside the large pump barrel and is a hollow structure; a small pump barrel, the upper end of which is connected to the lower end of the large pump barrel; a small plunger, which is arranged inside the small pump barrel and is a solid structure; a disconnector, the upper end of which is connected to the lower end of the large plunger, and the lower end of which is connected to the upper end of the small plunger; a steam injection outer tube, which is sleeved outside the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the above two pump barrels. The present invention can realize integrated exploitation of steam injection and oil production, and can also realize dynamic matching of displacement and well conditions, shorten the drainage period, improve the utilization rate of thermal energy, and extend the production cycle.

Description

Technical Field

[0001] The invention relates to the technical field of steam stimulation and extraction of heavy oil wells, in particular to a variable displacement lifting device and method for integrated steam injection and oil extraction. Background Art

[0002] In the steam-huffing well mining method, the integrated injection-production technology has been widely used. This technology can effectively improve the utilization rate of injected heat energy, enhance the mining effect of the huffing well, save construction procedures and reduce operating costs.

[0003] As the number of rounds of this type of steam well increases, the water storage in the formation continues to increase, and the time used for drainage in the early stage of the pumping is getting longer and longer. At the same time, due to the physical properties of the formation and crude oil, the throughput cycle of many wells is too short. In the limited oil production time, the drainage time accounts for a large proportion due to the displacement of the oil pump, and the effective oil production time is short. It is necessary to increase the displacement of the oil pump and shorten the drainage period. In the later stage of the oil production stage, the liquid volume drops significantly, and the displacement of the oil pump needs to be reduced to achieve supply and drainage coordination. The contradiction between rapid drainage in the early stage and slow oil production in the later stage is gradually increasing, and the demand for variable displacement oil production technology is increasing.

[0004] From this point of view, the demand for integrated injection and production technology and variable displacement lifting technology is increasingly overlapping. The existing lifting methods can meet the needs of single injection and production integration or single variable displacement lifting, such as long plunger injection and production pumps, offset valve oil pumps, etc., which can realize the integration of steam injection and oil production, save construction procedures, and reduce operating costs, but cannot complete the displacement change; conventional variable displacement oil pumps can achieve variable displacement lifting, achieve the matching of supply and discharge before and after the well, and improve the oil-gas ratio, but do not have the steam injection function and cannot achieve injection and production integration. It can be seen that there is no lifting method and device that combines the two functions of integrated injection and production and variable displacement lifting.

[0005] Application number: 201910395250.2, application date: 2019-05-13 It involves a tandem double-acting injection and production pump for high water-content oil wells, which is mainly composed of a disconnector, an upper oil pipe coupling, a double-acting oil well pump assembly, an intermediate coupling, an intermediate pump barrel, a core rod, a double-acting water injection pump assembly, a cyclone assembly, and a flow channel. The upper end of the double-acting oil well pump assembly is connected to the upper oil pipe coupling, an upper plunger is provided in the double-acting oil well pump assembly, the disconnector is installed at the upper end of the disconnector joint of the upper plunger, the lower end of the double-acting oil well pump assembly is connected to the intermediate coupling and the intermediate pump barrel in sequence, the lower end of the intermediate pump barrel is connected to the double-acting water injection pump assembly, the double-acting water injection pump assembly is provided with a lower plunger, the lower plunger is connected to the upper plunger through the core rod, and the cyclone assembly is installed at the lower end of the double-acting water injection pump assembly. The pump completes two oil productions and two water injections for one reciprocating motion of the sucker rod, which can reduce the flow fluctuation of the liquid entering the downhole cyclone and improve the separation efficiency of the downhole cyclone.

[0006] Application number: 201320847954.7, application date: 2013-12-22 relates to an oil production equipment, in particular to a series injection and production pump, the technical scheme of which is: comprising an oil pipe, a sucker rod, a small pump barrel, a small plunger, a disconnector, a large pump barrel, and a large plunger, a sucker rod is arranged inside the oil pipe, the oil pipe is connected to the small pump barrel and the large pump barrel in sequence from top to bottom, a small plunger is arranged inside the small pump barrel, a large plunger is arranged inside the large pump barrel, the sucker rod is connected to the small plunger, and the small plunger is connected to the large plunger through the disconnector; the beneficial effects of the utility model are: the structure of the oil production double-plunger pump in series realizes the integration of injection and production, improves the working efficiency, realizes the rapid pumping, and improves the production efficiency of the oil field.

[0007] Application No.: 201120187629.3, Application Date: 2011-05-24 Disclosed is an extra heavy oil injection and production pump, which is particularly suitable for the production of extra heavy oil wells. The utility model is composed of a disconnector (2), a pump barrel assembly (6), a plunger assembly (12), and a fixed valve assembly (19). The plunger assembly (12) is connected to a hollow sucker rod through the disconnector (2). A plurality of plunger steam injection grooves (8) and pump barrel steam injection grooves (9) are provided on the plunger (7) and the pump barrel (10). An outer barrel (11) is arranged outside the pump barrel (10). The upper and lower ends of the outer barrel (11) are connected to a heat-insulating oil pipe through an outer barrel upper joint (5) and an outer barrel lower joint (20). A lock ring (16) is arranged between the plunger lower joint (13) and the fixed valve upper joint (18). Since the disconnector (2) is provided between the sucker pump and the hollow sucker rod, the hollow sucker rod can be lowered after steam injection, thereby realizing a pump-up hot water seepage process and an electric heating process, and steam can be injected into the formation at any well section.

[0008] Application No.: 201320025350.4, Application Date: 2013-01-07 Disclosed is an ultra-heavy oil steam injection and oil production integrated oil pump, which is particularly suitable for the production of ultra-heavy oil wells. The utility model is composed of a disconnector assembly (2), a sealing and locking assembly (5), a pump barrel assembly (10), a plunger assembly (11), and a fixed valve assembly (18). The lower part of the plunger lower joint (13) of the plunger assembly (11) is provided with a groove (14) and two spiral claws (15). The upper part of the fixed valve assembly (18) is provided with a cross-connected push rod (16) and a cross rod (17). The upper end surface of the support ring (8) of the pump barrel assembly (10) is provided with a conical surface that matches with the sealing ring (6) of the sealing and locking assembly (5). The lower end surface of the support ring (8) of the pump barrel assembly (10) is provided with a conical surface that matches with the claws (7) of the sealing and locking assembly (5). The utility model can realize a large-diameter oil well pump and steam injection thermal recovery and heating processes such as mixing hot water or cable heating on the pump, and can inject steam into the formation at any well section.

[0009] Application number: 200520114995.0, application date: 2005-08-03 discloses a high-efficiency and energy-saving rod pump, which includes a rod, an oil pipe, a floating valve, a plunger, a pump barrel, a sealed rod, a sealing nipple, a fixed valve, a disconnection mechanism, and a fixed valve seat. The invention is characterized in that the fixed valve is located at the top of the pump barrel, the floating valve is placed below the fixed valve seat, a large-diameter pump barrel with an enlarged inner diameter is arranged in the middle of the pump barrel, and a spring push rod is arranged and fixed in the fixed valve channel. The formation fluid will generate an upward force on the plunger to achieve energy saving of the pumping unit, and the double effect of the upward inertial force of the formation fluid and the active downward capture force of the plunger can achieve the improvement of pump efficiency. The pump can meet the needs of steam injection and oil production in steam throughput or steam drive oil wells, and can also meet the process technologies of acidification, blockage removal, wax removal, and descaling without moving the pipe column in the oil well.

[0010] Application number: 89206034.4, application date: 1989-04-28 A variable displacement heavy oil pump for steam production, the device connects an oil inlet valve between the pump barrel and the sealing nipple, and connects a disconnecting device (6) between the plunger and the light rod of the pump, so that the plunger and the light rod can be separated or connected at will. The volume cavity becomes larger as the plunger and the light rod are separated; it becomes smaller as the plunger and the light rod are connected, so that the displacement of the pump also changes in size. The pump not only realizes the pumping without moving the pipe column after steam injection, but also meets the production needs of each stage of steam injection and oil production. In the same steam throughput cycle, it does not need to change the pump for production, reducing the heat loss of the oil layer, extending the pump inspection cycle, and increasing the oil well production.

[0011] The technical solutions, technical problems to be solved and beneficial effects produced by the above-disclosed technologies are different from the present invention, or are in different technical fields or application scenarios. Regarding more technical features, technical problems to be solved and beneficial effects of the present invention, the above-disclosed technical documents do not contain any technical inspiration. Summary of the invention

[0012] The purpose of the present invention is to provide an integrated variable displacement lifting device and method for steam injection and oil production, which can not only realize integrated production of steam injection and oil production, but also realize dynamic matching of displacement and well conditions, shorten the drainage period, improve thermal energy utilization, and extend the production cycle.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0015] A large pump barrel, the upper end of which is connected to an oil pipe;

[0016] A large plunger, wherein the large plunger is arranged inside the large pump barrel and has a hollow structure;

[0017] A small pump barrel, the upper end of which is connected to the lower end of the large pump barrel;

[0018] A small plunger, the small plunger is arranged inside the small pump barrel, and the small plunger is a solid structure;

[0019] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0020] The steam injection outer tube is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0021] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0022] Furthermore, the large pump barrel is provided with a radial second steam injection hole, which is connected to the annular steam injection channel. The large plunger is provided with a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole runs to the second steam injection hole.

[0023] Furthermore, it also includes:

[0024] A fixed valve is provided at the bottom of the inner cavity of the large pump barrel, and an oil supply port connected to the inner cavity of the steam injection outer pipe is opened at the bottom of the offset cavity. A fixed valve is installed in the offset cavity. The fixed valve blocks the oil supply port in one direction, that is, it is a one-way valve.

[0025] Furthermore, it also includes:

[0026] A traveling valve is arranged at the bottom port of the large plunger, which is also a one-way valve. The lower port of the traveling valve is connected to the bias chamber.

[0027] Furthermore, an oil outlet is provided at the upper end of the large plunger, and a diameter expansion limit ring is provided on the outer wall of the upper end of the small plunger, and the outer diameter of the diameter expansion limit ring is larger than the inner diameter of the upper port of the small pump barrel.

[0028] Furthermore, the upper end of the large plunger is connected to the sucker rod.

[0029] Furthermore, the disconnector comprises:

[0030] The disconnector upper body is a slot body connected to the lower end of the large plunger or the lower end of the traveling valve at the lower end of the large plunger;

[0031] The lower body of the disconnector is a clamping head, which is clamped into the clamping slot body, and the lower end of the clamping head is connected to a small plunger.

[0032] In order to achieve the above object, the present invention adopts the following technical solutions:

[0033] A variable displacement lifting method for integrated steam injection and oil production, comprising the following steps:

[0034] Steam injection steps: During construction, the small plunger is pre-set in the small pump barrel and lowered together with the oil pipe, and the large plunger is lowered together with the sucker rod; when the pump is touched, the upper body of the disconnector and the lower body of the disconnector enter a docking state, connecting the large and small plungers in series, and at the same time, the large plunger and the steam injection hole on the large pump barrel enter an overlapping state, and the steam injection channel is constructed. At this time, the hot steam injected into the well is injected into the formation along the steam injection channel;

[0035] After the well is soaked and the blowout is released, the sucker rod is lifted up with the large plunger upward until the disconnector is disengaged. At this time, the small plunger naturally falls back to the bottom of the pump. After the rod column is lifted to prevent the impact, the large plunger is lowered to the bottom dead center. At this time, only the large pump is used for production to achieve large-volume rapid discharge of liquid. When the liquid volume is insufficient in the later stage, the rod column is lowered through the pumping unit, the upper body of the disconnector and the lower body of the disconnector are docked again, the large and small plungers are connected in series, and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted.

[0036] Further, the following steps are included:

[0037] Lifting and steam injection steps: During construction, the small plunger is pre-set in the small pump barrel and lowered together with the oil pipe, and the large plunger is lowered together with the sucker rod; when the pump is touched, the upper body of the disconnector and the lower body of the disconnector enter the docking state, the anti-impact distance is measured, and a mark is made on the rod column, and then the sucker rod is lifted up to carry the plunger string upward until the disconnector is disengaged. At this time, the small plunger naturally falls back to the bottom of the pump, and the large plunger is continued to be lifted up to the outside of the pump barrel. The steam injection channel is completed, and the hot steam injected into the well is injected into the formation along the steam injection channel;

[0038] After soaking the well and releasing the blowout, the large plunger is lowered to the mark made before, that is, the bottom dead center of pumping. At this time, only the large pump is used for production to achieve large-volume rapid drainage. When the liquid volume is insufficient in the later stage, the rod column is lowered by the pumping unit, the upper body of the disconnector and the lower body of the disconnector are connected again, the large and small plungers are connected in series, and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] According to the on-site process requirements, the large plunger is lowered to the bottom, or the large plunger is completely lifted out of the pump barrel to construct a steam injection channel, thus realizing the steam injection function; the large plunger or plunger string is lifted up a certain distance to stagger the side holes on the large pump barrel and the large plunger, the steam injection hole is closed, and this position is used as the bottom dead center of pumping to carry out oil production. When the large pump barrel and the large plunger are used alone for production, the lifting capacity and displacement are large, which can realize the early rapid drainage of the throughput well; after the disconnector is docked to form a series of plunger strings, the lifting capacity is reduced, the displacement is reduced, but the feedback force is increased, which is more suitable for the working conditions in the later stage of throughput. According to the above functions, the integrated injection and production variable displacement lifting can be realized.

[0041] The lifting method and device can be applied in steam-huffing wells, which can not only realize integrated production of steam injection and oil production, but also realize dynamic matching of displacement and well conditions, shorten the drainage period, and improve the utilization rate of thermal energy. The application prospect is broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a variable displacement lifting device integrated with steam injection and oil production according to the present invention.

[0043] In the figure: 1-large pump barrel; 2-large plunger; 3-steam injection outer pipe; 4-steam injection hole; 5-disconnector upper body; 6-disconnector lower body; 7-small pump barrel; 8-small plunger; 9-traveling valve; 10-fixed valve; 11-sucker rod. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Embodiment 1:

[0046] See also Figure 1 , the present invention provides a technical solution:

[0047] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0048] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0049] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0050] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0051] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0052] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0053] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0054] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0055] Furthermore, the large pump barrel has a radial second steam injection hole, which is connected to the annular steam injection channel, and the large plunger has a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole moves to the second steam injection hole. The two steam injection holes are marked with a number on the drawing, namely, steam injection hole 4.

[0056] Furthermore, it also includes:

[0057] Fixed valve 10, an offset cavity is also arranged at the bottom end of the inner cavity of the large pump barrel, an oil supply port connected to the inner cavity of the steam injection outer pipe is opened at the bottom of the offset cavity, and a fixed valve is installed in the offset cavity. The fixed valve blocks the oil supply port in one direction, that is, it is a one-way valve.

[0058] Furthermore, it also includes:

[0059] The swimming valve 9, the swimming valve is arranged at the bottom port of the large plunger, which is also a one-way valve, and the lower port of the swimming valve is communicated with the bias cavity.

[0060] Furthermore, an oil outlet is provided at the upper end of the large plunger, and a diameter expansion limit ring is provided on the outer wall of the upper end of the small plunger, and the outer diameter of the diameter expansion limit ring is larger than the inner diameter of the upper port of the small pump barrel.

[0061] Furthermore, the upper end of the large plunger is connected to the sucker rod 11.

[0062] Furthermore, the disconnector comprises:

[0063] The disconnector upper body 5 is a card slot body connected to the lower end of the large plunger or the lower end of the traveling valve at the lower end of the large plunger;

[0064] The disconnector lower body 6 is a clamping head, which is clamped into the clamping slot body, and the lower end of the clamping head is connected to a small plunger.

[0065] The device consists of a large pump barrel 1, a large plunger 2, a steam injection outer tube 3, a disconnector upper body 5, a disconnector lower body 6, a small pump barrel 7, a small plunger 8, a floating valve 9, and a fixed valve 10. The large plunger 2 is connected to the sucker rod 11 and can move up and down with the sucker rod. Side holes are opened on the large pump barrel 1 and the large plunger 2. When the pump is hit, the side holes can be docked to form a steam injection hole 4, providing a channel for hot steam to enter the oil layer. In addition, the large plunger 2 can be completely lifted out of the pump barrel to make way for the steam injection channel. After the hot steam comes out of the steam injection hole, it goes down to the pump along the sandwich cavity constructed by the steam injection outer tube 3 and enters the oil layer. The upper body 5 of the disconnector is connected to the lower end of the large plunger 2, and the lower body 6 of the disconnector is connected to the upper end of the small plunger 8. The two can be connected by a bump pump and disconnected after a certain lifting stroke. The connection and disconnection of the disconnector are to achieve the connection and disconnection between the large plunger 2 and the small plunger 8. When the disconnectors are connected together, the large plunger 2 and the small plunger 8 are connected in series to form a plunger string, which can move up and down with the sucker rod 11.

[0066] The variable displacement lifting method for integrated injection and production is realized by relying on this device: according to the on-site process requirements, the large plunger 2 is lowered to the bottom, or the large plunger 2 is completely lifted out of the pump barrel to construct a steam injection channel, thus realizing the steam injection function; the large plunger or plunger string is lifted up a certain distance to stagger the side holes on the large pump barrel 1 and the large plunger 2, the steam injection hole is closed, and this position is used as the bottom dead center of pumping, and oil production can be carried out. When the large pump barrel 1 and the large plunger 2 are used alone for production, the lifting capacity is large and the displacement is also large, which can realize the early rapid drainage of the throughput well; after the disconnector is docked and a series of plungers is formed, the lifting capacity is reduced, the displacement is reduced, but the feedback force is increased, which is more suitable for the working conditions in the later stage of throughput. According to the above functions, the variable displacement lifting for integrated injection and production can be realized.

[0067] Method 1 (lowering steam injection): During construction, the small plunger 8 is pre-set in the small pump barrel 7 and lowered together with the oil pipe, and the large plunger 2 is lowered together with the sucker rod 11. When the pump is touched, the upper body 5 of the disconnector and the lower body 6 of the disconnector enter the docking state, connecting the large and small plungers in series, and at the same time, the large plunger 2 and the steam injection hole 4 on the large pump barrel 1 enter the overlapping state, and the steam injection channel is constructed. At this time, the hot steam injected into the well is injected into the formation along the steam injection channel.

[0068] After the well is soaked and the blowout is released, the sucker rod 11 is lifted up with the large plunger until the disconnector is disengaged. At this time, the small plunger 8 naturally falls back to the bottom of the pump. After the rod column is lifted to prevent the impact, the large plunger is lowered to the bottom dead center. At this time, only the large pump is used for production to achieve rapid drainage. When the liquid volume is insufficient in the later stage, the rod column is lowered by the pumping unit, the upper body 5 of the disconnector is docked with the lower body 6 of the disconnector again, and the large and small plungers are connected in series and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted.

[0069] Method 2 (lifting and steam injection): During construction, the small plunger 8 is pre-set in the small pump barrel 7 and lowered together with the oil pipe, and the large plunger 2 is lowered together with the sucker rod 11. When the pump is touched, the upper body 5 of the disconnector and the lower body 6 of the disconnector enter the docking state, the anti-collision distance is measured, and a mark is made on the rod column. Then the sucker rod 11 is lifted up to carry the plunger string upward until the disconnector is disengaged. At this time, the small plunger 8 naturally falls back to the bottom of the pump, and the large plunger 2 is continuously lifted up to the outside of the pump barrel. The steam injection channel is constructed, and the hot steam injected into the well is injected into the formation along the steam injection channel.

[0070] After soaking the well and releasing the blowout, the large plunger is lowered to the mark made before, that is, the bottom dead center of the pumping. At this time, only the large pump is used for production to achieve rapid drainage. When the liquid volume is insufficient in the later stage, the rod column is lowered by the pumping unit, the upper body 5 of the disconnector and the lower body 6 of the disconnector are connected again, and the large and small plungers are connected in series and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted.

[0071] Embodiment 2:

[0072] See also Figure 1 , the present invention provides a technical solution:

[0073] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0074] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0075] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0076] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0077] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0078] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0079] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0080] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0081] Furthermore, the large pump barrel has a radial second steam injection hole, which is connected to the annular steam injection channel, and the large plunger has a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole moves to the second steam injection hole. The two steam injection holes are marked with a number on the drawing, namely, steam injection hole 4.

[0082] Furthermore, it also includes:

[0083] Fixed valve 10, an offset cavity is also arranged at the bottom end of the inner cavity of the large pump barrel, an oil supply port connected to the inner cavity of the steam injection outer pipe is opened at the bottom of the offset cavity, and a fixed valve is installed in the offset cavity. The fixed valve blocks the oil supply port in one direction, that is, it is a one-way valve.

[0084] Furthermore, it also includes:

[0085] The swimming valve 9, the swimming valve is arranged at the bottom port of the large plunger, which is also a one-way valve, and the lower port of the swimming valve is communicated with the bias cavity.

[0086] Furthermore, an oil outlet is provided at the upper end of the large plunger, and a diameter expansion limit ring is provided on the outer wall of the upper end of the small plunger, and the outer diameter of the diameter expansion limit ring is larger than the inner diameter of the upper port of the small pump barrel.

[0087] Furthermore, the upper end of the large plunger is connected to the sucker rod 11.

[0088] Embodiment 3:

[0089] See also Figure 1 , the present invention provides a technical solution:

[0090] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0091] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0092] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0093] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0094] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0095] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0096] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0097] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0098] Furthermore, the large pump barrel has a radial second steam injection hole, which is connected to the annular steam injection channel, and the large plunger has a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole moves to the second steam injection hole. The two steam injection holes are marked with a number on the drawing, namely, steam injection hole 4.

[0099] Furthermore, it also includes:

[0100] Fixed valve 10, an offset cavity is also arranged at the bottom end of the inner cavity of the large pump barrel, an oil supply port connected to the inner cavity of the steam injection outer pipe is opened at the bottom of the offset cavity, and a fixed valve is installed in the offset cavity. The fixed valve blocks the oil supply port in one direction, that is, it is a one-way valve.

[0101] Furthermore, it also includes:

[0102] The swimming valve 9, the swimming valve is arranged at the bottom port of the large plunger, which is also a one-way valve, and the lower port of the swimming valve is communicated with the bias cavity.

[0103] Embodiment 4:

[0104] See also Figure 1 , the present invention provides a technical solution:

[0105] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0106] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0107] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0108] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0109] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0110] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0111] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0112] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0113] Furthermore, the large pump barrel has a radial second steam injection hole, which is connected to the annular steam injection channel, and the large plunger has a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole moves to the second steam injection hole. The two steam injection holes are marked with a number on the drawing, namely, steam injection hole 4.

[0114] Embodiment 5:

[0115] See also Figure 1 , the present invention provides a technical solution:

[0116] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0117] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0118] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0119] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0120] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0121] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0122] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0123] Furthermore, the upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel.

[0124] Embodiment 6:

[0125] See also Figure 1 , the present invention provides a technical solution:

[0126] A steam injection and oil production integrated variable displacement lifting device, comprising:

[0127] A large pump barrel 1, the upper end of which is connected to an oil pipe;

[0128] A large plunger 2, which is arranged inside the large pump barrel and has a hollow structure;

[0129] A small pump barrel 7, the upper end of which is connected to the lower end of the large pump barrel;

[0130] A small plunger 8, which is arranged inside the small pump barrel and is a solid structure;

[0131] A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger;

[0132] The steam injection outer tube 3 is sleeved on the outside of the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the steam injection outer tube and the outer walls of the two pump barrels.

[0133] Although all the above embodiments use Figure 1 However, as a person skilled in the art can clearly know, there is no need to provide a separate drawing to represent, as long as the missing parts or structural features in the embodiment are removed from the drawing. This is clear to those skilled in the art. Of course, the embodiment with more parts is only the optimal embodiment, and the embodiment with fewer parts is the basic embodiment, but it can also achieve the basic purpose of the invention, so all of them are within the scope of protection of the present invention.

[0134] All parts and components not discussed in detail in this application and the connection methods of the parts and components in this application belong to the well-known technology in this technical field and will not be described in detail, such as welding, threaded connection, etc.

[0135] In the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0136] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0137] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0138] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable displacement lifting device for integrated steam injection and oil production, characterized in that: include: A large pump barrel, the upper end of which is connected to an oil pipe; A large plunger, wherein the large plunger is arranged inside the large pump barrel and has a hollow structure; A small pump barrel, the upper end of which is connected to the lower end of the large pump barrel; A small plunger, the small plunger is arranged inside the small pump barrel, and the small plunger is a solid structure; A disconnector, wherein the upper end of the disconnector is connected to the lower end of the large plunger, and the lower end of the disconnector is connected to the upper end of the small plunger; An outer steam injection pipe, which is sleeved outside the large pump barrel and the small pump barrel, and an annular steam injection channel is formed between the inner wall of the outer steam injection pipe and the outer walls of the two pump barrels; The upper end of the steam injection outer pipe is also connected to the oil pipe, and the lower end of the oil pipe is blocked facing the upper port of the annular steam injection channel; The large pump barrel is provided with a radial second steam injection hole, which is connected to the annular steam injection channel; the large plunger is provided with a radial first steam injection hole, which is also connected to the annular steam injection channel when the first steam injection hole moves to the second steam injection hole; Also includes: A fixed valve, a bias cavity is also arranged at the bottom of the inner cavity of the large pump barrel, an oil supply port connected to the inner cavity of the steam injection outer pipe is opened at the bottom of the bias cavity, and a fixed valve is installed in the bias cavity, and the fixed valve blocks the oil supply port in one direction, that is, a one-way valve; A traveling valve is provided at the bottom port of the large plunger, which is also a one-way valve, and the lower port of the traveling valve is connected to the bias chamber; The upper end of the large plunger is provided with an oil outlet, and the outer wall of the upper end of the small plunger is provided with a diameter expansion limit ring, the outer diameter of the diameter expansion limit ring is larger than the inner diameter of the upper end of the small pump barrel; The upper end of the large plunger is connected to the sucker rod; The disconnector comprises: The disconnector upper body is a slot body connected to the lower end of the large plunger or the lower end of the traveling valve at the lower end of the large plunger; The lower body of the disconnector is a clamping head, which is clamped into the clamping slot body, and the lower end of the clamping head is connected to a small plunger.

2. A method for using the variable displacement lifting device for integrated steam injection and oil production as claimed in claim 1, characterized in that: The following steps are involved: Steam injection steps: During construction, the small plunger is pre-set in the small pump barrel and lowered together with the oil pipe, and the large plunger is lowered together with the sucker rod; when the pump is touched, the upper body of the disconnector and the lower body of the disconnector enter a docking state, connecting the large and small plungers in series, and at the same time, the large plunger and the steam injection hole on the large pump barrel enter an overlapping state, and the steam injection channel is constructed. At this time, the hot steam injected into the well is injected into the formation along the steam injection channel; After the well is soaked and blowout is released, the sucker rod is lifted up to carry the large plunger upward until the disconnector is disengaged. At this time, the small plunger naturally falls back to the bottom of the pump. After the rod column is lifted to prevent impact, the large plunger is lowered to the bottom dead center. At this time, only the large pump is used for production to achieve large-volume rapid discharge of liquid. When the liquid volume is insufficient in the later stage, the rod column is lowered through the pumping unit, the upper body of the disconnector and the lower body of the disconnector are connected again, the large and small plungers are connected in series, and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted; Lifting and steam injection steps: During construction, the small plunger is pre-set in the small pump barrel and lowered together with the oil pipe, and the large plunger is lowered together with the sucker rod; when the pump is touched, the upper body of the disconnector and the lower body of the disconnector enter the docking state, the anti-impact distance is measured, and a mark is made on the rod column, and then the sucker rod is lifted up to carry the plunger string upward until the disconnector is disengaged. At this time, the small plunger naturally falls back to the bottom of the pump, and the large plunger is continued to be lifted up to the outside of the pump barrel. The steam injection channel is completed, and the hot steam injected into the well is injected into the formation along the steam injection channel; After soaking the well and releasing the blowout, the large plunger is lowered to the mark made before, that is, the bottom dead center of pumping. At this time, only the large pump is used for production to achieve large-volume rapid drainage. When the liquid volume is insufficient in the later stage, the rod column is lowered by the pumping unit, the upper body of the disconnector and the lower body of the disconnector are connected again, the large and small plungers are connected in series, and then lifted to the original bottom dead center position. At this time, the displacement can be reduced and the small pump can be lifted.

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