Rodless oil production system and oil production method

Abstract

The rodless oil production system comprises a control device, a rotary power output device and a plunger pump, a plunger in the plunger pump is arranged in a cylinder body in a sliding mode and can do reciprocating motion, and one end of the plunger and the top of the cylinder body form a sealed working containing cavity; the other end of the plunger is connected with the rotating power output end of a threaded driving rod, and the rotating power input end of the threaded driving rod is used for extending out of the cylinder body to be connected with the rotating power output end of a rotating power output device. The liquid outlet one-way valve port and the liquid inlet one-way valve port are arranged at the upper part of the cylinder body, an inlet of the liquid outlet one-way valve port is communicated with the sealed working cavity, and an outlet is communicated with an overground oil outlet pipeline; an outlet of the liquid inlet one-way valve port is communicated with the sealed working cavity; the control device is electrically connected with the rotary power output device and used for sending an oil extraction instruction to the rotary power output device to control the threaded driving rod to rotate forwards and backwards, and the purpose of efficient acting is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil production, and more specifically, to a rodless oil production system and an oil production method. Background Art

[0002] The underground oil extraction process can be mainly divided into two stages. In the first extraction stage, the energy of the underground oil reservoir is used to extract oil, and the oil can gush to the ground by itself, which is called primary oil recovery. In the second extraction stage, the energy of machinery is used to extract oil, and the oil is lifted from underground to the ground under the action of mechanical energy, which is called secondary oil recovery. There are various types of mechanical equipment commonly used in secondary oil recovery, which can be applied to different underground oil extraction environments. For example, the commonly used secondary oil recovery equipment is divided into rod pump oil production devices and rodless pump oil production devices.

[0003] Among them, the commonly used rod pump oil production devices include pumping units and screw pumps.

[0004] A pumping unit converts the rotary motion of an electric motor into the up-and-down reciprocating motion of a walking beam through a crank connecting rod mechanism. The pumping rod transmits the reciprocating motion of the walking beam to the oil production pump, driving the piston of the oil production pump to reciprocate in the pump barrel. The oil production pump completes one suction of well fluid when the piston reciprocates once. When the formation fluid supply is sufficient and the working condition of the oil production pump is good, the pump efficiency of the pumping unit is relatively high. However, since it is a rod pumping method, the pumping unit that provides power is installed on the ground, and the reciprocating motion of the pumping unit must be transmitted to the oil production pump through the pumping rod. On the one hand, the pumping unit does work on the liquid column above the piston, and also does work on the pumping rod and the balance weight. At the same time, it also has to overcome the friction load and vibration load. Generally, about 80% of the electrical energy of the pumping unit motor is consumed in overcoming the mechanical itself and various friction and vibration loads, which belongs to useless work, and only about 20% of the electrical energy is used to lift the liquid column. This will result in a low electrical energy utilization rate. At the same time, due to material limitations, the oil production pump cannot be lowered too deep into the wellbore, and the ground pumping unit cannot be made too large, which limits the application of the pumping unit in oilfields that require deep pumping. The pumping rod often breaks and disconnects during use, causing accidents.

[0005] A screw pump drives the downhole screw pump to rotate through a speed reduction mechanism after the high-speed rotary motion of the electric motor, sucks and lifts the well fluid to the ground. Its disadvantages are that the screw pump cannot be lowered too deep into the well, the pumping rod is easily twisted off, and the torque is transmitted through the slender pumping rod, resulting in large energy loss and low electrical energy utilization rate.

[0006] Among them, the common rodless oil production devices include electric pumps, jet pumps, and hydraulic piston pumps. An electric pump transmits electrical energy to a downhole motor through a cable. The motor rotates to drive a centrifugal pump to rotate, thereby lifting well fluid to the ground. Since the electric pump unit has no redundant auxiliary equipment, the motor directly transmits kinetic energy to the centrifugal pump, and the centrifugal pump directly does work on the well fluid. However, the characteristics of the centrifugal pump's own characteristic curve result in a low pump efficiency under high lift and high displacement conditions, which is not conducive to the efficient utilization of electrical energy.

[0007] A jet pump is a ground device that pressurizes the power fluid on the ground and transports it to a downhole nozzle through a dedicated power fluid transmission pipeline. The pressure energy is converted into kinetic energy through the nozzle, forming a low-pressure area behind the nozzle. The formation produced fluid flows in and mixes with the power fluid, and the kinetic energy is converted into pressure energy through a diffuser pipe, thereby lifting the mixed fluid to the ground. Its characteristics are few moving parts and a compact structure, but it is not suitable for deep well oil production and has low efficiency.

[0008] A hydraulic piston pump is a ground device that pressurizes the power fluid and transports the power fluid to a downhole hydraulic motor through a tubing or a dedicated power fluid transmission pipeline. The power fluid drives the hydraulic motor to lift the crude oil to the ground. The characteristics of the hydraulic piston pump are that the unit structure is complex, the processing accuracy requirements are high, the ground supporting system is large, and the investment efficiency is low. Summary of the Invention

[0009] In order to solve the problems existing in the prior art, the present invention provides a rodless oil production system and an oil production method. By utilizing the high-efficiency characteristics of a piston pump, it abandons the disadvantages of doing work on the sucker rod during the operation of the oil production machine. It efficiently converts electrical energy into mechanical energy by using a rotary power output device, and efficiently converts mechanical energy into the pressure of formation fluid to lift the oil to the ground, with low energy consumption and great application prospects in the field of deep well oil production.

[0010] To achieve the above object, the present invention provides the following technical solution: A rodless oil production system includes a control device, a rotary power output device, and a piston pump. The piston in the piston pump is slidably arranged in the cylinder block and can reciprocate. One end of the piston forms a sealed working cavity with the top of the cylinder block. An outlet check valve port and an inlet check valve port are arranged on the upper part of the cylinder block. The inlet of the outlet check valve port is communicated with the sealed working cavity, and the outlet is communicated with the above-ground oil outlet pipeline; the inlet of the inlet check valve port is communicated with the oil layer, and the outlet is communicated with the sealed working cavity; the other end of the piston is connected to the rotary power output end of a threaded drive rod, and the rotary power input end of the threaded drive rod extends out of the cylinder block and is connected to the rotary power output end of the rotary power output device; the control device is electrically connected to the rotary power output device for sending an oil production instruction to the rotary power output device to control the forward and reverse rotation of the threaded drive rod.

[0011] Further, the cylinder block includes a pump head and a pump barrel. The pump head seals the first end opening of the pump barrel. The plunger is slidably arranged in the pump barrel and can reciprocate. The inlet check valve port is circumferentially arranged between the pump head and the first end opening of the pump barrel. The outlet check valve port is arranged at the top of the pump head. The rotational power input end of the threaded drive rod extends out of the pump barrel and is connected to the rotational power output end of the rotational power output device.

[0012] Further, the pump barrel includes a first pump barrel and a second pump barrel. The pump head covers the first end opening of the first pump barrel. The second end opening of the first pump barrel is sealingly connected to the first end opening of the second pump barrel. The top of the plunger reciprocates in the first pump barrel. The threaded drive rod passes through the shaft hole provided at the second end of the second pump barrel and is connected to the rotational power output end of the rotational power output device; a thrust bearing and a fixing nut are sleeved on the threaded drive rod, and the thrust bearing and the fixing nut are respectively arranged at both ends of the shaft hole at the second end of the second pump barrel.

[0013] Further, a plurality of guiding mechanisms are arranged on the inner wall of the cylinder block. The arrangement direction of the guiding mechanisms is parallel to the linear trajectory of the reciprocating movement of the plunger, and the plunger is slidably connected to the guiding mechanisms.

[0014] Further, the rotational power output device includes a lubricating oil tank, a reducer, and a driving motor. The driving motor is electrically connected to the control device. The motor output shaft of the driving motor is drivingly connected to the input shaft of the reducer. The output shaft of the reducer passes through the bottom shaft hole opened at the bottom of the lubricating oil tank and the top shaft hole opened at the top of the lubricating oil tank and is drivingly connected to the rotational power input end of the threaded drive rod. The shaft hole at the top of the reducer communicates with the lubricating oil storage chamber of the lubricating oil tank.

[0015] Further, the barrel at the bottom of the cylinder block is flange-sealingly connected to the barrel at the top of the lubricating oil tank. The barrel at the bottom of the lubricating oil tank is flange-sealingly connected to the barrel at the top of the reducer. The barrel at the bottom of the reducer is flange-sealingly connected to the barrel at the top of the driving motor.

[0016] Further, the axis of the cylinder block barrel, the axis of the lubricating oil tank barrel, and the axis of the reducer barrel are respectively coaxial with the axis of the output shaft of the reducer.

[0017] Further, the driving motor includes a motor bearing end cover, a motor stator, a motor rotor, and a motor output shaft. The first end of the motor rotor is rotatably connected to the shaft hole at the bottom end of the motor stator, and the second end of the motor rotor is rotatably connected to the shaft hole at the top end of the motor stator. The motor bearing end cover seals the shaft hole at the bottom end of the motor stator. The motor output shaft is arranged at the second end of the motor rotor. A spline sleeve is arranged on the input shaft of the reducer, and a spline is arranged on the motor output shaft. The spline of the motor output shaft is inserted into the spline sleeve of the input shaft of the reducer.

[0018] Further, the reducer is a speed reducer and torque increaser using a planetary gear structure.

[0019] The present invention also provides a method for oil production using a rodless oil production system, and the specific steps are as follows:

[0020] S1 Assemble the rodless oil production system, connect the plunger pump and the rotary power output device, connect the liquid outlet check valve port of the plunger pump to the above-ground oil outlet pipeline of the oil production well, and electrically connect the rotary power output device to the ground control device;

[0021] S2 Place the rodless oil production system under the oil production well, connect the new liquid inlet check valve port of the plunger pump to the oil layer under the oil production well, the control device sends an oil production instruction to the rotary power output device, and the rotary power output device outputs rotary power in the first rotary direction and rotary power in the second rotary direction, where the first rotary direction is opposite to the second rotary direction;

[0022] S3 The rotary power output device drives the threaded drive rod to rotate forward and backward, thereby driving the plunger to reciprocate. When the plunger moves towards the bottom of the cylinder block, the oil in the oil layer is sucked into the sealed working cavity through the liquid inlet check valve port. When the plunger moves towards the top of the cylinder block, the oil in the sealed working cavity is pushed into the above-ground oil outlet pipeline through the liquid outlet check valve port.

[0023] Further, the oil production instruction issued by the control device includes: 1) a first drive signal for controlling the rotary power output end of the rotary power output device to output rotary power in the first rotary direction; 2) a second drive signal for controlling the rotary power output end of the rotary power output device to output rotary power in the second rotary direction; 3) a number-of-turns adjustment signal for adjusting the number of rotation turns of the rotary power output end of the rotary power output device; 4) a rotational speed adjustment signal for adjusting the rotational speed of the rotary power output end of the rotary power output device;

[0024] Among them, the first drive signal controls the forward rotation of the rotary power output end of the rotary power output device, and the second drive signal controls the reverse rotation of the rotary power output end of the rotary power output device.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The present invention provides a rodless oil production system. When in use, the rodless oil production system is placed downhole in the oil well, such that the inlet check valve port communicates with the oil reservoir downhole in the oil well, and the outlet check valve port communicates with the above-ground oil outlet pipeline of the oil well. The ground control device transmits electrical energy to the downhole rotary power output device, and the rotary power output by the rotary power output device drives the threaded drive rod to rotate forward and backward. Under the threaded drive of the rotary power output end of the threaded drive rod and the plunger, the plunger reciprocates in the cylinder block, causing the volume of the sealed working cavity to change to achieve oil suction and oil pressure. Compared with the prior art, the present invention makes full use of the high efficiency characteristics of the plunger pump, abandons the disadvantage of doing work on the sucker rod during the working process of the pumping unit, and the rotary power output device of the present invention can efficiently convert electrical energy into mechanical energy, and the mechanical energy is efficiently converted into formation fluid pressure to lift the oil to the ground, with relatively low energy consumption.

[0027] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the embodiments of the present invention more clearly and to be implemented in accordance with the content of the description, the following takes the preferred embodiments of the present invention and describes them in detail in conjunction with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0029] Figure 1 FIG. is a schematic structural diagram of a rodless oil production system provided by an embodiment of the present invention;

[0030] Figure 2 is Figure 1 an enlarged structural view of A in;

[0031] In the drawings: 100 plunger pump, 1011 pump head, 1012 first pump barrel, 1013 second pump barrel; 102 plunger; 103 threaded drive rod; 104 inlet check valve port, 104a first mating valve groove, 104b second mating valve groove, 104c valve core, 104d elastic member, 104e oil groove; 105 outlet check valve port; 106 guiding mechanism; 107 sealing packing; 108 packing gland; 109 thrust bearing; 110 fixing nut;

[0032] 200 Rotary power output device; 210 Lubricating oil tank, 211 Box body, 212 Lubricating oil protection pipe, 2112 Partition board, 2111 Connecting pipe; 220 Reducer; 221 Upper gear set, 222 Upper support plate, 223 Lower gear set, Lower support plate 224, 225 Large cover gear, 226 Planetary gear set, 227 Planetary gear bracket, 228 Output shaft of the reducer, 229 Input shaft of the reducer; 230 Driving motor, 231 Motor bearing end cover, 232 Motor stator, 233 Motor rotor, 234 Motor output shaft. Detailed implementation manners

[0033] To further elaborate on the technical means and effects adopted by the present invention to achieve the purpose of the predetermined invention embodiments, the following describes in detail the specific implementation manners, structures, features and effects of the rodless oil production system and its plunger pump proposed according to the embodiments of the present invention in conjunction with the drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0034] Figures 1 to 2 For an embodiment of the rodless oil production system provided by the present invention, please refer to Figures 1 to 2 A rodless oil production system proposed in an embodiment of the present invention includes:

[0035] The plunger pump 100 includes a cylinder block 101, a plunger 102, a threaded drive rod 103, an inlet check valve port 104, and an outlet check valve port 105. The plunger 102 can reciprocate within the cylinder block 101. One end of the plunger 102 in the first direction of reciprocating movement forms a sealed working cavity with the inner wall of the cylinder block 101. A guiding mechanism 106 parallel to the linear trajectory of the reciprocating movement of the plunger 102 is formed within the cylinder block 101. The plunger 102 is slidably connected to the guiding mechanism 106. The rotary power output end of the threaded drive rod 103 is threadedly connected to one end of the plunger 102 in the second direction of reciprocating movement. The inlet check valve port 104 and the outlet check valve port 105 are respectively communicated with the sealed working cavity;

[0036] The rotary power output device 200, whose rotary power output end is drivingly connected to the rotary power input end of the threaded drive rod 103;

[0037] The plunger pump 100 and the rotary power output device 200 of the rodless oil production system are placed in the oil well from top to bottom, which is convenient for the inlet check valve port 104 to communicate with the oil layer under the oil well, and the outlet check valve port 105 to communicate with the above-ground oil outlet pipeline of the oil well.

[0038] Preferably, it further includes a control device, which is electrically connected to the drive motor 230 of the rotary power output device 200 and is configured to send an oil production instruction to the drive motor 230, so that the drive motor 230 cyclically outputs rotary power in a first rotation direction and rotary power in a second rotation direction according to the oil production instruction, and the first rotation direction is opposite to the second rotation direction. The control device can be arranged on the ground to send an oil production instruction to the drive motor 230 underground.

[0039] Preferably, the whole of the rodless oil production system can be cylindrical, and its outer diameter is smaller than the inner diameter of the oil well.

[0040] Preferably, the guiding mechanism 106 and the cylinder block 101 can be an integral structure or a split structure.

[0041] Preferably, the cylinder block 101 itself can be an integral structure or a split structure;

[0042] In some integral structures, for the convenience of production, the cylinder block 101 includes a pump head 1011 and a pump barrel, and the pump head 1011 seals the first end opening of the pump barrel;

[0043] In some split embodiments, the cylinder block 101 includes a pump head 1011, a first pump barrel 1012 and a second pump barrel 1013. The pump head 1011 covers the first end opening of the first pump barrel 1012, and the opening of the second end of the first pump barrel 1012 is sealingly connected to the opening of the first end of the second pump barrel 1013; the guiding mechanism 106 is a slide rail arranged on the inner wall of the second pump barrel 1013, and the top of the plunger 102 can reciprocate in the first pump barrel 1011, and the slider at the bottom of the plunger 102 is slidably connected to the slide rail.

[0044] Preferably, the slide rail is a chute of a straight rod, and the slider at the bottom of the plunger 102 is a slider slidably connected to the chute. Or, the slide rail is a slide rod of a straight rod, and the slider at the bottom of the plunger 102 is a chute slidably connected to the slide rod.

[0045] Preferably, the number of the slide rails is not limited to one, and can be multiple slide rail groups arranged oppositely on the inner wall of the second pump barrel 1013.

[0046] Preferably, in the realization of the sealing connection between the opening of the second end of the first pump barrel 1012 and the opening of the first end of the second pump barrel 1013, an outer ring groove opened on the outer side of the opening of the second end of the first pump barrel 1012 is clamped with an outer ring platform opened on the outer side of the opening of the first end of the second pump barrel 1013. A sealing inner ring groove is opened on the inner side of the opening of the second end of the first pump barrel 1012, the bottom of the sealing inner ring groove is filled with a sealing filler 107, the side part of the sealing inner ring groove is slidably connected to the side wall of the plunger 102, and the top of the sealing inner ring groove is buckled by a packing gland 108.

[0047] Preferably, the threaded drive rod 103 passes through the shaft hole provided at the second end of the second pump barrel 1013. At both ends of the shaft hole at the second end of the second pump barrel 1013, a thrust bearing 109 and a fixing nut 110 are respectively provided, and the thrust bearing 109 and the fixing nut 110 are sleeved on the threaded drive rod 103.

[0048] Preferably, the rotational power output end of the threaded drive rod 103 and the thread on one side of the second direction of the reciprocating movement of the plunger 102 can be connected by spline transmission. Under the drive of the rotational power at the rotational power output end of the threaded drive rod 103, since the plunger 102 is guided by the guiding mechanism 106, the plunger 102 can move on a straight-line track reciprocating within the cylinder block 101.

[0049] In implementation, in the first implementation manner, the rotational power output end of the threaded drive rod 103 is an external threaded rod, and one side of the second direction of the reciprocating movement of the plunger 102 has an internal threaded hole, and the external threaded rod is in threaded transmission connection with the internal threaded hole. The axis of the internal threaded hole and the axis of the external threaded rod are respectively coaxial with the axis of the cylinder block 101.

[0050] In the second implementation manner, the rotational power output end of the threaded drive rod 103 is an internal threaded hole, and one side of the second direction of the reciprocating movement of the plunger has an external threaded rod, and the internal threaded hole is in threaded transmission connection with the external threaded rod. The axis of the internal threaded hole and the axis of the external threaded rod are respectively coaxial with the axis of the cylinder block 101.

[0051] Preferably, the opening positions of the inlet check valve port 104 and the outlet check valve port 105 are selected according to needs. Optionally, the inlet check valve port 104 is opened on the side of the cylinder block 101; the outlet check valve port 105 is opened at the top of the cylinder block 101, or the inlet check valve port 104 is opened at the top of the cylinder block 101 and the outlet check valve port 105 is opened on the side wall of the cylinder block 101.

[0052] Preferably, the number of the inlet check valve ports 104 is not limited to one, and its opening position and quantity are determined according to the oil layer. Generally, the oil layer is located around the cylinder block 101, and there can be multiple inlet check valve ports 104. The multiple inlet check valve ports 104 are circumferentially arranged on the side of the cylinder block 101 to simultaneously suck oil from the oil layers around the cylinder block 101.

[0053] Preferably, the inlet check valve port 104 includes: an inlet valve seat, an inlet valve core, and an inlet elastic device. The inlet check valve port can be a separate valve component installed on the cylinder block, or the inlet valve seat is opened on the cylinder block.

[0054] Preferably, the liquid outlet check valve port 105 includes: a liquid outlet valve seat, a liquid outlet valve core, and a liquid outlet elastic device. The liquid outlet check valve port 105 can be a separate valve component installed on the cylinder block 101, or the liquid outlet valve seat is provided on the cylinder block 101. The number of liquid outlet valve cores is not limited to one. For example, the liquid outlet valve seat is a stepped drain hole with an increasing aperture in the liquid outlet direction. The liquid outlet valve core includes a larger spherical valve core and a smaller spherical valve core. The smaller spherical valve core is installed in the small-aperture installation hole of the stepped drain hole, and the larger spherical valve core is installed in the large-aperture installation hole of the stepped drain hole. The shape of the liquid outlet valve core is not limited to spherical, and it can also be a valve core of other shapes. Its function is to ensure the one-way flow of liquid. Valve covers of different sizes are installed in the large-aperture installation hole and the small-aperture installation hole.

[0055] The rotary power output device 200 includes: a lubricating oil tank 210, a speed reducer 220, and a driving motor 230 arranged in sequence from top to bottom; the output shaft of the speed reducer 220 passes through the bottom shaft hole opened at the bottom of the lubricating oil tank 210 and the top shaft hole opened at the top of the lubricating oil 210 tank and is in transmission connection with the rotary power input end of the threaded drive rod 103. The shaft hole at the top of the speed reducer 220 communicates with the lubricating oil storage chamber of the lubricating oil tank 210; the motor output shaft of the driving motor 230 is in transmission connection with the input shaft of the speed reducer 220. The lubricating oil in the lubricating oil tank 210 flows into the speed reducer 220 under the action of gravity to lubricate the reduction gears in the speed reducer 220. Specifically, the shaft hole at the bottom of the speed reducer 220 communicates with the shaft hole of the driving motor 230, so that the lubricating oil tank 210 lubricates the output shaft of the driving motor 230 at the same time.

[0056] In some sealing solutions, the cylinder body at the bottom of the cylinder block 101 is flange-sealed to the cylinder body at the top of the lubricating oil tank 210, the cylinder body at the bottom of the lubricating oil tank 210 is flange-sealed to the cylinder body at the top of the speed reducer 220, and the cylinder body at the bottom of the speed reducer 220 is flange-sealed to the cylinder body at the top of the driving motor 230. The axis of the cylinder body of the cylinder block 101, the axis of the cylinder body of the lubricating oil tank 210, and the axis of the cylinder body of the speed reducer 220 are respectively coaxial with the axis of the output shaft of the speed reducer 230.

[0057] Preferably, the motor output shaft of the drive motor 230 and the input shaft of the speed reducer 220 can be connected by spline drive. For example, the drive motor 230 includes a motor bearing end cover 231, a motor stator 232, a motor rotor 233, and a motor output shaft 234. The first end of the motor rotor 233 is rotatably connected to the shaft hole at the bottom end of the motor stator 232, and the second end of the motor rotor 233 is rotatably connected to the shaft hole at the top end of the motor stator 233. The motor bearing end cover 231 is hermetically sealed to the shaft hole at the bottom end of the motor stator 233, and the motor output shaft 234 is provided at the second end of the motor rotor 233. A spline sleeve is provided on the input shaft of the speed reducer 220, and a spline is provided on the motor output shaft 234. The spline of the motor output shaft 234 is inserted into the spline sleeve of the input shaft of the speed reducer 22.

[0058] Preferably, the drive motor 230 can be an ordinary high-torque motor.

[0059] Preferably, the speed reducer 220 can adopt a planetary gear structure. For example, the speed reducer is a speed reduction and torque increase device, which includes: a speed reduction and torque increase housing, an upper gear set 221, an upper support plate 222, a lower gear set 223, a lower support plate 224, a large cover gear 225, a planetary gear set 226, a planetary gear bracket 227, an output shaft 228 of the speed reducer, and an input shaft 229 of the speed reducer. The upper support plate 222, the lower support plate 224, and the planetary gear bracket 227 are stacked from top to bottom in the speed reduction and torque increase housing. The upper gear set 221 is provided between the top plate of the speed reduction and torque increase housing and the upper support plate 222. The lower gear set 223 is placed between the upper support plate 222 and the lower support plate 224. The large cover gear 225 and the planetary gear set 226 are provided between the lower support plate 224 and the planetary gear bracket 227.

[0060] The input shaft 229 of the speed reducer is provided in the shaft hole at the bottom plate of the speed reduction and torque increase housing and is in transmission connection with the first transmission end of the planetary gear set 226. The second transmission end of the planetary gear set 226 is in transmission connection with the first transmission end of the large cover gear 225. The second transmission end of the large cover gear 225 is in transmission connection with the first transmission end of the lower gear set 223. The second transmission end of the lower gear set 223 is in transmission connection with the first transmission end of the upper gear set 221. The second transmission end of the upper gear set 221 is in transmission connection with the output shaft 228 of the speed reducer. The output shaft 228 of the speed reducer is provided in the shaft hole at the top plate of the speed reduction and torque increase housing.

[0061] In the technical solution provided by the embodiment of the present invention, a rodless oil production system is placed downhole in the oil well, such that the inlet check valve port 104 communicates with the oil reservoir downhole in the oil well, and the outlet check valve port 105 communicates with the above-ground oil outlet pipeline of the oil well. The ground control device transmits electrical energy to the downhole rotary power output device 200, and the rotary power output by the rotary power output device 200 drives the threaded drive rod 103 to rotate forward and backward. Under the threaded drive of the rotary power output end of the threaded drive rod 103 and the plunger 102, the plunger 102 reciprocates in the cylinder block 101, causing the volume of the sealed working chamber to change to achieve oil suction and oil pressure. Compared with the prior art, the high-efficiency characteristics of the plunger pump are fully utilized, and the disadvantage of doing work on the sucker rod during the operation of the pumping unit is eliminated. Among them, in the technical solution provided by the embodiment of the present invention, the rotary power output device 200 efficiently converts electrical energy into mechanical energy, and the mechanical energy is efficiently converted into the formation fluid pressure and the oil is lifted to the ground with relatively low energy consumption.

[0062] Figures 1 to 2 The following is an embodiment of the plunger pump of the rodless oil production system provided by the above embodiment of the present invention. Please refer to Figures 1 to 2 A plunger pump 100 of a rodless oil production system proposed in an embodiment of the present invention includes:

[0063] A cylinder block 101, a plunger 102, a threaded drive rod 103, an inlet check valve port 104, and an outlet check valve port 105. The plunger 102 can reciprocate within the cylinder block 101. One end of the plunger 102 in the first direction of reciprocating movement forms a sealed working chamber with the inner wall of the cylinder block 101. A guiding mechanism 106 parallel to the linear trajectory of the reciprocating movement of the plunger 102 is provided within the cylinder block 101. The plunger 102 is slidably connected to the guiding mechanism 106. The rotary power output end of the threaded drive rod 103 is threadedly connected to one end of the plunger 102 in the second direction of reciprocating movement. The inlet check valve port 104 and the outlet check valve port 105 are respectively communicated with the sealed working chamber;

[0064] In the technical solution provided by the embodiment of the present invention, since a plurality of inlet check valve ports 104 are circumferentially arranged around the side wall of the cylinder block 101, and the outlet check valve port 105 is arranged at the top of the cylinder block 101, during the downhole installation of the plunger pump 100, the cylinder block 101 is placed at the height of the oil reservoir, which is convenient for the inlet check valve port 104 to communicate with the oil reservoir downhole in the oil well, and the outlet check valve port 105 to communicate with the above-ground oil outlet pipeline of the oil well, and the installation is convenient.

[0065] Further, for the convenience of production, the cylinder block 101 includes a pump head 1011 and a pump barrel. The pump head 1011 seals the first end opening of the pump barrel; the inlet check valve port 104 is arranged between the pump head 1011 and the first end opening of the pump barrel. The inlet check valve port 104 can be a separate valve component. After assembly, oil leakage is likely to occur around the separate valve component. To improve its reliability, the inserted section of the pump head 1011 is inserted into the first end opening of the pump barrel; the inlet check valve port 104 includes a first mating valve groove 104a arranged on the outer wall of the inserted section of the pump head, a second mating valve groove 104b arranged on the inner wall of the first end opening of the pump barrel, a valve core 104c, and an elastic member 104d. The first mating valve groove 104a and the second mating valve groove 104b mate to form a valve seat, and the valve seat communicates with the outside of the cylinder block and the sealed working cavity respectively. The valve core 104c is abutted by the elastic member 104d against the inlet where the valve seat communicates with the outside of the cylinder block.

[0066] Preferably, the valve core 104c can be a spherical valve, and the elastic member 104d can be a stainless steel spring, etc., but is not limited thereto. Specifically, the exposed section of the pump head 1011 extends with an enlarged diameter from the inserted section away from the first end opening of the pump barrel, and an annular oil inlet groove 104e is formed between the enlarged diameter surface of the exposed section of the pump head 1011 and the first end opening of the pump barrel. During operation, the oil on the outer periphery first enters the oil groove 104e and then enters the inlet check valve port 104, which can prevent larger particles of impurities from blocking the inlet check valve port 104, and the larger particles of impurities will be clamped at the notch of the oil inlet groove 104e.

[0067] In implementation, there are multiple inlet check valve ports 104, and the multiple inlet check valve ports 104 are circumferentially arranged around the side wall of the pump barrel. Simultaneous oil production in the axial direction can be achieved. In practice, the arrangement of the inlet check valve ports 104 is not limited to one circle, and the opening positions and quantities are determined according to the oil layer. The inlet check valve port 104 is a single valve core or multiple valve cores.

[0068] In some embodiments, a first flange is arranged on the outer wall of the pump head 1011, a second flange is arranged on the pump barrel, and the first flange and the second flange are fixedly connected by bolts. During assembly, first insert the inserted section of the pump head 1011 into the first end opening of the pump barrel, and then fixedly connect the first flange and the second flange by bolts.

[0069] In some other embodiments, an external thread is arranged on the outer wall of the inserted section of the pump head 1011, an internal thread is arranged on the inner wall of the first end opening of the pump barrel, and the outer wall of the inserted section of the pump head 1011 is threadedly connected to the inner wall of the first end opening of the pump barrel. During assembly, screw the inserted section of the pump head 1011 into the first end opening of the pump barrel and make the first mating valve groove 104a and the second mating valve groove 104b mate to form a valve seat.

[0070] Preferably, the liquid outlet check valve port 105 can be arranged in the middle of the top of the pump head 1011. When the rodless oil production system is vertically installed underground, the cylinder block is placed at the oil layer height, and the liquid outlet check valve port 105 can facilitate the connection with the above-ground oil outlet pipeline of the oil production well. The liquid outlet check valve port 105 has a single valve core or multiple valve cores.

[0071] Please refer to Figures 1 to 2 , the rotational power output device 200 of the rodless oil production system proposed in an embodiment of the present invention includes: a lubricating oil tank 210, a speed reducer 220, and a driving motor 230 arranged in sequence from top to bottom;

[0072] The lubricating oil tank 210 includes a box body 211 and a lubricating oil protection pipe 212. A top shaft hole is opened at the top of the box body 211, a bottom shaft hole is opened at the bottom of the box body 211, a lubricating oil storage chamber is provided inside the box body 211, the lubricating oil protection pipe 212 is communicated with the bottom shaft hole, and the top of the lubricating oil protection pipe 212 extends towards the top of the box body 211 and is higher than the bottom of the box body 211;

[0073] The output shaft of the speed reducer 220 sequentially passes through the lubricating oil protection pipe 212 and the top shaft hole, and the reduction gear lubricating oil of the speed reducer 220 is communicated with the lubricating oil storage chamber through the lubricating oil protection pipe 212;

[0074] The motor output shaft of the driving motor 230 is in transmission connection with the input shaft of the speed reducer 220.

[0075] After the rodless oil production system is vertically arranged under the oil production well, the lubricating oil tank 210, the speed reducer 220, and the driving motor 230 are arranged in sequence from top to bottom. After the rodless oil production system has been producing oil from the oil layer for a long time, the water-containing oil stain in the oil layer may flow downward through the cylinder block into the interior of the lubricating oil tank 210 and cause rusting of the gears inside the speed reducer, resulting in a poor service life. In the technical solution provided by the embodiment of the present invention, after the water-containing oil stain flows into the lubricating oil tank, the water with a density greater than that of the lubricating oil will sink to the bottom of the lubricating oil tank, while the lubricating oil with a smaller density will flow into the speed reducer through the top of the lubricating oil protection pipe higher than the bottom of the box body, which can prevent the water sinking to the bottom of the lubricating oil tank from entering the speed reducer and improve its service life.

[0076] In practice, water-containing oil stains may directly enter the top of the lubricating oil protection tube 212 during the falling process. Furthermore, in some embodiments provided by the present invention, the box body 211 includes an outer shell, a partition 2112, a connecting pipe 2111, a top plate and a bottom plate; the top plate is sealed to the top opening of the outer shell, the bottom plate is sealed to the bottom opening of the outer shell, the partition 2112 is arranged between the top plate and the bottom plate, and a sealing shaft hole for passing the output shaft of the reducer 220 is opened on the partition 2112, the top shaft hole is opened in the top plate, and the bottom shaft hole is opened in the bottom plate; the lubricating oil storage chamber includes: a first oil storage chamber formed between the top plate and the partition 2112, and a second oil storage chamber formed between the bottom plate and the partition 2112; the connecting pipe 2111 vertically penetrates the partition 2112 to connect the first oil storage chamber and the second oil storage chamber, and the first end of the connecting pipe 2111 is higher than the first preset height distance of the partition 2112. The water-containing oil dirt can fall into the bottom of the first oil storage chamber, and the lubricating oil in the first oil storage chamber can enter the second oil storage chamber through the first end of the connecting pipe 2111.

[0077] Furthermore, the second end of the connecting pipe 2111 is lower than the second preset height distance of the partition 2112, so that the water-containing oil dirt entering the second oil storage chamber through the second end of the connecting pipe 2111, the water therein sinks from a position lower than the second preset height distance of the partition 2112 to the bottom of the second oil storage chamber, reducing the possibility of falling into the lubricating oil protection tube.

[0078] Specifically, the top of the lubricating oil protection tube 212 is lower than the partition 2112 by a third preset height distance, and the third preset height distance is smaller than the second preset height distance, further reducing the possibility of falling into the lubricating oil protection tube.

[0079] In addition, it may also include: a drainage tube (not shown in the figure) arranged in the first oil storage chamber, which is sleeved on the output shaft of the reducer, the first end of the drainage tube is connected to the top shaft hole, and the second end of the drainage tube extends toward the partition 2112, which is higher than the fourth preset height distance of the partition 2112. The fourth preset height distance is smaller than the first preset height distance, which can reduce the moisture entering the second oil storage chamber from the first oil storage chamber.

[0080] Preferably, the cylinder at the bottom of the lubricating oil tank 210 is sealed with the cylinder flange at the top of the reducer 220, and the cylinder at the bottom of the reducer 220 is sealed with the cylinder flange at the top of the driving motor 230, so that the outer cylinder wall of the entire rotary power output device 200 is sealed.

[0081] Preferably, the output shaft of the reducer 220 includes a first output shaft led out from the barrel of the reducer 220 and a second output shaft connected to the first output shaft by a spline, and the second output shaft passes through the lubricating oil protection tube 212 and the top shaft hole in sequence. The second output shaft serves as the output shaft of the rotary power output device 200.

[0082] The oil production method of the rodless oil production system proposed by an embodiment of the present invention is as follows:

[0083] Place the rodless oil production system under the oil production well, so that the inlet check valve port 104 is connected to the oil layer under the oil production well, and the outlet check valve port 105 is connected to the above-ground oil outlet pipeline of the oil production well, and send an oil production command to the rotary power output device 200;

[0084] The rotary power output device 200 cyclically outputs the rotary power in the first rotation direction and the rotary power in the second rotation direction according to the oil production command. The first rotation direction is opposite to the second rotation direction, so that the oil in the oil layer is sucked into the sealed working cavity by the plunger moving in the second direction through the inlet check valve port 104, and the oil in the sealed working cavity is pushed into the above-ground oil outlet pipeline by the plunger 102 moving in the first direction through the outlet check valve port 105.

[0085] Furthermore, in the technical solution provided by the embodiment of the present invention, the rodless oil production system is placed under the oil production well, so that the inlet check valve port 104 is connected to the oil layer under the oil production well, and the outlet check valve port 105 is connected to the above-ground oil outlet pipeline of the oil production well. The ground control device transmits electric energy to the downhole rotary power output device 200. The rotary power output by the rotary power output device 200 drives the threaded drive rod 103 to rotate forward and backward. Under the threaded drive of the rotary power output end of the threaded drive rod 103 and the plunger 102, the plunger 102 reciprocates in the cylinder body, so that the volume of the sealed working cavity changes to realize oil suction and oil pressure. Compared with the prior art, the high-efficiency characteristics of the plunger pump are fully utilized, and the disadvantage of doing work on the oil production rod during the working process of the oil production machine is abandoned. Among them, in the technical solution provided by the embodiment of the present invention, the rotary power output device efficiently converts electric energy into mechanical energy, and the mechanical energy is efficiently converted into formation fluid pressure and the oil is lifted to the ground with lower energy consumption.

[0086] Among them, the oil production command includes:

[0087] 1) The first drive signal and the second drive signal that the rotary power output device 200 executes cyclically. The first drive signal controls the rotary power output end of the rotary power output device 200 to output rotary power in the first rotation direction, and the second drive signal controls the rotary power output end of the rotary power output device 200 to output rotary power in the second rotation direction. The first drive signal and the second drive signal make the rotary power output by the rotary power output device 200 drive the threaded drive rod 103 to rotate forward and backward.

[0088] 2) The number-of-turns adjustment signal for adjusting the number of rotation turns of the power output end of the rotary power output device 200.

[0089] 3) The rotational speed adjustment signal for adjusting the rotational speed of the power output end of the rotary power output device 200.

[0090] By setting parameters to control the rotational speed, forward and reverse rotation, and number of revolutions of the drive motor 230 of the rotational power output device 200, the reciprocating linear motion of the plunger 102 in the cylinder body, as well as the stroke and motion frequency of the plunger 102, are realized. The stroke adjustment of the plunger 102 is achieved by controlling the rotational speed.

[0091] Place the rodless oil production system downhole in the oil well, making the inlet check valve port 104 communicate with the oil layer downhole in the oil well, and the outlet check valve port 105 communicate with the above-ground oil outlet pipeline of the oil well. Specifically, it includes:

[0092] The plunger pump 100 and the rotational power output device 200 are arranged from top to bottom downhole in the oil well, making the inlet check valve port 104 on the side wall of the cylinder body 101 communicate with the oil layer downhole in the oil well, and the outlet check valve port 105 at the top of the cylinder body communicate with the above-ground oil outlet pipeline of the oil well.

[0093] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] It can be understood that the relevant features in the above devices can be referred to each other. In addition, the "first", "second", etc. in the above embodiments are used to distinguish each embodiment, and do not represent the superiority or inferiority of each embodiment.

[0095] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known structures and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0096] Similarly, it should be understood that in order to streamline this disclosure and help understand one or more of the various aspects of the invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed device should not be construed as reflecting the intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the aspects of the invention lie in less than all the features of the single preceding disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim stands on its own as a separate embodiment of the present invention.

[0097] Those skilled in the art can understand that the components in the devices of the embodiments can be adaptively changed and arranged in one or more devices different from the embodiments. The components in the embodiments can be combined into one component, and in addition, they can be divided into multiple sub-components. Except that at least some of such features are mutually exclusive, any combination can be used to combine all the features disclosed in this specification (including the accompanying claims, abstract and drawings) and all the components of any device so disclosed. Unless otherwise clearly stated, each feature disclosed in this specification (including the accompanying claims, abstract and drawings) can be replaced by alternative features that provide the same, equivalent or similar purpose.

[0098] In addition, those skilled in the art can understand that although some of the embodiments herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments means that it is within the scope of the present invention and forms different embodiments. For example, in the following claims, any one of the claimed embodiments can be used in any combination. Each component embodiment of the present invention can be implemented in hardware or in their combination.

[0099] It should be noted that the above embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or elements not listed in the claims. The word "a" or "an" preceding a component or element does not exclude the presence of a plurality of such components or elements. The present invention can be implemented by means of a device including several different components. In the claims listing several components, several of these components can be embodied by the same item of component. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0100] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A rodless oil production system, characterized in that, It includes a control device, a rotary power output device (200) and a plunger pump (100). In the plunger pump (100), a plunger (102) is slidably arranged in a cylinder block (101) and can reciprocate. One end of the plunger (102) forms a sealed working cavity with the top of the cylinder block (101). A liquid outlet check valve port (105) and a liquid inlet check valve port (104) are arranged at the upper part of the cylinder block (101). The inlet of the liquid outlet check valve port (105) communicates with the sealed working cavity, and the outlet communicates with the above-ground oil outlet pipeline. The inlet of the liquid inlet check valve port (104) communicates with the oil layer, and the outlet communicates with the sealed working cavity. The other end of the plunger (102) is in threaded driving connection with the rotary power output end of a threaded driving rod (103). The rotary power input end of the threaded driving rod (103) extends out of the cylinder block (101) and is connected to the rotary power output end of the rotary power output device (200). The control device is electrically connected to the rotary power output device (200) and is used to send an oil production instruction to the rotary power output device (200) to control the forward and reverse rotation of the threaded driving rod (103).

2. The rodless oil production system according to claim 1, wherein The cylinder block (101) includes a pump head (1011) and a pump barrel. The pump head (1011) covers the first end opening of the pump barrel. The plunger (102) is slidably arranged in the pump barrel and can reciprocate. The liquid inlet check valve port (104) is circumferentially arranged between the pump head (1011) and the first end opening of the pump barrel. The liquid outlet check valve port (105) is arranged at the top of the pump head (1011). The rotary power input end of the threaded driving rod (103) extends out of the pump barrel and is connected to the rotary power output end of the rotary power output device (200).

3. The rodless oil production system according to claim 2, wherein The pump barrel includes a first pump barrel (1012) and a second pump barrel (1013). The pump head (1011) covers the first end opening of the first pump barrel (1012). The second end opening of the first pump barrel (1012) is hermetically connected to the first end opening of the second pump barrel (1013). The top of the plunger (102) reciprocates in the first pump barrel (1011). The threaded driving rod (103) passes through a shaft hole arranged at the second end of the second pump barrel (1013) and is connected to the rotary power output end of the rotary power output device (200). A thrust bearing (109) and a fixing nut (110) are sleeved on the threaded driving rod (103), and the thrust bearing (109) and the fixing nut (110) are respectively arranged at both ends of the shaft hole at the second end of the second pump barrel (1013).

4. The rodless oil production system according to claim 1, wherein A plurality of guiding mechanisms (106) are arranged on the inner wall of the cylinder block (101). The arrangement direction of the guiding mechanisms (106) is parallel to the linear track of the reciprocating motion of the plunger (102). The plunger (102) is slidably connected to the guiding mechanisms (106).

5. A rodless oil production system according to claim 1, wherein, The rotary power output device (200) includes a lubricating oil tank (210), a speed reducer (220) and a driving motor (230). The driving motor (230) is electrically connected to the control device. The motor output shaft of the driving motor (230) is drivingly connected to the input shaft of the speed reducer (220). The output shaft of the speed reducer (220) passes through the bottom shaft hole opened at the bottom of the lubricating oil tank (210) and the top shaft hole opened at the top of the lubricating oil (210) tank and is drivingly connected to the rotary power input end of the threaded driving rod (103). The shaft hole at the top of the speed reducer (220) communicates with the lubricating oil storage chamber of the lubricating oil tank (210). The axis of the cylinder body (101), the axis of the lubricating oil tank (210), and the axis of the speed reducer (220) are respectively coaxial with the axis of the output shaft of the speed reducer (230).

6. The rodless oil production system according to claim 5, wherein The cylinder body at the bottom of the cylinder body (101) is flange-sealed to the cylinder body at the top of the lubricating oil tank (210). The cylinder body at the bottom of the lubricating oil tank (210) is flange-sealed to the cylinder body at the top of the speed reducer (220). The cylinder body at the bottom of the speed reducer (220) is flange-sealed to the cylinder body at the top of the driving motor (230).

7. A rodless oil production system according to claim 5, characterized in that, The driving motor (230) includes a motor bearing end cover (231), a motor stator (232), a motor rotor (233), and a motor output shaft (234). The first end of the motor rotor (233) is rotatably connected to the shaft hole at the bottom end of the motor stator (232). The second end of the motor rotor (233) is rotatably connected to the shaft hole at the top end of the motor stator (233). The motor bearing end cover (231) is hermetically sealed to the shaft hole at the bottom end of the motor stator (233). The motor output shaft (234) is arranged at the second end of the motor rotor (233). A spline sleeve is provided on the input shaft of the speed reducer (220). The motor output shaft (234) is provided with splines. The splines of the motor output shaft (234) are inserted into the spline sleeve of the input shaft of the speed reducer (22).

8. The rodless oil production system according to claim 5, characterized in that, The speed reducer (220) is a speed increasing and torque increasing device adopting a planetary gear structure.

9. A method for oil production using a rodless oil production system according to any one of claims 1 to 8, characterized in that, The specific steps are as follows: S1 Assemble the rodless oil production system, connect the plunger pump (100) and the rotary power output device (200). The liquid outlet check valve port (105) of the plunger pump (100) communicates with the above-ground oil outlet pipeline of the oil production well. The rotary power output device (200) is electrically connected to the ground control device; S2 Place the rodless oil production system under the oil production well, so that the liquid inlet check valve port (104) of the plunger pump (100) communicates with the oil layer under the oil production well. The control device sends an oil production instruction to the rotary power output device (200). The rotary power output device (200) outputs rotary power in the first rotary direction and rotary power in the second rotary direction. The first rotary direction is opposite to the second rotary direction; The S3 rotary power output device (200) drives the threaded drive rod (103) to rotate forward and backward, thereby driving the plunger (102) to reciprocate. When the plunger (102) moves towards the bottom of the cylinder block (101), the oil in the oil layer is sucked into the sealed working cavity through the inlet check valve port (104). When the plunger (102) moves towards the top of the cylinder block (101), the oil in the sealed working cavity is pushed into the above-ground oil outlet pipeline through the outlet check valve port (105).

10. The rodless oil production system according to claim 9, characterized in that, The oil production instructions issued by the control device include: 1) a first drive signal for controlling the rotary power output end of the rotary power output device (200) to output rotary power in the first rotation direction; 2) a second drive signal for controlling the rotary power output end of the rotary power output device (200) to output rotary power in the second rotation direction; 3) a number-of-turns adjustment signal for adjusting the number of turns of the rotary power output end of the rotary power output device (200); 4) a rotational speed adjustment signal for adjusting the rotational speed of the rotary power output end of the rotary power output device (200); Among them, the first drive signal controls the forward rotation of the rotary power output end of the rotary power output device (200), and the second drive signal controls the reverse rotation of the rotary power output end of the rotary power output device (200).

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