Screw pump tubing anti-disengagement device, screw pump energy storage system and method

Abstract

This invention relates to the field of oil and gas field development, and discloses a screw pump tubing anti-disengagement device, a screw pump energy storage system, and a method. The anti-disengagement device includes: a first anti-disengagement assembly and a second anti-disengagement assembly for connecting two screw pump tubings. The first anti-disengagement assembly includes a first ring body and a first engagement tooth disposed at one end of the first ring body, with the other end of the first ring body used for connection to the screw pump tubing. The second anti-disengagement assembly includes a second ring body and a second engagement tooth disposed at one end of the second ring body, with the other end of the second ring body used for connection to the screw pump tubing. The first engagement tooth and the second engagement tooth can engage with each other. Through this technical solution, when the first engagement tooth and the second engagement tooth are engaged, the first anti-disengagement assembly and the second anti-disengagement assembly will not rotate relative to each other when the screw pump tubing rotates, preventing disengagement during the rotation of the screw pump tubing and laying the foundation for energy storage using the screw pump.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development, specifically to a screw pump tubing anti-disengagement device. Furthermore, it also relates to a screw pump energy storage system and a screw pump energy storage method. Background Technology

[0002] A screw pump mainly consists of a stator and a rotor, and the rotation of the rotor transfers the medium. Using screw pumps in oil extraction has several advantages: First, screw pumps have a simple structure and few moving parts, resulting in lower initial investment costs; second, screw pumps can continuously lift fluids, have stable loads during operation, low mechanical losses, and high efficiency; furthermore, screw pumps have a wide range of applications, suitable for oil and gas wells producing heavy oil, high-sand, and high-gas content oil. Therefore, screw pump oil extraction technology is a widely used technology in the petroleum extraction industry.

[0003] However, in screw pump oil production, the screw pump tubing often reverses direction when the pump stops or gets stuck. This is because after the screw pump stops, the deformation and torsional potential energy stored in the rod string is rapidly released. Simultaneously, under the influence of the high-pressure fluid in the tubing and external pipeline and the hydraulic pressure difference in the casing, the screw pump becomes a hydraulic screw motor, causing the rotor and connected rod string to reverse rapidly. This reversal phenomenon can not only lead to hazards such as screw pump tubing disengagement, polished rod bending, and damage to surface drive components, but it can also cause some components to overheat, ignite free gas at the wellhead, and trigger serious safety problems such as wellhead combustion and explosion.

[0004] Currently, various technical solutions exist for preventing reverse rotation in screw pump oil production processes. Chinese patent CN108916043B discloses a downhole reverse rotation release device for screw pumps, including a main drive connector, a secondary drive connector, a disconnector, and a braking mechanism. The main drive connector and secondary drive connector transmit torque through a plug-in structure. One end of the disconnector is rotatably connected to the main drive connector, and the other end is threadedly connected to the secondary drive connector in the opposite direction. The disconnector has an installation groove, and the braking mechanism is located within this groove. The braking mechanism brakes the disconnector when the screw pump rotor's reverse rotation speed reaches a dangerous speed, causing relative rotation between the secondary drive connector and the disconnector until they disengage. Therefore, this patent's technical solution can solve the problem of surface accidents caused by the failure of the reverse rotation control system in screw pump oil production systems.

[0005] Chinese patent CN207048983U discloses a device for preventing reverse rotation and slowly releasing reverse torque in a ground-driven screw pump. The device includes a drive shaft, a block-type one-way overrunning clutch, a worm gear, a worm wheel, and a protective cover. The drive shaft is mounted on the sucker rod, and the block-type one-way overrunning clutch is mounted on the drive shaft. The block-type one-way overrunning clutch includes an inner bearing ring, an outer bearing ring, a block-type one-way bearing assembly, and a two-way bearing assembly. The worm wheel is fixed to the outer bearing ring, and the protective cover is located outside the block-type one-way overrunning clutch. The worm gear is mounted on the protective cover and engages with the worm wheel. The worm wheel is embedded in the outer bearing ring. A torque meter is mounted on the drive shaft, and the worm gear is connected to a motor. This patent's technical solution effectively prevents reverse rotation and enables quantifiable and controllable torque release.

[0006] Currently, existing technologies for screw pumps generally focus on preventing or controlling their reverse rotation, with little research on technologies that utilize screw pump reversal for energy storage. Summary of the Invention

[0007] The purpose of this invention is to overcome the problem that the existing technology does not utilize the reverse rotation of screw pumps, and to provide a screw pump tubing anti-disengagement device, a screw pump energy storage system and method. The anti-disengagement device can prevent the screw pump tubing from disengaging in the forward or reverse rotation state, thereby creating the possibility for screw pump energy storage.

[0008] To achieve the above objectives, a first aspect of the present invention provides a screw pump tubing anti-disengagement device, comprising: a first anti-disengagement assembly and a second anti-disengagement assembly for connecting two screw pump tubings, wherein the first anti-disengagement assembly includes a first ring body and a first engagement tooth disposed at one end of the first ring body, and the other end of the first ring body is used to connect to the screw pump tubing; the second anti-disengagement assembly includes a second ring body and a second engagement tooth disposed at one end of the second ring body, and the other end of the second ring body is used to connect to the screw pump tubing; wherein the first engagement tooth can engage with the second engagement tooth, such that when the screw pump tubing rotates in a first direction, the second engagement tooth can prevent the first engagement tooth from rotating relative to it in the first direction, and when the screw pump tubing rotates in a second direction opposite to the first direction, the first engagement tooth can prevent the second engagement tooth from rotating relative to it in the second direction.

[0009] Through the above technical solution, a first anti-disengagement component and a second anti-disengagement component are respectively connected to two screw pump tubes. The first engagement tooth of the first anti-disengagement component and the second engagement tooth of the second anti-disengagement component are then engaged to connect the two screw pump tubes. Furthermore, when the first and second engagement teeth are engaged, when the screw pump tube rotates in the first direction, the second engagement tooth prevents the first engagement tooth from rotating relative to it in the first direction; when the screw pump tube rotates in the second direction, the first engagement tooth prevents the second engagement tooth from rotating relative to it in the second direction. Therefore, when the screw pump tube rotates in either the first or second direction, the first and second anti-disengagement components will not rotate relative to each other, preventing disengagement during the rotation of the screw pump tube. Therefore, the anti-disengagement device provided by this invention can maintain the connection of the screw pump tube during both forward and reverse rotation, laying the foundation for energy storage using screw pumps.

[0010] In some embodiments, the first anti-disengagement assembly further includes a first slip unit disposed on the other end of the first ring body, the first slip unit being capable of embedding into the end face of the screw pump tube, so that the other end of the first ring body is connected to the screw pump tube; the second anti-disengagement assembly further includes a second slip unit disposed on the other end of the second ring body, the second slip unit being capable of embedding into the end face of the screw pump tube, so that the other end of the second ring body is connected to the screw pump tube.

[0011] In some embodiments, there are multiple first slip units and multiple second slip units, which are respectively disposed at the other end of the first ring body and the second ring body.

[0012] In some embodiments, the first slip unit includes a plurality of first slips, with the centers of any two adjacent first slips offset from each other; the second slip unit includes a plurality of second slips, with the centers of any two adjacent second slips offset from each other.

[0013] In some embodiments, the anti-disengagement device further includes a coupling for being fitted over the first anti-disengagement assembly and the second anti-disengagement assembly, the inner wall of the coupling having coupling threads for engaging with the threads on the outer wall of the screw pump tube.

[0014] A second aspect of the present invention provides a screw pump energy storage system, comprising: a power unit, a screw pump string, and a screw pump body sequentially connected from the ground to the underground. The screw pump string includes a plurality of screw pump tubes and the aforementioned anti-disengagement device connected between two of the screw pump tubes. The screw pump energy storage system further includes oil tubing spaced outside the screw pump string and communicating with the output end of the screw pump body, and a storage device disposed on the ground and communicating with the oil tubing. The screw pump string, the screw pump body, and the oil tubing are disposed in a wellbore. The screw pump energy storage system has the following characteristics: In the energy storage state, the power unit drives the screw pump string to rotate and store rotational deformation elastic energy. The screw pump string drives the screw pump body to work, pumping the fluid in the wellbore to the storage device to store the fluid's potential energy; and, In the energy release state, the fluid in the storage device flows back to the wellbore, driving the screw pump body to rotate the screw pump string, releasing the rotational deformation elastic energy and the potential energy of the fluid, thus enabling the power device to store energy.

[0015] In some embodiments, the power unit includes a power input unit and a top drive motor electrically connected to the power input unit via a cable, the output end of the top drive motor being drivenly connected to the screw pump column.

[0016] In some embodiments, the storage device includes a wellhead unit, a delivery pipeline, and a surface fluid storage unit connected in sequence, wherein the wellhead unit is connected to the tubing.

[0017] In some embodiments, the screw pump energy storage system further includes a sleeve spaced outside the oil pipe to form an annulus and a packer disposed in the annulus and sealing the annulus. The packer is disposed on the side of the screw pump body closer to the ground, and the annulus communicates with at least a portion of the formation on the side of the packer away from the ground.

[0018] A third aspect of the present invention provides a screw pump energy storage method using the aforementioned screw pump energy storage system, comprising the following: Energy storage: In the energy storage device, the power unit drives the screw pump string to rotate and store rotational deformation elastic energy. The screw pump string drives the screw pump body to work and pump the fluid in the wellbore to the storage device to store the potential energy of the fluid. Energy release involves returning the fluid in the storage device to the wellbore, driving the screw pump body to rotate the screw pump string, releasing the rotational deformation elastic energy and the potential energy of the fluid, and enabling the power device to store energy.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the screw pump energy storage system disclosed in this invention; Figure 2 This is a schematic diagram of the connection between the anti-disengagement device disclosed in this invention and the screw pump tubing; Figure 3 This is a schematic diagram of an embodiment of the anti-disengagement device disclosed in this invention in the forward rotation state; Figure 4 This is a schematic diagram of an embodiment of the anti-disengagement device disclosed in this invention in the reverse state; Figure 5 This is a top view of the anti-disengagement device disclosed in this invention.

[0021] Explanation of reference numerals in the attached figures 1-Power input unit; 11-Cable; 2-Surface fluid storage unit; 21-Transport pipeline; 3-Top drive motor; 31-Screw pump string; 32-Screw pump body; 33-Coupling; 34-Thread; 4-Wellhead unit; 40-Anti-disengagement device; 41-First ring; 42-First slip; 43-First engagement tooth; 44-Second ring; 45-Second slip; 46-Second engagement tooth; 5-Packer; 6-Casing; 7-Tubing; 8-Water layer; 9-Blocker; 10-Surface. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] In this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] The first aspect of the present invention provides a screw pump tubing anti-disengagement device 40, as shown in the figure. Figures 2-4 As shown, the anti-disengagement device 40 includes: a first anti-disengagement assembly and a second anti-disengagement assembly for connecting two screw pump tubes. The first anti-disengagement assembly includes a first ring body 41 and a first engagement tooth 43 disposed at one end of the first ring body 41. The other end of the first ring body 41 can be connected to the screw pump tube. The second anti-disengagement assembly includes a second ring body 44 and a second engagement tooth 46 disposed at one end of the second ring body 44. The other end of the second ring body 44 can be connected to the screw pump tube. The first engagement tooth 43 and the second engagement tooth 46 can engage with each other, such that when the screw pump tube rotates in a first direction A, the second engagement tooth 46 can prevent the first engagement tooth 43 from rotating relative to it in the first direction; when the screw pump tube rotates in a second direction C opposite to the first direction, the first engagement tooth 43 can prevent the second engagement tooth 46 from rotating relative to it in the second direction.

[0028] In the anti-disengagement device 40 provided by this invention, a first anti-disengagement component and a second anti-disengagement component are respectively connected to two screw pump tubes. The first engagement tooth 43 of the first anti-disengagement component and the second engagement tooth 46 of the second anti-disengagement component are then engaged to connect the two screw pump tubes. Furthermore, when the first engagement tooth 43 and the second engagement tooth 46 are engaged, when the screw pump tube rotates along the first direction A, the second engagement tooth 46 prevents the first engagement tooth 43 from rotating relative to it along the first direction A. When the screw pump tube rotates along the second direction C, the first engagement tooth 43 prevents the second engagement tooth 46 from rotating relative to it along the second direction C. Therefore, when the screw pump tube rotates along either the first direction A or the second direction C, the first anti-disengagement component and the second anti-disengagement component will not rotate relative to each other, preventing disengagement during the rotation of the screw pump tube. Therefore, the anti-disengagement device 40 provided by this invention can maintain the connection of the screw pump tube during both forward and reverse rotation, and also lays the foundation for energy storage using screw pumps.

[0029] In some embodiments, the first anti-disengagement assembly further includes a first slip unit disposed on the other end of the first ring body 41, the first slip unit being able to be embedded in the end face of the screw pump tube, so that the other end of the first ring body 41 is connected to the screw pump tube; the second anti-disengagement assembly further includes a second slip unit disposed on the other end of the second ring body 44, the second slip unit being able to be embedded in the end face of the screw pump tube, so that the other end of the second ring body 44 is connected to the screw pump tube.

[0030] In some embodiments, there are multiple first slip units and multiple second slip units, which are respectively disposed on the other end of the first ring body 41 and the second ring body 44. Furthermore, the multiple first slip units and multiple second slip units are evenly disposed on the other end of the first ring body 41 and the second ring body 44, thereby improving the stability of the connection between the first ring body 41 and the second ring body 44 and the screw pump tube.

[0031] In some embodiments, refer to Figures 3-5 As shown, the first slip unit includes multiple first slips 42, with the centers of any two adjacent first slips 42 being staggered from each other; the second slip unit includes multiple second slips 45, with the centers of any two adjacent second slips 45 being staggered from each other, thereby further improving the stability of the connection between the first ring body 41 and the second ring body 44 and the screw pump tube.

[0032] In some embodiments, refer to Figure 3 and Figure 4 As shown, the ends of the first slip 42 and the second slip 45 near the screw pump tube are respectively formed into sharp points, which facilitates the first slip 42 and the second slip 45 to be embedded into the end face of the screw pump tube.

[0033] In some embodiments, refer to Figure 2As shown, the anti-disengagement device also includes a coupling 33 for sleeved outside the first anti-disengagement assembly and the second anti-disengagement assembly. The inner wall of the coupling 33 has a coupling thread for engaging with the thread 34 on the outer wall of the screw pump tube, thereby further improving the connection strength between the two screw pump tubes and preventing the two screw pump tubes from disengaging.

[0034] A second aspect of the present invention provides a screw pump energy storage system, referring to... Figures 1-2 As shown, the screw pump energy storage system includes: a power unit, a screw pump string 31, and a screw pump body 32, which are sequentially connected along the direction from the ground surface 10 to the underground. The screw pump string 31 includes multiple screw pump tubes and the aforementioned anti-disengagement device 40 connected between two screw pump tubes. The screw pump energy storage system also includes an oil pipe 7 that is spaced outside the screw pump string 31 and connected to the output end of the screw pump body 32, and a storage device located on the ground surface 10 and connected to the oil pipe 7. The screw pump string 31, the screw pump body 32, and the oil pipe 7 are arranged in the wellbore. The screw pump energy storage system has an energy storage state and an energy release state. In the energy storage state, the power unit drives the screw pump string 31 to rotate and store rotational deformation elastic energy. The screw pump string 31 drives the screw pump body 32 to work, pumping the fluid in the wellbore to the storage device to store the potential energy of the fluid. In the energy release state, the fluid in the storage device flows back to the wellbore, driving the screw pump body 32 to rotate the screw pump string 31, releasing the rotational deformation elastic energy and the potential energy of the fluid, thus enabling the power unit to store energy.

[0035] The screw pump energy storage system provided by this invention has an energy storage state and an energy release state. In the energy storage state, the power unit drives the screw pump string 31 to rotate, which in turn drives the screw pump body 32 to work. The screw pump body 32 begins to pump fluid from the formation to the storage device on the ground 10, for example, referring to... Figure 1As shown, the screw pump body 32 transports water flowing from the water layer 8 into the wellbore through the oil pipe 7 to the storage device on the surface 10 for storage. It should be noted that because the screw pump body 32 is buried at a great depth, usually several kilometers, the screw pump string 31 is quite long. Thus, when the power device on the surface 10 starts to operate, the rotational torque cannot be immediately transmitted to the underground screw pump body 32. Instead, it gradually accumulates in the screw pump string 31, allowing the screw pump string 31 to continuously store rotational deformation elastic energy until the rotational torque is transmitted to the screw pump body 32, at which point the screw pump body 32 begins to pump fluid. In the energy release state, the fluid in the storage device flows back to the wellbore. As the fluid enters the wellbore from the storage device via the tubing 7 and the screw pump body 32, the liquid level difference (i.e., the height difference between the surface 10 and the dynamic liquid level inside the wellbore) drives the screw pump body 32 to reverse, causing the screw pump string 31 to reverse as well. The screw pump string 31 is connected to the power unit, thereby converting the potential energy of the fluid and the rotational deformation elastic energy stored in the screw pump string into the mechanical energy of the power unit, thus achieving energy storage for the power unit. Therefore, the screw pump energy storage system provided by this invention can put the power unit into an energy storage state during periods of low energy consumption, and into an energy release state during periods of high energy consumption, storing energy for the power unit, thus achieving peak-shifting energy use, increasing the penetration rate of green energy, and reducing the economic cost of energy use. In existing screw pump oil production processes, screw pump reversal is generally considered detrimental to oil and gas well development. Existing technologies primarily aim to prevent or control screw pump reversal. However, the technical solution of this application overcomes existing technical biases and takes a different approach, cleverly utilizing the forward and reverse rotation of the screw pump for energy storage and release, thereby increasing the penetration rate of green energy.

[0036] In the screw pump energy storage system provided by this invention, the power unit may include, but is not limited to, hydraulic top drive, electric top drive, etc. In some embodiments, refer to Figure 1 As shown, the power unit includes a power input unit 1 and a top drive motor 3 electrically connected to the power input unit via a cable 11. The output end of the top drive motor 3 is connected to the screw pump string 31. In the energy storage state, the top drive motor 3 drives the screw pump string 31 to rotate forward, driving the screw pump body 32 to work and pumping the fluid in the wellbore to the storage device. In the energy release state, the fluid flows back to the wellbore, driving the screw pump body 32 to drive the screw pump string to rotate in reverse, causing the top drive motor 3 to store electrical energy, thereby converting the potential energy of the fluid into electrical energy.

[0037] In some embodiments, the storage device includes a wellhead unit 4, a delivery pipeline 21, and a surface liquid storage unit 2 connected in sequence, with the wellhead unit 4 connected to the tubing 7.

[0038] In some embodiments, the screw pump energy storage system further includes a sleeve 6 spaced outside the oil pipe 7 to form an annulus, and a packer 5 disposed in the annulus and sealing the annulus. The packer 5 is disposed on the side of the screw pump body 32 closest to the ground 10, and the annulus communicates with at least a portion of the formation on the side of the packer 5 furthest from the ground 10. (Refer to...) Figure 1 As shown, the formation may include a partition layer 9 and a water layer 8. The water layer 8 is connected to the annulus. The water in the water layer 8 can enter the annulus and is located on the side of the packer 5 away from the ground 10. In the energy storage state, the screw pump body 32 pumps the water in the annulus to the storage device.

[0039] A third aspect of the present invention provides a screw pump energy storage method, which uses the aforementioned screw pump energy storage system and includes the following: Energy storage: In the energy storage, the power unit drives the screw pump string 31 to rotate and store the rotational deformation elastic energy. The screw pump string 31 drives the screw pump body 32 to work, pumping the fluid in the wellbore to the storage device to store the potential energy of the fluid. Energy release involves returning the fluid in the storage device to the wellbore, driving the screw pump body 32 to rotate the screw pump string 31, releasing the rotational deformation elastic energy and the potential energy of the fluid, thus enabling the power unit to store energy.

[0040] The specific process of the screw pump energy storage method provided by the present invention is described in detail below.

[0041] First, the screw pump string 31 is lowered into the wellbore. During the lowering process, the aforementioned anti-disengagement device 40 is placed at the corresponding male and female thread connections of the upper and lower screw pump tubing. As the male thread is screwed in, the distance between the first and second anti-disengagement components in the anti-disengagement device 40 gradually decreases until the male thread enters the bottom end of the female thread. At this point, the first engagement tooth 43 and the second engagement tooth 46 engage, and simultaneously, the first slip 42 and the second slip 45 are embedded into the end faces of the male and female threads of the two screw pump tubings, respectively. This prevents relative displacement of the first ring 41 and the second ring 44 when the screw pump string 31 reverses, thus achieving anti-disengagement.

[0042] Specifically, refer to Figure 3 As shown, the power unit drives the screw pump string 31 along the first direction (i.e., Figure 3 When rotating in the forward direction (A), this forward direction (A) is the tightening direction of the male and female threads of the screw pump tube. When the screw pump tube column 31 rotates forward, the rotational torque is from top to bottom (i.e., Figure 3 The drive direction B) transmits power, which is equivalent to the upper screw pump tube driving the lower screw pump tube to rotate, causing the upper and lower screw pump tubes to rotate synchronously. Since this forward rotation direction A is the tightening direction of the male and female threads, each screw pump tube becomes tighter and tighter as the screw pump tube column 31 rotates forward. (Refer to...) Figure 4As shown, fluid flows back from the ground 10 to the screw pump body 32, driving the screw pump body 32 to reverse, which in turn drives the screw pump string 31 along the second direction (i.e., Figure 4 Rotate in the opposite direction (C), with the rotational torque from bottom to top (i.e.) Figure 4 When the drive direction D is transmitted, the first engagement tooth 43 limits the second engagement tooth 46, preventing the second engagement tooth 46 from rotating relative to the first engagement tooth 43 in the reverse direction C, that is, in the direction of loosening the male and female threads, thereby achieving anti-disengagement of the two screw pump tubes.

[0043] After the screw pump body 32 is lowered to the target layer, the power unit is turned on during the off-peak period of energy use, such as when the electricity price is low. As the top drive motor 3 rotates, the screw pump string 31 gradually stores rotational deformation elastic energy from top to bottom. When the top drive motor 3 reaches a certain cumulative number of revolutions, the torque is transmitted to the screw pump body 32, and the formation water is gradually pumped to the surface.

[0044] The rotational deformation of the screw pump tubing 31 is described by the relative rotation angle between the upper and lower end faces, and its unit torsion angle formula is: θ= =

[0045] In the formula, θ is the unit torsion angle, ° / m; T is the torque, N·m; G is the shear modulus, GPa; I p For the polar moment of inertia, m 4 .

[0046] Taking a screw pump tubing 31 with a diameter of 38mm as an example, under the condition of an input torque of 1500N·m, the unit torsion angle is 6.66° / m. Therefore, the number of torsion turns per 1000m of screw pump tubing 31 is 18.5r.

[0047] When the screw pump string 31 transmits power to the screw pump body 32, causing it to start rotating, the screw pump body 32 begins to lift the fluid at the bottom of the well to the surface 10, gradually converting the input electrical energy of the top drive motor 3 into the potential energy of the fluid lifted to the surface 10.

[0048] When the off-peak electricity price ends and the peak electricity price begins, the top drive motor 3 is stopped, and the fluid that has been lifted in the storage device is returned to the bottom of the well. Under the liquid level difference (the height difference between the ground surface 10 and the dynamic liquid level at the bottom of the well), the screw pump body 32 reverses. The formula for the number of reverse rotations is: n=

[0049] In the formula, n is the number of revolutions; V is the volume of the reflux liquid, m 3 P represents pump displacement, m 3 / r.

[0050] Example 1 This embodiment illustrates the application of the screw pump energy storage system or method provided by the present invention in depleted water-bearing oil reservoirs in old oilfields.

[0051] In depleted water-bearing oil reservoirs, for wells with good wellbore conditions (e.g., intact casing, undamaged wellhead, and normal production functions), and with complete facilities and equipment (mainly referring to external power access), a screw pump energy storage system is installed. During the running of the screw pump tubing 31, an anti-disengagement device 40 is placed between the two screw pump tubing.

[0052] Open the target well and target layer, for example, refer to Figure 1 Water layer 8 is connected to the annulus, with a depth of 2000m. Since it has dried up, the liquid level is low, with a static liquid level height of 300m. Therefore, the screw pump body 32 is lowered to a depth of 1900m, with a submersion depth of 200m. The screw pump body 32 is selected with a displacement of 0.8L / r, the screw pump string 31 has a pipe diameter of 38mm, and the top drive motor 3 has an input torque of 2500N·m and a speed of 100r / min.

[0053] The designed off-peak electricity price is 0.8 yuan / kW·h, the normal electricity price is 1.6 yuan / kW·h, and the peak electricity price is 3.2 yuan / kW·h. The designed daily off-peak hours are 22:00~6:00 (8 hours), the peak hours are 10:00~14:00+17:00~21:00 (8 hours), and the rest of the time is normal (8 hours).

[0054] During off-peak electricity pricing periods, the top-drive motor 3 drives the screw pump body 32 to pump water. In 8 hours, the cumulative input electrical energy is 33.33 kW (electricity cost 26.66 yuan), and the cumulative water lifted (calculated based on 70% comprehensive pump efficiency) is 26.88 m³. 3 .

[0055] Normally, the pump is shut down due to electricity price fluctuations. During peak electricity price periods, water is returned to the storage device, and the screw pump body 32 reverses. At this time, the height difference between the ground 10 and the static liquid level in the reservoir is 1700m, and the torque generated by the liquid level difference is approximately 2176 N·m, calculated to be 26.88m. 3 The stored water can rotate 33,600 times cumulatively. Assuming a system efficiency of 70%, this translates to 23,520 rotations. Controlling the rotation speed at 100 r / min, the total release and rotation time is 3.92 hours (only level difference rotation). The screw pump string 31's rotational deformation elastic energy results in 58.58 rotations, bringing the total combined rotation time to 3.93 hours. The calculated total rotation power is 3626.7W, and the total output energy, considering the duration, is 14.22kW (saving 26.93 yuan in electricity costs). Therefore, based on the total output and input power, the energy storage efficiency is 42.67%. Under current energy storage efficiency conditions, it is economically feasible when the peak-to-valley electricity price ratio exceeds 2.34.

[0056] The above calculations are for a single well. A well group can be further constructed using screw pump energy storage systems. This group includes multiple of the aforementioned single wells, thereby increasing energy storage capacity, enabling peak-shaving and reverse rotation, and reducing sudden changes in grid load. For example, taking a well group of 20 wells, the first four hours are powered by reverse rotation from wells 1-10 of the screw pump energy storage system, and the next four hours are powered by reverse rotation from wells 11-20 of the screw pump energy storage system. This ensures a continuous 36kW power output to the grid during peak periods, reducing fluctuations.

[0057] Example 2 This embodiment illustrates the application of the screw pump energy storage system or method provided by the present invention in the cavity-building process of salt cavern gas storage and hydrogen storage.

[0058] The cavity engineering of salt cavern gas and hydrogen storage facilities is a relatively long-term injection-production cycle, typically spanning more than 5 years. The cavity engineering process involves continuous circulation of fresh water and extraction of brine. A screw pump body (32mm) is lowered to the bottom of the well to a depth of 1000m. The cavity depth is 1000-1100m, resulting in a total depth of 100m and a liquid level difference of 1050m-1000m. A screw pump with a displacement of 2L / r and a tubing diameter of 38mm is selected. The top drive motor has an input torque of 1500 N·m and a speed of 200 r / min.

[0059] The designed off-peak electricity price is 0.8 yuan / kW·h, the normal electricity price is 1.6 yuan / kW·h, and the peak electricity price is 3.2 yuan / kW·h. The designed daily off-peak hours are 22:00~6:00 (8 hours), the peak hours are 10:00~14:00+17:00~21:00 (8 hours), and the rest of the time is normal (8 hours).

[0060] During off-peak electricity pricing periods, the screw pump was used to extract brine. Over 8 hours, the cumulative electrical energy input was 40.0 kW (electricity cost 32.0 yuan), and the cumulative water lift (calculated at 70% overall pump efficiency) was 134.4 m³. 3 .

[0061] Normally, the pump is shut down due to electricity price fluctuations. During peak electricity price periods, clean water is injected, and the screw pump body 32 reverses direction. At this time, the height difference between the ground level 10 and the static liquid level in the reservoir is 1000m. The torque generated by this level difference is approximately 1280 N·m, calculated to be 134.4m. 3 The system can rotate 67,200 times cumulatively. Assuming a system efficiency of 70%, this translates to 47,040 rotations. With the rotation speed controlled at 100 r / min, the total release and rotation time is 7.84 hours (reversal only due to liquid level difference). The calculated total power of the rotation is 2133.3 W, and the total output energy, considering the duration, is 16.73 kW. Based on the total power output and output, the energy storage efficiency is calculated to be 41.83%.

[0062] The screw pump tubing anti-disengagement device, screw pump energy storage system, and method provided by this invention have the following beneficial effects: (1) Installing an anti-disengagement device between the screw pump tubes can prevent the screw pump tubes from disengaging, and at the same time lays the foundation for using the screw pump to store energy in both forward and reverse rotation. (2) The screw pump energy storage system stores the potential energy of the fluid in the energy storage state and releases the potential energy of the fluid by utilizing the liquid level difference in the energy release state, thus providing the applicability of the screw pump energy storage system; (3) Apply screw pump energy storage system in depleted oil and gas wells with high water content in old oilfields to realize the utilization of abandoned wells in old oilfields and improve the green energy penetration rate of old oilfields; (4) The application of screw pump energy storage systems in salt cavern gas storage and hydrogen storage facilities has improved energy utilization and reduced carbon emissions; (5) The system efficiency of the screw pump energy storage system was quantified.

[0063] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A screw pump tubing anti-disengagement device, characterized in that, include: A first anti-disengagement assembly and a second anti-disengagement assembly are used to connect two screw pump tubes. The first anti-disengagement assembly includes a first ring body (41) and a first engagement tooth (43) disposed on one end of the first ring body (41). The other end of the first ring body (41) is used to connect with the screw pump tube. The second anti-disengagement assembly includes a second ring body (44) and a second engagement tooth (46) disposed on one end of the second ring body (44). The other end of the second ring body (44) is used to connect with the screw pump tube. The first engagement tooth (43) can engage with the second engagement tooth (46) so that when the screw pump tube rotates in the first direction, the second engagement tooth (46) can prevent the first engagement tooth (43) from rotating relative to it in the first direction, and when the screw pump tube rotates in the second direction opposite to the first direction, the first engagement tooth (43) can prevent the second engagement tooth (46) from rotating relative to it in the second direction.

2. The anti-disengagement device for the screw pump tubing according to claim 1, characterized in that, The first anti-disengagement assembly also includes a first slip unit disposed on the other end of the first ring body (41), the first slip unit being able to be embedded in the end face of the screw pump tube, so that the other end of the first ring body (41) is connected to the screw pump tube; The second anti-disengagement assembly also includes a second slip unit disposed on the other end of the second ring (44), the second slip unit being able to be embedded in the end face of the screw pump tube, so that the other end of the second ring (44) is connected to the screw pump tube.

3. The anti-disengagement device for the screw pump tubing according to claim 2, characterized in that, The number of the first slip unit and the second slip unit are both multiple and are respectively disposed on the other end of the first ring body (41) and the second ring body (44).

4. The anti-disengagement device for the screw pump tubing according to claim 3, characterized in that, The first slip unit includes a plurality of first slips (42), and the centers of any two adjacent first slips (42) are offset from each other; The second kava unit includes a plurality of second kava (45), with the centers of any two adjacent second kava (45) being offset from each other.

5. The anti-disengagement device for the screw pump tubing according to any one of claims 1-4, characterized in that, The anti-disengagement device further includes a coupling (33) for sleeved on the first anti-disengagement component and the second anti-disengagement component, the inner wall of the coupling (33) having a coupling thread for engaging with the thread (34) on the outer wall of the screw pump tube.

6. A screw pump energy storage system, characterized in that, include: A power unit, a screw pump string (31), and a screw pump body (32) are sequentially connected from the ground (10) to the underground. The screw pump string (31) includes a plurality of screw pump tubes and an anti-disengagement device according to any one of claims 1-5 connected between two of the screw pump tubes. The screw pump energy storage system also includes an oil pipe (7) that is spaced outside the screw pump string (31) and communicates with the output end of the screw pump body (32), and a storage device that is set on the ground (10) and communicates with the oil pipe (7). The screw pump string (31), the screw pump body (32), and the oil pipe (7) are set in the wellbore. The screw pump energy storage system has the following features: In the energy storage state, the power unit drives the screw pump string (31) to rotate and store rotational deformation elastic energy. The screw pump string (31) drives the screw pump body (32) to work, pumping the fluid in the wellbore to the storage device to store the potential energy of the fluid; and, In the energy release state, the fluid in the storage device flows back to the wellbore, driving the screw pump body (32) to rotate the screw pump string (31), releasing the rotational deformation elastic energy and the potential energy of the fluid, so that the power device stores energy.

7. The screw pump energy storage system according to claim 6, characterized in that, The power unit includes a power input unit (1) and a top drive motor (3) electrically connected to the power input unit (1) via a cable (11). The output end of the top drive motor (3) is connected to the screw pump column (31) for transmission.

8. The screw pump energy storage system according to claim 6, characterized in that, The storage device includes a wellhead unit (4), a delivery pipeline (21), and a surface liquid storage unit (2) connected in sequence. The wellhead unit (4) is connected to the oil pipe (7).

9. The screw pump energy storage system according to claim 6, characterized in that, The screw pump energy storage system also includes a sleeve (6) spaced outside the oil pipe (7) to form an annulus and a packer (5) disposed in the annulus and sealing the annulus. The packer (5) is disposed on the side of the screw pump body (32) close to the ground (10), and the annulus is connected to at least part of the stratum on the side of the packer (5) away from the ground (10).

10. A screw pump energy storage method, characterized in that, The screw pump energy storage system according to any one of claims 6-9 includes the following: Energy storage: In the energy storage, the power device drives the screw pump string (31) to rotate and store rotational deformation elastic energy. The screw pump string (31) drives the screw pump body (32) to work and pump the fluid in the well to the storage device to store the potential energy of the fluid. Energy release involves returning the fluid in the storage device to the wellbore, driving the screw pump body (32) to rotate the screw pump string (31), releasing the rotational deformation elastic energy and the potential energy of the fluid, and enabling the power device to store energy.

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