Wellhead pulsed chemical injection device

Abstract

The application discloses a wellhead pulse type dosing device and relates to the technical field of oil pipe dosing. The wellhead pulse type dosing device comprises a sleeve, an oil pipe located in the sleeve and a sucker rod located in the oil pipe, and further comprises a medicine storage barrel, a main pumping mechanism, a pump cylinder assembly and the like. The main pumping mechanism comprises a dosing pipe located in the oil pipe, the dosing pipe is in communication with the medicine storage barrel, the sucker rod can drive the main pumping mechanism to convey the medicine in the medicine storage barrel downward along the dosing pipe when the sucker rod reciprocates, and the lower end of the dosing pipe is fixedly communicated with a dosing flow channel formed in the sandwiched layer of the pump cylinder assembly. The dosing pipe is arranged, the dosing flow channel is formed in the sandwiched layer of the pump cylinder assembly, the main pumping mechanism makes the medicine enter the dosing pipe, the medicine in the dosing pipe is conveyed to the formation liquid to play a role through the dosing flow channel in the sandwiched layer of the pump cylinder assembly, the dosing pipe is prevented from penetrating through the packer to affect the quality of crude oil, and the auxiliary pumping mechanism can assist in dosing.

Description

Technical Field

[0001] This invention relates to the field of tubing chemical dosing technology, specifically to a wellhead pulse dosing device. Background Technology

[0002] In the early stages of oil extraction, natural formation energy is relied upon for self-flowing extraction. In the middle and later stages, as formation energy depletes, water and gas injection are needed to replenish formation pressure, and artificial lifting equipment such as pumping units are used to lift crude oil to the surface. As the most important mechanical oil production equipment in onshore oilfields, pumping units play a core role in ensuring stable oil well production and are a key link in stabilizing production and increasing efficiency in the middle and later stages of oilfield development.

[0003] In oilfield development, deep wells with high pressure, high wax content, and high pour point often experience tubing blockage. The cause is attributed to the high wax content and high pour point of the oil and gas well fluids. During migration, the wax reaches its precipitation and solidification points, rendering the wells unusable. Chemical dosing to remove wax and scale is crucial for maintaining normal oil well production and is a primary means of extending the maintenance-free period of oil wells.

[0004] In existing technologies, chemical agents are typically pumped periodically into the annulus between the tubing and casing to address the aforementioned problems. However, due to the high pressure and great depth of these wells, the wellbore structure is complex, making annular chemical injection difficult and preventing the agents from effectively reaching the wax deposition sites. To address this, the wellhead chemical injection system and oil production system disclosed in publication number CN205778746U involve setting up a chemical injection pipeline that directly passes through the packer and extends into the formation fluid to complete the injection. However, the installation of the chemical injection pipeline affects the packer's function, thereby impacting crude oil quality.

[0005] In addition, existing chemical dosing systems mostly require additional power to drive them, making them unsuitable for remote pumping wells without electricity, resulting in high energy costs; moreover, the dosing rate cannot be synchronized with the stroke and number of strokes of the sucker rod, and the dosing amount cannot be adaptively adjusted according to the oil production of the well. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a wellhead pulse dosing device that solves the problem of difficult annular dosing.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a wellhead pulse-type chemical dosing device, comprising a casing, tubing located within the casing, and a sucker rod located within the tubing, and further comprising:

[0008] The medicine storage tank is located on one side of the wellhead.

[0009] The main pumping mechanism includes a dosing pipe located inside the oil pipe, which is connected to a storage tank. When the sucker rod reciprocates, it can drive the main pumping mechanism to deliver the medicine in the storage tank downward along the dosing pipe.

[0010] The pump cylinder assembly has a chemical dosing channel in its interlayer. The lower end of the chemical dosing pipe is fixedly connected to the chemical dosing channel. The chemical dosing channel is also equipped with a chemical discharge mechanism that is connected to the formation fluid.

[0011] An auxiliary pumping mechanism is located at the lower end of the pump cylinder assembly. When the lower valve ball of the pump cylinder assembly moves up and down, the auxiliary pumping mechanism can cause the dosing channel to draw in and discharge the drug.

[0012] Furthermore, the pump barrel assembly includes an upper long section and a lower short section;

[0013] The drug delivery channel includes:

[0014] A first flow channel is opened along the axial direction on one side of the upper long section interlayer, and the lower end of the dosing pipe is fixedly connected to the first flow channel;

[0015] The second flow channels are arranged circumferentially in the interlayer of the lower short section, and each second flow channel is arranged along the axial direction of the lower short section. The upper end face of the lower short section is provided with an annular confluence cavity that communicates with the second flow channels and the first flow channel.

[0016] The drug dispensing mechanism is installed on the outside of the second flow channel.

[0017] Furthermore, the lower valve ball is located within the lower short section;

[0018] The auxiliary pumping mechanism includes a lower piston located in the second flow channel and a connecting frame for connecting the lower valve ball and the lower piston.

[0019] Furthermore, the connecting frame includes a mounting rod, which is fixed to the lower surface of the lower valve ball and extends to the outside of the lower short section. A plurality of first connecting rods are fixed to the lower end of the mounting rod, and the lower piston is mounted on the first connecting rods via a piston rod.

[0020] Furthermore, a bottom dosing check valve is provided at the connection between the first flow channel and the annular manifold, which allows the drug to enter the second flow channel;

[0021] The drug discharge mechanism includes a drug discharge pipe located on one side of the lower subsection, and a one-way valve is provided inside the drug discharge pipe, which allows the drug to enter the formation fluid.

[0022] Furthermore, the discharge pipe has an L-shaped structure, and a sieve pipe is provided at the lower end of the discharge pipe.

[0023] Furthermore, the upper end of the sucker rod extends to the outside of the tubing, and the lower end of the sucker rod extends to the inside of the upper section;

[0024] The main sampling organizations include:

[0025] The dosing tube is equipped with an upper piston inside, which is in a sealed sliding fit with the inner wall of the dosing tube. A second connecting rod is sleeved on the sucker rod located outside the oil tube, and the upper piston is fixedly connected to the second connecting rod through the piston rod.

[0026] The storage tank is connected to the dosing pipe via a connecting pipe. The connecting pipe is equipped with an upper dosing check valve, which allows the medicine to enter the dosing pipe from the storage tank.

[0027] Furthermore, it also includes a plunger, which is located inside the upper section and is in a sealing sliding fit with the inner wall of the upper section. The lower end of the sucker rod is fixedly connected to the plunger, and the upper end of the plunger has an oil outlet.

[0028] The plunger is equipped with an upper valve. The up-and-down movement of the plunger causes pressure changes within the upper section, thereby controlling the opening and closing of the upper valve.

[0029] Furthermore, the number of the first flow channel is one, and the number of the second flow channel is six.

[0030] Furthermore, a packer is provided between the casing and the tubing, and the packer is located above the drug discharge mechanism.

[0031] The present invention has the following beneficial effects:

[0032] 1. This wellhead pulse dosing device is equipped with a dosing pipe and a dosing channel is opened in the interlayer of the pump assembly. The main pumping mechanism allows the agent to enter the dosing pipe and delivers the agent in the dosing pipe to the formation fluid through the dosing channel in the interlayer of the pump assembly to exert its effect. This avoids the dosing pipe passing through the packer, which would affect the quality of the crude oil. At the same time, the auxiliary pumping mechanism can assist in the dosing.

[0033] 2. This wellhead pulse dosing device, through the setting of a main pumping mechanism, utilizes the periodic pressure fluctuations generated in the dosing pipe by the mechanical movement of the sucker rod to achieve pulse dosing. It requires no additional power source, is suitable for remote pumping wells, and achieves zero energy consumption. Moreover, the main pumping mechanism is synchronized with the stroke of the sucker rod, adaptively adjusting the oil production. The faster the sucker rod stroke, the more pulses there are, and the dosing amount automatically increases; the slower the stroke, the dosing amount automatically decreases, achieving adaptive dosing.

[0034] 3. This wellhead pulse dosing device, by setting an auxiliary pumping mechanism, allows the main pumping mechanism to send the reagent in the storage tank into the dosing pipe when the sucker rod moves upward. At this time, the reagent in the dosing channel cannot be discharged by the main pumping mechanism. Instead, the lower valve ball moves upward, causing the auxiliary pumping mechanism to discharge the reagent in the dosing channel to the formation fluid in a pulse form. Dosing can be achieved in both strokes of the sucker rod, improving the dosing frequency and efficiency.

[0035] 4. This wellhead pulse dosing device, by setting up multiple second flow channels, allows the agent to be discharged into the formation fluid from multiple directions with the lower short section as the center, so as to achieve uniform dosing.

[0036] 5. This wellhead pulse dosing device, by setting up an L-shaped dosing pipe and screen pipe, reduces the contact between solid impurities in crude oil and the dosing check valve, and avoids solid impurities getting stuck in the dosing check valve, thus affecting its service life.

[0037] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0038] Figure 1 This is an overall schematic diagram of the present invention;

[0039] Figure 2 This is a schematic diagram of the medicine storage tank and the main pumping mechanism of the present invention;

[0040] Figure 3 This is a cross-sectional view of the sleeve of the present invention;

[0041] Figure 4 This is a schematic diagram of the structure of the oil pipe, pump barrel assembly, and plunger of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of the upper section and plunger of the present invention;

[0043] Figure 6 This is a schematic diagram of the installation of the upper long section and the lower short section of the present invention;

[0044] Figure 7 for Figure 6 Enlarged view of part A;

[0045] Figure 8 This is a schematic diagram of the installation of the lower section and auxiliary pumping mechanism of the present invention;

[0046] Figure 9 This is a cross-sectional view of the lower section of the present invention;

[0047] Figure 10 This is a schematic diagram of the one-way valve structure for discharging medicine according to the present invention;

[0048] Figure 11 This is a schematic diagram of the permissible flow direction of the drug dosing channel and the one-way valve of the present invention.

[0049] In the diagram, 1. Casing; 2. Oil pipe; 3. Upper long section; 31. First flow channel; 32. Oil outlet one; 4. Lower short section; 41. Second flow channel; 42. Annular manifold; 5. Auxiliary pumping mechanism; 51. Lower piston; 52. First connecting rod; 53. Mounting rod; 6. Plunger; 61. Oil outlet two; 71. Discharge pipe; 72. Screen pipe; 73. Discharge check valve; 8. Storage tank; 81. Connecting pipe; 82. Upper dosing check valve; 9. Main pumping mechanism; 91. Upper piston; 92. Second connecting rod; 10. Upper valve; 11. Lower valve ball; 12. Packer; 13. Sucker rod; 14. Oil outlet pipe; 15. Lower dosing check valve; 16. Dosing pipe. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0052] The following is based on Figures 1-11 This invention describes a wellhead pulse dosing device provided in an embodiment of the invention.

[0053] Please refer to Figure 1 and Figure 3 This invention provides a wellhead pulse dosing device, including a casing 1, an oil pipe 2 located inside the casing 1, and a sucker rod 13 located inside the oil pipe 2. The casing 1 is a protective pipe for the well wall, and the oil pipe 2 serves as a flow channel for lifting crude oil and transporting crude oil from the well to the surface. A packer 12 is provided between the casing 1 and the oil pipe 2. The packer 12 is located above the dosing mechanism and seals the annular space between the casing 1 and the oil pipe 2, separating the upper and lower oil layers, water layers, and gas layers to prevent fluid from flowing randomly. The formation fluid is located below the packer 12.

[0054] However, during the process of gathering and transporting crude oil from the bottom of the well to the surface, problems such as waxing, scaling, corrosion, fluid accumulation, and high viscosity are prone to occur. It is necessary to add chemicals to the wellhead and deliver the chemicals to the formation fluid to exert their effects.

[0055] Please refer to Figures 1-9 and Figure 11It also includes a medicine storage tank 8, a pump assembly, a main pumping mechanism 9, and an auxiliary pumping mechanism 5.

[0056] The chemical storage tank 8 is located on one side of the wellhead and is used to store special chemicals. These special chemicals can solve problems such as waxing, scaling, corrosion, fluid accumulation, and high viscosity in the entire process of crude oil gathering and transportation from the bottom of the well to the surface, ensuring smooth oil and gas flow and protecting equipment.

[0057] To facilitate the delivery of medicines within the medicine storage tank 8, such as Figure 1 and Figure 2 The main pumping mechanism 9 is equipped with a dosing pipe 16 located inside the tubing 2. The upper end of the dosing pipe 16 is fixedly connected to the tubing 2 and is connected to the storage tank 8. When the sucker rod 13 reciprocates, it drives the main pumping mechanism 9 to transport the chemicals in the storage tank 8 downwards along the dosing pipe 16. The chemical delivery is achieved through the mechanical movement of the sucker rod 13, which is suitable for remote pumping wells and achieves zero energy consumption. The main pumping mechanism 9 and the sucker rod 13 are synchronized in stroke, which adapts to the oil production rate. The faster the sucker rod 13 strikes, the more pulses there are, and the more chemicals are automatically added; the slower the strike, the more chemicals are automatically added, thus achieving adaptive chemical addition. The pulsed chemical addition has a high instantaneous pressure, which can still stably inject chemicals even under high back pressure, high viscosity, and waxing conditions. It is also conducive to the instantaneous mixing and uniform diffusion of chemicals with crude oil, and the wax removal, viscosity reduction, and corrosion inhibition effects are better than continuous dripping.

[0058] To ensure that the chemical is delivered to the formation fluid without affecting the function of the packer 12, a chemical delivery channel is provided in the interlayer of the pump assembly. The lower end of the chemical delivery pipe 16 is fixedly connected to the chemical delivery channel. The chemical delivery channel is also equipped with a discharge mechanism that is connected to the formation fluid, so that the chemical is delivered to the formation fluid through the chemical delivery channel of the pump assembly interlayer to exert its effect, and to prevent the chemical delivery pipe 16 from passing through the packer 12 and affecting the quality of crude oil.

[0059] To improve the delivery efficiency of the chemical agent, the auxiliary pumping mechanism 5 is located at the lower end of the pump barrel assembly. When the lower valve ball 11 of the pump barrel assembly moves up and down, the auxiliary pumping mechanism 5 can draw in and discharge the chemical agent through the dosing channel. Specifically, when the sucker rod 13 moves upward, the chemical agent in the dosing channel cannot be discharged by the main pumping mechanism 9. Instead, the lower valve ball 11 moves upward, causing the auxiliary pumping mechanism 5 to discharge the chemical agent in the dosing channel to the formation fluid in a pulse form, thus realizing pulse dosing. Dosing can be achieved in both strokes of the sucker rod 13, improving the dosing frequency and efficiency.

[0060] Please refer to Figure 1 , Figures 3-6 , Figure 9 and Figure 11To facilitate the delivery of chemicals through the dosing channel, the pump assembly includes an upper long section 3 and a lower short section 4. The dosing channel includes a first channel 31 axially formed on one side of the interlayer of the upper long section 3, with the lower end of the dosing pipe 16 fixedly connected to the first channel 31; second channels 41 arranged circumferentially in the interlayer of the lower short section 4, with each second channel 41 arranged axially along the lower short section 4; and an annular manifold 42 connected to the second channels 41 and the first channel 31 on the upper end face of the lower short section 4. A discharging mechanism is installed outside the second channels 41. When the sucker rod 13 moves upward, the main pumping mechanism 9 causes the chemicals in the storage tank 8 to enter the dosing pipe 16. When the sucker rod 13 moves downward, the main pumping mechanism 9 causes the chemicals in the dosing pipe 16 to enter the first channel 31 and converge into the annular manifold 42, then disperse them to each of the second channels 41 through the annular manifold 42, and finally discharge them to the formation fluid through the discharging mechanism.

[0061] Optionally, the number of first flow channels 31 is one, and the number of second flow channels 41 is six. The arrangement of six second flow channels 41 allows the reagent to be discharged into the formation fluid from multiple directions with the lower section 4 as the center, achieving uniform reagent discharge. Because the mechanical movement distance of the sucker rod 13 is much greater than the movement distance of the lower valve ball 11, the amount of reagent added to a single first flow channel 31 is much greater than the volume of the six second flow channels 41. Consequently, the downward movement of the sucker rod 13 causes the main pumping mechanism 9 to carry the reagent to fill the second flow channels 41 and complete the pulse-type dosing through the dosing mechanism, and undertakes the main pulse-type dosing function.

[0062] Preferably, the upper section 3 has a weight-reducing cavity in the interlayer to reduce the weight of the upper section 3 and save materials. The weight-reducing cavity is not connected to the first flow channel 31 and does not affect the sealing performance of the first flow channel 31.

[0063] Please refer to Figure 6 , Figure 8 and Figure 9 To enable the auxiliary pumping mechanism 5 to suck and discharge the agent, the lower valve ball 11 is located inside the lower short section 4. The auxiliary pumping mechanism 5 includes a lower piston 51 located in the second flow channel 41 and a connecting frame for connecting the lower valve ball 11 and the lower piston 51. The lower piston 51 moves upward in the second flow channel 41, and the volume of the second flow channel 41 is rapidly compressed and reduced. The agent is squeezed to form high pressure. Under the action of high pressure, the agent in the chamber is rapidly discharged to the formation fluid in the form of pulses through the discharge mechanism.

[0064] Furthermore, to facilitate the movement of the lower piston 51 within the second flow channel 41, the connecting frame is equipped with a mounting rod 53. The mounting rod 53 is fixed to the lower surface of the lower valve ball 11 and extends to the outside of the lower sub-section 4. Multiple first connecting rods 52 are fixed to the lower end of the mounting rod 53, and the lower piston 51 is mounted on the first connecting rods 52 via piston rods. The upward movement of the sucker rod 13 increases the chamber volume of the pump assembly, reduces the pressure, and the pressure difference causes the lower valve ball 11 to move upward, allowing crude oil to enter the lower sub-section 4 from the bottom of the well. Simultaneously, the upward movement of the lower valve ball 11, through the connecting frame, drives the lower piston 51 to move upward within the second flow channel 41.

[0065] Please refer to Figures 3-11 To ensure that the main pumping mechanism 9 and the auxiliary pumping mechanism 5 function effectively with the reciprocating motion of the sucker rod 13 without interfering with each other, a bottom-feeding check valve 15 is provided at the connection between the first flow channel 31 and the annular manifold 42. The bottom-feeding check valve 15 allows the chemical to enter the second flow channel 41. The discharge mechanism includes a discharge pipe 71 located on one side of the lower short section 4, and a discharge check valve 73 is provided inside the discharge pipe 71 (e.g., ...). Figure 10 The discharge check valve 73 allows the chemical to enter the formation fluid. When the sucker rod 13 moves upward, the lower valve ball 11 moves upward, causing the lower piston 51 to move upward in the second flow channel 41. Under the action of pressure difference, the lower chemical dosing check valve 15 is pressed closed, and the second flow channel 41 forms a sealed chamber. The discharge check valve 73 is opened, and the chemical in the second flow channel 41 is quickly discharged to the formation fluid in the form of pulses through the discharge mechanism. The upward movement of the lower piston 51 will not affect the main pumping mechanism 9 from obtaining the chemical from the storage tank 8. When the sucker rod 13 moves downward, the lower chemical dosing check valve 15 allows the chemical to enter the second flow channel 41, and the main pumping mechanism 9 can transport the chemical in the dosing pipe 16 to the second flow channel 41.

[0066] Furthermore, the discharge pipe 71 has an L-shaped structure, and the discharge check valve 73 is located near the second flow channel 41 in the discharge pipe 71. The lower end of the discharge pipe 71 is provided with a screen pipe 72. The L-shaped structure reduces the contact between crude oil and the discharge check valve 73. The screen pipe 72 can filter solid impurities in the crude oil and prevent solid impurities from getting stuck in the discharge check valve 73.

[0067] Please refer to Figure 1 and Figure 2 To facilitate the main pumping mechanism 9 in conveying the medicine in the storage tank 8 downward along the dosing pipe 16, the upper end of the sucker rod 13 extends to the outside of the oil pipe 2, and the lower end of the sucker rod 13 extends into the inside of the upper section 3; the main pumping mechanism 9 includes an upper piston 91 disposed inside the dosing pipe 16, the upper piston 91 is in a sealed sliding fit with the inner wall of the dosing pipe 16, and a second connecting rod 92 is sleeved on the sucker rod 13 located outside the oil pipe 2, and the upper piston 91 is fixedly connected to the second connecting rod 92 through the piston rod.

[0068] Furthermore, the storage tank 8 is connected to the dosing pipe 16 via a connecting pipe 81. The connecting pipe 81 is equipped with an upper dosing check valve 82, which allows the agent to enter the dosing pipe 16 from the storage tank 8.

[0069] Specifically, when the sucker rod 13 moves upward, the upper piston 91 moves upward simultaneously in the dosing pipe 16 via the second connecting rod 92, increasing the volume of the chamber in the dosing pipe 16 and reducing the pressure. The pressure difference causes the lower dosing check valve 15 to be closed, forming a sealed chamber between the dosing pipe 16 and the first flow channel 31. At the same time, the upper dosing check valve 82 is opened, and the agent in the storage tank 8 enters the dosing pipe 16 through the connecting pipe 81. When the sucker rod 13 moves downward, the upper piston 91 moves downward simultaneously in the dosing pipe 16 via the second connecting rod 92, compressing the volume of the chamber in the dosing pipe 16 and causing the agent to be squeezed and forming high pressure. The pressure difference causes the upper dosing check valve 82 to be closed, discharging the agent. When check valve 73 is closed and lower dosing check valve 15 is opened, the dosing pipe 16, first flow channel 31, annular manifold 42, and second flow channel 41 form a sealed chamber. The agent in the dosing pipe 16 enters the first flow channel 31 and converges into the annular manifold 42, then disperses to each of the second flow channels 41 without flowing back to the storage tank 8. When the lower piston 51 moves to the lower end of the second flow channel 41 and stops moving, the sucker rod 13 drives the upper piston 91 to continue moving downward. The agent is compressed, creating high pressure. The pressure difference causes the discharge check valve 73 to open, and the agent is discharged to the formation fluid in a pulse form through the discharge mechanism, achieving pulsed dosing. Pulsed dosing is achieved by utilizing the periodic pressure fluctuations generated by the reciprocating motion of the sucker rod 13 within the dosing pipe 16, eliminating the need for an additional power source.

[0070] Please refer to Figures 3-5 To enable the sucker rod 13 to move up and down, driving the lower valve ball 11 of the pump assembly to move up and down, a plunger 6 is also provided. The plunger 6 is located inside the upper section 3 and is in a sealed sliding fit with the inner wall of the upper section 3. The lower end of the sucker rod 13 is fixedly connected to the plunger 6, and the upper end of the plunger 6 has an oil outlet 61. The upper valve 10 is provided inside the plunger 6. The up and down movement of the plunger 6 causes pressure changes in the upper section 3 to control the opening and closing of the upper valve 10. The upper section 3 provides a sealed cavity for the movement of the plunger 6. The plunger 6 reciprocates in the upper section 3, changing the chamber volume of the pump assembly, causing pressure changes in the pump assembly to control the opening and closing of the upper valve 10 and the lower valve ball 11, thereby realizing oil suction and discharge.

[0071] Furthermore, the upper end of the upper section 3 is provided with an oil outlet 32. The sucker rod 13 moves up and down repeatedly, causing crude oil to enter the upper end of the pump barrel assembly through the oil outlet 61, and then enter the oil pipe 2 through the oil outlet 32. The oil pipe 2 is provided with an oil outlet pipe 14 near the upper part. The sucker rod 13 moves up and down repeatedly, pushing the crude oil upwards in sections, and finally continuously discharged from the oil outlet pipe 14.

[0072] In use, the pumping unit drives the sucker rod 13 to move up and down reciprocally, which in turn moves the plunger 6 up and down to change the chamber volume of the pump barrel assembly, thereby changing the chamber pressure of the pump barrel assembly to control the opening and closing of the upper valve 10 and the lower valve ball 11, thus realizing the suction and discharge of oil.

[0073] The specific dosing process is described below (e.g.) Figure 11 ):

[0074] When the sucker rod 13 moves upward, the upper piston 91 moves upward synchronously in the dosing pipe 16 via the second connecting rod 92, increasing the volume of the chamber in the dosing pipe 16 and reducing the pressure. The pressure difference causes the lower dosing check valve 15 to be pressed and closed, forming a sealed chamber between the dosing pipe 16 and the first flow channel 31. At the same time, the upper dosing check valve 82 is opened, and the agent in the storage tank 8 enters the dosing pipe 16 through the connecting pipe 81. Meanwhile, the lower valve ball 11 moves upward, causing the lower piston 51 to move upward in the second flow channel 41. The pressure difference causes the lower dosing check valve 15 to be pressed and closed, forming a sealed chamber in the second flow channel 41. At the same time, the discharge check valve 73 is opened, and the agent in the second flow channel 41 is rapidly discharged to the formation fluid in a pulse form through the discharge mechanism, realizing pulse dosing.

[0075] As the sucker rod 13 begins to descend, the upper piston 91 moves synchronously downwards in the dosing pipe 16 via the second connecting rod 92. The lower piston 51 moves downwards in the second flow channel 41 via the lower valve ball 11. The volume of the dosing pipe 16 chamber is compressed, and the chemical is squeezed to form high pressure. The pressure difference causes the upper dosing check valve 82 to be pressed shut, preventing the chemical in the dosing pipe 16 from flowing back to the storage tank 8. The discharge check valve 73 is closed to prevent crude oil from entering the second flow channel 41 through the discharge check valve 73. The lower dosing check valve 15 is opened. At this time, the dosing pipe 16, the first flow channel 31, and the annular confluence are connected. The cavity 42 and the second flow channel 41 form a sealed chamber. The agent in the dosing pipe 16 enters the first flow channel 31 and converges into the annular manifold 42, and is then dispersed into each of the second flow channels 41. The lower valve ball 11 moves down to block the lower port of the lower short section 4 and then stops moving. Subsequently, the lower piston 51 moves to the lower end of the second flow channel 41 and stabilizes there. The sucker rod 13 drives the upper piston 91 to continue moving down, and the agent is squeezed to form high pressure. The pressure difference causes the discharge check valve 73 to be opened, and the agent is discharged to the formation fluid in a pulse form through the discharge mechanism, realizing pulse dosing. The sucker rod 13 moves up and down continuously, and the agent can be discharged in a pulse form during the up and down movement of the sucker rod 13.

[0076] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0077] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A wellhead pulse dosing device, comprising a casing (1), tubing (2) located within the casing (1), and a sucker rod (13) located within the tubing (2), characterized in that, Also includes: The medicine storage tank (8) is located on one side of the wellhead; The main pumping mechanism (9) includes a dosing pipe (16) located in the oil pipe (2), which is connected to the storage tank (8). When the sucker rod (13) reciprocates, it can drive the main pumping mechanism (9) to transport the medicine in the storage tank (8) downward along the dosing pipe (16). The pump cylinder assembly has a dosing channel in the interlayer. The lower end of the dosing pipe (16) is fixedly connected to the dosing channel. The dosing channel is also provided with a discharge mechanism that is connected to the formation fluid. The auxiliary pumping mechanism (5) is located at the lower end of the pump cylinder assembly. When the lower valve ball (11) of the pump cylinder assembly moves up and down, the auxiliary pumping mechanism (5) can make the dosing channel suck and discharge the drug. The pump cylinder assembly includes an upper long section (3) and a lower short section (4). The drug delivery channel includes: A first flow channel (31) is opened along the axial direction on one side of the interlayer of the upper section (3), and the lower end of the dosing pipe (16) is fixedly connected to the first flow channel (31); The second flow channels (41) are arranged circumferentially in the interlayer of the lower short section (4), and each second flow channel (41) is arranged along the axial direction of the lower short section (4). The upper end face of the lower short section (4) is provided with an annular confluence cavity (42) that communicates with the second flow channel (41) and the first flow channel (31). The drug dispensing mechanism is installed on the outside of the second flow channel (41); The lower valve ball (11) is located within the lower short section (4); The auxiliary pumping mechanism (5) includes a lower piston (51) located in the second flow channel (41) and a connecting frame for connecting the lower valve ball (11) and the lower piston (51); The upper end of the sucker rod (13) extends to the outside of the tubing (2), and the lower end of the sucker rod (13) extends to the inside of the upper section (3); The main sampling organization (9) includes: The dosing tube (16) is provided with an upper piston (91) inside. The upper piston (91) is in a sealed sliding fit with the inner wall of the dosing tube (16). A second connecting rod (92) is sleeved on the sucker rod (13) located outside the oil pipe (2). The upper piston (91) is fixedly connected to the second connecting rod (92) through the piston rod. The storage tank (8) is connected to the dosing pipe (16) via a connecting pipe (81). The connecting pipe (81) is equipped with an upper dosing check valve (82), which allows the medicine to enter the dosing pipe (16) from the storage tank (8).

2. The wellhead pulse dosing device according to claim 1, characterized in that, The connecting frame includes a mounting rod (53), which is fixed to the lower surface of the lower valve ball (11) and extends to the outside of the lower short section (4). A plurality of first connecting rods (52) are fixed at the lower end of the mounting rod (53), and the lower piston (51) is mounted on the first connecting rods (52) through a piston rod.

3. A wellhead pulse-type chemical dosing device according to claim 2, characterized in that, A bottom dosing check valve (15) is provided at the connection between the first flow channel (31) and the annular manifold (42), which allows the drug to enter the second flow channel (41). The drug discharge mechanism includes a drug discharge pipe (71) located on one side of the lower short section (4), and a drug discharge check valve (73) is provided in the drug discharge pipe (71), which allows the drug to enter the formation fluid.

4. A wellhead pulse-type chemical dosing device according to claim 3, characterized in that, The discharge pipe (71) has an L-shaped structure, and a sieve pipe (72) is provided at the lower end of the discharge pipe (71).

5. A wellhead pulse-type chemical dosing device according to claim 1, characterized in that, It also includes a plunger (6), which is located inside the upper section (3). The plunger (6) is in a sealed sliding fit with the inner wall of the upper section (3). The lower end of the sucker rod (13) is fixedly connected to the plunger (6). The upper end of the plunger (6) is provided with an oil outlet (61). The plunger (6) is equipped with an upper valve (10). The up and down movement of the plunger (6) causes pressure changes in the upper section (3) to control the opening and closing of the upper valve (10).

6. A wellhead pulse-type chemical dosing device according to claim 1, characterized in that, The first flow channel (31) has a single channel, and the second flow channel (41) has six channels.

7. A wellhead pulse-type chemical dosing device according to claim 1, characterized in that, A packer (12) is provided between the casing (1) and the oil pipe (2), and the packer (12) is located above the drug discharge mechanism.

Images