Solid medicament delivery device, solid medicament delivery tube and method of use

Abstract

The application discloses a solid medicament releasing device, a solid medicament delivery pipe column and a use method, and the releasing device comprises a solid medicament containing cylinder, a blocking mechanism and a locking and unlocking mechanism; the lower end of the solid medicament containing cylinder is of an open structure, the lower end of the solid medicament containing cylinder is connected with the blocking mechanism, the lower end of the blocking mechanism is connected with the locking and unlocking mechanism, and the locking and unlocking mechanism controls the opening of the blocking mechanism. The solid medicament releasing device adopts a pressing mode to open, precise control of a releasing time can be realized, and the releasing time is more reliable; the solid medicament releasing device can be provided with multiple stages, and the effective period of the medicament is prolonged; when the solid anticorrosive slow-release medicament particles are delivered, the solid medicament releasing device can realize full wellbore anticorrosion, the protection is more comprehensive, long-acting anticorrosion of the oil well is realized, the production cycle of the oil well is prolonged, and the production rate of the oil well is improved.

Description

Technical Field

[0001] This invention relates to the field of oil well corrosion prevention technology, specifically to a solid agent release device, a solid agent delivery string, and a method of use. Background Technology

[0002] As oilfield development enters its later stages, corrosion failures in well tubing with high water cut and high salinity account for over 70%. Furthermore, advancements in development processes, such as chemical flooding and carbon dioxide flooding, increase the concentration of Cl- and HCO3- in the produced fluids, further exacerbating corrosion and severely impacting oilfield development efficiency. Currently, the main method for reducing corrosion rates is the quantitative addition of liquid corrosion inhibitors in the annulus, which has achieved some success. However, the corrosion inhibition effect of annular dripping of liquid corrosion inhibitors has a short maintenance period, requiring continuous addition, resulting in significant consumption of both reagents and electricity. Additionally, liquid corrosion inhibitors are easily adsorbed onto the oil and casing surfaces, leading to waste. Furthermore, the automatic surface dosing system requires regular replenishment, heating, and maintenance, making management difficult. Moreover, in flowing wells, due to high wellhead pressure, it is difficult to add liquid corrosion inhibitors in the annulus, failing to achieve full wellbore corrosion protection. Solid reagent release is still at a single-stage release stage, with excessively rapid release leading to a short effective period.

[0003] Announcement No.: CN206487446U, relates to a downhole solid corrosion prevention string, which includes casing, tubing, packer, thick-walled screen pipe and plug. The string also includes an internal solid corrosion inhibitor and an external solid corrosion inhibitor. The internal solid corrosion inhibitor has a cavity containing a solid corrosion inhibitor, and the external solid corrosion inhibitor has a cavity containing a solid corrosion inhibitor.

[0004] Announcement No.: CN211201895U, which relates to a high gas-liquid ratio oil well anti-corrosion tubing string. The technical solution of coating the outer wall of the tubing with a graphene anti-corrosion coating improves the corrosion resistance of the tubing, effectively extends the maintenance-free period of the oil well, and reduces the oilfield development cost. The corrosion inhibition mechanism connected to the lower surface of the screen tube, with solid corrosion inhibitors separated by baffles, allows the corrosion inhibitors to slowly dissolve and release, extending the action time.

[0005] Announcement No. CN220101256U discloses a device for using downhole slow-release solid agents, including an oil pump, one end of which is connected to a sand setter pipe, and the other end of which is connected to a perforated pipe; a plug is provided at the connection between the perforated pipe and the sand setter pipe, and a sealing plug is provided at the other end of the perforated pipe; multiple holes are evenly distributed on the surface of the perforated pipe, and a shielding mesh is provided on the outer surface of the perforated pipe; a solid agent is placed inside each perforated pipe to play a role in corrosion prevention and scale inhibition.

[0006] The existing technology has a fixed dosage of solid drug. After the tubing is run into the well, it comes into contact with the well fluid and can only protect for one release cycle. At the same time, it cannot achieve corrosion protection for the casing at the bottom of the tubing.

[0007] Publication number CN111236889A discloses a downhole delayed chemical dosing device and its usage method for oil wells, which consists of three cylinders, A, B, and C, connected sequentially from top to bottom. Cylinder A has a delay plug at its lower part and a flow channel on its side wall; cylinder B has a delay plug at its lower part, a delay channel on its side wall, and a delay plug connected to the delay channel; cylinder C has a delay channel on its side wall, and a delay plug connected to the delay channel.

[0008] Publication No. CN116792061A discloses a wellbore corrosion prevention system and method for highly corrosive oil wells. The wellbore corrosion prevention system consists of tubing, a heat-resistant sacrificial anode, a packer, and a long-lasting controlled-release tool. Multiple soluble baffles in the long-lasting controlled-release tool dissolve one by one from bottom to top at preset time intervals, and the solid agent placed on the dissolved soluble baffles falls down accordingly.

[0009] The aforementioned existing technologies all achieve the staged release of solid corrosion inhibitors through soluble partitions, thereby improving the protection cycle. However, due to the diverse well conditions and complex well fluid composition, it is difficult to accurately control the soluble partitions under different well conditions. During some well washing, pressurization and other operations, when the soluble partitions become thinner and their mechanical strength decreases, the partitions may open prematurely, resulting in overlapping or gap periods in agent release, which affects the corrosion prevention effect of the oil well.

[0010] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of the present invention. Regarding the more technical features, technical problems to be solved, and beneficial effects of the present invention, the above-disclosed technical documents do not provide any technical inspiration. Summary of the Invention

[0011] In view of the above-mentioned defects in the existing technology, the purpose of the present invention is to provide a solid drug release device, a solid drug delivery column and a method of use.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] On one hand, the present invention provides a solid drug dispensing device, including a solid drug receiving tube, a blocking mechanism, and a locking and unlocking mechanism; the lower end of the solid drug receiving tube is an open structure, the lower end of the solid drug receiving tube is connected to the blocking mechanism, the lower end of the blocking mechanism is connected to the locking and unlocking mechanism, and the locking and unlocking mechanism controls the opening of the blocking mechanism.

[0014] Furthermore, the blocking mechanism includes a swing plate seat and a swing plate;

[0015] Specifically, the upper end of the swing plate seat is connected to the lower end of the solid medicine container tube, and the swing plate seat is provided with an axial through hole;

[0016] Specifically, the lower end face of the swing plate seat is provided with a rotating shaft, the rotating shaft is connected to the swing plate, and the swing plate can rotate around the rotating shaft;

[0017] Specifically, a swing plate seal is provided on the lower end face of the swing plate seat around the axial through hole, and the swing plate seal cooperates with the swing plate to seal.

[0018] Specifically, the lower end of the swing plate base is connected to the locking and unlocking mechanism.

[0019] Furthermore, the locking and unlocking mechanism includes a locking cylinder, a central tube, an outer tube, a sliding locking mechanism, and a sliding unlocking mechanism;

[0020] Specifically, the upper end of the outer tube is connected to the lower end of the swing plate seat, the central tube is slidably disposed inside the outer tube, the locking cylinder is disposed between the swing plate and the central tube, and the locking cylinder pushes against the swing plate so that the swing plate and the swing plate sealing element are in full contact and sealed.

[0021] Specifically, the locking cylinder is connected to the outer tube via a sliding locking mechanism, and the central tube is connected to the outer tube via a sliding unlocking mechanism.

[0022] Furthermore, the sliding locking mechanism includes a locking ball and a locking ball screw;

[0023] Specifically, the locking cylinder is provided with an inner locking ball hole, and the outer tube is provided with an outer locking ball hole;

[0024] Specifically, a locking ball is provided between the inner locking ball hole and the outer locking ball hole, and the locking ball fixes the locking cylinder to the outer tube; a locking ball screw is provided in the outer locking ball hole, and the locking ball screw is used to fix the position of the locking ball.

[0025] Furthermore, the sliding unlocking mechanism includes a stepped surface, a pressure transmitting hole, a pressure bearing chamber, a shear pin, a travel chamber, and a limiting joint;

[0026] Specifically, the outer wall of the central tube is provided with a first stepped surface, a second stepped surface, a third stepped surface, a fourth stepped surface, and a fifth stepped surface;

[0027] Specifically, the first stepped surface and the second stepped surface form a first transition shoulder;

[0028] Specifically, the second step surface and the third step surface form a second transition shoulder;

[0029] Specifically, the third step surface and the fourth step surface are connected by a third transition shoulder;

[0030] Specifically, the fourth step surface and the fifth step surface are connected by a fourth transition shoulder;

[0031] Specifically, the inner wall of the locking cylinder mates with the second stepped surface, the first transition shoulder is higher than the upper edge of the locking ball hole inside the locking cylinder, and the second transition shoulder is lower than the lower edge of the locking ball hole inside the locking cylinder;

[0032] Specifically, there is a ball-placement space between the inner wall of the locking cylinder and the first stepped surface. When the first stepped surface corresponds to the inner locking ball hole of the locking cylinder, the locking ball can completely leave the outer tube, releasing the locking cylinder from the outer tube.

[0033] Specifically, the inner wall of the outer tube is provided with an upper small inner diameter and a lower large inner diameter, and the diameter-changing step between the upper small inner diameter and the lower large inner diameter is located below the second transition shoulder; the upper small inner diameter mates with the third stepped surface, and the mating surface is sealed by the third stepped surface sealing element.

[0034] Specifically, the fourth stepped surface mates with the lower large inner diameter of the outer tube, and the mating surface is sealed by the fourth stepped seal; the space enclosed by the third transition shoulder, the diameter-changing shoulder, the lower large inner diameter, and the third stepped surface is a pressure-bearing cavity, and the outer tube is provided with a pressure-transmitting hole, which communicates with the pressure-bearing cavity; a shear pin is provided above the fourth stepped seal on the outer tube, and the shear pin is embedded in the central tube to fix the central tube;

[0035] Specifically, the lower end of the outer tube is connected to a limiting joint, and the inner wall of the limiting joint is provided with an inner convex ring. The inner wall of the inner convex ring mates with the fifth step surface and is sealed by the fifth step surface sealing element. The space enclosed by the limiting joint, the fifth step surface, the fourth transition step, and the outer tube is a stroke cavity. The height of the stroke cavity is greater than the sum of the rotation radius of the swing plate and the distance from the first transition step to the lower edge of the locking ball hole in the locking cylinder.

[0036] Furthermore, the swing plate is cylindrical, and a torsion spring is provided on the rotating shaft to give the swing plate a tendency to rotate downwards and open; a guide surface is provided at the upper end of the axial through hole of the swing plate seat.

[0037] Furthermore, the inner diameter of the locking cylinder is smaller than the maximum outer diameter of the swing plate;

[0038] Specifically, the portion of the locking ball in the inner locking ball hole is greater than half, and the width of the ball placement space is greater than the portion of the locking ball in the outer locking ball hole;

[0039] Specifically, the outer diameters of the first, second, third, and fourth stepped surfaces of the central tube increase sequentially; the outer diameter of the fifth stepped surface is smaller than that of the fourth stepped surface.

[0040] Furthermore, the solid agent is one or a mixture of at least two of the following: solid anti-corrosion slow-release agent particles, solid anti-wax agent particles, and solid anti-scaling agent particles;

[0041] Specifically, the pharmaceutical particles are spherical or cylindrical in shape; the maximum projected external dimension of a single solid pharmaceutical particle is less than half the diameter of the axial through hole of the swing plate seat.

[0042] Secondly, the present invention provides a solid agent delivery column, including an oil pipe, an oil pump and a screen pipe are provided on the oil pipe, and a solid agent release device as described in one aspect is also provided on the oil pipe;

[0043] Specifically, an oil pump is installed above the screen tube, a solid agent release device is installed below the screen tube, at least one solid agent release device is provided, and the uppermost solid agent receiving tube has a closed structure at its upper end.

[0044] Furthermore, at least two solid drug release devices are provided, and the two solid drug release devices are connected by a tailpipe;

[0045] Specifically, the outer wall of the tailpipe is hollowed out, and the upper end of each solid agent receiving tube is a closed structure, so that the liquid in the well can dissolve the solid agent falling into the tailpipe; or, the tailpipe is a non-perforated circular tube, the uppermost solid agent receiving tube is a closed structure, and the upper ends of the remaining solid agent receiving tubes are open structures, so that the solid agent falls to the bottom of the artificial well.

[0046] Furthermore, all the pressure transmission holes of the solid agent release devices are connected in series through capillary tubes. After the tubing string is lowered into the well, the main capillary tube is connected to the wellhead and then to the pressure pump.

[0047] Thirdly, the present invention provides a method for using a solid drug delivery column, characterized in that the method of using the solid drug delivery column described in the second aspect includes the following steps:

[0048] S1. Before running the anti-corrosion tubing, add solid chemicals from the wellhead;

[0049] Select an appropriate number of solid drug release devices according to production needs. The number of shear pins or the diameter of the shear pins of all solid drug release devices gradually decreases from top to bottom, which means the unlocking pressure decreases.

[0050] S2. During the oil well production process, monitor the effective components of the solid agent in the produced fluid. When the effective components of the solid agent are below the required dosage, pressurize the pressure transmission hole. The pressure enters the pressure bearing chamber and acts on the third transition step. At this time, the shear pin is subjected to shear force.

[0051] When the lowest level shear pin is cut, in the lowest level solid agent release device, the central tube moves downward, the locking ball leaves the outer locking ball hole of the outer tube, the locking cylinder moves downward, the swing plate opens, and the solid agent falls from the solid agent container, and the well fluid dissolves the solid agent;

[0052] S3. When the effective component of the solid agent in the produced liquid is again detected to be below the required dosage, increase the pressurization pressure and repeat step S2.

[0053] Furthermore, for wells without pressure at the wellhead, once all the solid agent in the downhole solid agent release device is consumed, the agent is injected into the artificial well bottom through the casing gate to achieve full wellbore corrosion protection.

[0054] Compared with the prior art, the present invention has the following advantages:

[0055] 1. The solid drug release device of the present invention is opened by pressure, which can achieve precise control of the release timing and make the release timing more reliable.

[0056] 2. The solid agent release device of the present invention can be set in multiple stages to extend the effective period of the agent. When solid anti-corrosion slow-release agent particles are released, long-term anti-corrosion of oil wells can be achieved, the production cycle of oil wells can be extended, and the production rate of oil wells can be improved.

[0057] 3. This invention delivers solid agents to the bottom of the well. When delivering solid anti-corrosion slow-release agent particles, it achieves full wellbore corrosion protection, providing more comprehensive protection.

[0058] 4. This invention can achieve corrosion protection of the tubing in a flowing well. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of a solid drug release device according to the present invention;

[0060] Figure 2 This is a schematic diagram of the structure of a solid drug delivery column in this invention;

[0061] Figure 3 This is a schematic diagram of a structure in this invention that includes multiple solid drug release devices.

[0062] In the diagram: 1-Wellhead; 2-Casing gate valve; 3-Casing; 4-Tubing; 5-Pump; 6-Screw pipe; 7-Solid agent release device; 7.1-Solid agent container; 7.2-Swing plate seat; 7.3-Swing plate; 7.4-Swing plate seal; 7.5-Rotating shaft; 7.6-Locking cylinder; 7.7-First stepped surface; 7.8-Second stepped surface; 7.9-Center pipe; 7.10-Locking ball; 7.11-Locking ball screw; 7. 12-Outer tube; 7.13-Third stepped surface; 7.14-Pressure transmission hole; 7.15-Pressure bearing cavity; 7.16-Third stepped surface seal; 7.17-Shear pin; 7.18-Fourth stepped surface seal; 7.19-Fourth stepped surface; 7.20-Fifth stepped surface; 7.21-Stroke cavity; 7.22-Limiting joint; 7.23-Fifth stepped surface seal; 7.24-Central through hole; 7.25-Tail tube; 8-Solid agent. Detailed Implementation

[0063] 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.

[0064] Example 1:

[0065] Please see Figure 1 The present invention provides a solid drug release device, including a solid drug container 7.1, a blocking mechanism, and a locking and unlocking mechanism.

[0066] Specifically, the upper end of the solid medicine container tube 7.1 is a closed structure, and the lower end of the solid medicine container tube 7.1 is an open structure. The solid medicine container tube 7.1 contains solid medicine 8, and the lower end of the solid medicine container tube 7.1 is connected to a stop mechanism by a thread. The length of the solid medicine container tube 7.1 is determined according to the actual situation.

[0067] Specifically, the stopping mechanism includes a swing plate seat 7.2 and a swing plate 7.3. The upper end of the swing plate seat 7.2 is connected to the lower end of the solid agent receiving tube 7.1 via a thread. The swing plate seat 7.2 is provided with an axial through hole as a falling channel for the solid agent 8. A rotating shaft 7.5 is provided on the lower end face of the swing plate seat 7.2. The rotating shaft 7.5 is connected to the swing plate 7.3, and the swing plate 7.3 can rotate around the rotating shaft 7.5. A swing plate sealing element 7.4 is provided on the lower end face of the swing plate seat 7.2 around the axial through hole. The swing plate sealing element 7.4 cooperates with the swing plate 7.3 to seal the solid agent receiving tube 7.1. The lower end of the swing plate seat 7.2 is connected to a locking and unlocking mechanism via a thread.

[0068] Preferably, the swing plate 7.3 is cylindrical, and a torsion spring is provided on the rotating shaft 7.5 so that the swing plate 7.3 has a tendency to rotate downward and open; the upper end of the axial through hole of the swing plate seat 7.2 is provided with a guide surface to facilitate the falling of the solid agent 8.

[0069] Preferably, the solid agent 8 is a solid anti-corrosion slow-release agent particle, and the agent particle shape can be sphere, cylinder or other shape; the maximum projected external dimension of a single agent particle of the solid agent 8 is less than half the diameter of the axial through hole of the swing plate seat 7.2.

[0070] Specifically, the locking and unlocking mechanism includes a locking cylinder 7.6, a central tube 7.9, an outer tube 7.12, a sliding locking mechanism, and a sliding unlocking mechanism. The upper end of the outer tube 7.12 is threadedly connected to the lower end of the swing plate seat 7.2. The central tube 7.9 is slidably disposed inside the outer tube 7.12. The locking cylinder 7.6 is disposed between the swing plate 7.3 and the central tube 7.9. The locking cylinder 7.6 is connected to the outer tube 7.12 through the sliding locking mechanism. The central tube 7.9 is connected to the outer tube 7.12 through the sliding unlocking mechanism. The locking cylinder 7.6 pushes against the swing plate 7.3, so that the swing plate 7.3 and the swing plate seal 7.4 are in full contact and sealed.

[0071] Specifically, the sliding locking mechanism includes a locking ball 7.10 and a locking ball screw 7.11. The locking cylinder 7.6 is provided with an inner locking ball hole, and the outer tube 7.12 is provided with an outer locking ball hole. The locking ball 7.10 is provided between the inner locking ball hole and the outer locking ball hole. The locking ball 7.10 fixes the locking cylinder 7.6 and the outer tube 7.12 and positions the locking cylinder 7.6. The locking ball screw 7.11 is provided in the outer locking ball hole and is used to fix the position of the locking ball 7.10.

[0072] Specifically, the sliding unlocking mechanism includes a stepped surface, a pressure transmitting hole 7.14, a pressure bearing cavity 7.15, a shear pin 7.17, a stroke cavity 7.21, and a limiting joint 7.22; the outer wall of the central tube 7.9 is provided with a first stepped surface 7.7, a second stepped surface 7.8, a third stepped surface 7.13, a fourth stepped surface 7.19, and a fifth stepped surface 7.20. The first stepped surface 7.7 and the second stepped surface 7.8 form a first transition shoulder, the second stepped surface 7.8 and the third stepped surface 7.13 form a second transition shoulder, the third stepped surface 7.13 and the fourth stepped surface 7.19 form a third transition shoulder, and the fourth stepped surface 7.19 and the fifth stepped surface 7.20 form a fourth transition shoulder.

[0073] The inner wall of the locking cylinder 7.6 mates with the second stepped surface 7.8, the first transition shoulder is higher than the upper edge of the inner locking ball hole of the locking cylinder 7.6, and the second transition shoulder is lower than the lower edge of the inner locking ball hole of the locking cylinder 7.6.

[0074] There is a ball-placement space between the inner wall of the locking cylinder 7.6 and the first stepped surface 7.7. When the first stepped surface 7.7 corresponds to the inner locking ball hole of the locking cylinder 7.6, the locking ball 7.10 can completely leave the outer tube 7.12. At this time, the locking ball 7.10 can release the locking cylinder 7.6 and the outer tube 7.12 from locking.

[0075] The outer tube 7.12 has an upper small inner diameter and a lower large inner diameter on its inner wall. The transition step between the upper small inner diameter and the lower large inner diameter is located below the second transition shoulder. The upper small inner diameter mates with the third stepped surface 7.13 and the mating surface is sealed by the third stepped surface seal 7.16.

[0076] The fourth stepped surface 7.19 mates with the lower large inner diameter of the outer tube 7.12 and the mating surface is sealed by the fourth stepped seal 7.18. The space enclosed by the third transition shoulder, the diameter-changing shoulder, the lower large inner diameter, and the third stepped surface is a pressure-bearing cavity 7.15. The outer tube 7.12 is provided with a pressure-transmitting hole 7.14, which communicates with the pressure-bearing cavity 7.15. The outer tube 7.12 is provided with a shear pin 7.17 above the fourth stepped seal 7.18, which is embedded in the central tube 7.9 to fix the central tube 7.9.

[0077] The outer tube 7.12 is threaded to a limiting connector 7.22 at its lower outer wall. The inner wall of the limiting connector 7.22 is provided with an inner convex ring. The inner wall of the inner convex ring mates with the fifth step surface 7.20 and is sealed by the fifth step surface seal 7.23. The limiting connector 7.22, the fifth step surface 7.20, the fourth transition step, and the outer tube 7.12 form a travel cavity 7.21. The height of the travel cavity 7.21 is greater than the sum of the rotation radius of the swing plate 7.3 and the distance from the first transition step to the lower edge of the inner locking ball hole of the locking cylinder 7.6, which allows the swing plate 7.3 to have a larger opening.

[0078] The lower end of the limiting connector 7.22 is connected to the tail tube 7.25 by a thread.

[0079] Preferably, the tailpipe 7.25 is a short-connector to the oil pipe.

[0080] When in use, this device applies downward pressure to the third transition shoulder of the central tube 7.9 by applying pressure, cutting the shear pin 7.17. The central tube 7.9 moves downward to compress the stroke chamber 7.21, and the locking ball 7.10 is squeezed into the ball placement space. The locking cylinder 7.6 moves downward along with the central tube 7.9. Under the pressure and gravity of the solid agent 8, the swing plate 7.3 rotates downward around the shaft, opening the axial through hole of the swing plate seat 7.2. The solid agent 8 falls through the axial through hole and the central through hole 7.24 inside the central tube 7.9, and enters the bottom of the well.

[0081] Example 2:

[0082] Based on Example 1, this example provides a more specific solid drug release device.

[0083] The inner diameter of the locking cylinder 7.6 is smaller than the maximum outer diameter of the swing plate 7.3.

[0084] The portion of the locking ball 7.10 in the inner locking hole is greater than half, and the width of the ball placement space is greater than the portion of the locking ball 7.10 in the outer locking hole, so that the locking ball 7.10 can be smoothly extruded.

[0085] Multiple inner locking ball holes, outer locking ball holes, locking balls 7.10, and locking ball screws 7.11 can be provided.

[0086] Multiple third-step surface seals 7.16, multiple fourth-step seals 7.18, and multiple fifth-step surface seals 7.23 can be provided.

[0087] The outer diameters of the first stepped surface 7.7, the second stepped surface 7.8, the third stepped surface 7.13, and the fourth stepped surface 7.19 of the central tube 7.9 increase sequentially; the outer diameter of the fifth stepped surface 7.20 is smaller than that of the fourth stepped surface 7.19.

[0088] The outer tube 7.12 has a radial threaded hole on its lower inner diameter. The threaded hole corresponds to the fourth stepped surface 7.19 and is located above the fourth stepped surface seal 7.18. The threaded hole is used to install shear pins 7.17. The fourth stepped surface 7.19 has an annular shear pin groove corresponding to the threaded hole. Multiple threaded holes and shear pins 7.17 can be provided.

[0089] Example 3:

[0090] Based on Example 2, combined with Figure 2 , Figure 3 This embodiment provides a corrosion inhibitor delivery string, including an oil pipe 4, on which an oil pump 5, a screen pipe 6, and a solid agent release device 7 are provided.

[0091] The tubing 4 is installed inside the casing 3, and the upper end of the tubing 4 and the upper end of the casing 3 are both connected to the wellhead 1.

[0092] An oil pump 5 is installed above the screen tube 6, and a solid agent release device 7 is installed below the screen tube 6. At least one solid agent release device 7 is provided.

[0093] When at least two solid drug release devices 7 are provided, the two solid drug release devices 7 are connected by a tail pipe 7.25.

[0094] One configuration of the tailpipe 7.25 is such that the outer wall of the tailpipe 7.25 is hollowed out, allowing the liquid in the well to dissolve the solid reagent 8 that falls into the tailpipe 7.25.

[0095] Another way to set up the 7.25 tailpipe is as follows: Figure 3 As shown, the outer wall of the tailpipe 7.25 is a non-perforated circular tube. At this time, the upper end of the solid agent receiving tube 7.1 of the uppermost solid agent release device 7 is a closed structure, while the upper ends of the remaining solid agent receiving tubes 7.1 are all open structures. At this time, the tailpipe 7.25 of the upper solid agent release device 7 is connected to the solid agent receiving tube 7.1 of the lower solid agent release device 7 in sequence. Multiple solid agent release devices 7 connected in this way can allow the solid agent 8 to fall to the bottom of the artificial well, achieving full wellbore corrosion protection.

[0096] Specifically, a method for operating a corrosion inhibitor dosing column and its solid agent release device:

[0097] S1. Before the anti-corrosion agent is lowered into the tubing, a certain amount of solid agent 8 can be added from the wellhead 1.

[0098] During well completion, the anti-corrosion agent delivery string consists of tubing 4, oil pump 5, screen pipe 6, and solid agent release device 7 from top to bottom. The swing plate 7.2 of the solid agent release device 7 seals the solid agent container 7.1. The solid agent release device 7 can be set in multiple stages. From top to bottom, the number or diameter of the shear pins 7.17 of the solid agent release device 7 gradually decreases, that is, the unlocking pressure decreases.

[0099] S2. During the oil well production process, the effective components of solid agent 8 in the produced fluid are monitored. When the effective components of solid agent 8 are below the required dosage for corrosion prevention, the casing gate 2 is connected to the pump truck. The pump truck pressurizes the pump, and the hydraulic pressure enters the pressure-bearing chamber 7.15 through the pressure transmission hole 7.14 and acts on the third transition step. At this time, the shear pin 7.17 is subjected to shear force.

[0100] When the lowest-level shear pin 7.17 cuts, in the lowest-level solid agent release device, the central tube 7.9 descends, and the fourth transition shoulder sits on the inner convex ring. At this time, the first stepped surface 7.7 matches the inner locking ball hole of the locking cylinder 7.6. The locking ball 7.7 leaves the outer locking ball hole of the outer tube 7.12 and rolls towards the center of the central tube 7.9 to the first stepped surface 7.7, thereby releasing the locking cylinder 7.6 from the outer tube 7.12. Under the action of gravity, the locking cylinder 7.6 descends with the central tube 7.9. When enough space is cleared, the swing plate 7.3 opens under the combined action of its own weight, spring force, and the gravity of the solid agent 8. The solid agent 8 falls from the solid agent container 7.1 and through the center of the central tube 7.9 via 7.24 to the bottom of the artificial well or the hollow tailpipe 7.25. The well fluid dissolves the solid agent 8, and by slowly releasing the effective components, it protects the casing, tubing, pump, and sucker rod, reducing corrosion.

[0101] S3. After a period of time, when the effective component of the solid agent 8 in the produced fluid is below the required anti-corrosion dosage, repeat step S2 and gradually increase the pressurization pressure. Then, the solid agent release device 7 can be opened sequentially from bottom to top, thereby realizing the multiple release of the solid anti-corrosion agent, improving the anti-corrosion effective period, and achieving the anti-corrosion extension of the oil well.

[0102] Example 4:

[0103] Based on Example 3, the pressure transmission holes 7.14 of the solid drug release device 7 are connected in series through capillary tubes. The main pipe of the capillary tubes is connected to the wellhead and connected to the pressure pump. The pressure can be precisely controlled with a small discharge volume, thereby accurately controlling the release of each (stage) of the solid drug release device 7.

[0104] For wells without pressure at the wellhead 1, once all the solid agent in the downhole solid agent release device 7 is consumed, the agent can be injected into the artificial well bottom through the casing gate 2 to achieve full wellbore corrosion protection.

[0105] This patented technology can also be used in the application of solid wax inhibitor particles, solid scale inhibitor particles, etc. in oil and water wells.

[0106] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0107] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0108] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0109] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present 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.

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A solid drug dispensing device, comprising a solid drug receiving cylinder and a blocking mechanism, characterized in that, It also includes locking and unlocking mechanisms; The lower end of the solid medicine container tube is open, and the lower end of the solid medicine container tube is connected to a blocking mechanism. The lower end of the blocking mechanism is connected to a locking and unlocking mechanism, and the locking and unlocking mechanism controls the opening of the blocking mechanism.

2. The solid drug dispensing device according to claim 1, characterized in that, The blocking mechanism includes a swing plate seat and a swing plate; The upper end of the swing plate seat is connected to the lower end of the solid medicine container tube, and the swing plate seat is provided with an axial through hole; The lower end face of the swing plate seat is provided with a rotating shaft, which is connected to the swing plate, and the swing plate can rotate around the rotating shaft. A swing plate seal is provided on the lower end face of the swing plate seat around the outer periphery of the axial through hole, and the swing plate seal cooperates with the swing plate to seal. The lower end of the swing plate base is connected to the locking and unlocking mechanism.

3. A solid drug dispensing device according to claim 2, characterized in that, The locking and unlocking mechanism includes a locking cylinder, a central tube, an outer tube, a sliding locking mechanism, and a sliding unlocking mechanism; The upper end of the outer tube is connected to the lower end of the swing plate seat. The central tube is slidably disposed inside the outer tube. The locking cylinder is disposed between the swing plate and the central tube. The locking cylinder pushes against the swing plate, so that the swing plate and the swing plate sealing element are in full contact and sealed. The locking cylinder is connected to the outer tube via a sliding locking mechanism, and the central tube is connected to the outer tube via a sliding unlocking mechanism.

4. A solid drug dispensing device according to claim 3, characterized in that, The sliding locking mechanism includes a locking ball and a locking ball screw; The locking cylinder is provided with an inner locking ball hole, and the outer tube is provided with an outer locking ball hole; A locking ball is provided between the inner locking ball hole and the outer locking ball hole, and the locking ball fixes the locking cylinder to the outer tube; a locking ball screw is provided in the outer locking ball hole, and the locking ball screw is used to fix the position of the locking ball.

5. A solid drug dispensing device according to claim 4, characterized in that, The sliding unlocking mechanism includes a stepped surface, a pressure transmitting hole, a pressure bearing chamber, a shear pin, a travel chamber, and a limiting joint; The outer wall of the central tube is provided with a first stepped surface, a second stepped surface, a third stepped surface, a fourth stepped surface, and a fifth stepped surface; The first step surface and the second step surface form a first transition shoulder; The second transition shoulder is located between the second and third stepped surfaces; The third transition shoulder is located between the third and fourth stepped surfaces. The fourth transition shoulder is located between the fourth and fifth stepped surfaces. The inner wall of the locking cylinder mates with the second stepped surface, the first transition shoulder is higher than the upper edge of the locking ball hole in the locking cylinder, and the second transition shoulder is lower than the lower edge of the locking ball hole in the locking cylinder; There is a ball-placement space between the inner wall of the locking cylinder and the first stepped surface. When the first stepped surface corresponds to the inner locking ball hole of the locking cylinder, the locking ball can completely leave the outer tube, releasing the locking cylinder from the outer tube. The inner wall of the outer tube is provided with an upper small inner diameter and a lower large inner diameter. The diameter-changing step between the upper small inner diameter and the lower large inner diameter is located below the second transition shoulder. The upper small inner diameter mates with the third stepped surface, and the mating surface is sealed by the third stepped surface seal. The fourth stepped surface mates with the lower large inner diameter of the outer tube, and the mating surface is sealed by the fourth stepped seal; the space enclosed by the third transition shoulder, the diameter-changing shoulder, the lower large inner diameter, and the third stepped surface is a pressure-bearing cavity; the outer tube is provided with a pressure-transmitting hole, which communicates with the pressure-bearing cavity; a shear pin is provided above the fourth stepped seal on the outer tube, and the shear pin is embedded in the central tube to fix the central tube; The lower end of the outer tube is connected to a limiting joint. The inner wall of the limiting joint is provided with an inner convex ring. The inner wall of the inner convex ring mates with the fifth step surface and is sealed by the fifth step surface seal. The space enclosed by the limiting joint, the fifth step surface, the fourth transition step, and the outer tube is a stroke cavity. The height of the stroke cavity is greater than the sum of the rotation radius of the swing plate and the distance from the first transition step to the lower edge of the locking ball hole in the locking cylinder.

6. A solid drug dispensing device according to claim 2, characterized in that, The swing plate is cylindrical, and a torsion spring is provided on the rotating shaft to give the swing plate a tendency to rotate downward and open; a guide surface is provided at the upper end of the axial through hole of the swing plate seat.

7. A solid drug dispensing device according to claim 5, characterized in that, The inner diameter of the locking cylinder is smaller than the maximum outer diameter of the swing plate; The portion of the locking ball in the inner locking ball hole is greater than half, and the width of the ball placement space is greater than the portion of the locking ball in the outer locking ball hole; The outer diameters of the first, second, third, and fourth stepped surfaces of the central tube increase sequentially; the outer diameter of the fifth stepped surface is smaller than that of the fourth stepped surface.

8. A solid drug dispensing device according to any one of claims 2-7, characterized in that, The solid agent is one or a mixture of at least two of the following: solid corrosion inhibitor granules, solid wax inhibitor granules, and solid scale inhibitor granules. The pharmaceutical particles are spherical or cylindrical in shape; the maximum projected external dimension of a single solid pharmaceutical particle is less than half the diameter of the axial through hole of the swing plate seat.

9. A solid drug delivery string, comprising an oil pipe, wherein an oil pump and a screen pipe are mounted on the oil pipe, characterized in that, The oil pipe is also provided with a solid agent release device as described in claim 5; An oil pump is installed above the screen tube, and a solid agent release device is installed below the screen tube. At least one solid agent release device is provided, and the uppermost solid agent receiving tube has a closed structure at its top.

10. A solid drug delivery column according to claim 9, characterized in that, At least two solid drug release devices are provided, and the two solid drug release devices are connected by a tail pipe; The outer wall of the tailpipe is hollowed out, and the upper end of each solid agent receiving tube is a closed structure, so that the liquid in the well can dissolve the solid agent that falls into the tailpipe; Alternatively, the tailpipe can be a non-perforated circular pipe, with the uppermost solid agent receiving pipe having a closed structure at the top and the remaining solid agent receiving pipes having an open structure at the top, allowing the solid agent to fall to the bottom of the artificial well.

11. A solid drug delivery column according to claim 10, characterized in that, All the pressure transmission holes of the solid agent release device are connected in series through capillary tubes. After the tubing is lowered into the well, the main capillary tube is connected to the wellhead and then to the pressure pump.

12. A method for using a solid drug delivery column, characterized in that, Using the solid drug delivery column according to claim 9, the following steps are included: S1. Before running the anti-corrosion tubing, add solid chemicals from the wellhead; Select an appropriate number of solid drug release devices according to production needs. The number of shear pins or the diameter of the shear pins of all solid drug release devices gradually decreases from top to bottom, which means the unlocking pressure decreases. S2. During the oil well production process, monitor the effective components of the solid agent in the produced fluid. When the effective components of the solid agent are below the required dosage, pressurize the pressure transmission hole. The pressure enters the pressure bearing chamber and acts on the third transition step. At this time, the shear pin is subjected to shear force. When the lowest level shear pin is cut, in the lowest level solid agent release device, the central tube moves downward, the locking ball leaves the outer locking ball hole of the outer tube, the locking cylinder moves downward, the swing plate opens, and the solid agent falls from the solid agent container, and the well fluid dissolves the solid agent; S3. When the effective component of the solid agent in the produced liquid is again detected to be below the required dosage, increase the pressurization pressure and repeat step S2.

13. The method of using the anti-corrosion tubular string according to claim 12, characterized in that, For wells without pressure at the wellhead, once all the solid agent in the downhole solid agent release device is consumed, the agent is injected into the artificial well bottom through the casing gate to achieve full wellbore corrosion protection.

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