Tubular column well washing device capable of protecting stratum
By designing a column well washing device including fusible parts and lock rings, the existing well washing protector is easily damaged when going down the well, and the casing is effectively sealed, preventing the well washing water from entering the formation, protecting the oil layer and saving costs.
Patent Information
- Application Number
- CN202422361440.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-09-27
AI Technical Summary
The existing well wash protectors are prone to damage when going down the well and cannot effectively seal the casing, causing the well wash water to enter the formation and contaminate the oil layer.
A pipe column well washing device including an upper joint, an unsealing cylinder, a restraint sleeve, an upper inner tube, a rubber tube, a lower inner tube, a sealing cylinder, a fuse, a locking ring and a single flow valve is designed. The device uses the internal pressure of the well to seal the sleeve by combining the fuse and the locking ring to prevent the well washing water from entering the formation.
The device will not be damaged when going down the well, and can effectively seal the casing, prevent the well washing water from entering the formation, protect the formation from contamination, and do not require ground pressure, saving equipment and construction costs.
Smart Images
Figure CN222991472U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to downhole equipment for oilfield pumping wells, which is a device for preventing well-washing water from entering into the formation when the pumping well is washed, and is specifically a pipe column well-washing device for protecting the formation. Background Art
[0002] In the production of heavy oil, wax deposition, and deep pumping wells, it is necessary to frequently circulate hot water to wash the well pump and the tubing above the well pump to maintain normal production of the well. The well washing method is to pump hot water into the casing, mix the hot water with the well fluid under the well pump, and then return it from the oil pipe (tubing) on the well pump. Since the casing is connected to the oil layer, the well washing pressure is generally very high, which produces a high back pressure on the oil layer. The static liquid column pressure generated by the well washing water in the formation is higher than the formation pressure, and the well washing water is easily injected into the formation. After the well washing water is injected into the formation, on the one hand, it causes damage to the formation that is allergic to the well washing water (called oil layer pollution on site), crushes the formation, and makes the formation stop producing oil; on the other hand, it increases the amount of well washing water used, the well washing time is long, and manpower and material resources are increased.
[0003] In order to solve the above problems, technicians have developed a well-washing protector, which is a device placed above the formation to seal the casing (well wall) and form a well-washing circulation channel above the formation, so that the well-washing water does not enter the formation and the formation is prevented from being polluted by the well-washing water. For example, Chinese Patent 2008200205618 "Fuzheng Formation Well-Washing Protector" is such a device. This device relies on the leather cup packer on it to seal the casing. Although its sealing method is simple and does not require ground pressure, it can save equipment and construction costs, but its reliability is very poor. The outer diameter of the leather cup on the leather cup packer is larger than the inner diameter of the casing, and the leather cup on the leather cup packer is upward. After it is in place, it will self-seal with the casing, so that the liquid flow above cannot flow downward. However, it must be close to the inner wall of the casing when it is lowered into the well, and it must rub and collide with the casing. It is easy to be damaged during the process of lowering into the well. It cannot seal the casing after lowering into the well, and it cannot protect the formation when washing the well. Summary of the invention
[0004] The utility model aims to provide a pipe column well washing device for protecting the formation, so that the pipe column will not be damaged when it is lowered into the well, and the well washing water is separated from the formation, so as to prevent the well washing fluid from entering the formation and polluting the formation, thereby protecting the formation from damage.
[0005] The object of the present utility model is achieved as follows: It includes an upper joint, a releasing cylinder, a releasing pin, a restraint sleeve, an upper inner tube, an upper rubber cylinder seat, a rubber cylinder, a lower rubber cylinder seat, a lower inner tube, a sealing cylinder, a fusible part, a locking ring, a check valve, and a lower joint. There is a valve ball inside the check valve. After the valve ball drops, it blocks the liquid flow channel, so that the formation fluid can only enter from the outside of the check valve above the valve ball, and the liquid flow cannot flow downward from below the valve ball into the formation. The lower rubber cylinder seat, the rubber cylinder, and the upper rubber cylinder seat are sleeved on the upper inner tube. The lower rubber cylinder seat is limited by the lower shoulder of the upper inner tube, so that the lower rubber cylinder seat can only move upward and not downward on the upper inner tube. The upper part of the upper inner tube is milled into strips so that it can deform radially. The external thread at the upper part of the upper inner tube is connected to the internal thread of the restraint sleeve. The lower part of the upper joint has a restraint section, and the middle part of the upper joint has a release section. The diameter of the restraint section is greater than the diameter of the release section. There is a restraint hole inside the upper part of the upper inner tube, and there is an expanding section inside the upper inner tube. The inner diameter of the restraint hole is smaller than the inner diameter of the expanding section, and the inner diameter of the restraint hole is equal to the diameter of the restraint section. The restraint section is inserted into the restraint hole, so that the strips milled on the upper part of the upper inner tube cannot deform radially. The lower thread of the releasing cylinder is connected to the thread of the upper rubber cylinder seat, and the middle internal thread of the releasing cylinder is connected to the external thread of the restraint sleeve. The upper internal shoulder of the releasing cylinder is suspended on the external shoulder of the upper joint. A releasing pin is installed between the upper joint and the releasing cylinder. The lower part of the upper inner tube is the lower inner tube. The upper part of the sealing cylinder is sleeved on the outer part of the lower part of the upper inner tube and then connected to the lower rubber cylinder seat. There is a sealing ring for sealing between the upper inner wall of the sealing cylinder and the lower outer wall of the upper inner tube. The inner convex section of the sealing cylinder is sleeved on the lower thread of the lower inner tube, and there is a sealing ring for sealing the gap between the two. A closed annular cavity is formed between the sealing cylinder and the lower inner tube. There are single-direction external teeth on the outer wall of the locking ring, and the circular locking ring has a notch, so that the diameter of the locking ring can change when it is subjected to a radial force. The locking ring is installed in the annular groove on the outer wall of the check valve. The lower part of the sealing cylinder has single-direction internal teeth that match the single-direction external teeth on the outer wall of the locking ring. The upper part of the check valve is connected to the lower part of the lower inner tube, and the connection part is sealed, so that the lower part of the sealing cylinder is sleeved on the upper part of the outer wall of the check valve, and there is a sealing ring for sealing the gap between the two, so that the well fluid cannot enter from outside the sealing cylinder to the upper end face of the check valve. The locking ring is engaged with the single-direction internal teeth. There is a channel communicating with the inside of the check valve or the inside of the lower inner tube in the cavity between the upper end face of the check valve and the lower end face of the convex section. A fusible part is installed in this channel, so that the cavity between the upper end face of the check valve and the lower end face of the convex section is sealed. The lower part of the check valve is connected to the lower joint.
[0006] There is an internal communication groove on the upper inner tube, and the internal communication groove is above the upper rubber cylinder seat. There is an external communication groove on the releasing cylinder. The check valve is a sand-settling type check valve.
[0007] Advantages of the present utility model: The fusible part makes the cavity between the upper end surface of the check valve and the lower end surface of the boss section a sealed cavity, so that when the sealing cylinder is in the well fluid during downhole operation, it does not receive an upward axial force, and the rubber cylinder will not be deformed by force and will not be damaged during downhole operation, overcoming the problems existing in the prior art. After reaching the downhole position, the present utility model is below the liquid level, and the well fluid can melt the fusible part, so that the hydrostatic pressure at the position acts on the lower end surface of the boss section. Since the annular cavity is sealed and there is no pressure inside, the sealing cylinder can receive an upward thrust, so that the rubber cylinder compresses and expands to seal the casing. During well flushing, the flushing water is blocked by the check valve and will not enter the formation, which can prevent the pollution of the formation by the flushing fluid. The present utility model uses the pressure in the well itself to seat the rubber cylinder and does not require ground pumping to seal the casing, so it is convenient to use and has significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Attached Figure 1 is the assembly drawing of an embodiment of the present utility model.
[0009] Attached Figure 2 is the present utility model in Figure 1 the assembly drawing after adding a first-stage thrust mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0010] The following describes the specific embodiments of the present utility model with reference to the drawings.
[0011] Such as Figure 1As shown in the figure, the embodiments of the present utility model include an upper joint 1, a releasing cylinder 2, a releasing pin 3, a restraint sleeve 4, an upper inner tube 5, an upper rubber cylinder seat 6, a rubber cylinder 7, a lower rubber cylinder seat 8, a lower inner tube 9, a sealing cylinder 11, a fusible part 12, a locking ring 13, a check valve 15, and a lower joint 16. There is a valve ball in the check valve 15. After the valve ball drops, it blocks the liquid flow channel, so that the formation fluid can only enter from the outside of the check valve 15 above the valve ball, and the liquid flow cannot flow downward from below the valve ball into the formation. The lower rubber cylinder seat 8, the rubber cylinder 7, and the upper rubber cylinder seat 6 are sleeved on the upper inner tube 5. The lower rubber cylinder seat 8 is limited by the lower shoulder of the upper inner tube 5, so that the lower rubber cylinder seat 8 can only move upward and not downward on the upper inner tube 5. The upper part of the upper inner tube 5 is milled into strips so that it can deform radially. The external thread on the upper part of the upper inner tube 5 is connected to the internal thread of the restraint sleeve 4 (the thread is on the upper part of the strip). The lower part of the upper joint 1 has a restraint section 1-2, and the middle part of the upper joint 1 has a release section 1-1. The diameter of the restraint section 1-2 is greater than the diameter of the release section 1-1. There is a restraint hole 5-1 in the upper inner part of the upper inner tube 5, and there is an expanding section 5-2 in the upper inner tube 5. The inner diameter of the restraint hole 5-1 is smaller than the inner diameter of the expanding section 5-2. The inner diameter of the restraint hole 5-1 is equal to the diameter of the restraint section 1-2. The restraint section 1-2 is inserted into the restraint hole 5-1, so that the strip milled on the upper part of the upper inner tube 5 cannot deform radially, and its thread is always connected to the internal thread of the restraint sleeve 4. The lower thread of the releasing cylinder 2 is connected to the thread of the upper rubber cylinder seat 6, and the middle internal thread of the releasing cylinder 2 is connected to the external thread of the restraint sleeve 4. The upper inner shoulder of the releasing cylinder 2 is suspended on the outer shoulder of the upper joint 1. A releasing pin 3 is installed between the upper joint 1 and the releasing cylinder 2. The lower part of the upper inner tube 5 is the lower inner tube 9 (the upper inner tube 5 and the lower inner tube 9 can be an integral structure, or they can be two parts connected together by threads. If they are two parts connected, the connection part is kept sealed. From the perspective of cost saving, it is reasonable to assemble them into two parts. Whether it is an integral structure or a two-piece structure is within the protection scope of the present utility model). The upper part of the sealing cylinder 11 is sleeved on the outer part of the lower part of the upper inner tube 5 and then connected to the lower rubber cylinder seat 8. There is a sealing ring between the upper inner wall of the sealing cylinder 11 and the lower outer wall of the upper inner tube 5 for sealing. The inner boss section 11-1 of the sealing cylinder 11 is sleeved on the lower thread of the lower inner tube 9, and there is a sealing ring in the sleeved section to seal the gap between the two. A closed annular cavity 10 is formed between the sealing cylinder 11 and the lower inner tube 9. There are single-direction external teeth on the outer wall of the locking ring 13. The circular locking ring 13 has a cut (opening), so that the diameter of the locking ring 13 can change when it is subjected to a radial force. The locking ring 13 is installed in the outer wall annular groove of the check valve 15, and the locking ring 13 cannot move axially in the outer wall annular groove of the check valve 15. The lower part of the sealing cylinder 11 has a single-direction internal tooth 11-2 that matches the single-direction external teeth on the outer wall of the locking ring 13. The upper part of the check valve 15 is connected to the lower part of the lower inner tube 9, and the connection part is kept sealed, so that the lower part of the sealing cylinder 11 is sleeved on the upper part of the outer wall of the check valve 15, and there is a sealing ring in the sleeved part to seal the gap between the two.The well fluid cannot enter the upper end face of the check valve 15 from the outside of the sealing tube 11. The one-way outer teeth on the lock ring 13 are engaged with the one-way inner teeth 11-2. The cavity between the upper end face of the check valve 15 and the lower end face of the boss section 11-1 has a channel communicating with the inside of the check valve 15 or the inside of the lower inner tube 9 (the channel 12-1 communicating with the inside of the check valve 15 in the attached figure). The fusible element 12 is installed in this channel to seal the cavity between the upper end face of the check valve 15 and the lower end face of the boss section 11-1. The lower part of the check valve 15 is connected to the lower joint 16.
[0012] The upper inner tube 5 is provided with an inner connecting groove 5-3, and the inner connecting groove 5-3 is located above the upper rubber tube seat 6, and the unsealing tube 2 is provided with an outer connecting groove 2-1, and the check valve 15 is a sand-sinking check valve. The combination of these features enables the sand falling from the rubber tube during well washing to fall into the tail pipe under the lower joint 13. The structure of the sand-sinking check valve is like the oil inlet valve on the anti-sand-stuck oil pump, the liquid flow enters from the side, and the sand falls through the diversion. A certain number of tail pipes must be connected under the lower joint 16, and the lower part of the tail pipe is connected to a screw plug, so that the sand is deposited in the tail pipe, and the well washing water cannot flow out from the screw plug.
[0013] The utility model is equipped with a screen tube, which is installed under the oil pump and is located below the dynamic liquid level of the oil well (generally, the submergence of the oil well is greater than 300m) and above the formation. After a certain period of time (generally 10-20h), the fusible part 12 melts, the passage 12-1 is opened, and the liquid column pressure generated by the dynamic liquid level (called sinking pressure on site) acts on the lower end surface of the boss section 11-1. Since the annular cavity 10 is a closed space, the pressure on the upper end surface of the boss section 11-1 is low, so the liquid column pressure generated by the dynamic liquid level pushes the sealing cylinder upward to compress the rubber cylinder 7, so that it expands the sealing casing. When washing the well, the liquid well fluid will not enter the formation under the action of the check valve 15. When the sealing cylinder 11 moves upward, the lock ring 13 is buckled with another position of the one-way inner teeth 11-2, so that the rubber cylinder 7 will not return to its original state and the casing is always sealed.
[0014] When the pumping pipe string is pulled out next time, the pipe string is lowered first. The friction between the rubber sleeve 7 and the casing is fixed, and the downward pressure of the pipe string breaks the unsealing pin 3. The constraint section 1-2 leaves the constraint hole 5-1 and presses on the internal shoulder of the upper inner pipe 5. The strip milled on the upper part of the upper inner pipe 5 produces radial deformation, and the upper part of the upper inner pipe 5 is separated from the constraint sleeve 4. The upper joint 1 pushes the upper inner pipe 5 downward to make room for the rubber sleeve 7 to release and achieve unsealing.
[0015] If the sinking pressure is too low, or the wellbore diameter is small, the driving force generated by the sealing tube cannot meet the thrust required for the expansion of the rubber tube 7, and a two-stage sealing tube can be set, such as Figure 2As shown in the figure. If a two-stage sealing cylinder is adopted, the fusible part of the driving mechanism in the upper stage is installed on the side wall channel of the lower inner pipe 9. For installation, the upper inner pipe 5 and the lower inner pipe 9 need to be made of two connected parts.
[0016] The external communication groove 2-1, the internal communication groove 5-3, and the sand-settling single-flow valve are provided for collecting sand. The sand generated during well flushing can fall along the external communication groove 2-1, the internal communication groove 5-3, the upper inner pipe 5, the lower inner pipe 9, and the sand-settling channel of the single-flow valve 15, and the well fluid enters from the side of the single-flow valve 15.
[0017] To prevent the movement of the sealing cylinder 11 caused by collision during well lowering, an anti-movement pin 14 can be installed between the sealing cylinder 11 and the single-flow valve 15. The force required to cut off the anti-movement pin 14 should be less than the thrust generated by the lowest submergence pressure on the sealing cylinder.
[0018] For installation, a nail is installed in the annular groove on the outer wall of the single-flow valve 15, and the opening of the locking ring 13 stops the nail, so that the locking ring 13 cannot rotate in the annular groove on the outer wall of the single-flow valve 15.
Claims
1. A pipe column well washing device for protecting formations, comprising an upper joint (1), an unsealing cylinder (2), an unsealing pin (3), a restraining sleeve (4), an upper inner tube (5), an upper rubber cylinder seat (6), a rubber cylinder (7), a lower rubber cylinder seat (8), a lower inner tube (9), a sealing cylinder (11), a fusible part (12), a locking ring (13), a check valve (15), and a lower joint (16), wherein a valve ball is arranged in the check valve (15), and when the valve ball falls, a liquid flow channel is blocked, so that formation fluid can only enter the valve ball from the outside of the check valve (15), and the liquid cannot flow downward from under the valve ball into the formation, and the device is characterized in that: The lower rubber cylinder seat (8), the rubber cylinder (7), and the upper rubber cylinder seat (6) are sleeved on the upper inner tube (5); the lower rubber cylinder seat (8) is limited by the lower shoulder of the upper inner tube (5) so that the lower rubber cylinder seat (8) can only move upward but not downward on the upper inner tube (5); the upper part of the upper inner tube (5) is milled into a strip body so that it can be radially deformed; the outer thread of the upper part of the upper inner tube (5) is connected with the inner thread of the constraint sleeve (4); the lower part of the upper joint (1) has a constraint section (1-2); the middle part of the upper joint (1) has a release section (1-1); the diameter of the constraint section (1-2) is larger than the diameter of the release section (1-1); the upper inner part of the upper inner tube (5) has a constraint hole (5-1); the upper inner tube (5) has an expansion section (5-2); the inner diameter of the constraint hole (5-1) is The inner diameter of the constraint hole (5-1) is smaller than the inner diameter of the expansion section (5-2), the inner diameter of the constraint hole (5-1) is equal to the diameter of the constraint section (1-2), the constraint section (1-2) is inserted into the constraint hole (5-1), so that the strip body milled at the upper part of the upper inner tube (5) cannot be radially deformed, the lower thread of the unsealing tube (2) is connected to the thread of the upper glue tube seat (6), the middle inner thread of the unsealing tube (2) is connected to the outer thread of the constraint sleeve (4), the upper inner shoulder of the unsealing tube (2) is suspended on the outer shoulder of the upper joint (1), the unsealing pin (3) is installed between the upper joint (1) and the unsealing tube (2), the lower part of the upper inner tube (5) is the lower inner tube (9), and the upper part of the sealing tube (11) is sleeved on the outer part of the lower part of the upper inner tube (5) and connected to the lower glue tube seat (8). A sealing ring is provided between the upper inner wall of the sealing cylinder (11) and the lower outer wall of the upper inner tube (5). The inner boss section (11-1) of the sealing cylinder (11) is sleeved on the lower thread of the lower inner tube (9). The sleeve section has a sealing ring to seal the gap between the two. A closed annular cavity (10) is formed between the sealing cylinder (11) and the lower inner tube (9). A one-way outer tooth is provided on the outer wall of the locking ring (13). The circular locking ring (13) has a notch so that the diameter of the locking ring (13) can change when a radial force is applied. The locking ring (13) is installed in the annular groove on the outer wall of the check valve (15). The lower part of the sealing cylinder (11) has a one-way inner tooth (11-2) matching the one-way tooth on the outer wall of the locking ring (13). The upper part of the check valve (15) and the lower inner tube are connected. The lower part of the sealing cylinder (11) is connected to the lower part of the one-way valve (15), and the connection is kept sealed, so that the lower part of the sealing cylinder (11) is sleeved on the upper part of the outer wall of the one-way valve (15). A sealing ring is provided at the sleeved part to seal the gap between the two, so that well fluid cannot enter the upper end surface of the one-way valve (15) from the outside of the sealing cylinder (11). The lock ring (13) is engaged with the one-way internal teeth (11-2). The cavity between the upper end surface of the one-way valve (15) and the lower end surface of the boss section (11-1) has a channel that communicates with the inside of the one-way valve (15) or the inside of the lower inner tube (9). A fusible part (12) is installed in the channel to seal the cavity between the upper end surface of the one-way valve (15) and the lower end surface of the boss section (11-1). The lower part of the one-way valve (15) is connected to the lower joint (16).
2. A pipe column well washing device for protecting formations according to claim 1, characterized in that : An inner connecting groove (5-3) is provided on the upper inner tube (5), and the inner connecting groove (5-3) is located above the upper glue cylinder seat (6). An outer connecting groove (2-1) is provided on the unsealing cylinder (2), and the check valve (15) is a sand settling type check valve.