Auxiliary device and method for sand washing outside underground screen pipe
By designing an auxiliary device for external sand flushing of downhole screen pipes, and utilizing the interference connection of the retrieval bottom plug and the delivery device, an external circulation channel is established, which solves the problem that conventional screen pipe sand control strings cannot achieve external sand flushing, improves production efficiency and retrieval success rate, and reduces operating costs.
Patent Information
- Application Number
- CN202410617412.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-11-18
AI Technical Summary
Conventional screen pipe sand control strings cannot achieve external sand flushing, resulting in reduced well productivity in the later stages of screen pipe production, low success rate of first-time retrieval, and loss of sand-collecting bags.
Design an auxiliary device for external sand flushing of downhole screen pipes, including a retrievable bottom plug and a delivery device. An external circulation channel is realized through an interference fit. By combining the retrievable bottom plug and the delivery device, a method for external sand flushing of screen pipes is established.
This technology enables the recycling of gravel from the screen sleeve to the surface, improving the production efficiency of the screen tube and the success rate of one-time retrieval, while reducing operating costs.
Smart Images
Figure CN120968484A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of fine sand prevention in loose sandstone oil field, and particularly relates to a method for sand washing outside a downhole screen pipe. BACKGROUND
[0002] At present, a conventional screen pipe sand prevention pipe column comprises, from bottom to top, a nipple, a screen pipe and a packer, and sand washing after screen pipe lowering can only circulate gravel in the screen pipe to the ground, and the conventional screen pipe sand prevention pipe column cannot realize sand washing outside the pipe, gravel in the screen pipe cannot be circulated to the ground due to the absence of a circulation channel, and problems such as a decrease in oil well productivity in the later stage of screen pipe production, a low success rate of one-time fishing and loss of sand pocket occur. SUMMARY
[0003] In order to solve the above problems, the present application provides a downhole screen pipe sand washing auxiliary device, which comprises a fishable bottom plug and a delivery device, the fishable bottom plug is in interference connection with the delivery device, the fishable bottom plug comprises a shell, a spring, a sand washing pipe, a first ball and a fishing barrel, the sand washing pipe is embedded in the shell, the first ball and the spring are arranged in the sand washing pipe, the first ball is in spherical surface contact sealing with the sand washing pipe, the upper end of the spring abuts against the first ball, the lower end of the spring abuts against the bottom wall of the sand washing pipe, and the lower end of the fishing barrel is fixedly connected to the upper end of the sand washing pipe; the delivery device comprises a push pipe, a second ball, a connecting hoop, a hook and a convex ring pipe, the fishing barrel is sleeved in the middle part of the connecting hoop, the push pipe is movably arranged in the connecting hoop, the second ball is placed on the upper end of the push pipe for sealing, the convex ring pipe is fixedly connected to the lower end of the push pipe, a plurality of hooks are fixedly connected to the middle part of the connecting hoop at equal angles, the lower part of the hook supports the convex ring pipe, and the lower part of the hook is embedded in the groove in the inner wall of the fishing barrel, and the connection of the hook and the convex ring pipe realizes the connection of the fishable bottom plug and the delivery device.
[0004] A downhole screen pipe sand washing method according to the above downhole screen pipe sand washing auxiliary device, comprising the following steps:
[0005] S1, after determining the screen pipe sand prevention of an oil well, relevant tools are sent to the downhole through a tubing, the relevant tools comprise, from bottom to top, a fishable bottom plug, a screen pipe, a packer and a tubing, and the tools are connected through threads.
[0006] Further, the method further comprises the following step S2, after the ball is put into the tubing, the packer is released by ground pressure, the tubing is pulled out of the oil well, and the fishable bottom plug, the screen pipe and the packer are left in the well.
[0007] Further, the method further comprises the following step S3, after the oil well is produced for a period of time, if there is liquid reduction, the screen pipe sand washing outside the pipe is realized through the following procedures.
[0008] Further, it further comprises the step S4, the tubing is connected with the fishable bottom plug through the delivery device, the spring, the sand washing pipe, the first ball and the fishing tool inside the fishable bottom plug are fished up, after reaching the fishable bottom plug position, the tubing string is lifted, the device inside the fishable bottom plug is fished out of the well along with the fishing string, after being fished out, the inner cavity of the screen pipe is communicated with the sand setting chamber, at this time, the tubing string combination in the well from bottom to top is the shell outside the fishable bottom plug, the screen pipe and the packer.
[0009] Further, it further comprises the step S5, after the device inside the fishable bottom plug is fished out of the well, the sand washing server is lowered into the inner cavity of the screen pipe through the tubing, the sealing connection is carried out through the interference rubber bowl and the screen pipe, the reverse circulation sand washing is carried out, the water is punched from the casing, and the flow direction of the water flow is the wall between the tubing and the screen pipe, the wall between the screen pipe and the casing, the outer part of the fishable bottom plug, the inner part of the sand washing server and the inner part of the tubing, the tubing is moved from bottom to top, and the screen sleeve annular gravel is circulated out of the ground.
[0010] Further, it further comprises the step S6, after the sand washing outside the screen pipe is completed, the sand washing server is lifted out of the oil well along with the tubing, the device inside the fishable bottom plug and the delivery device are lowered, the tubing string from bottom to top is the fishable bottom plug, the delivery device and the tubing, and is lowered to the shell position outside the fishable bottom plug, the fishable bottom plug inside is disconnected with the delivery device, the delivery device is lifted out of the oil well along with the tubing, at this time, the tubing string in the well from bottom to top is the fishable bottom plug, the screen pipe and the packer, and is restored to the structure of the step S1.
[0011] Further, it further comprises the step S7, the pump is lowered to produce.
[0012] The beneficial effects of the present application are that: a downhole screen pipe external sand washing method is developed on the basis of a conventional screen pipe sand prevention string, corresponding matching tools are developed, a pipe external circulation channel is established, screen pipe external sand washing is realized, the screen sleeve annular gravel is circulated out of the ground, the bottom plug and the screen pipe adopt the interference fit mode, the bottom plug can be conveniently fished and installed, and the sand cleaning work at the well bottom is more convenient. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 It is a perspective view of the bottom plug and the delivery device combination form of the present application;
[0014] Figure 2 It is a sectional view of the bottom plug and the delivery device combination form of the present application;
[0015] Figure 3 It is a sectional view of the bottom plug and the delivery device combination form of the present application; Figure 2 It is an enlarged view of the middle D;
[0016] Figure 4 It is a structure schematic view of the sand washing server;
[0017] Figure 5The sand washing principle diagram of the auxiliary device for sand washing outside the screen pipe in the well.
[0018] Wherein, the reference signs are:
[0019] 1, the bottom plug, 2, the delivery device, 11, the shell, 12, the spring, 13, the sand washing pipe, 14, the first ball, 15, the fishing barrel, 21, the push tube, 22, the second ball, 23, the connecting hoop, 24, the hook, 25, the convex ring tube. DETAILED DESCRIPTION
[0020] In order to make the technical means and achieve the purpose of the application easy to understand, the following specific embodiments are combined to further illustrate the application, an auxiliary device for sand washing outside the screen pipe in the well, as shown in Figures 1-3 , including the bottom plug 1 and the delivery device 2, the bottom plug 1 and the delivery device 2 are connected with interference, the bottom plug 1 includes the shell 11, the spring 12, the sand washing pipe 13, the first ball 14 and the fishing barrel 15, the shell 11 is embedded in the sand washing pipe 13, the sand washing pipe 13 is provided with the first ball 14 and the spring 12 inside, the first ball 14 and the sand washing pipe 13 are in surface contact sealing, at the same time, the upper end of the spring 12 abuts against the first ball 14, the lower end of the spring 12 abuts against the bottom wall of the sand washing pipe 13, and the lower end of the fishing barrel 15 is fixedly connected to the upper end of the sand washing pipe 13; the delivery device 2 includes the push tube 21, the second ball 22, the connecting hoop 23, the hook 24 and the convex ring tube 25, the fishing barrel 15 is sleeved in the middle part of the connecting hoop 23, the push tube 21 is movably arranged in the connecting hoop 23, the upper end of the push tube 21 is placed for sealing the second ball 22, the lower end of the push tube 21 is fixedly connected with the convex ring tube 25, a plurality of hooks 24 are fixedly connected to the middle part of the connecting hoop 23 at equal angles, the lower part of the hook 24 supports the convex ring tube 25, and the lower part of the hook 24 is embedded in the recess in the inner wall of the fishing barrel 15, and the connection of the hook 24 and the convex ring tube 25 realizes the connection of the bottom plug 1 and the delivery device 2.
[0021] A sand washing method outside the screen pipe in the well according to the auxiliary device for sand washing outside the screen pipe in the well described above, as shown in Figures 4-5 , includes the following steps:
[0022] S1, after determining the screen pipe sand prevention of the oil well, the related tools are sent to the well through the oil pipe, the related tools are in turn from bottom to top the bottom plug 1, the screen pipe, the packer and the oil pipe, and the tools are connected through the threads.
[0023] S2, after the ball is thrown in the oil pipe, the packer is released (disconnected) by ground pressure, the oil pipe is pulled out of the oil well, and the bottom plug 1, the screen pipe and the packer are left in the well.
[0024] S3, after the oil well is produced for a period of time, if there is liquid drop, the sand washing outside the screen pipe is realized through the following procedures.
[0025] S4, the oil pipe is connected with the fishable bottom plug 1 through the delivery device 2, the spring 12, the sand washing pipe 13, the first ball 14 and the fishing tool 15 in the fishable bottom plug 1 are fished up, after reaching the position of the fishable bottom plug 1, the pipe string is pulled up, the device in the fishable bottom plug 1 is fished out of the well along with the fishing pipe string, after being fished out, the inner cavity of the screen pipe is communicated with the sand setting chamber, at this time, the downhole pipe string combination from bottom to top is the shell 11 outside the fishable bottom plug, the screen pipe and the packer.
[0026] S5, after the device in the fishable bottom plug is fished out of the well, the sand washing server is lowered into the inner cavity of the screen pipe through the oil pipe, and is sealed and connected with the screen pipe through the interference rubber bowl, reverse circulation sand washing is carried out, water is punched from the casing, and the flow direction of the water flow is the wall between the oil pipe and the screen pipe, the wall between the screen pipe and the casing, the outside of the fishable bottom plug, the inside of the sand washing server and the inside of the oil pipe in turn, the oil pipe moves from bottom to top, and the screen sleeve annulus gravel is circulated out of the ground.
[0027] S6, after the screen pipe is sand-washed outside, the sand washing server is pulled out of the oil well along with the oil pipe, the device in the fishable bottom plug 1 and the delivery device 2 are lowered, the pipe string from bottom to top is the fishable bottom plug 1, the delivery device 2 and the oil pipe, and is lowered to the position of the shell 11 outside the fishable bottom plug, the fishable bottom plug inside is disconnected with the delivery device 2 by ball pressing, the delivery device 2 is pulled out of the oil well along with the oil pipe, at this time, the pipe string in the well from bottom to top is the fishable bottom plug 1, the screen pipe and the packer, and is restored to the structure of step S1.
[0028] S7, pump production.
[0029] A downhole screen pipe sand washing method, including a fishable bottom plug 1 which is interference fitted in the inner part of the lower end of the screen pipe, the interference fitting mode can facilitate the installation of the bottom plug 1 in the lower part of the screen pipe, and is also beneficial to the use of the fishing device to fish out the device in the bottom plug 1 and carry out sand washing treatment on the well bottom, and a sand setting chamber is reserved between the shell 11 outside the bottom plug 1 and the well bottom.
[0030] The inside of the sand washing pipe 13 is provided with the first ball 14 and the spring 12, the first ball 14 and the sand washing pipe 13 are in sealed contact, the upper end of the spring 12 abuts against the first ball 14, and the lower end of the spring 12 abuts against the bottom wall of the sand washing pipe 13. Under high pressure, the spring 12 is pressed, the sand can be melted into the sand washing pipe 13, and the plugging condition in the screen pipe can be reduced.
[0031] The process also includes a delivery device 2 for delivering the bottom plug 1, the delivery device 2 includes a connecting collar 23, the middle part of the connecting collar 23 is sleeved with a fishing tool 15, and the lower end of the fishing tool 15 is fixedly connected to the upper end of the sand washing pipe 13.
[0032] The inner activity of the connecting hoop 23 is provided with a push tube 21, the upper end of the push tube 21 is placed with a second ball 22 for sealing, the lower end of the push tube 21 is fixedly connected with a convex ring tube 25, the middle part of the connecting hoop 23 is fixedly connected with a plurality of hooks 24 at equal angles on the side wall, the lower part of the hook 24 holds the convex ring tube 25, and the lower part of the side wall of the hook 24 is embedded in the pre-set groove in the inner wall of the fishing barrel 15, and the connection of the bottom plug 1 and the delivery device 2 is realized by means of the hook 24 and the convex ring tube 25. When the connecting hoop 23 is filled with high pressure, the push tube 21 is pressed downward to move, realizing that the convex ring tube 25 passes over the hook 24, at this time the bottom plug 1 and the delivery device 2 are separated, and the delivery device 2 can be lifted out.
[0033] When the sand washing treatment needs to be carried out on the well bottom, the internal device of the bottom plug 1 is taken out. After the internal device of the bottom plug 1 is fished out of the well, the sand washing server is lowered into the screen pipe inner cavity bottom through the oil pipe, and the sealing connection with the screen pipe is carried out through the interference bowl, the back flushing sand is carried out, the oil pipe moves from bottom to top, realizes the screen sleeve annulus gravel circulation out of the ground, realizes a kind of external sand washing method, the principle is as shown in Figure 5 After cleaning, the internal device of the bottom plug 1 is installed on the screen pipe using the delivery device 2.
[0034] Field application
[0035] The fishable screen pipe bottom plug combination is composed of "fishable bottom plug 1, delivery device 2".
[0036] S1, when first lowered, the fishable bottom plug 1 is connected with the screen pipe through the thread, and is lowered into the well, and the pipe string structure of the sealing and the like from bottom to top is in turn fishable bottom plug 1+screen pipe+blind pipe+special screen pipe hanger+oil pipe to wellhead.
[0037] S2, the lowering should be stable at 5m / min, and sudden drilling and sliding should be strictly prohibited. If the sand prevention server is seated in the middle of the well during the process of lowering into the well, it should not be pulled or pressed hard, and the type, structural characteristics and operation procedures of the sand prevention packer should be followed to carry out the unjamming and unsealing.
[0038] S3, after the sand prevention pipe string is sent to the designed position, the professional technical personnel is responsible for the site packer releasing and seating construction.
[0039] S4, the pipe string after releasing is lifted out, and after releasing, it is slowly lifted up at a speed of 5m / min, and the change of the weight indicator is paid attention to, and after 5 oil pipes are continuously lifted out, if there is no abnormal condition, it is lifted out at the normal pipe lifting speed.
[0040] S5, the released packer releasing head is checked.
[0041] S6, production observation.
[0042] S7, the special tool is lowered to fish the 3T internal part of the bottom plug, and the sealing is released. After being fished out, the screen pipe inner cavity is communicated with the sand settling chamber.
[0043] S8, after the internal device of the bottom plug is fished out of the well, the sand washing server is lowered into the screen pipe lumen bottom through the oil pipe, sealed with the screen pipe through the interference bowl, back-flushed, and the oil pipe is moved from bottom to top to realize the screen sleeve annulus gravel circulation to the ground.
[0044] S9, if the original well screen pipe is reused for sand prevention and production, a new fishable bottom plug combination is lowered to press 0.4T to seal with the bottom plug outside, and the ball is pressed to 20MPa to release the hand; if the screen pipe is fished out of the well, the fishing operation only faces the fishing problem of the screen pipe hanger, avoids the screen pipe sand sticking problem, and becomes simple, greatly saving the operation cost.
[0045] After the fishable special bottom plug and sand washing server are developed, the screen pipe external sand washing demand is met through operation cooperation, and the problems of decreased oil well productivity in the later stage of screen pipe production, low one-time fishing success rate and lost sand pocket are solved.
[0046] Precautions
[0047] 1. Non-operation personnel enter the site, and do well the protection of hydrogen sulfide and personal safety protection;
[0048] 2. Tools are prone to slip and fall during installation and transportation. Labor protection should be worn, and tools should be carried uniformly, cooperatively, and gently to prevent object impact injury.
[0049] 3. Stay away from the rotating area of the equipment, and safety warning signs must be set at important positions; detection instruments must be worn when entering the hydrogen sulfide place, and the place must be entered after passing the detection; if the concentration exceeds 10mg / m3, immediately evacuate the site and report.
[0050] A screen pipe external sand washing method, the focus is on the interference fit of the bottom plug inside the lower end of the screen pipe, and the technical difficulty lies in:
[0051] ① Interference. The interference fit of the bottom plug inside the lower end of the screen pipe needs to meet the sealing function during normal production of the oil well.
[0052] ② Fishability. The interference fit of the bottom plug inside the lower end of the screen pipe has a fishing mechanism, which can be fished out of the well, and then the sand washing pipe string can be lowered to clean the sand chamber and the gravel in the screen sleeve annulus.
[0053] ③ Re-entering. Record the fishing position of the bottom plug, lower a new interference fit of the bottom plug inside the lower end of the screen pipe through the oil pipe, determine the re-entering position, set and release the hand, so as to realize the reuse of the screen pipe string and prolong the service life of the screen pipe.
[0054] ④ Reliability: the switching of the two states is reliable.
[0055] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical scheme and concept of the present application within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.
Claims
1. A sand washing assist device for use with a downhole screen pipe, the device comprising: The application relates to a fishing bottom plug (1) and a delivery device (2), wherein the fishing bottom plug (1) is in interference connection with the delivery device (2), the fishing bottom plug (1) comprises a shell (11), a spring (12), a sand washing pipe (13), a first ball (14) and a fishing barrel (15), the sand washing pipe (13) is embedded in the shell (11), the first ball (14) and the spring (12) are arranged in the sand washing pipe (13), the first ball (14) is in spherical surface contact sealing with the sand washing pipe (13), the upper end of the spring (12) abuts against the first ball (14), the lower end of the spring (12) abuts against the bottom wall of the sand washing pipe (13), and the lower end of the fishing barrel (15) is fixedly connected to the upper end of the sand washing pipe (13); the delivery device (2) comprises a push pipe (21), a second ball (22), a connecting hoop (23), a grab hook (24) and a convex ring pipe (25), the fishing barrel (15) is sleeved in the middle part of the connecting hoop (23), the push pipe (21) is movably arranged in the connecting hoop (23), the upper end of the push pipe (21) is provided with the second ball (22) for sealing, the lower end of the push pipe (21) is fixedly connected with the convex ring pipe (25), a plurality of grab hooks (24) are fixedly connected to the middle part of the connecting hoop (23) at equal angles, the lower part of the grab hook (24) supports the convex ring pipe (25), and the lower part of the grab hook (24) is embedded in the preset groove in the inner wall of the fishing barrel (15), and the fishing bottom plug (1) and the delivery device (2) are connected through the connection of the grab hook (24) and the convex ring pipe (25).
2. A method of sand washing outside a downhole screen pipe of a sand washing auxiliary device outside the downhole screen pipe according to claim 1, characterized in that, The application further relates to a method for preventing sand from entering a screen pipe, comprising the following steps: S1, after determining that the screen pipe is prevented from sand, the relevant tools are sent to the well through the oil pipe, the relevant tools are arranged from bottom to top as the fishing bottom plug (1), the screen pipe, the packer and the oil pipe, and the tools are connected through threads.
3. The method of claim 2, wherein, The application further relates to a method for preventing sand from entering a screen pipe, comprising the following steps:
4. The method of claim 3, wherein, S2, after the ball is put into the oil pipe, the packer is released through ground pressure, the oil pipe is pulled out of the well, and the fishing bottom plug (1), the screen pipe and the packer are left in the well.
5. The method of claim 4, wherein, S3, after the well is produced for a period of time, if there is liquid reduction, the screen pipe is subjected to sand washing outside through the following process.
6. The method of claim 5, wherein, S4, the oil pipe is in interference connection with the fishing bottom plug (1) through the delivery device (2), the spring (12), the sand washing pipe (13), the first ball (14) and the fishing barrel (15) in the fishing bottom plug (1) are fished up, the inner device of the fishing bottom plug (1) is fished out of the well after the fishing bottom plug (1) is lifted, the inner cavity of the screen pipe is communicated with the sand sink chamber, and the well string combination is arranged from bottom to top as the shell (11) outside the fishing bottom plug, the screen pipe and the packer. S5, after the inner device of the fishing bottom plug is fished out of the well, the sand washing server is lowered into the inner cavity of the screen pipe through the oil pipe, is sealed and connected with the screen pipe through the interference skin bowl, is subjected to reverse circulation sand washing, water is punched from the casing, and the water flow direction is the wall between the oil pipe and the screen pipe, the wall between the screen pipe and the casing, the outer part of the fishing bottom plug, the inner part of the sand washing server and the inner part of the oil pipe in sequence, the oil pipe is moved from bottom to top, and the screen annular space gravel is circulated out of the ground.
7. The method of claim 6, wherein, Also include step S6, after the completion of the sand washing screen pipe outside, sand washing server with tubing up oil well, put into the fishable bottom plug (1) internal device and delivery device (2), the string from bottom to top in turn for the fishable bottom plug (1), delivery device (2), tubing, down to the fishable bottom plug outside the shell (11) position, throw ball pressure, fishable bottom plug inside and delivery device (2) is disconnected, delivery device (2) with tubing up oil well, at this time the string in the well from bottom to top in turn for the fishable bottom plug (1), screen pipe, packer, restore to step S1 structure.
8. The method of claim 7, wherein, Also include step S7, down pump production.