Complex well open hole plugging well completion device and method
By using a complex well naked eye blocking the well, including the expansion tube column and the expansion mechanism, the cement slurry and the tube of the upper rubber and the lower rubber tube are tightly pasted, which solves the poor blocking effect in the existing technology. The difficulty of drilling the construction difficulties achieved efficient blocking and simplified well body structure.
Patent Information
- Application Number
- CN202310919662.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-25
- Publication Date
- 2025-01-28
AI Technical Summary
The prior art has problems such as poor sealing effect, difficulty in drilling and plug construction, and long time in the open hole sealing of complex wells. In particular, the secondary rotary expansion naked eye subsidy technology cannot ensure the sealing effect.
A complicated well -eye blocking the well, which includes the expansion tube column, the upper plastic tube, the lower plastic barrel, the expansion mechanism, the connector, the drilling mechanism, and the plug. By injecting cement slurry in the expansion tube column, and using the expansion mechanism, the upper plastic tube and the lower rubber cylinder are tightly pasted to ensure the blocking effect.
The effective blocking of the complicated well leakage layer is achieved, the structure of the well body is simplified, the passage of the subsequent drilling is guaranteed, the drilling time is shortened and the efficiency is improved.
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Figure CN119373451A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of complex leakage layer plugging, and in particular to a complex well open hole plugging completion device and method. Background Art
[0002] At present, the number of complex wells and deep wells in oil and gas well drilling at home and abroad is gradually increasing, and the risk of complex downhole accidents such as leakage and well kick during drilling is increasing. The current solution is mainly to use well control equipment to continue drilling under complex well conditions, or to use the method of inserting technical casing to isolate complex layers. The above methods not only increase drilling risks, drilling time and drilling costs, reduce drilling speed, but also greatly increase the complexity of the wellbore structure of the oil well. The final wellbore is getting smaller and smaller. For ultra-deep wells, it may even be impossible to reach the target layer due to the shrinkage of the wellbore.
[0003] The prior art discloses a secondary rotary expansion tool for expansion pipe and an open hole patching process, wherein the mobile expansion cone is connected to the piston by a screw; when leakage is found in the open hole section during drilling, the open hole patching process is adopted, the expansion pipe is first lowered into the open hole leakage section, and then the secondary rotary expansion tool is connected to the lower end of the pipe string and lowered into the upper end of the expansion pipe. The secondary rotary expansion tool rotates and moves downward with the pipe string, and the rotating expansion cone first enters the expansion pipe for the first rotary expansion operation, and the mobile expansion cone moves outward with the piston under the pressure of the drilling fluid, and the expansion pipe is subjected to a second rotary expansion operation. This process relies only on the expansion pipe for plugging, and the plugging effect for complex layers is poor. At the same time, the supporting tool structure is complex, the construction time of the drilling plugging operation is long, the drilling plugging efficiency is low, and there are certain risks in the drilling plugging process; the secondary expansion method is adopted, the process is complex, and the expansion effect is difficult to guarantee.
[0004] Based on this, the existing technology still needs to be improved. Summary of the invention
[0005] In order to solve the above technical problems, the embodiments of the present invention provide a complex well open hole plugging and completion device and method to solve the technical problems existing in the open hole plugging of the lost section in the prior art.
[0006] On the one hand, in order to solve the above technical problems, some embodiments of the present invention disclose a complex well open hole plugging completion device, characterized in that it includes an expansion string, an upper rubber cylinder, a lower rubber cylinder, an expansion mechanism, a joint, a drilling plug mechanism and a rubber plug;
[0007] Wherein, the upper rubber cylinder and the lower rubber cylinder are fixed on the outer wall of the expansion pipe string, and the distance between the upper rubber cylinder and the lower rubber cylinder is greater than the height of the leakage layer;
[0008] The expansion mechanism is located in the expansion column, and the expansion mechanism has a through hole penetrating from top to bottom;
[0009] The lower end of the joint is connected to the upper end of the expansion mechanism, and the upper end of the joint has a connection portion for connecting a drill pipe;
[0010] The drilling plug mechanism is fixed at the lower end of the expansion pipe column, and a plugging cavity is provided inside the drilling plug mechanism. The plugging cavity has an upper opening for the rubber plug to enter, and a lower opening which can be sealed by the rubber plug.
[0011] In some embodiments, the expansion pipe string includes an expansion pipe and a launch pipe, and the launch pipe is fixedly connected to the lower end of the expansion pipe;
[0012] The expansion mechanism is located in the launch tube, the plug drilling mechanism is installed at the lower end of the launch tube, and the middle part of the launch tube has a transition step to prevent the expansion mechanism from moving upward without applying external force;
[0013] The upper rubber cylinder and the lower rubber cylinder are sleeved on the outside of the expansion tube.
[0014] In some embodiments, the upper end of the launch tube is threadedly connected to the lower end of the expansion tube.
[0015] In some embodiments, the expansion mechanism includes a central tube, an expansion cone and a pressure sleeve, wherein:
[0016] The central tube comprises an upper tube and a lower tube, the outer diameter of the upper tube is larger than the outer diameter of the lower tube, and the joint is partially inserted into the upper tube and fixedly connected to the upper tube;
[0017] The expansion cone is sleeved on the outer wall of the lower tube, the upper end of the expansion cone is located below the transition step of the launch tube, and the pressure sleeve is sleeved on the outer wall of the lower tube and located below the expansion cone.
[0018] In some embodiments, the transition step is a conical tube, so that the lower inner diameter of the launch tube is larger than the upper inner diameter of the launch tube; the middle of the expansion cone has a conical slope, and the conical slope is located in the conical tube.
[0019] In some embodiments, the joint is threadedly connected to the inner wall of the central tube, and the outer wall of the lower end of the central tube is threadedly connected to the pressure sleeve.
[0020] In some embodiments, the drilling plug mechanism includes a bottom plugging cylinder, a plug seat and a booster cylinder;
[0021] Wherein, the bottom plugging tube partially extends into the launch tube from the lower end of the launch tube and is fixedly connected to the inner wall of the launch tube, the outer wall of the booster tube is connected to the inner wall of the bottom plugging tube, and the outer wall of the plug seat is connected to the inner wall of the booster tube;
[0022] The plug seat has an inner cavity matched with the rubber plug.
[0023] In some embodiments, the drilling plug mechanism further includes a sealing ring and a clamping ring;
[0024] The outer wall of the bottom plugging tube has a first step that forms an annular gap between the upper outer wall of the bottom plugging tube and the inner wall of the launch tube, and the sealing ring is located in the annular gap;
[0025] The outer wall of the upper end of the boost cylinder has a second step, and the outer diameter of the boost cylinder above the second step is larger than the outer diameter below the second step;
[0026] The upper end of the clamping ring presses against the second step, and the lower end of the clamping ring presses against the sealing ring.
[0027] In some embodiments, the upper rubber cylinder and the lower rubber cylinder are fixed to the outer wall of the expansion string by vulcanization.
[0028] In some embodiments, the inner wall of the plug seat is provided with a locking step for locking the rubber plug in the plug seat.
[0029] In some embodiments, the lower end of the lower tube is connected to the upper end of the drilling mechanism via a connecting assembly, so that the drilling mechanism can inhibit the rotation of the central tube.
[0030] In some embodiments, the connection assembly includes a convex tooth disposed at the lower end of the lower tube, and a groove disposed at the upper end of the drilling plug mechanism, and the convex tooth is matched with the groove.
[0031] On the other hand, some embodiments of the present invention further disclose a complex well open hole plugging and completion method, which uses the complex well open hole plugging and completion device described above, and the steps include:
[0032] S1 assembles the launching tube of the expansion string with the expansion mechanism and the drilling plug mechanism to obtain a string structure;
[0033] S2: connecting the pipe string structure to the expansion pipe and lowering it to a predetermined position in the open hole well, so that the leakage zone is located between the upper rubber tube and the lower rubber tube;
[0034] S3 pumps in a predetermined amount of cement slurry, which is then returned from the bottom of the tubing structure and enters the annulus between the expansion tubing and the open hole;
[0035] S4 puts in the rubber plug to completely replace the cement in the pipe string structure;
[0036] The S5 expansion mechanism expands to make the upper rubber cylinder and the lower rubber cylinder close to the open hole wall;
[0037] S6: drilling out the drilling plug mechanism and the rubber plug.
[0038] In some embodiments, the launching tube of the expansion string is assembled with the expansion mechanism and the drilling plug mechanism to obtain a string structure including:
[0039] S11: installing the expansion mechanism into the launch tube from the lower end of the launch tube;
[0040] S12 connects the drilling plug mechanism to the launching tube.
[0041] In some embodiments, connecting the tubular structure to an expansion pipe and lowering it to a predetermined position in a bare hole well further comprises: S21 inserting a joint into the upper end of the expansion pipe, connecting the lower end of the expansion mechanism with the upper end of the drilling plug mechanism, and rotating the joint to threadably connect the joint to the center pipe.
[0042] By adopting the above technical solution, the present invention has at least the following beneficial effects:
[0043] The present invention provides a complex well open hole plugging completion device and method. In view of the problems that the current secondary rotary expansion open hole compensation technology does not have the cementing function and cannot ensure the plugging effect, the drilling and plugging construction is difficult, and the drilling and plugging time is long, the open hole compensation is used to ensure that after the complex layer is isolated, the wellbore still has a large inner diameter to ensure subsequent drilling, simplifying or even not changing the original wellbore structure. The present invention can perform cementing operations before expansion construction to ensure the plugging effect of the leakage layer. By adopting a multi-stage reverse buckle design and an easy-to-drill material design, the subsequent drilling and plugging efficiency is improved and the drilling and plugging time is shortened. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0045] Figure 1 A schematic diagram of the structure of a complex well open hole plugging and completion device disclosed in some embodiments of the present invention;
[0046] Figure 2 A schematic diagram of the structure of a complex well open hole plugging completion device disclosed in some embodiments of the present invention when a pipe string is lowered to a predetermined position;
[0047] Figure 3 A schematic diagram of the structure of a complex well open hole plugging and completion device during cementing and expansion construction disclosed in some embodiments of the present invention;
[0048] Figure 4A schematic structural diagram of a drilling plug and well retention structure of a complex well open hole plugging and completion device disclosed in some embodiments of the present invention.
[0049] Description of reference numerals:
[0050] 1. Expansion tube; 2. Upper rubber tube; 3. Lower rubber tube; 4. Joint; 5. Launch tube; 6. Center tube; 7. Expansion cone; 8. Pressure sleeve; 9. Compression ring; 10. Sealing ring; 11. Bottom plugging tube; 12. Booster tube; 13. Plug seat; 14. Loss layer; 15. Rubber plug. DETAILED DESCRIPTION
[0051] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.
[0052] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.
[0053] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0054] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.
[0055] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.
[0056] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.
[0057] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.
[0058] like Figures 1 to 4 As shown, some embodiments of the present invention disclose a complex well open hole plugging completion device, including an expansion string, an upper rubber cylinder 2, a lower rubber cylinder 3, an expansion mechanism, a joint 4, a drilling plug mechanism and a rubber plug 15; wherein, the upper rubber cylinder 2 and the lower rubber cylinder 3 are fixed to the outer wall of the expansion string, and the distance between the upper rubber cylinder 2 and the lower rubber cylinder 3 is greater than the height of the leakage layer 14; the expansion mechanism is located in the expansion string, and the expansion mechanism has a through hole that runs from top to bottom; the lower end of the joint 4 is connected to the upper end of the expansion mechanism, and the upper end of the joint 4 has a connection portion for connecting a drill pipe; the drilling plug mechanism is fixed to the lower end of the expansion string, and the drilling plug mechanism has a plugging cavity inside, and the plugging cavity has an upper end opening that allows the rubber plug 15 to enter, and a lower end opening that can be sealed by the rubber plug 15. The upper rubber cylinder 2 and the lower rubber cylinder 3 can be fixed to the outer wall of the expansion string by vulcanization.
[0059] When the leakage layer 14 is plugged in this embodiment, the assembled expansion pipe string is first lowered into the open hole, so that the leakage layer 14 is located between the upper rubber tube 2 and the lower rubber tube 3, and then cement slurry is injected from the through hole, and the cement slurry flows into the annulus from the plugging cavity of the drilling plug mechanism, and fills into the space between the upper rubber tube 2 and the lower rubber tube 3. Then, the rubber plug 15 is lowered to squeeze out the cement slurry remaining in the expansion pipe string, and at the same time, after plugging the plugging cavity, the expansion operation is carried out, the expansion mechanism moves up, so that the upper rubber tube 2 and the lower rubber tube 3 are close to the inner wall of the open hole, the expansion mechanism pulls out the expansion pipe string, and then the drilling operation is carried out, and the rubber plug 15 and the related parts of the drilling plug mechanism left in the well can be directly drilled out. Through the open hole subsidy, it can be ensured that after the complex layer is sealed, the wellbore still has a large inner diameter, which ensures the subsequent drilling and simplifies or even does not change the original wellbore structure. The present invention can carry out cementing operations before the expansion construction, which ensures the plugging effect of the leakage layer 14. The subsequent drilling efficiency can be improved and the drilling time can be shortened by adopting multi-level reverse buckle design and easy-to-drill material design.
[0060] The complex well open hole plugging completion device disclosed in some embodiments of the present invention, on the basis of the above embodiments, the expansion pipe string may include an expansion pipe 1 and a launch pipe 5, the launch pipe 5 is fixedly connected to the lower end of the expansion pipe 1; the expansion mechanism is located in the launch pipe 5, the drilling plug mechanism is installed at the lower end of the launch pipe 5, and the middle part of the launch pipe 5 has a transition step that blocks the expansion mechanism from moving upward without applying external force; the upper rubber cylinder 2 and the lower rubber cylinder 3 are sleeved on the outside of the expansion pipe 1. Among them, the installation of the launch pipe 5, the drilling plug mechanism and the expansion mechanism can be carried out indoors, and the installation of the expansion pipe 1 and the installation of the joint 4 can be installed during the process of going down to the well. The installation of the joint 4 is to lower the joint 4 from the wellhead and then tighten it with the thread on the expansion mechanism. The corresponding number of expansion pipes 1 can be installed as needed. The upper end of the launch pipe 5 and the lower end of the expansion pipe 1 are generally connected by threads.
[0061] The complex well open hole plugging and completion device disclosed in some embodiments of the present invention, on the basis of the above embodiments, the expansion mechanism includes a central tube 6, an expansion cone 7 and a pressure sleeve 8, wherein the central tube 6 includes an upper tube and a lower tube, the outer diameter of the upper tube is larger than the outer diameter of the lower tube, the joint 4 is partially inserted into the upper tube and fixedly connected to the upper tube; the expansion cone 7 is sleeved on the outer wall of the lower tube, the upper end of the expansion cone 7 is located below the transition step of the launch tube 5, and the pressure sleeve 8 is sleeved on the outer wall of the lower tube and located below the expansion cone 7. The joint 4 can be threadedly connected to the inner wall of the central tube 6, and the outer wall of the lower end of the central tube 6 and the pressure sleeve 8 are also threadedly connected. The position of the expansion cone 7 when installed is limited by the step between the pressure sleeve 8 and the upper and lower tubes of the central tube 6, and the expansion cone 7 is limited in this position during cementing operation. When subjected to an upward force, the expansion cone 7 moves upward, first expanding the launching tube 5. As it moves upward, the expansion tube 1 also expands, eventually reducing the gap between the expansion pipe string and the wall of the open hole, making the upper rubber tube 2 and the lower rubber tube 3 close to each other, and combining the cement plugging with the expansion tube 1 to ensure the plugging effect.
[0062] In the complex well open hole plugging and completion device disclosed in some embodiments of the present invention, on the basis of the above embodiments, the transition step is a tapered tube, so that the lower inner diameter of the launch tube 5 is larger than the upper inner diameter of the launch tube 5; the middle of the expansion cone 7 has a tapered slope, and the tapered slope is located in the tapered tube. The arrangement of the tapered tube combined with the tapered slope enables the expansion to be completed more smoothly when the expansion action is performed.
[0063] The complex well open hole plugging and completion device disclosed in some embodiments of the present invention, on the basis of the above embodiments, the drilling plug mechanism includes a bottom plugging tube 11, a plug seat 13 and a booster tube 12; wherein the bottom plugging tube 11 partially extends into the launch tube 5 from the lower end of the launch tube 5 and is fixedly connected to the inner wall of the launch tube 5, the outer wall of the booster tube 12 is connected to the inner wall of the bottom plugging tube 11, and the outer wall of the plug seat 13 is connected to the inner wall of the booster tube 12; the plug seat 13 has an inner cavity that cooperates with the rubber plug 15. The plug seat 13 is used to cooperate with the rubber plug 15 to achieve the bottom seal so as to apply pressure, and the drilling plug mechanism can be made of easy-to-drill materials so that it can be drilled out more easily after the plugging is completed.
[0064] To further ensure the sealing performance, in some embodiments, the drilling plug mechanism may further include a sealing ring 10 and a clamping ring 9; the outer wall of the bottom plugging tube 11 has a first step that forms an annular gap between the upper outer wall of the bottom plugging tube 11 and the inner wall of the launch tube 5, and the sealing ring 10 is located in the annular gap; the upper outer wall of the booster tube 12 has a second step, and the outer diameter of the booster tube 12 above the second step is greater than the outer diameter below the second step; the upper end of the clamping ring 9 presses against the second step, and the lower end of the clamping ring 9 presses against the sealing ring 10. At the same time, the inner wall of the plug seat 13 is provided with a locking step for locking the rubber plug 15 in the plug seat 13.
[0065] In order to achieve the installation of the joint 4 and avoid the difficulty of installation caused by the rotation of the center tube 6 during the installation of the joint 4, the lower end of the lower tube and the upper end of the drilling mechanism can be connected through a connecting assembly to inhibit the rotation of the center tube 6 through the drilling mechanism. Specifically, the connecting assembly may include a convex tooth arranged at the lower end of the lower tube, and a groove arranged at the upper end of the drilling mechanism, and the convex tooth and the groove are adapted. When installing the joint 4, the convex tooth at the lower end of the center tube 6 is inserted into the groove at the upper end of the drilling mechanism. Generally, the groove can be arranged at the upper end of the booster cylinder 12 of the drilling mechanism. Under the action of the convex tooth and the groove, the center tube 6 is kept in a state. The external thread on the joint 4 is screwed into the internal thread at the upper end of the center tube 6 to complete the installation of the joint 4. The upper end of the joint 4 is the drill pipe connection end.
[0066] A method for plugging and completing a complex open hole well disclosed in some embodiments of the present invention comprises the following steps:
[0067] S1 assembles the launching tube 5 of the expansion string with the expansion mechanism and the drilling plug mechanism to obtain a string structure;
[0068] S2: Connect the pipe string structure to the expansion pipe 1 and lower it to a predetermined position in the open hole, so that the leakage zone 14 is located between the upper rubber tube 2 and the lower rubber tube 3;
[0069] S3 pumps in a predetermined amount of cement slurry, which is then returned from the bottom of the tubing structure and enters the annulus between the expansion tubing and the open hole;
[0070] S4 puts in the rubber plug 15 to completely displace the cement in the pipe string structure;
[0071] S5 The expansion mechanism expands, so that the upper rubber cylinder 2 and the lower rubber cylinder 3 are in close contact with the open hole wall;
[0072] S6 drills out the drilling plug mechanism and the rubber plug 15.
[0073] The launching tube 5 of the expansion string is assembled with the expansion mechanism and the drilling plug mechanism to obtain a string structure including:
[0074] S11: Install the expansion mechanism into the launch tube 5 from the lower end of the launch tube 5;
[0075] S12 connects the drilling plug mechanism to the launching tube 5.
[0076] Connecting the tubular structure to the expansion pipe 1 and lowering it to a predetermined position in the open hole well also includes: S21 inserting the joint 4 from the upper end of the expansion pipe 1, connecting the lower end of the expansion mechanism with the upper end of the drilling plug mechanism, rotating the joint 4, and threading the joint 4 with the center pipe 6.
[0077] like Figures 1 to 4As shown, some embodiments of the present invention disclose a complex well open hole plugging completion device and method, which is composed of an expansion tube 1, an upper rubber tube 2, a lower rubber tube 3, a joint 4, a launch tube 5, a center tube 6, an expansion cone 7, a pressure sleeve 8, a clamping ring 9, a V-shaped sealing ring 10, a bottom plugging tube 11, a booster tube 12, a plug seat 13, a leakage layer 14, and a rubber plug 15. The outer side of the upper end of the expansion tube 1 is processed with an external thread, which can be connected to the upper end expansion tube. The inner side of the lower side of the lower end of the expansion tube 1 is processed with an internal thread, which can be connected with the external thread of the launch tube 5. The upper rubber tube 2 is provided on the outer side of the middle and upper part of the expansion tube 1, and the two are fixed together by vulcanization. The lower rubber tube 3 is provided on the outer side of the middle and lower part of the expansion tube 1, and the two are fixed together by vulcanization. The middle part of the launch tube 5 is processed with a step transition (transition step). The inner side of the lower end of the launch tube 5 is processed with an internal thread, which can be connected with the external thread of the bottom plugging tube 11, and both are reversed. The middle position of the inner side of the bottom plugging tube 11 is processed with an internal thread, which can be connected with the thread in the middle position of the outer side of the boosting tube 12, and both are reversed. The outer side of the upper end of the bottom plugging tube 11 is processed with a step (first step), and the V-shaped sealing ring 10 is installed between the bottom plugging tube 11 and the launch tube 5. The upper end of the V-shaped sealing ring 10 is pressed against the lower end of the clamping ring 9. The upper end of the clamping ring 9 is pressed against the step (second step) on the outer side of the upper end of the boosting tube 12. The inner side of the lower end of the boosting tube 12 is processed with an internal thread, which can be connected with the plug seat 13 by thread, and both are reversed. The lower end of the inner side of the plug seat 13 is processed with a step (locking step), which can be locked together with the rubber plug 15. The rubber plug 15 finally falls on the inclined surface on the inner side of the upper end of the plug seat 13. The upper end of the joint 4 is processed with an internal thread, which can be connected to the drill pipe. The outer side of the lower end of the joint 4 is processed with a trapezoidal buckle, which can be connected with the trapezoidal buckle on the inner side of the upper end of the center tube 6. The outer side of the lower end of the center tube 6 is processed with an external thread, which can be connected with the internal thread inside the pressure sleeve 8. The upper end of the pressure sleeve 8 is pressed tightly against the lower end surface of the expansion cone 7. The upper end surface of the expansion cone 7 is pressed tightly against the middle transition step of the center tube 6. The expansion cone 7 and the inner wall of the launch tube 5 are directly clearance-fitted. The pressure sleeve 8 and the inner wall of the launch tube 5 are directly clearance-fitted.
[0078] When in use, first assemble the open hole plugging tool and the tubing string indoors and at the wellhead to form the open hole plugging tool tubing string structure. Next is to lower the open hole plugging tubing string to the predetermined position, where the leakage layer 14 is required to be located between the upper rubber cylinder 2 and the lower rubber cylinder 3. Next is cementing and expansion construction. Pump in the designed amount of cement slurry, the cement part enters from the inside of the tubing string, returns from the plug seat 13, and enters the annulus between the expansion pipe 1 and the open hole. Put in the rubber plug 15 to completely replace the cement inside the tubing string. Then carry out the expansion construction. Finally, the plug drilling operation. Use a drill bit to drill out the clamping ring 9, V-shaped sealing ring 10, bottom plug 11, booster cylinder 12, plug seat 13, and rubber plug 15 together, and leave the rest in the well.
[0079] To sum up, the complex well open hole plugging and completion device and method disclosed in the embodiment of the present invention perform cementing operations before expansion to ensure the leakage plugging effect; the joint is designed with a trapezoidal buckle structure to ensure the reliability of docking; the design of the V-shaped sealing structure and the clamping structure ensures the sealing effect; the bottom plug and the launch tube, the bottom plug and the booster cylinder, and the booster cylinder and the plug seat are all reverse buckle designs to ensure that the subsequent drill plug does not rotate and ensure the drilling plug efficiency; after expansion, the upper rubber cylinder and the lower rubber cylinder are in close contact with the open hole wall to play a role in sealing the leakage layer.
[0080] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.
[0081] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.
Claims
1. A complex well open hole plugging and completion device, characterized in that: It includes an expansion pipe string, an upper rubber cylinder, a lower rubber cylinder, an expansion mechanism, a joint, a drilling plug mechanism and a rubber plug; Wherein, the upper rubber cylinder and the lower rubber cylinder are fixed on the outer wall of the expansion pipe string, and the distance between the upper rubber cylinder and the lower rubber cylinder is greater than the height of the leakage layer; The expansion mechanism is located in the expansion column, and the expansion mechanism has a through hole penetrating from top to bottom; The lower end of the joint is connected to the upper end of the expansion mechanism, and the upper end of the joint has a connection portion for connecting a drill pipe; The drilling plug mechanism is fixed at the lower end of the expansion pipe column, and a plugging cavity is provided inside the drilling plug mechanism. The plugging cavity has an upper opening for the rubber plug to enter, and a lower opening which can be sealed by the rubber plug.
2. The complex well open hole plugging and completion device according to claim 1 is characterized in that: The expansion pipe string includes an expansion pipe and a launch pipe, and the launch pipe is fixedly connected to the lower end of the expansion pipe; The expansion mechanism is located in the launch tube, the plug drilling mechanism is installed at the lower end of the launch tube, and the middle part of the launch tube has a transition step to prevent the expansion mechanism from moving upward without applying external force; The upper rubber cylinder and the lower rubber cylinder are sleeved on the outside of the expansion tube.
3. The complex well open hole plugging and completion device according to claim 2 is characterized in that: The upper end of the launch tube is threadedly connected to the lower end of the expansion tube.
4. The complex well open hole plugging and completion device according to claim 2, characterized in that: The expansion mechanism includes a central tube, an expansion cone and a pressure sleeve, wherein: The central tube comprises an upper tube and a lower tube, the outer diameter of the upper tube is larger than the outer diameter of the lower tube, and the joint is partially inserted into the upper tube and fixedly connected to the upper tube; The expansion cone is sleeved on the outer wall of the lower tube, the upper end of the expansion cone is located below the transition step of the launch tube, and the pressure sleeve is sleeved on the outer wall of the lower tube and located below the expansion cone.
5. The complex well open hole plugging and completion device according to claim 4 is characterized in that: The transition step is a conical tube, so that the inner diameter of the lower part of the launch tube is larger than the inner diameter of the upper part of the launch tube; the middle part of the expansion cone has a conical slope, and the conical slope is located in the conical tube.
6. The complex well open hole plugging and completion device according to claim 4, characterized in that: The joint is threadedly connected to the inner wall of the central tube, and the outer wall of the lower end of the central tube is threadedly connected to the pressure sleeve.
7. The complex well open hole plugging and completion device according to claim 2, characterized in that: The drilling plug mechanism comprises a bottom plugging cylinder, a plug seat and a booster cylinder; Wherein, the bottom plugging tube partially extends into the launch tube from the lower end of the launch tube and is fixedly connected to the inner wall of the launch tube, the outer wall of the booster tube is connected to the inner wall of the bottom plugging tube, and the outer wall of the plug seat is connected to the inner wall of the booster tube; The plug seat has an inner cavity matched with the rubber plug.
8. The complex well open hole plugging and completion device according to claim 7, characterized in that: The drilling plug mechanism also includes a sealing ring and a clamping ring; The outer wall of the bottom plugging tube has a first step that forms an annular gap between the upper outer wall of the bottom plugging tube and the inner wall of the launch tube, and the sealing ring is located in the annular gap; The outer wall of the upper end of the boost cylinder has a second step, and the outer diameter of the boost cylinder above the second step is larger than the outer diameter below the second step; The upper end of the clamping ring presses against the second step, and the lower end of the clamping ring presses against the sealing ring.
9. The complex well open hole plugging and completion device according to claim 1, characterized in that: The upper rubber cylinder and the lower rubber cylinder are fixed to the outer wall of the expansion pipe string by vulcanization.
10. The complex well open hole plugging and completion device according to claim 7, characterized in that: The inner wall of the plug seat is provided with a locking step for locking the rubber plug in the plug seat.
11. The complex well open hole plugging and completion device according to claim 4, characterized in that: The lower end of the lower tube is connected to the upper end of the drilling mechanism through a connecting assembly, so that the rotation of the central tube is suppressed by the drilling mechanism.
12. The complex well open hole plugging and completion device according to claim 11, characterized in that: The connecting assembly comprises a convex tooth arranged at the lower end of the lower tube, and a groove arranged at the upper end of the drilling plug mechanism, and the convex tooth is matched with the groove.
13. A method for plugging and completing a complex open hole well, characterized in that: The complex well open hole plugging and completion device according to any one of claims 1 to 8 is used, and the steps include: S1 assembles the launching tube of the expansion string with the expansion mechanism and the drilling plug mechanism to obtain a string structure; S2: connecting the pipe string structure to the expansion pipe and lowering it to a predetermined position in the open hole well, so that the leakage zone is located between the upper rubber tube and the lower rubber tube; S3 pumps in a predetermined amount of cement slurry, which is then returned from the bottom of the tubing structure and enters the annulus between the expansion tubing and the open hole; S4 puts in the rubber plug to completely replace the cement in the pipe string structure; The S5 expansion mechanism expands to make the upper rubber cylinder and the lower rubber cylinder close to the open hole wall; S6: drilling out the drilling plug mechanism and the rubber plug.
14. The complex well open hole plugging and completion method according to claim 13, characterized in that: The launching tube of the expansion string is assembled with the expansion mechanism and the drilling plug mechanism to obtain a string structure including: S11: installing the expansion mechanism into the launch tube from the lower end of the launch tube; S12 connects the drilling plug mechanism to the launching tube.
15. The complex well open hole plugging and completion method according to claim 13, characterized in that: Connecting the pipe string structure to the expansion pipe and lowering it to a predetermined position in the open hole well also includes: S21 inserting a joint into the upper end of the expansion pipe, connecting the lower end of the expansion mechanism with the upper end of the drilling plug mechanism, and rotating the joint to thread the joint with the center pipe.