Coiled tubing cross-frac drilling packer and method

Abstract

This invention relates to the field of petroleum engineering technology, specifically to a coiled tubing wellbore plugging device and plugging method with a fracture. The plugging device includes deformable abutment members disposed at both ends of a rubber sleeve. During lowering of the plugging device, the diameter of the deformable abutment members differs significantly from the diameter of the wellbore inner wall, facilitating lowering. During setting, the diameter of the deformable abutment members increases under the action of control components to match the diameter of the wellbore inner wall, preventing bulging out of the gap between the deformable abutment members and the wellbore inner wall when the rubber sleeve expands, thus improving the sealing performance of the plugging device. Simultaneously, the variable diameter deformable abutment members can accommodate diameter parameter errors generated during drilling, improving the adaptability of the plugging device. The plugging method employs directional drilling of the new wellbore with coiled tubing, deep penetration through a perforation to connect the old and new wellbores, and finally completes the shut-off plugging through open-hole layered injection. This method features a short construction cycle, high construction efficiency, strong equipment and tool adaptability, reliable construction quality, and a high shut-off success rate.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering technology, specifically to a coiled tubing wellbore plugging device and plugging method with a fracture. Background Technology

[0002] As oilfield development enters its mid-to-late stages, the proportion of wells with missing channels due to misalignment continues to rise. These wells are extremely complex and difficult to access, and are characterized by casing misalignment underground, resulting in misaligned upper and lower casing sections, loss of access, and inability to locate or contact the "fish head" (broken casing). This makes conventional well workover techniques difficult to implement. Even with processes such as casing milling and reverse milling, these wells are still difficult to effectively manage, hindering the restoration of the oilfield's injection-production relationship and resource utilization. Currently, there is no mature and effective scrapping technology system for wells with missing channels due to misalignment, both domestically and internationally. Therefore, a reliable and effective plugging method and plugging device are urgently needed for high-quality scrapping of wells with missing channels due to misalignment.

[0003] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a continuous tubing well-drilling plug and plugging method with a cross-section, in order to solve the problem of the difficulty in abandoning wells that cannot be opened.

[0005] The present invention provides a method for sealing wellbore fractures in coiled tubing, which adopts the following technical solution: specifically including the following steps: Step 1: Measurement of wellbore trajectory data above the fracture surface; Step 2, fracture surface pretreatment; Step 3: Open a window at the break point; Step 4: Drill the new wellbore to the preset depth at the bottom boundary of the perforated section of the original wellbore, and control the distance between the new and old wellbores to be less than or equal to the preset value. Step 5: Deeply penetrate the transmission hole to connect the old and new wellbores; Step 6: Lower the plugging device to the preset position below the new wellbore fracture and above the perforated section and set it to seal the new and old wellbores.

[0006] Optionally, the distance between the new and old wellbores at the original perforated section location is less than or equal to 0.3m.

[0007] Optionally, the new wellbore may be drilled at least 10m to the bottom boundary of the original wellbore perforation section.

[0008] Optionally, the perforations are arranged in a spiral pattern, with the perforation positions corresponding to the original wellbore perforation sections and penetrating the original wellbore casing.

[0009] A coiled tubing wellbore plugging device for over-fracture drilling, applicable to the aforementioned method for plugging over-fracture coiled tubing wellbore, comprising: Central tube; The first fixed sleeve is coaxial and fixedly sleeved on the outside of the central tube, and the upper side wall of the first fixed sleeve is provided with an annular cavity with an open bottom. The second fixed sleeve is coaxial and fixedly sleeved on the lower part of the central tube. The second fixed sleeve is located outside the first fixed sleeve and forms a lower control cavity between the second fixed sleeve and the first fixed sleeve. A sliding sleeve is coaxially fitted onto the first fixed sleeve and can slide up and down. The upper end of the sliding sleeve is inserted into the annular cavity and the lower end is inserted into the lower control cavity. A locking pin is provided between the sliding sleeve and the side wall of the annular cavity. Two limiting sleeves, one of which is coaxially fixedly sleeved on the outer side of the upper part of the first fixed sleeve and forms an upper control cavity one between it and the first fixed sleeve; the other limiting sleeve is coaxially fixedly sleeved on the outer side of the sliding sleeve and forms an upper control cavity two between it and the sliding sleeve. Two deformable abutment members, one of which is sleeved on the outside of the first fixed sleeve, and the other is sleeved on the outside of the sliding sleeve and can move under the drive of the sliding sleeve. The deformable abutment members can deform and thus change their diameter. A rubber sleeve is fitted onto a sliding sleeve and sandwiched between two deformable abutment members. A sealing ring is sandwiched between the deformable abutment members and the rubber sleeve. The sealing ring is fitted onto the sliding sleeve. The sealing ring is in the shape of a thin plate and is configured to seal the gap between the deformable abutment members and the sliding sleeve and the first fixed sleeve after deformation. Two control components, one of which is slidably disposed in the upper control cavity and can act on the deformable abutment located on the first fixed sleeve; the other control component is slidably disposed in the upper control cavity and can act on the deformable abutment located on the sliding sleeve; the control components are configured to increase the diameter of the deformable abutment when they approach the deformable abutment. The first control channel and the second control channel are connected. The first control channel is connected to the central tube and the upper control cavity one. The second control channel is connected to the central tube, the lower control cavity and the upper control cavity two.

[0010] Optionally, the outer periphery of the second fixed sleeve is provided with a plurality of slips, which can move radially along the second fixed sleeve. A push tube is provided in the lower control cavity, which can act on the slips and push the slips outward radially along the second fixed sleeve when moving downward.

[0011] Optionally, the deformable abutment is an annular part with a break opening, and the two mating surfaces at the break opening are inclined surfaces. The inclination direction of the two mating surfaces is such that the distance between them gradually increases from the area near the rubber sleeve to the area far away from the rubber sleeve. The outer peripheral wall of the deformable abutment is provided with several circumferentially evenly spaced slots. The control component includes a ring, a first locking block, and a second locking block. Both the first and second locking blocks are located at the end of the ring near the sealing ring. There are multiple first locking blocks, each corresponding to a slot of the deformation abutment and having a matching shape. There is one second locking block, which corresponds to the breakout of the deformation abutment and has a matching shape. One ring of the control component is fitted onto the first fixed sleeve and located in the first upper control cavity, while the ring of the other control component is fitted onto the sliding sleeve and located in the second upper control cavity. The ends of the first and second locking blocks away from the ring extend out of the limiting sleeve.

[0012] Optionally, the first card block includes a connecting part, a plug-in part, and a deformable part connected in sequence. The connecting part is connected to the ring, and the deformable part has supporting capacity and can deform. The length of the second card block is less than the length of the first card block.

[0013] Optionally, overlapping plates are provided on the two mating surfaces near the rubber sleeve at the break point of the deformable abutment, and the two overlapping plates slide to overlap.

[0014] Optionally, the locking pin includes a locking part and an elastic part. The outer wall of the annular chamber is provided with two locking grooves, which are spaced apart vertically. The locking pin is located on the top of the sliding sleeve, and the locking part of the initial locking pin is engaged in the lower locking groove.

[0015] The beneficial effects of this invention are as follows: The coiled tubing wellbore plugging method provided by this invention optimizes the process design, uses specialized tools and high-pressure equipment, adopts directional drilling of new wellbore with coiled tubing, connects the new and old wellbore through deep penetration holes, and finally completes the plugging through open hole layered injection, shortening the construction cycle, significantly improving construction efficiency, with strong equipment and tool adaptability, equipped with high-pressure mud pump and complete solids control system, solving the high-pressure circulation problem in coiled tubing construction, ensuring reliable construction quality and high success rate of plugging.

[0016] This invention provides a coiled tubing wellbore plugging device with a cross-section. Through the design of a deformable abutment and a control component, during the lowering of the plugging device, the diameter of the deformable abutment differs significantly from the diameter of the wellbore's inner wall, facilitating the lowering and movement of the plugging device. During sealing, the diameter of the deformable abutment changes under the action of the control component, increasing to a size compatible with the wellbore's inner wall diameter. This prevents the rubber sleeve from bulging out through the gap between the deformable abutment and the wellbore's inner wall, forming a shoulder protrusion, thus improving the plugging device's sealing performance. Simultaneously, the variable-diameter deformable abutment can accommodate diameter parameter errors generated during drilling, enhancing the plugging device's adaptability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the overall structure of a continuous tubing over-fracture drilling plug provided by the present invention; Figure 2 A front view (initial state) of a coiled tubing over-fracture drilling plug provided by the present invention. Figure 3 for Figure 2 Sectional view of AA; Figure 4 for Figure 2 BB section view; Figure 5 A front view (setting state) of a coiled tubing over-fracture drilling plug provided by the present invention. Figure 6 for Figure 5 CC section view; Figure 7 for Figure 5 DD section view; Figure 8 An exploded view of a coiled tubing over-fracture drilling plug provided by the present invention; Figure 9 for Figure 3 Enlarged view at point E in the middle; Figure 10 for Figure 6 Enlarged view at point F; Figure 11 This is a schematic diagram of the directional drilling stage in a continuous tubing well sealing method with a fracture point provided by the present invention. Figure 12 This is a schematic diagram of the sealing injection (plugging) stage in a continuous tubing well sealing method for drilling through a break, provided by the present invention.

[0019] In the picture: 110. Central pipe; 111. First oil inlet; 112. Second oil inlet 120. First fixed sleeve; 1201. Annular chamber; 121. Locking pin; 130. Second fixed sleeve; 1301. Lower control cavity; 131. Slip; 132. Push tube; 140. Sliding sleeve; 141. Snap ring; 150. Limiting sleeve; 151. Upper control chamber one; 152. Upper control chamber two; 153. Sealing ring; 160. Deformable abutment; 161. Slot; 162. Disconnection point; 170. Control component; 171. Ring; 172. First locking block; 1721. Connecting part; 1722. Insertion part; 1723. Deformation part; 173. Second locking block; 180. Rubber sleeve; 190. Sealing ring. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Reference Figure 11 As shown, the present invention provides a method for sealing wells with a broken casing through a continuous tubing break. This method is applicable to the effective abandonment of wells with no access and where fish have been lost due to misalignment. When determining whether a well is a well with a broken casing and where fish have been lost due to misalignment, the well first needs to be milled and reamed multiple times to retrieve the debris above the casing damage point. Then, a lead mold is used to print the casing. Based on the imprint, it is determined that the casing is broken at a certain position downhole (e.g., at 858.82m downhole) without access. After multiple milling and reaming to a point slightly below the broken position in the well (e.g., at a depth of 860.93m), if creating an access point is ineffective, the method for sealing wells with a broken casing through a continuous tubing break provided by the present invention can be used to achieve effective sealing and abandonment.

[0022] Reference Figures 11-12 The present invention provides a method for sealing wellbore fractures in coiled tubing, specifically comprising the following steps: (1) Measurement of wellbore trajectory data above the fracture: The wellbore trajectory (inclination, azimuth, etc.) of the unobstructed wellbore above the fracture is remeasured using a gyroscope. A point is measured every 10m, and the measurement is carried out to the depth of the fracture. The direction of the original wellbore trajectory is initially determined. The trajectory change trend of the missing trajectory data below the fracture is predicted and restored. The wellbore trajectory curve is drawn, the wellbore trajectory design is formulated, and the initial orientation is determined.

[0023] (2) Fracture surface pretreatment: Mill the lower mill to 2m above the upper fracture surface, start the pump for circulation, recommended discharge rate is 0.5-0.8m. 3 / min, rotation speed 50-90r / min, drilling pressure 5-20kN, milling and shaping of the upper fracture surface to ensure that the directional drilling tool and the string can pass smoothly without obstruction.

[0024] Tubing structure: continuous tubing + rivet joint + double-lobe check valve + hydraulic release handle + shock absorber + screw motor + long conical milling taper.

[0025] (3) Opening a window at the fracture: After shaping the upper part of the fracture, use a flat-bottomed grinding shoe + milling cone short joint to continue drilling to open a window to 3-4m below the fracture, enter the stable formation, and repeatedly ream until there is no clamping force; Recommended construction parameters: drilling pressure 10-20kN, circulation displacement 0.5-0.8m 3 / min, rotation speed 60-90r / min.

[0026] Tubing structure: continuous tubing + rivet joint + double-disc check valve + hydraulic release handle + shock absorber + screw motor + milling taper connector + flat-bottomed grinding shoe.

[0027] (4) Directional accompanying drilling: The drilling tool string is delivered through coiled tubing to open a window at the casing break, and the old well casing is drilled along with the new well to the preset depth at the bottom boundary of the original wellbore perforation section to form a new wellbore. Figure 11 For newly drilled open holes, the preset depth is preferably 10m. During drilling, the wellbore trajectory is monitored in real time using a wireless drilling gyroscope. The tool face angle is dynamically adjusted using an electric steering mechanism to control the distance between the old and new wellbores (especially within the perforated section) to be less than or equal to 0.3m. Recommended operating parameters: pump pressure: 25-30MPa, rotation speed 40r / min, displacement: 1.3-1.6m³ / min, drilling pressure: 30-50kN.

[0028] Drilling tool string: coiled tubing + connector + release handle + weighted drill pipe + electric steering gear + non-magnetic drill collar + directional joint (built-in MWD instrument) + bent screw motor + drill bit; the electric steering gear is battery powered (100-200h battery life) and supports wireless remote 360° adjustment of the tool face angle.

[0029] Surface solids control system: Equipped with mud pumps that meet high pressure and high discharge requirements, high frequency vibrating screens, integrated mud and sand removal machines, horizontal screw sedimentation centrifuges and agitators, mud tanks and other equipment to build a closed-loop solids control circulation system to ensure stable drilling fluid performance.

[0030] Workover fluid preparation: It is recommended to use a polymer anti-collapse workover fluid system. Each well should be equipped with at least viscosity reducer, lubricating oil, ammonium salt, filtration loss reducer, soda ash, bentonite, etc. Through preparation, the functions of anti-collapse, control of water loss, viscosity reduction and shearing can be achieved to meet the high pressure circulation requirements.

[0031] (5) Deep penetration through-hole to connect new and old wellbores: Circumferential deep penetration through-holes are implemented in the new wellbore to establish a connection channel between the new and old wellbores and ensure the subsequent sealing effect; spiral hole layout is required, and the corresponding level of blowout preventer is installed before perforation construction. The delivery method is continuous tubing delivery, and the perforation gun is started hydraulically. The position of the deep penetration through-hole is required to correspond to the depth of the original well perforation section and to perforate the original wellbore casing.

[0032] (6) Lower sealing device ( Figure 11 Open-hole packer (in the case of open-hole plugging): Using a special open-hole plugging tool for coiled tubing to achieve reliable plugging of both new and old wellbores.

[0033] Tubing string structure: coiled tubing + connector + sealing release + open-hole packer + tubing shorting + sealing switch.

[0034] The specific operating method is as follows: ① Use coiled tubing to deliver the material to the expected depth, requiring the open-hole packer to be lowered below the break point.

[0035] ② Connect the cementing equipment and perform appropriate pressure tests on the connection parts.

[0036] ③ Open-hole packer setting: Circulate clean water through the pump truck once, control the pump pressure and flow rate as required, and open the one-way valve of the bottom sealing switch; insert the corresponding size steel ball, and wait for the steel ball to fall freely to the upper end of the sandblaster ball seat. The pump truck gradually pressurizes and stabilizes the pressure, initiating the open-hole packer setting process. Continue to increase and stabilize the pump pressure; at this point, the sealing part of the open-hole packer opens and seals on the open-hole section, completing the open-hole packer setting. Increase the pump pressure again to the set value, disengage the inner sliding sleeve of the sealing switch, and form an injection channel. After setting, test squeeze clean water into the coiled tubing; fluid returns from the wellhead casing, confirming that a communication channel has been formed between the old and new wellbores.

[0037] ④ Open the casing gate valve and circulate cement slurry in the coiled tubing. First, seal the new and old wellbores below the open hole packer depth through the connecting channel constructed after perforation. Then, inject cement slurry to seal the original formation. The injection pressure should not exceed the formation fracture pressure. During construction, the continuity of construction must be ensured.

[0038] ⑤ Throw the steel ball into the well. Once the ball lands on the upper end of the sealing sleeve, pressurize the pump to the set value and release the safety connector. Thoroughly circulate clean water to flush out excess cement slurry from the wellhead until no more slurry returns. Replace the drilling mud with the same workover fluid used during drilling. Monitor the mud properties during circulation (using wellbore stabilizers and other agents as needed) to ensure wellbore stability. After circulation, raise the tubing string, shut in the well under pressure, and after solidification, deepen the burr depth in the tubing to verify the plug depth. Then, pull out the tubing.

[0039] ⑥ Lower the tubing to 2m above the open-hole packer depth and set the tubing hanger. Connect the cementing equipment and perform appropriate pressure tests on the connection. Open the tubing and casing gate valves, circulate the isolation fluid, and circulate the cement slurry to seal the wellbore. Determine whether it is necessary to inject cement slurry to seal the break according to design requirements, and replace with clean water. Raise the tubing string to the designed cement level depth, and thoroughly circulate clean water to flush the well, washing away excess cement slurry until no cement slurry returns from the wellhead. Pull out all tubing strings in the well. Close the oil and casing gate valves, shut in the well under pressure and wait for 48 hours for the cement to solidify, then probe the cement level and perform pressure tests as required.

[0040] This invention optimizes process design, uses specialized tools and high-pressure equipment, and employs coiled tubing for directional drilling of new wellbores, deep-penetrating through-holes to connect old and new wellbores, and finally completes the shut-off process through open-hole layered injection. The efficient delivery of coiled tubing and precise directional control with an electric steering system reduce the frequency of tripping in and out of the well, significantly improving construction efficiency. The equipment and tools are highly adaptable, featuring a high-pressure mud pump and a complete solids control system to solve the high-pressure circulation problem in coiled tubing construction. Construction quality is reliable; the electric steering system ensures the spacing between old and new wellbores meets requirements, the open-hole packer has the ability to set in the open-hole section with good sealing performance, and the injection tools are reliable, resulting in a high shut-off success rate. Furthermore, the reduced drilling and shut-off steps before construction do not affect production output.

[0041] In the above method, it is necessary to create a new wellbore ( Figure 11 and Figure 12 The lower plugging device (shown by the dashed line) Figure 12 In wellbore sealing, packers (also known as plugs) are downhole tools used to seal the annular space between the tubing and the casing or open hole wall of an oil or gas well. Packers can be classified into compression, expansion, and self-sealing types based on the working principle of their sealing elements. Existing compression packers utilize compression to expand the sealing element (usually rubber) and press it against the wellbore wall to form a seal. During expansion, the sealing element is squeezed out from the gap between the end stops and the wellbore wall, forming a shoulder protrusion. This shoulder protrusion weakens the sealing force in the radial direction, affecting the sealing effect and thus the overall sealing performance. Therefore, in related technologies, the stop elements at both ends of the sealing element are usually set to fit as closely as possible to the well wall to reduce the shoulder protrusion when the sealing element expands. However, the small gap between the stop element and the well wall results in greater friction when running the well, making it difficult to run the well. At the same time, due to the depth of the wellbore, there is an error in the diameter of the wellbore extension direction, which existing stop elements cannot adapt to, exacerbating the difficulty of running the well. In particular, when using the coiled tubing through-fracture drilling and plugging method provided by this invention to plug the wellbore, when drilling down from the old wellbore above the fracture to the new wellbore, it is necessary to gradually tilt and bend to transition to the new wellbore. The plugging device of related technologies will undoubtedly further exacerbate the difficulty of running the well.

[0042] Therefore, the present invention also provides a coiled tubing wellbore plugging device with a break, which is applicable to the above-mentioned coiled tubing wellbore plugging method with a break. Naturally, it is also particularly applicable to conventional wellbore drilling, completion, oil production, water injection and well workover processes, so as to achieve reliable isolation of the annulus and ensure the safety and efficiency of stratified operations.

[0043] like Figures 1 to 10 As shown, the continuous tubing over-break drilling plug provided by the present invention specifically includes a central tube 110, a first fixed sleeve 120, a second fixed sleeve 130, a sliding sleeve 140, two limiting sleeves 150, two deformable abutment members 160, a rubber sleeve 180, two control members 170, and a first control flow channel and a second control flow channel.

[0044] The central tube 110 is hollow inside with both ends open, and can be connected to coiled tubing, etc.; the first fixed sleeve 120 is coaxially sleeved on the outside of the central tube 110 and fixed to the central tube 110; the upper side wall of the first fixed sleeve 120 is provided with an annular chamber 1201, and the bottom of the annular chamber 1201 is open; the second fixed sleeve 130 is coaxially sleeved on the lower part of the central tube 110 and fixed to the central tube 110, and the second fixed sleeve 130 is located outside the first fixed sleeve 120 and is fixed to the first fixed sleeve 120. A lower control cavity 1301 is formed between 20; a sliding sleeve 140 is coaxially and slidably sleeved on the first fixed sleeve 120. The upper end of the sliding sleeve 140 is inserted into the annular cavity 1201 and the lower end is inserted into the lower control cavity 1301. A locking pin 121 is provided between the sliding sleeve 140 and the side wall of the annular cavity 1201. The locking pin 121 is configured to initially hinder the sliding of the sliding sleeve 140, and can be sheared when the force on the sliding sleeve 140 is greater than a preset value, so as to allow the sliding sleeve 140 to slide. One of the two limiting sleeves 150 is coaxially fixedly sleeved on the outer side of the upper part of the first fixed sleeve 120, and an upper control cavity 151 is formed between the limiting sleeve 150 and the first fixed sleeve 120. The other limiting sleeve 150 is coaxially fixedly sleeved on the outer side of the sliding sleeve 140, and an upper control cavity 152 is formed between the limiting sleeve 150 and the sliding sleeve 140. One of the two deformable abutting members 160 is sleeved on the outer side of the first fixed sleeve 120, and the other deformable abutting member 160 is sleeved on the outer side of the sliding sleeve 140 and can move under the drive of the sliding sleeve 140. The two deformable abutting members 160 are arranged opposite to each other, and the deformable abutting member 160 can deform and thus change its diameter. A rubber sleeve 180 is fitted onto a sliding sleeve 140 and sandwiched between two deformable abutment members 160. A sealing ring 190 is sandwiched between the deformable abutment members 160 and the rubber sleeve 180. The sealing ring 190 is fitted onto the sliding sleeve 140 and is in the shape of a thin plate. The sealing ring 190 is configured to seal the gaps generated between the deformable abutment member 160 and the sliding sleeve 140 and the first fixed sleeve 120 after deformation. Specifically, the outer diameter of the sealing ring 190 can be set to be larger than the inner diameter of the deformable abutment member 160 at its maximum diameter. One of the control components 170 is slidably disposed in the upper control cavity 151 and can act on the deformation abutment 160 located on the first fixed sleeve 120; the other control component 170 is slidably disposed in the upper control cavity 152 and can act on the deformation abutment 160 located on the sliding sleeve 140; the control component 170 is configured to increase the diameter of the deformation abutment 160 when it approaches the deformation abutment 160, thereby adapting to the diameter of the oil well. The first control channel connects the central tube 110 and the upper control cavity 151, and the second control channel connects the central tube 110, the lower control cavity 1301 and the upper control cavity 2 152.

[0045] The initial state of the device is as follows Figure 2 , 3 As shown in Figures 4 and 9, at this time, the control component 170 does not cooperate with the deformation abutment component 160. The deformation abutment component 160 is wrapped around the first fixed sleeve 120 and the sliding sleeve 140, and the deformation abutment component 160 is in the minimum diameter state.

[0046] The coiled tubing drives the plugger down into the well. Because the deformable contact 160 is at its minimum diameter at this time, it does not contact the inner wall of the well, and the plugger is lowered smoothly. In particular, when passing through the inclined, curved, and deflected sections at the junction of the old and new wellbores, it can still maintain smooth lowering into the well. After the plugger is lowered into place, steel balls are thrown into the coiled tubing to seal the lower end of the coiled tubing, preparing for the plugger to set.

[0047] Subsequently, pressure is increased inside the coiled tubing at the wellhead. High-pressure oil enters the upper control chamber 151 through the first control channel and the lower control chamber 1301 and upper control chamber 2 152 through the second channel. Due to the restriction of the locking pin 121, the sliding sleeve 140 does not move temporarily. The pressure in the upper control chamber 151 and upper control chamber 2 152 increases to push the control component 170 closer to the deformation abutment component 160 and act on the deformation abutment component 160, thereby increasing the diameter of the deformation abutment component 160 until the deformation abutment component 160 fits against the inner wall of the oil well.

[0048] As the coiled tubing is pressurized, when the pressure in the current control chamber 1301 is sufficient to overcome the clamping force of the locking pin 121, the sliding sleeve 140 shears off the locking pin 121 and moves upward. As the sliding sleeve 140 moves upward, it drives the deformable abutment 160 located on it to move synchronously, simultaneously compressing the rubber sleeve 180. This causes the rubber sleeve 180 to expand radially and press tightly against the inner wall of the well to form a seal, completing the setting of the plug (see reference). Figure 5 , 6 7, 10).

[0049] In this embodiment, the design incorporates a deformable abutment 160 and a control element 170. When the plugging device is lowered, the diameter of the deformable abutment 160 differs significantly from the diameter of the well's inner wall, facilitating the movement of the plugging device. During plugging, the diameter of the deformable abutment 160 changes under the control of the control element 170, increasing to a size that matches the diameter of the well's inner wall. This prevents the rubber sleeve 180 from bulging out through the gap between the deformable abutment 160 and the well's inner wall, thus improving the plugging device's sealing performance. Simultaneously, the variable-diameter deformable abutment 160 can accommodate diameter parameter errors generated during drilling, enhancing the plugging device's adaptability.

[0050] It should also be noted that the outer periphery of the second fixed casing 130 is provided with a number of slips 131, which can move radially along the second fixed casing 130. The lower control cavity 1301 is provided with a push tube 132, which can act on the slips 131. Specifically, the contact surface between the push tube 132 and the slips 131 is inclined, so that when the push tube 132 moves downward, it pushes the slips 131 outward along the radial direction of the second fixed casing 130, so that the slips 131 abut against the inner peripheral wall of the oil well, thus fixing the position of the plug. With the installation of slip 131 and push tube 132, when the plug is set, high pressure enters the lower control chamber 1301. Due to the action of the locking pin 121, the push tube 132 moves before the sliding sleeve 140. The push tube 132 moves downward to push the slip 131 radially out. The top pressure between the slip 131 and the well wall is used to fix the position of the plug. Then the sliding sleeve 140 moves upward to compress the rubber sleeve 180, causing the rubber sleeve 180 to expand and further seal the oil well, improving the sealing effect.

[0051] In a further embodiment, refer to Figure 8 The deformable abutment 160 is an annular part with a break opening 162, that is, the deformable abutment 160 is an annular break opening. The two mating surfaces at the break opening 162 are inclined surfaces, and the inclination direction of the two mating surfaces is set so that the distance between them gradually increases from the vicinity of the rubber sleeve 180 to the distance from the rubber sleeve 180. The outer peripheral wall of the deformable abutment 160 is provided with a number of circumferentially evenly spaced slots 161. The control component 170 includes a ring 171, a first locking block 172, and a second locking block 173. The first locking block 172 and the second locking block 173 are both disposed at the end of the ring 171 near the sealing ring 190. There are multiple first locking blocks 172, and each first locking block 172 corresponds to a slot 161 of the deformable abutment 160 and is adapted in shape. There is one second locking block 173, and the second locking block 173 corresponds to the breakout 162 of the deformable abutment 160 and is adapted in shape. The ring 171 of one control component 170 is sleeved on the first fixed sleeve 120 and located in the upper control cavity 151. The ring 171 of the other control component 170 is sleeved on the sliding sleeve 140 and located in the upper control cavity 2 152. The ends of the first locking block 172 and the second locking block 173 away from the ring 171 extend out of the limiting sleeve 150.

[0052] Initially, no high pressure is applied to the central tube 110. The two control components 170 are at their extreme positions, far from the rubber sleeve 180. The first locking block 172 and the second locking block 173 are not inserted into the deformation abutment 160. The deformation abutment 160 surrounds the outside of the first fixed sleeve 120 and the sliding sleeve 140 and is in its minimum diameter state under its own elasticity. At this time, the deformation abutment 160 does not contact the inner wall of the oil well, and the plug can be smoothly lowered into the oil well. After the plug is lowered into place, pressure is increased into the central tube 110. High-pressure oil enters the upper control chamber 151 and the upper control chamber 2 152 and acts on the ring 171 of the control component 170, thereby pushing... The control component 170 moves closer to the rubber sleeve 180. The first locking block 172 gradually inserts into the slot 161, and the second locking block 173 gradually inserts into the disconnection port 162 and expands the disconnection port 162 under the action of the inclined plane, so as to increase the diameter of the deformable abutment 160 and make the deformable abutment 160 fit with the inner peripheral wall of the oil well. Then, the central tube 110 continues to pressurize. When the pressure of the lower control chamber 1301 increases to the preset value, the sliding sleeve 140 shears the locking pin 121 and moves upward, driving the deformable abutment 160 on it to move upward, while compressing the rubber sleeve 180, so that the rubber sleeve 180 abuts with the inner wall of the oil well and seals the oil well.

[0053] The solution in this embodiment utilizes the disconnection setting of the deformable abutment 160 to achieve the diameter change of the deformable abutment 160. The structure is ingenious, the control is simple, and it is easy to implement.

[0054] In a further embodiment, the first locking block 172 includes a connecting portion 1721, an insertion portion 1722, and a deformable portion 1723 connected in sequence. The connecting portion 1721 is connected to the ring 171, and the deformable portion 1723 has a certain supporting capacity and can deform. Specifically, it can adopt a structure such as a metal spring. The length of the second locking block 173 is less than the length of the first locking block 172. This allows the first locking block 172 to first insert into the slot 161 to restrict the shape of the deformable abutment 160 during the insertion of the control member 170 into the deformable abutment 160. Then, when the second locking block 173 inserts into the disconnection 162 to expand the deformable abutment 160, the deformation of the deformable abutment 160 becomes more uniform and more circular. When the first locking block 172 is inserted to its limit position, the deformable portion 1723 can deform to allow the second locking block 173 to continue to be inserted, expanding the adjustment range of the deformable abutment 160.

[0055] It should also be noted that when the first locking block 172 is inserted to its limit position, it is flush with the end of the deformable abutment 160 near the rubber sleeve 180, thereby improving the support capacity for the rubber sleeve 180. Specifically, a limit block is provided at one end of the slot 161 near the rubber sleeve 180, and a limit shoulder is provided at one end of the first locking block 172 near the rubber sleeve 180. The limit shoulder is adapted to the limit block, and the first locking block 172 is inserted into the slot 161 until the limit shoulder abuts against the limit block, at which point it is in its limit position (the insertion part 1722 is inserted to the limit position).

[0056] Furthermore, overlapping plates are provided on the two mating surfaces of the break 162 of the deformable abutment 160 at the end near the rubber sleeve 180. The two overlapping plates slide to overlap, and the two overlapping plates can block the end of the break 162 near the rubber sleeve 180, making the stop of the deformable abutment 160 on the rubber sleeve 180 more reliable.

[0057] In a further embodiment, the locking pin 121 includes a locking portion and an elastic portion. The outer wall of the annular chamber 1201 is provided with two locking grooves, which are spaced apart vertically. The locking pin 121 is disposed on the top of the sliding sleeve 140 and the locking portion of the initial locking pin 121 is engaged in the lower locking groove. When the thrust on the sliding sleeve 140 exceeds the preset value, the locking part of the locking pin 121 is sheared off, the sliding sleeve 140 moves upward and drives the elastic part and part of the locking part of the locking pin 121 to move upward synchronously. When the sliding sleeve 140 moves to the point where the locking pin 121 corresponds to the upper slot, the remaining locking part of the locking pin 121 is pushed into the upper slot under the action of the elastic part, locking the upper limit position of the sliding sleeve 140.

[0058] In a further embodiment, to facilitate the installation and movement of the control component 170, the end of the limiting sleeve 150 near the rubber sleeve 180 is provided with several elastic flaps evenly distributed in the circumferential direction. The elastic flaps facilitate the extension of the first locking block 172 and the second locking block 173 out of the limiting sleeve 150. Both the upper control cavity 151 and the upper control cavity 152 are provided with sealing rings 153. The sealing rings 153 can slide along the axial direction of the first fixed sleeve 120 and the sliding sleeve 140, thereby pushing the ring 171 to move. The sealing rings 153 can seal the upper control cavity 151 and the upper control cavity 152, preventing high-pressure oil from leaking from the elastic flaps at the end of the limiting sleeve 150.

[0059] Furthermore, a backstop structure is provided between the inner peripheral wall of the ring 171 of the control member 170 and the outer peripheral wall of the first fixed sleeve 120. The backstop structure is configured to allow the control member 170 to move toward the deformation abutment 160 and prevent the control member 170 from retracting away from the deformation abutment 160, thereby making the control member 170's control of the deformation abutment 160 more reliable.

[0060] The anti-reverse structure can specifically adopt a one-way ratchet structure.

[0061] In a further embodiment, both the first fixed sleeve 120 and the sliding sleeve 140 are provided with retaining rings 141. The retaining rings 141 are located at the end of the corresponding deformable abutment 160 away from the rubber sleeve 180. The retaining rings 141 can limit the axial position of the deformable abutment 160.

[0062] In a further embodiment, the side wall of the central tube 110 is provided with a first oil inlet 111 and a second oil inlet 112, and the first fixed sleeve 120 is provided with a first connecting port and a second connecting port. The first oil inlet 111 is connected to the first connecting port, and the first connecting port is connected to the upper control chamber 151. The first oil inlet 111 and the first connecting port form the first control flow channel mentioned above, which is used to pressurize the upper control chamber 151. The second oil inlet 112 is connected to the second connecting port, which is connected to the lower control chamber 1301. The bottom of the sliding sleeve 140 is provided with an oil passage, which is connected to the upper control chamber 152 and the lower control chamber 1301. The second oil inlet 112, the second connecting port, and the oil passage form the second control flow channel, which is used to pressurize the lower control chamber 1301 and the upper control chamber 152.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for plugging a coiled tubing well over a break, characterized in that, Specifically, the following steps are included: Step 1: Measurement of wellbore trajectory data above the fracture surface; Step 2, fracture surface pretreatment; Step 3: Open a window at the break point; Step 4: Drill the new wellbore to the preset depth at the bottom boundary of the perforated section of the original wellbore, and control the distance between the new and old wellbores to be less than or equal to the preset value. Step 5: Deeply penetrate the transmission hole to connect the old and new wellbores; Step 6: Lower the plugging device to the preset position below the new wellbore fracture and above the perforated section and set it to seal the new and old wellbores.

2. The method for plugging a coiled tubing well over a break point according to claim 1, characterized in that, The distance between the old and new wellbores at the original perforated section is less than or equal to 0.3m.

3. The method for plugging a coiled tubing well over a break point according to claim 1, characterized in that, The new wellbore should be drilled at least 10m to the bottom boundary of the perforated section of the original wellbore.

4. The method for plugging a coiled tubing well over a break according to claim 1, characterized in that, The perforations are arranged in a spiral pattern, with the perforation positions corresponding to the original wellbore perforation sections and penetrating the original wellbore casing.

5. A coiled tubing wellbore plugging device for over-fracture drilling, applicable to the coiled tubing wellbore plugging method according to any one of claims 1-4, characterized in that, include: Central tube; The first fixed sleeve is coaxial and fixedly sleeved on the outside of the central tube, and the upper side wall of the first fixed sleeve is provided with an annular cavity with an open bottom. The second fixed sleeve is coaxial and fixedly sleeved on the lower part of the central tube. The second fixed sleeve is located outside the first fixed sleeve and forms a lower control cavity between the second fixed sleeve and the first fixed sleeve. A sliding sleeve is coaxially fitted onto the first fixed sleeve and can slide up and down. The upper end of the sliding sleeve is inserted into the annular cavity and the lower end is inserted into the lower control cavity. A locking pin is provided between the sliding sleeve and the side wall of the annular cavity. Two limiting sleeves, one of which is coaxially fixedly sleeved on the outer side of the upper part of the first fixed sleeve and forms an upper control cavity one between it and the first fixed sleeve; the other limiting sleeve is coaxially fixedly sleeved on the outer side of the sliding sleeve and forms an upper control cavity two between it and the sliding sleeve. Two deformable abutment members, one of which is sleeved on the outside of the first fixed sleeve, and the other is sleeved on the outside of the sliding sleeve and can move under the drive of the sliding sleeve. The deformable abutment members can deform and thus change their diameter. A rubber sleeve is fitted onto a sliding sleeve and sandwiched between two deformable abutment members. A sealing ring is sandwiched between the deformable abutment members and the rubber sleeve. The sealing ring is fitted onto the sliding sleeve. The sealing ring is in the shape of a thin plate and is configured to seal the gap between the deformable abutment members and the sliding sleeve and the first fixed sleeve after deformation. Two control components, one of which is slidably disposed in the upper control cavity and can act on the deformable abutment located on the first fixed sleeve; the other control component is slidably disposed in the upper control cavity and can act on the deformable abutment located on the sliding sleeve; the control components are configured to increase the diameter of the deformable abutment when they approach the deformable abutment. The first control channel and the second control channel are connected. The first control channel is connected to the central tube and the upper control cavity one. The second control channel is connected to the central tube, the lower control cavity and the upper control cavity two.

6. A coiled tubing over-fracture drilling plug as described in claim 5, characterized in that, The outer periphery of the second fixed sleeve is provided with several slips, which can move radially along the second fixed sleeve. A push tube is provided in the lower control cavity, which can act on the slips and push the slips out radially along the second fixed sleeve when moving downward.

7. A coiled tubing over-fracture drilling plug as described in claim 5, characterized in that, The deformable abutment is an annular part with a break opening. The two mating surfaces at the break opening are inclined surfaces, and the inclination direction of the two mating surfaces gradually increases from the closer to the rubber sleeve to the farther away from the rubber sleeve. The outer peripheral wall of the deformable abutment is provided with several circumferentially evenly spaced slots. The control component includes a ring, a first locking block, and a second locking block. Both the first and second locking blocks are located at the end of the ring near the sealing ring. There are multiple first locking blocks, each corresponding to a slot of the deformation abutment and having a matching shape. There is one second locking block, which corresponds to the breakout of the deformation abutment and has a matching shape. One ring of the control component is fitted onto the first fixed sleeve and located in the first upper control cavity, while the ring of the other control component is fitted onto the sliding sleeve and located in the second upper control cavity. The ends of the first and second locking blocks away from the ring extend out of the limiting sleeve.

8. A coiled tubing over-fracture drilling plugging device according to claim 7, characterized in that, The first card block includes a connecting part, a plug-in part, and a deformable part connected in sequence. The connecting part is connected to the ring, and the deformable part has supporting capacity and can deform. The length of the second card block is less than the length of the first card block.

9. A coiled tubing over-fracture drilling plug as described in claim 7, characterized in that, The two mating surfaces at the break point of the deformable abutment are provided with overlapping plates at the end near the rubber sleeve, and the two overlapping plates slide to overlap.

10. A coiled tubing over-fracture drilling plugging device according to claim 5, characterized in that, The locking pin includes a locking part and an elastic part. The outer wall of the annular chamber is provided with two locking grooves, which are spaced apart vertically. The locking pin is located at the top of the sliding sleeve, and the locking part of the initial locking pin is engaged in the lower locking groove.

Images