Downhole plugging and repair device

Abstract

The application provides a downhole plugging repair device. It relates to the technical field of oil and gas exploitation. The downhole plugging repair device comprises a hot melting mechanism, a charging mechanism and a spraying mechanism. The spraying mechanism comprises a slow flow structure and a flow guide assembly. The hot melting mechanism is fixedly connected with the top end of the charging mechanism, and the bottom end of the charging mechanism is connected with the flow guide assembly. The hot melting mechanism is configured to initiate a hot melting reaction of the plugging agent in the charging mechanism by heat conduction to convert the plugging agent into a molten state, so that the molten plugging agent flows to the target position for plugging after passing through the slow flow structure and the flow guide assembly in turn, wherein the plugging comprises ablation, filling and / or sealing. The application can achieve effective and durable oil and gas well plugging repair effect.

Description

Technical Field

[0001] This application relates to the field of oil and gas extraction technology, and in particular to a downhole plugging and repair device. Background Technology

[0002] During the exploration and extraction of oil and gas, the cement sheath in oil and gas wells is prone to failure, causing inter-layer flow and annular pressure problems, which seriously affect the efficiency of oil and gas recovery and pose potential risks. Therefore, it is necessary to repair the cement sheath after it fails to improve the efficiency and safety of oil and gas extraction operations.

[0003] In related technologies, injecting high-temperature steam into oil and gas wells to melt low-melting-point alloys for cement sheath repair has the problem of not being able to uniformly and effectively fill the cracks in the cement sheath. Heating low-melting-point metals in oil and gas wells via cable-connected heating devices for cement sheath repair has difficulty penetrating micron-level interface gaps, leading to a high risk of secondary failure.

[0004] Therefore, there is an urgent need for an effective and durable thermal melting plugging and repair solution for oil and gas wells. Summary of the Invention

[0005] This application provides a downhole plugging and repair device to achieve effective and durable oil and gas well plugging and repair effects.

[0006] In a first aspect, this application provides a downhole plugging and repair device, comprising: a thermal fusion mechanism, a charging mechanism, and an injection mechanism.

[0007] The injection mechanism includes a flow-slowing structure and a flow-guiding component; the hot-melt mechanism is fixedly connected to the top end of the charging mechanism, and the bottom end of the charging mechanism is connected to the flow-guiding component.

[0008] The hot-melting mechanism is configured to induce a hot-melting reaction in the plugging agent in the charging mechanism through heat conduction, converting it into a molten state. This allows the molten plugging agent to flow sequentially through the slow-flow structure and the flow guiding assembly to the target location for plugging. The plugging process includes ablation, filling, and / or sealing.

[0009] In one possible implementation, the flow guiding assembly includes a flow guide, a guide block, and a heat insulation element;

[0010] The flow guide has a flow channel and a concave groove inside, and a pin is provided in the concave groove; the guide block is engaged in the concave groove by the pin, and the bottom of the guide block is fixedly connected to the heat insulation component by connecting bolts; wherein, the heat insulation component is configured to prevent the guide block from deforming and affecting the sealing performance.

[0011] In one possible implementation, the hot-melt mechanism includes: a housing, an upper end cover, a hot-melt component, and a heat-resistant buffer component; the housing, the upper end cover, and the heat-resistant buffer component enclose a receiving cavity;

[0012] The upper end cap is fixed to the top of the drug loading mechanism by threads;

[0013] The body of the hot melt component is disposed within the accommodating cavity, and the end of the hot melt component extends through the heat-resistant buffer and out of the accommodating cavity, contacting the sealing agent within the loading mechanism.

[0014] In one possible implementation, the accommodating cavity is further filled with a core matrix to fix the body of the hot melt component.

[0015] In one possible implementation, the device further includes: a tension member, one end of which is connected to a cable rope, and the other end of which is electrically connected to the thermoplastic component body;

[0016] The pulling element is configured to provide a pulling force after the sealing agent at the target location has cooled to shear the pin, thereby separating the loading mechanism from the guide block.

[0017] In one possible implementation, the loading mechanism includes a loading housing; the inner cavity of the loading housing is filled with the sealing agent in layers.

[0018] In one possible implementation, the spraying mechanism further includes a rubber sleeve disposed on the housing of the spraying mechanism.

[0019] In one possible implementation, the slow-flow structure is an asbestos plug.

[0020] In one possible implementation, the heat insulation element is a ceramic heat insulation plate.

[0021] In one possible implementation, the heat-resistant buffer is a silicon carbide impact-resistant heat insulation board.

[0022] Secondly, this application provides a method for applying a downhole plugging and repair device, including:

[0023] The target location of the target oil and gas well is obtained by acoustic positioning or optical fiber positioning within the target oil and gas well.

[0024] Using drilling tools, the casing and cement sheath at the target location are drilled to obtain the drilling location corresponding to the target location;

[0025] The downhole plugging and repair device is lowered to the borehole location. The downhole plugging and repair device includes a heat-melting mechanism, a charging mechanism, and a jetting mechanism. The downhole plugging and repair device is the downhole plugging and repair device of the first aspect and / or the possible implementation of the first aspect.

[0026] The hot-melting mechanism is activated, causing the plugging agent in the charging mechanism to undergo a hot-melting reaction and be converted into a molten state. The molten plugging agent then flows through the slow-flow structure and the flow guiding component in the spraying mechanism to the target position for plugging.

[0027] Control the tensioning component in the downhole plugging and repair device to lift it upwards, break the pin in the injection mechanism, remove the remaining downhole plugging and repair device, and obtain the plugged oil and gas well.

[0028] Thirdly, this application provides an application device for a downhole plugging and repair device, comprising:

[0029] The acquisition module is used to acquire the target location of the target oil and gas well. The target location is obtained by locating the target oil and gas well using acoustic positioning or optical fiber.

[0030] The control module is used to drill holes in the casing and cement sheath at the target location using drilling tools to obtain the corresponding drilling position; to lower a downhole plugging and repair device to the drilling position, the downhole plugging and repair device including a thermal melting mechanism, a charging mechanism, and an injection mechanism, wherein the downhole plugging and repair device is the downhole plugging and repair device of the first aspect and / or possible embodiments of the first aspect; to activate the thermal melting mechanism, causing the plugging agent in the charging mechanism to undergo a thermal melting reaction and convert into a molten state, so that the molten plugging agent flows to the target position for plugging after passing through the slow flow structure and the flow guiding component in the injection mechanism; to control the pulling component in the downhole plugging and repair device to lift the pulling component upward, break the pin in the injection mechanism, remove the remaining downhole plugging and repair device, and obtain the plugged oil and gas well.

[0031] The downhole plugging and repair device provided in this application uses a thermal melting mechanism to transfer heat to the charging mechanism, triggering a thermal melting reaction in the plugging agent loaded within the charging mechanism. This causes the plugging agent to transform from a solid to a molten state, providing a fluid material for filling and sealing the target location in downhole plugging and repair operations. The injection mechanism guides the molten plugging agent to the target location in the oil and gas well where plugging and repair operations are required. The injection mechanism includes a flow-slowing structure to reduce the flow velocity of the molten plugging agent. By reducing the flow speed of the molten plugging agent during injection, it ensures that the plugging agent flows relatively smoothly and accurately to the subsequent guiding components. Simultaneously, the flow-slowing structure's suppression of the plugging agent's flow velocity allows the plugging agent to settle to a certain extent, causing impurities in the plugging agent to float to the surface. This ensures that the material that ultimately sinks and flows through the guiding components for downhole plugging and repair is relatively clean, improving the quality of the plugging agent used for downhole plugging and repair. The injection mechanism includes a flow guiding component to accurately guide the molten plugging agent to the target location, preventing loss or deviation during delivery and achieving effective plugging, thus significantly improving the quality and efficiency of downhole plugging repair. The downhole plugging repair device provided in this application achieves metallurgical bonding, fundamentally eliminating secondary failures and improving plugging effectiveness and quality. Simultaneously, the flow-slowing structure inhibits the flow velocity of the plugging agent, ensuring the purity of the materials used for plugging and further enhancing the plugging quality. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0033] Figure 1 Schematic diagram of the downhole plugging and repair device provided in the embodiments of this application Figure 1 ;

[0034] Figure 2 Schematic diagram of the downhole plugging and repair device provided in the embodiments of this application Figure 2 ;

[0035] Figure 3 A schematic flowchart illustrating the application method of the downhole plugging and repair device provided in this application embodiment;

[0036] Figure 4 This application provides an operational schematic diagram of the downhole plugging and repair device provided in its embodiments. Figure 1 ;

[0037] Figure 5 This application provides an operational schematic diagram of the downhole plugging and repair device provided in its embodiments. Figure 2 ;

[0038] Figure 6The sealing effect diagram of the downhole plugging and repair device provided in the embodiments of this application;

[0039] Figure 7 This is a schematic diagram of the structure of the application device of the downhole plugging and repair device provided in the embodiments of this application.

[0040] Reference numerals: 12-Heat-melting mechanism; 121-Shell; 122-Upper end cover; 123-Heat-melting component; 124-Heat-resistant buffer component; 125-Solid core substrate; 13-Charging mechanism; 131-Charging shell; 14-Spraying mechanism; 142-Rubber sleeve; 141-Slow flow structure; 15-Flow guiding assembly; 151-Flow guide; 152-Guide block; 153-Heat insulation component; 154-Flow channel; 155-Pin; 156-Connecting bolt; 111-Tension component; and 112-Cable rope.

[0041] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0043] Related technology 1 involves a multi-stage activation method for long-term sealing devices. When annular pressure occurs in the wellbore, a pre-embedded device is selected above the leakage location. High-temperature steam is injected to melt a low-melting-point alloy. The thermally expanding fluid drives the low-melting-point alloy to be squeezed into the location where the seal integrity fails, flowing into micro-annular gaps or micro-cracks to achieve material sealing. The solidification expansion of the low-melting-point alloy is used to achieve mechanical sealing to establish a well barrier. However, this method suffers from difficulties in achieving uniform heating, and improper temperature control can lead to poor alloy fluidity or damage to the cement sheath bonding interface. Related technology 2 involves a downhole cement sheath metal repair method. This method utilizes a surface support system, a perforating gun, cement sheath repair tools, and drill bits. The internal heating system of the cement sheath repair tool is controlled by the surface control system to melt the external low-melting-point metal for repair. However, this method suffers from difficulties in penetrating micron-level interface gaps, making it difficult to effectively solve the micro-annular gap filling problem. Related technology 3 utilizes a downhole heat source generated by the reaction of a solid bismuth-tin alloy with a slow-setting thermosetting resin. The bismuth-tin alloy melts and flows into the casing failure point, solidifying to form a plug. However, this technology suffers from the problem of high surface tension and insufficient fluidity of the rigid bismuth-tin alloy, making it difficult to effectively penetrate and wet micron-level cement sheath fissures and bonding interfaces. This results in the plug remaining only on the surface, easily causing displacement differences with the flexible cement sheath, leading to plug fragmentation and detachment, and subsequent secondary failure. In summary, this technology suffers from difficulty in penetrating micron-level interface fissures and is prone to secondary failure.

[0044] The downhole plugging and repair device provided in this application includes an injection mechanism 14, which guides molten plugging agent to the target location in the oil and gas well where plugging and repair operations are required. The injection mechanism 14 includes a flow-retarding structure 141, which slows down the flow rate of the molten plugging agent. By reducing the flow velocity of the molten plugging agent during injection, it ensures that the plugging agent flows relatively smoothly and accurately to the subsequent flow guiding component 15. Simultaneously, the suppression of the plugging agent's flow velocity allows it to settle to a certain extent, ensuring that the material ultimately flowing through the flow guiding component 15 for downhole plugging and repair is relatively clean, thus improving the quality of the plugging agent used for downhole plugging and repair.

[0045] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0046] Figure 1 Schematic diagram of the downhole plugging and repair device provided in the embodiments of this application Figure 1 .like Figure 1As shown, the device includes a heat-melting mechanism 12, a charging mechanism 13, and a spraying mechanism 14. The spraying mechanism 14 includes a flow-retarding structure 141 and a flow-guiding component 15. The heat-melting mechanism 12 is fixedly connected to the top end of the charging mechanism 13, and the bottom end of the charging mechanism 13 is connected to the flow-guiding component 15. The heat-melting mechanism 12 is configured to induce a heat-melting reaction in the plugging agent in the charging mechanism 13 through heat conduction, so that the molten plugging agent flows to the target position for plugging after passing through the flow-retarding structure 141 and the flow-guiding component 15 in sequence. The plugging includes ablation, filling, and / or sealing.

[0047] The thermal fusion mechanism 12 is a component in the downhole plugging and repair device used to generate heat and cause the plugging agent loaded in the charging mechanism 13 to undergo a thermal fusion reaction. The thermal fusion mechanism 12 can transfer heat to the plugging agent in the charging mechanism 13 through heat conduction, initiating a thermal fusion reaction in the plugging agent, causing it to change from a solid to a molten state. This provides a fluid material for downhole plugging and repair operations, and is a key mechanism for the downhole plugging and repair device to achieve its plugging function.

[0048] The charging mechanism 13 is a container structure used to store the plugging agent. The charging mechanism 13 can hold and store the plugging agent, and under the action of the thermal fusion mechanism 12, the plugging agent inside the charging mechanism 13 will become molten. As a storage structure for the plugging agent, the charging mechanism 13, in cooperation with the thermal fusion mechanism 12, realizes the transformation of the plugging agent's state, providing a material basis for downhole plugging and repair.

[0049] The injection mechanism 14 is used to guide the molten plugging agent to the target location for plugging operations. The target location is the specific location in the oil and gas well where plugging and repair operations need to be performed. The injection mechanism 14 is the key channel and guiding structure for the plugging agent to reach the target location from inside the downhole plugging and repair device. The flow-slowing structure 141 is the part of the injection mechanism 14 used to slow down the flow rate of the molten plugging agent. By reducing the flow velocity of the molten plugging agent during the injection process, the flow-slowing structure 141 ensures that the plugging agent can flow relatively smoothly and accurately to the subsequent guiding component 15. Simultaneously, by suppressing the flow velocity of the plugging agent through the flow-slowing structure 141, the plugging agent can be allowed to settle to a certain extent, ensuring a relatively clean composition.

[0050] The flow guiding component 15 is a part of the injection mechanism 14 used to guide the molten plugging agent accurately to the target location. By using the flow guiding component 15, it is possible to ensure that the plugging agent accurately reaches the designated area, achieving an effective plugging effect and improving the quality and efficiency of downhole plugging and repair.

[0051] In one possible implementation, the sealing agent can be a liquid metal oxide, a liquid metal, or a product of an aluminothermic reaction.

[0052] Furthermore, the sealing agent may include a mixture of substances such as aluminum, ferric oxide, and substances corresponding to elements such as manganese and / or nickel.

[0053] Furthermore, additives that promote liquid phase flow can be added to the plugging agent. Optionally, the additive could be calcium fluoride, which promotes liquid phase flow.

[0054] For example, when the plugging agent is a product made through an aluminothermic reaction, firstly, a block or substance participating in the aluminothermic reaction is placed in the charging mechanism 13. Then, the block or substance loaded in the charging mechanism 13 undergoes an aluminothermic reaction via the hot-melting mechanism 12, and the product is used as a plugging agent for downhole plugging repair. At this time, there may be incompletely reacted blocks or substances and aluminothermic reaction products in the charging mechanism 13; by slowing the flow rate of the molten plugging agent through the flow-retarding structure 141, the material in the charging mechanism 13 can be kept to a certain degree of stillness, so that the material component ultimately flowing through the flow guide assembly 15 for downhole plugging repair is the product of the aluminothermic reaction.

[0055] Table 1. Information on the aluminothermic reaction

[0056]

[0057] Table 1 is an information table of the aluminothermic reaction provided in the embodiments of this application. As shown in Table 1: the reactants of the aluminothermic reaction are... The thermite reaction is a reaction between aluminum and iron oxide. The density of the reactants in the thermite reaction is 4.175. Without a phase transition, the aluminothermic reaction reaches a temperature of 4382 K; considering a phase transition, the reaction reaches a temperature of 3135 K. The oxide products of the aluminothermic reaction are in a liquid state. The metallic products of the aluminothermic reaction are in a... This indicates that the metal is in a liquid state. In the aluminothermic reaction, every 100 grams of reactants produces 0.1404 moles of gas, with a mass of 0.0784 g. The heat released per gram of reactant is 945.4 cal / g. The heat released per gram of reactant is 3947 cal / g. .

[0058] When the plugging agent is a product manufactured through an aluminothermic reaction, the high-temperature molten plugging agent can effectively ablate, fill, and seal micron-level grooves and micro-gaps within the casing, resulting in a metallurgical bond and / or extremely strong mechanical interlocking between the steel casing and the casing, and good bonding with the ablated formation and / or residual cement. After the plugging agent cools at the target location, it forms a material structure with mechanical strength and density far exceeding that of cement. This material structure also exhibits high resistance to high temperatures, high pressures, and corrosion in the plugging layer, enabling it to adapt to the harsh downhole environment of oil and gas wells.

[0059] The downhole plugging and repair device provided in this application embodiment transfers heat from the thermal fusion mechanism 12 to the charging mechanism 13 via heat conduction, causing the plugging agent loaded in the charging mechanism 13 to undergo a thermal fusion reaction, transforming the plugging agent from a solid state to a molten state. This provides a fluid material for filling and sealing the target location in the downhole plugging and repair operation. The injection mechanism 14 guides the molten plugging agent to the target location in the oil and gas well where the plugging and repair operation is required. The injection mechanism 14 includes a flow-slowing structure 141, which slows down the flow rate of the molten plugging agent. By reducing the flow speed of the molten plugging agent during the injection process, it ensures that the plugging agent can flow relatively smoothly and accurately to the subsequent guiding component 15. At the same time, the suppression of the plugging agent's flow rate allows the plugging agent to settle to a certain extent, ensuring that the material components that finally flow through the guiding component 15 for downhole plugging and repair are relatively clean, thus improving the quality of the plugging agent used for downhole plugging and repair. The flow guiding component 15 included inside the injection mechanism 14 is used to guide the molten plugging agent to the target position accurately, avoiding the loss or deviation of the plugging agent from the target position during the delivery process, so as to achieve an effective plugging effect and greatly improve the quality and efficiency of downhole plugging and repair.

[0060] Figure 2 Schematic diagram of the downhole plugging and repair device provided in the embodiments of this application Figure 2 .like Figure 2 As shown, in Figure 1 Based on the embodiments, the downhole plugging and repair device is described in detail, including:

[0061] Specifically, the flow guiding assembly 15 includes a flow guide 151, a guide block 152, and a heat insulation component 153; the flow guide 151 has a flow channel 154 and a concave groove inside, and a pin 155 is provided in the concave groove; the guide block 152 is engaged in the concave groove by the pin 155, and the guide block 152 is fixedly connected to the heat insulation component 153 below by a connecting bolt 156; wherein, the heat insulation component 153 is configured to prevent the guide block 152 from deforming and affecting the sealing performance.

[0062] The flow guide 151 has a flow channel 154 inside for guiding the flow of molten plugging agent. A concave groove inside the flow guide 151 is used to engage the guide block 152 and the flow guide 151. The flow channel 154 provides a flow path for the molten plugging agent, ensuring smooth and stable flow, and guiding the plugging agent to the target location along a predetermined path, reducing resistance during the flow process and improving the delivery efficiency of the plugging agent.

[0063] The concave groove provides a snap-fit ​​position for the connection between the guide block 152 and the flow guiding assembly 15, ensuring the stability of the installation of the guide block 152, and thus ensuring that the downhole sealing and repair device can work normally.

[0064] The guide block 152 supports the sealing agent and works in conjunction with the flow guide 151 to form a more precise flow system, ensuring that the sealing agent can be accurately applied to the target location and preventing the sealing agent from deviating during the flow process.

[0065] The heat insulation component 153 is fixedly connected to the guide block 152 via connecting bolts 156. The combination of the heat insulation component 153 and the guide block 152 guides the directional release of the heat energy of the plugging agent, allowing the plugging agent to fully ablate the casing wall and simultaneously repair the outer cement annulus cracks in the oil and gas well casing. Simultaneously, the heat insulation component 153 can suppress the deformation of the guide block 152 caused by the high-temperature environment around the flow guiding assembly 15 or the heat carried by the plugging agent, thereby ensuring the sealing between the guide block 152 and the flow guide 151, preventing leakage of the plugging agent during flow, ensuring the smooth progress of the plugging operation, and improving the reliability and stability of the downhole plugging and repair device. Furthermore, the size of the heat insulation component 153 can be determined according to the size of the oil and gas well to be plugged and repaired.

[0066] The pin 155 is set in the concave groove of the flow guide 151 to securely install the guide block 152 in the concave groove of the flow guide 151, ensuring that the relative position between the guide block 152 and the flow guide 151 is fixed, so that the guide block 152 can accurately perform the flow guiding function, preventing the guide block 152 from loosening or falling off during operation, and ensuring the normal operation of the flow guide assembly 15.

[0067] The connecting bolt 156 is used to fix the guide block 152 to the heat insulation component 153, so that the guide block 152 and the heat insulation component 153 become a whole, enhance the connection strength between the guide block 152 and the heat insulation component 153, ensure that the heat insulation component 153 can stably perform its heat insulation function, and prevent the guide block 152 from separating from the heat insulation component 153 due to force or heat.

[0068] Specifically, the heat-melting mechanism 12 includes: a housing 121, an upper cover 122, a heat-melting component 123, and a heat-resistant buffer 124; the housing 121, the upper cover 122, and the heat-resistant buffer 124 enclose a receiving cavity; the upper cover 122 is fixed to the top of the loading mechanism 13 by threads; the body of the heat-melting component 123 is disposed in the receiving cavity, and the end of the heat-melting component 123 extends out of the receiving cavity through the heat-resistant buffer 124 and contacts the sealing agent in the loading mechanism 13.

[0069] In the heat-melting mechanism 12, the housing 121, the upper end cover 122, and the heat-resistant buffer 124 enclose a cavity to provide installation space for other components within the heat-melting component 123. The housing 121 is the main support structure of the heat-melting mechanism 12, protecting the heat-melting component 123 and other components within the cavity from interference and damage from the external environment.

[0070] The upper end cap 122 is fixedly connected to the top of the charging mechanism 13 by threads, realizing a stable connection between the heat fusion mechanism 12 and the charging mechanism 13, ensuring the sealing of the accommodating cavity, preventing external impurities from entering the accommodating cavity and affecting the operation of the heat fusion component 123; at the same time, it enables the heat fusion mechanism 12 to stably provide heat to the charging mechanism 13, ensuring that the sealing agent can undergo a smooth heat fusion reaction.

[0071] The heat-melting component 123 is disposed within the receiving cavity of the heat-melting mechanism 12. The end of the heat-melting component 123 passes through the heat-resistant buffer 124 and extends out of the receiving cavity to contact the sealing agent in the charging mechanism 13. The heat-melting component 123 transfers heat to the sealing agent in the charging mechanism 13 through its own heat generation, triggering a heat-melting reaction of the sealing agent and causing the sealing agent to change from a solid state to a molten state.

[0072] The hot melt component 123 is a key structure for realizing the transformation of the plugging agent from a solid state to a molten state. The stability and reliability of the heating performance of the hot melt component 123 can improve the hot melt reaction effect of the plugging agent, thereby improving the effect of the downhole plugging and repair device.

[0073] The heat-resistant buffer 124 has excellent heat resistance, capable of withstanding the high temperatures generated by the hot melt component 123, preventing sealing failure caused by high-temperature deformation. Simultaneously, in the high-temperature chamber where the plugging agent is continuously released, the heat-resistant buffer 124 provides physical insulation against heat, preventing excessive heat transfer to the casing 121 and / or other components in the downhole plugging and repair kit, thus preventing overheating damage to the hot melt mechanism 12. Furthermore, the heat-resistant buffer 124 also acts as a buffer, reducing the impact of stress generated by vibration and other factors during operation of the hot melt component 123 on other components, and to a certain extent, bearing the energy released during the hot melt reaction of the plugging agent in the charging mechanism 13, extending the service life of the hot melt mechanism 12.

[0074] Optionally, the cavity may also be filled with a core substrate 125 to fix the body of the heat-fused component 123.

[0075] The core substrate 125 fills the cavity of the hot-melt mechanism 12 and is used to fix the body of the hot-melt component 123. The core substrate 125 is typically made of a material with certain strength and stability to achieve a tight wrapping of the hot-melt component 123, preventing displacement or loosening due to vibration or stress, and ensuring that the hot-melt component 123 is fixed within the cavity. Simultaneously, the core substrate 125 can, to some extent, assist in the conduction and dissipation of heat generated by the hot-melt component 123. The core substrate 125 ensures that the heat generated by the hot-melt component 123 is more evenly distributed within the cavity, preventing localized overheating and ensuring that the hot-melt component 123 operates in a suitable temperature environment, thereby extending its service life.

[0076] Furthermore, the surface of the core substrate 125 has grooves, and a sealing ring is embedded in the grooves. The sealing ring ensures that the core substrate 125 is tightly fixed to the hot-melt mechanism 12, while effectively preventing leakage and / or contamination of the sealing agent due to sealing problems, thus ensuring the reliability of the downhole sealing and repair operation.

[0077] In one possible implementation, the device further includes a tension member 111, one end of which is connected to the cable 112, and the other end of which is electrically connected to the body of the thermoplastic component 123; the tension member 111 is configured to provide a pulling force to shear the pin 155 after the sealing agent at the target location has cooled, thereby separating the loading mechanism 13 from the guide block 152.

[0078] One end of the tension member 111 is connected to the cable rope 112, and the other end is electrically connected to the body of the heat-melting member 123. It can transmit the power of the cable rope 112 to the heat-melting member 123, provide the electrical energy required for the heat-melting member 123 to work, and ensure that the heat-melting member 123 can work normally to trigger the heat-melting reaction of the sealing agent.

[0079] After the sealing agent cools, it anchors and locks the guide block 152 and the structure below it. At this point, the tension applied by the cable rope 112 is accurately transferred to the pin 155 via the tension member 111, achieving separation between the loading mechanism 13 and the guide block 152. This facilitates the retrieval of the downhole sealing and repair device after the sealing operation is completed, preventing it from becoming stuck due to the anchoring effect of the cooled sealing agent and improving its utilization rate. Retrieving the downhole sealing and repair device reduces the operating cost of downhole sealing and repair. Simultaneously, the tension member 111 has a certain degree of toughness, capable of withstanding stress changes before and after the pin 155 breaks, preventing the cable rope 112 from directly bearing drastic stress changes and improving the safety of downhole sealing and repair operations. Optionally, the tension member 111 can be a tension rod.

[0080] In one possible implementation, the loading mechanism 13 includes a loading housing 131; the inner cavity of the loading housing 131 is filled with a sealing agent in layers.

[0081] The charge housing 131 is a hollow outer shell used to contain the plugging agent. The inner cavity of the charge housing 131 can serve as a container for the plugging agent, protecting it from external environmental contamination and damage, while providing a relatively stable space for the hot-melt reaction of the plugging agent under the action of the hot-melt mechanism 12.

[0082] Furthermore, the inner cavity of the charge housing 131 is filled with a layered sealing agent, which allows the sealing agent to be heated more evenly during the hot-melt reaction, ensuring the full progress of the hot-melt reaction, controlling the rate of the hot-melt reaction, and reducing the pressure generated by the hot-melt reaction on the charge housing 131.

[0083] In one possible implementation, the spraying mechanism 14 further includes a rubber sleeve 142 disposed on the housing of the spraying mechanism 14.

[0084] A rubber sleeve 142 is used to install on the housing of the injection mechanism 14. The rubber sleeve 142 can provide a certain buffering and shock absorption effect, reducing the damage to other components inside the downhole sealing and repair device caused by vibration or impact during the downhole sealing and repair operation.

[0085] Meanwhile, the rubber sleeve 142 can also prevent the sealing agent from overflowing, so that the sealing agent can achieve sealing and repair of the oil and gas well casing at the target location, while avoiding the sealing agent overflowing and damaging the upper oil and gas well casing at the target location.

[0086] In one possible implementation, the slow-flow structure 141 is an asbestos plug.

[0087] Because of the porous structure in asbestos plugs, and the large frictional force of the porous structure, asbestos plugs can hinder the rapid flow of the plugging agent and suppress the flow rate of the plugging agent, thus serving as a slow-flow structure 141.

[0088] Furthermore, asbestos plugs can also prevent impurities from entering the loading mechanism 13 during the process of the downhole plugging and repair device being lowered to the target location, ensuring that the plugging agent can undergo a stable thermal melting reaction.

[0089] In one possible implementation, the heat insulation element 153 is a ceramic heat insulation plate.

[0090] Ceramic insulation panels are plate-shaped components with heat insulation properties, made primarily of ceramic. They possess extremely low thermal conductivity, effectively preventing heat transfer. In downhole sealing and repair devices, ceramic insulation panels can isolate the guide block 152 from direct contact with the surrounding high-temperature environment or heat source, preventing the guide block 152 from deforming due to heat.

[0091] In one possible implementation, the heat-resistant buffer 124 is a silicon carbide impact-resistant heat insulation board.

[0092] The silicon carbide impact-resistant heat insulation board is a plate-shaped component made of silicon carbide material that combines heat resistance and cushioning functions. Using the silicon carbide impact-resistant heat insulation board as a heat-resistant buffer 124 can extend the service life of the heat-melting mechanism 12 and improve the stability and reliability of the heat-melting mechanism 12.

[0093] Figure 3 This is a schematic flowchart illustrating the application method of the downhole plugging and repair device provided in this application embodiment. Figure 3 As shown, the method includes:

[0094] S301. Obtain the target location of the target oil and gas well. The target location is obtained by locating the target oil and gas well using acoustic positioning or optical fiber.

[0095] Acoustic positioning technology utilizes the different propagation speeds and reflection characteristics of sound waves in different media. When an acoustic signal is emitted into an oil or gas well, the sound wave encounters a breach or leak point, and the change in the medium at the breach or leak point generates a reflected wave. By receiving and analyzing the reflected wave, the target location of the oil or gas well can be determined.

[0096] Fiber optic positioning technology leverages the sensitivity of optical fibers to parameters such as temperature and pressure. When a breach or leak occurs in an oil or gas well, the environmental parameters at that point change. The fiber optic cable can sense these changes and convert them into electrical signals. By analyzing these signals, the breach and / or leak can be identified, thus pinpointing the location of the target oil or gas well.

[0097] S302. Using drilling tools, drill holes in the casing and cement sheath at the target location to obtain the drilling position corresponding to the target location.

[0098] Drilling tools are used to create a channel at the target location so that subsequent plugging operations can directly target the area. Drilling tools can penetrate both the casing and the cement sheath. The casing is a crucial structure in oil and gas wells used to protect the wellbore and maintain pressure, while the cement sheath serves to secure the casing and isolate the formation.

[0099] The casing and cement sheath at the target location are drilled using drilling tools. It is necessary to precisely control the drilling depth and diameter to ensure that the target location is reached without causing excessive damage to the surrounding structure. This provides an accurate channel for the subsequent injection of the sealing agent, ensuring that the sealing agent can successfully reach the target location for sealing.

[0100] S303. The downhole sealing and repair device is lowered to the borehole position. The downhole sealing and repair device includes a heat-melting mechanism 12, a charging mechanism 13, and a jetting mechanism 14.

[0101] When lowering the downhole plugging and repair device to the borehole location, precise control of the lowering speed and position ensures that the device accurately reaches the target location, guaranteeing the smooth progress of the plugging operation. Specifically, the thermal fusion mechanism 12 generates heat to cause the plugging agent in the charging mechanism 13 to undergo a thermal fusion reaction; the charging mechanism 13 stores the plugging agent; and the injection mechanism 14 is responsible for accurately injecting the molten plugging agent to the target location.

[0102] Furthermore, when the products of the aluminothermic reaction are used as the sealing agent, the charging mechanism 13 is loaded with the reactants from the aluminothermic reaction. Simultaneously, the mass of the reactants from the aluminothermic reaction loaded in the charging mechanism 13 is determined based on the size of the area requiring sealing and repair at the target location. That is, the mass and quantity of reactants loaded in the charging mechanism 13 can be determined according to actual operational requirements.

[0103] S304. Start the hot melt mechanism 12 to cause the plugging agent in the charging mechanism 13 to undergo a hot melt reaction and be converted into a molten state, so that the molten plugging agent flows to the target position for plugging after passing through the slow flow structure 141 and the flow guiding component 15 in sequence.

[0104] After the thermal fusion mechanism 12 is activated, heat is transferred to the plugging agent in the charging mechanism 13 through heat conduction, causing the plugging agent to undergo a thermal fusion reaction, changing from a solid state to a molten state. The function of the slowing flow structure 141 is to slow down the flow rate of the molten plugging agent, allowing it to flow smoothly and accurately to the flow guide assembly 15. The flow guide assembly 15 is responsible for precisely guiding the plugging agent to the target location, ensuring that the plugging agent reaches the target location in the appropriate state and at the appropriate speed, achieving effective plugging.

[0105] Figure 4 This application provides an operational schematic diagram of the downhole plugging and repair device provided in its embodiments. Figure 1 .like Figure 4 As shown, when the molten plugging agent 17 flows through the slow-flow structure 141 and the flow guiding component 15 in sequence to the target position for plugging, the guide block 152 and the structure below the guide block 152 can be anchored and locked to achieve downhole plugging operation.

[0106] S305. Control the pulling component 111 in the downhole plugging and repair device to lift the pulling component 111 upward, break the pin 155 in the injection mechanism 14, remove the remaining downhole plugging and repair device, and obtain the plugged oil and gas well.

[0107] The function of the pulling component 111 is to break the pin 155 in the injection mechanism 14 by pulling upward after the sealing operation is completed, so that the downhole sealing and repair device can be separated from the injection part, making it easier to remove the remaining downhole sealing and repair device.

[0108] Figure 5 This application provides an operational schematic diagram of the downhole plugging and repair device provided in its embodiments. Figure 2 .like Figure 5 As shown, when the molten plugging agent 17 cools and solidifies to form the plugging structure 18, the pin 155 in the injection mechanism 14 is broken. When the remaining downhole plugging and repair device is removed, the guide block 152 and the structure below the guide block 152 will remain in the oil and gas well due to anchoring and locking. The structure above the guide block 152 can be removed by breaking the pin 155.

[0109] Furthermore, the wellbore of the sealed oil and gas well is repaired by drilling, resulting in a repaired oil and gas well.

[0110] After the plugging operation is completed, the well wall may become uneven due to drilling and plugging operations. Using a drill bit to correct the well wall can restore it to a smooth surface, ensuring normal production of the oil and gas well.

[0111] Figure 6 The diagram illustrates the sealing effect of the downhole plugging and repair device provided in this embodiment of the application. Figure 6 As shown, a downhole plugging and repair device is used to plug the target location, and the casing at the target location is cut to demonstrate the plugging effect of the device in detail. The plugging agent is a liquid metal product resulting from an aluminothermic reaction. It includes:

[0112] Figure 6 -a is a diagram showing the sealing effect on the outer casing of the downhole sealing and repair device. For example... Figure 6 As shown in -a, the sealing agent has largely filled the damaged area of ​​the casing. The sealing agent adheres tightly to the inner wall of the casing and the damaged area, forming a relatively thick filling layer, indicating that the sealing agent has successfully reached the target location and effectively sealed and repaired the damage. Figure 6 This clearly demonstrates that the use of downhole plugging and repair devices for plugging operations has a good plugging effect and can effectively achieve plugging and repair of oil and gas wells.

[0113] Figure 6 -b is a diagram showing the sealing effect of the casing transverse section of the downhole sealing and repair device. For example... Figure 6 As shown in -b, the casing remains relatively intact in the plugging area without any obvious deformation or damage, indicating that the operation of the downhole plugging and repair device has little impact on the casing itself. While achieving plugging, it does not damage the key downhole structure, ensuring the normal use of the oil and gas well in the future.

[0114] Figure 6 -c is a diagram showing the sealing effect of the casing longitudinal section of the downhole sealing and repair device. For example... Figure 6 As shown in -c, the sealing agent is in close contact with the inner wall of the casing, with no obvious gap between them. This indicates that the sealing material can adapt well to the shape of the casing during the solidification process and form a tight fit with the casing, which helps to improve the sealing effect of the sealing repair.

[0115] Figure 7 This is a schematic diagram of the application device of the downhole plugging and repair device provided in the embodiments of this application. (See attached diagram.) Figure 7 As shown, the application device 70 of the downhole plugging and repair device provided in this embodiment includes:

[0116] The acquisition module 701 is used to acquire the target location of the target oil and gas well. The target location is obtained by locating the target oil and gas well using acoustic positioning or optical fiber.

[0117] The control module 702 is used to drill holes in the casing and cement sheath at the target location using drilling tools to obtain the drilling position corresponding to the target location; to lower the downhole plugging and repair device to the drilling position, the downhole plugging and repair device including a thermal melting mechanism, a charging mechanism and an injection mechanism, wherein the downhole plugging and repair device is the downhole plugging and repair device of the first aspect and / or possible embodiments of the first aspect; to activate the thermal melting mechanism to cause the plugging agent in the charging mechanism to undergo a thermal melting reaction and be converted into a molten state, so that the molten plugging agent flows to the target location for plugging after passing through the slow flow structure and the flow guiding component in the injection mechanism; to control the pulling member in the downhole plugging and repair device to lift the pulling member upward, break the pin in the injection mechanism, and remove the remaining downhole plugging and repair device to obtain the plugged oil and gas well.

[0118] The application device of the downhole plugging and repair device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0119] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A downhole plugging and repair device, characterized in that, The device includes: a heat-melting mechanism, a charging mechanism, and a spraying mechanism. The injection mechanism includes a flow-slowing structure and a flow-guiding component; the hot-melt mechanism is fixedly connected to the top end of the charging mechanism, and the bottom end of the charging mechanism is connected to the flow-guiding component. The hot-melting mechanism is configured to initiate a hot-melting reaction of the plugging agent in the charging mechanism through heat conduction, converting it into a molten state. The molten plugging agent then flows through the slow-flow structure and the flow guiding assembly to the target location for plugging. The plugging includes ablation, filling, and / or sealing. The flow guiding assembly includes a flow guide, a guide block, and a heat insulation component; The flow guide has a flow channel and a concave groove inside, and a pin is installed in the concave groove; the guide block is engaged in the concave groove by the pin, and the bottom of the guide block is fixedly connected to the heat insulation component by connecting bolts; wherein, the heat insulation component is configured to prevent the guide block from deforming and affecting the sealing performance, and the loading mechanism can be separated from the guide block after the pin is sheared; The hot-melting mechanism includes: a shell, an upper end cover, a hot-melting component, and a heat-resistant buffer component; the shell, the upper end cover, and the heat-resistant buffer component enclose a receiving cavity; The upper end cap is fixed to the top of the drug loading mechanism by threads; The body of the hot melt component is disposed within the accommodating cavity, and the end of the hot melt component extends through the heat-resistant buffer and out of the accommodating cavity, contacting the sealing agent within the loading mechanism.

2. The apparatus according to claim 1, characterized in that, The cavity is also filled with a core matrix to fix the body of the hot melt component.

3. The apparatus according to claim 1, characterized in that, The device further includes: a tension member, one end of which is connected to a cable rope, and the other end of which is electrically connected to the thermoplastic component body; The pulling element is configured to provide a pulling force after the sealing agent at the target location has cooled to shear the pin, thereby separating the loading mechanism from the guide block.

4. The apparatus according to claim 1, characterized in that, The loading mechanism includes a loading shell; the inner cavity of the loading shell is filled with the sealing agent in layers.

5. The apparatus according to claim 1, characterized in that, The spraying mechanism also includes a rubber sleeve disposed on the housing of the spraying mechanism.

6. The apparatus according to claim 1, characterized in that, The slow-flow structure is an asbestos plug.

7. The apparatus according to claim 1, characterized in that, The heat insulation component is a ceramic heat insulation board.

8. The apparatus according to claim 1, characterized in that, The heat-resistant buffer component is a silicon carbide impact-resistant heat insulation board.

9. A method for applying a downhole plugging and repair device, characterized in that, include: The target location of the target oil and gas well is obtained by acoustic positioning or optical fiber positioning within the target oil and gas well. Using drilling tools, the casing and cement sheath at the target location are drilled to obtain the drilling position corresponding to the target location; The downhole plugging and repair device is lowered to the borehole location. The downhole plugging and repair device includes a heat-melting mechanism, a charging mechanism, and a jetting mechanism. The downhole plugging and repair device is the downhole plugging and repair device according to any one of claims 1-8. The hot-melting mechanism is activated, causing the plugging agent in the charging mechanism to undergo a hot-melting reaction and be converted into a molten state. The molten plugging agent then flows through the slow-flow structure and the flow guiding component in the spraying mechanism to the target position for plugging. Control the pulling component in the downhole plugging and repair device to lift it upwards, break the pin in the injection mechanism, remove the remaining downhole plugging and repair device, and obtain the plugged oil and gas well.

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