Micro-lift self-locking integrated top water channeling prevention tool, tool string, system and application

Abstract

The application discloses a micro-lifting self-locking integrated top water channeling prevention tool, a tool string, a system and application, and the tool can comprise a central pipe, a micro-lifting self-locking centralizing assembly, a reciprocating pumping power assembly and a sealing rubber tube which are arranged outside the central pipe; wherein, a joint of the micro-lifting self-locking centralizing assembly is connected with the central pipe; the micro-lifting self-locking centralizing assembly is used for locking the micro-lifting self-locking integrated top water channeling prevention tool on the well wall after wellhead pressure; the reciprocating pumping power assembly is used for pumping the cement slurry outside the tool into a filling cavity between the sealing rubber tube and the central pipe, so that the sealing rubber tube is expanded to realize sealing. The tool can not only play a role of zonal isolation but also realize pipe string centralizing, greatly reduces the length of the pipe string, and avoids the problems that when the top water channeling prevention tool and the elastic centralizer are combined to realize the zonal isolation and centralizing functions, the length of the whole tool string is too long, and the running is blocked in the wellbore with large dogleg angles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drilling well completion water channeling prevention, and particularly relates to a micro-lifting self-locking integrated water channeling prevention tool, a tool string, a system and application. BACKGROUND

[0002] After multiple rounds of steam injection production, the existing super heavy oil wells, due to repeated erosion of the cement sheath by high-temperature wet steam, and the difference in expansion coefficients of cement, rock and casing, the casing cement sheath is prone to damage or fall off locally, and a gap is formed between the cement sheath and the pipe wall, causing abnormal communication between the formations, ultimately resulting in unclear production layer, easy water invasion into the oil layer, and low production efficiency, and no effective measures can be taken.

[0003] For example, due to the complex oil-water relationship, some oilfields have edge, top, bottom water and interlayer water, and the water production problem of the oil well is serious, among which the pipe outside groove water treatment is difficult to control. Before plugging the pipe outside channeling, it is necessary to determine whether there is channeling, and there are many methods, such as using production conditions to determine, mechanical method in operation construction, and well logging method to verify channeling. The current methods for controlling top water channeling mainly include mechanical water plugging, casing repair and cement plugging. Among them, mechanical water plugging and casing repair are mainly for water production wells whose channeling does not connect the oil layer and water layer, and are limited by well conditions and limited by analysis and understanding, so they are not suitable for many oil wells. Cement plugging generally includes perforation cementing, abandoning part of the well section and cementing or lowering the liner to re-cement. Because the cement slurry channels between the channeling and the formation, the cement plugging pressure is not high, the cement plugging amount is large, and the test pressure is not stable after drilling the cement plug, which leads to construction failure. Especially after cement plugging, the cement that seals the channeling appears channeling again after being heated by high-temperature steam during production. The main reason for the low success rate and short effective period of the previous cement plugging measures is the deficiency in materials and construction technology. According to the research on the performance of the plugging agent and the construction technology of the current domestic cement plugging, it is believed that by compounding the plugging agent and improving the technology, the success rate of top water control in super heavy oil reservoirs can be effectively improved. The cement slurry plugging technology is widely used in the treatment of pipe channeling problems in the later development process of oilfields, which is a powerful tool for oilfield stable oil control and water control. According to the application in oilfields, the recommended pipe channeling treatment methods are casing extrusion pressure control method and pre-plugging segmented extrusion method, especially the deep adjustment and shallow plugging technology, which has certain reference significance for improving the success rate of construction. At present, to solve the problem of low success rate of pipe channeling sealing, it is necessary to improve the performance of cement slurry, mechanical plugging, chemical agents and other aspects.

[0004] The mechanical channeling is researched more at home and abroad, and the tools are mostly pipe external packers. The high-temperature-resistant pipe external packer is used in non-reservoir to separate water layer and lower layer, so that even if the top water channeling occurs, it is difficult to channel to the lower reservoir section. SUMMARY

[0005] In order to adapt to different sizes of wellbores and effectively prevent top water channeling, the embodiment of the present application provides a micro-lifting self-locking integrated top water channeling prevention tool, tool string, system and application.

[0006] In the first aspect, the embodiment of the present application provides a micro-lifting self-locking integrated top water channeling prevention tool, which can include: a central pipe, a micro-lifting self-locking centralizing assembly, a reciprocating suction power assembly and a sealing rubber tube, which are arranged outside the central pipe.

[0007] The joint of the micro-lifting self-locking centralizing assembly is connected with the central pipe; the micro-lifting self-locking centralizing assembly is used to lock the micro-lifting self-locking integrated top water channeling prevention tool on the well wall after wellhead pressurization; and the reciprocating suction power assembly is used to suck the cement slurry outside the tool into the filling cavity between the sealing rubber tube and the central pipe, so that the sealing rubber tube is inflated to achieve sealing.

[0008] Optionally, the micro-lifting self-locking centralizing assembly can include: a joint, a centralizing seat, a centralizing body, a first piston, a valve assembly and a cylinder sleeve.

[0009] The cylinder sleeve is arranged outside the joint and the central pipe and is threadedly connected with the joint.

[0010] The centralizing seat is fixed outside the joint at a preset distance from the cylinder sleeve; one end of the centralizing body is limited by the centralizing seat, and the other end is adjacent to the cylinder sleeve.

[0011] The first piston is located between the joint and the cylinder sleeve, and one end of the first piston is connected with the centralizing body.

[0012] The joint is provided with a fluid passage, and the valve assembly is located in the fluid passage.

[0013] High-pressure fluid enters between the cylinder sleeve and the joint from the joint through the fluid passage to push the first piston and drive the centralizing body to slide, and the centralizing body is lifted under the action of the centralizing seat.

[0014] Optionally, the valve assembly can include: a valve block, a first spring and a plug.

[0015] The valve block and the first spring are located in the fluid passage, and the plug is fixed on the fluid passage to limit the valve block and the first spring.

[0016] In the state of injecting high-pressure fluid into the center pipe, the high-pressure fluid extrudes the valve block to compress the first spring, and then the fluid channel is opened so that the high-pressure fluid acts on the first piston; in the state of not injecting high-pressure fluid into the center pipe, the first spring extrudes the valve block under the action of the elastic force, so that the valve block closes the fluid channel.

[0017] Optionally, the micro-lifting self-locking centralizing assembly can further comprise a blocking ring located between the first piston and the cylinder sleeve, and the blocking ring is connected with the cylinder sleeve.

[0018] Optionally, the contact surface of the blocking ring is provided with a first barb, and the first piston is provided with a second barb matched with the first barb.

[0019] Optionally, the micro-lifting self-locking centralizing assembly can further comprise a plurality of first sealing rubber rings.

[0020] Part of the first sealing rubber rings are located between the center pipe and the first piston, and part of the first sealing rubber rings are located between the first piston and the cylinder sleeve.

[0021] Optionally, the reciprocating pumping power assembly can comprise a second piston, a piston sleeve, a piston head, an elastic sealing component, and a sealing joint.

[0022] The second piston is located between the center pipe and the cylinder sleeve of the micro-lifting self-locking centralizing assembly; one end of the piston sleeve is connected with the cylinder sleeve, and the other end is connected with the sealing joint; the other end of the sealing joint is connected with the sealing rubber cylinder.

[0023] The end of the second piston close to the micro-lifting self-locking centralizing assembly is adjacent to the joint of the micro-lifting self-locking centralizing assembly, and the end away from the micro-lifting self-locking centralizing assembly is connected with the piston head.

[0024] The elastic sealing component is located between the center pipe and the sealing joint, and one end of the elastic sealing component is limited by the sealing joint, and the other end of the elastic sealing component is abutted with the piston sleeve.

[0025] The piston sleeve is radially provided with an inlet for sucking the cement slurry outside the tool, and the inner wall of the piston sleeve is provided with a protrusion, and the piston head is provided with a groove matched with the protrusion; in the state of wellhead pressing, the second piston drives the piston head to slide, so that the protrusion and the groove are separated, the external cement slurry is sucked into the space between the piston sleeve and the central pipe, and the elastic split plug assembly is opened under the extrusion of the piston head to enter the sealing rubber cylinder through the sealing joint; in the state of wellhead unpressing, the second piston rebounds, the protrusion and the groove are engaged, and the elastic plug assembly rebounds and abuts against the piston sleeve, so as to prevent the cement slurry in the sealing rubber cylinder from flowing back.

[0026] Optionally, the elastic plug assembly can include an inner suction pressure sealing ring and a second spring; one end of the second spring is limited by the sealing joint, and the other end is connected with the inner suction pressure sealing ring; one end of the inner suction pressure sealing ring is connected with the second spring, and the other end abuts against the piston sleeve to close the fluid filling port between the piston sleeve and the central pipe.

[0027] Optionally, the elastic plug assembly can further include a rubber plug located between the inner suction pressure sealing ring and the central pipe.

[0028] Optionally, the reciprocating suction power assembly can further include a plurality of second sealing rubber rings.

[0029] Part of the second sealing rubber rings are located between the central pipe and the second piston, and part of the second sealing rubber rings are located between the second piston and the cylinder sleeve.

[0030] Optionally, the sealing rubber cylinder can include an inner rubber cylinder, a steel belt layer and an outer rubber cylinder; the inner rubber cylinder is pre-stored with a chemical agent.

[0031] The cement slurry is sucked into the sealing rubber cylinder through the reciprocating suction power assembly, the water in the cement slurry reacts with the chemical agent to increase the volume of the inner rubber cylinder to generate a thrust force, so as to push the steel belt layer and the outer rubber cylinder to isolate the formation.

[0032] In the second aspect, the embodiments of the present application provide a drilling tool string, which can include a casing / screen pipe and the micro-lifting self-locking integrated water head prevention tool of the first aspect; wherein the casing / screen pipe and the micro-lifting self-locking integrated water head prevention tool are connected through a coupling.

[0033] In the third aspect, the embodiments of the present application provide a drilling system, which can include a mud pump and the drilling tool string of the second aspect, and the mud pump repeatedly pumps high-pressure mud into the casing to make the micro-lifting self-locking integrated water head prevention tool in the drilling tool string stand upright and set.

[0034] In a fourth aspect, the embodiments of the present application provide an application of the micro-lifting self-locking integrated water head control and channeling prevention tool in the drilling system.

[0035] The beneficial effects of the above technical solutions provided in the embodiments of the present application at least include:

[0036] The micro-lifting self-locking integrated water head control and channeling prevention tool, tool string, system and application provided in the embodiments of the present application can not only seal the formation but also right the pipe string, greatly reduces the length of the pipe string, improves the safety of the pipe string running, and greatly reduces the overall cost of the tool string, is more economical and practical than the combined tool, and solves the problems that the original water head control and channeling prevention tool only has the sealing function and cannot right the pipe string, and when the water head control and channeling prevention tool and the elastic centralizer are combined to realize the sealing and righting functions, the length of the entire tool string is too long, and the running is blocked in the wellbore with a large dogleg angle.

[0037] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the structure particularly pointed out in the written description and the accompanying drawings.

[0038] The technical solutions of the present application will be further described in detail below with the help of the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation to the present application. In the drawings:

[0040] Figure 1 The structural diagram of the micro-lifting self-locking integrated water head control and channeling prevention tool provided in the embodiments of the present application is shown in the figure;

[0041] Figure 2 The working principle schematic diagram of the water head control and channeling prevention tool provided in the embodiments of the present application is shown in the figure;

[0042] Figure 3 The enlarged structural diagram of the micro-lifting self-locking righting assembly provided in the embodiments of the present application is shown in the figure;

[0043] Figure 4 The structural diagram of the righting seat provided in the embodiments of the present application is shown in the figure;

[0044] Figure 5 The structural diagram of the righting body provided in the embodiments of the present application is shown in the figure;

[0045] Figure 6An enlarged structural diagram of the reciprocating pumping power assembly provided in the embodiments of the present application;

[0046] Figure 7 A structural diagram of the piston sleeve and piston head provided in the embodiments of the present application;

[0047] Figure 8 A structural diagram of the sealing rubber tube provided in the embodiments of the present application;

[0048] Figure 9 A sectional structural diagram of Figure 8 ;

[0049] Wherein, 1-micro-lift self-locking integrated water head tool; 2-casing / screen pipe; 3-coupling;

[0050] 11-central pipe; 12-micro-lift self-locking centralizing assembly; 13-reciprocating pumping power assembly; 14-sealing rubber tube;

[0051] 121-joint; 122-centralizing seat; 123-centralizing body; 124-first piston; 125-valve assembly; 126-cylinder sleeve; 127-retaining ring; 128-first sealing rubber ring; 1211-fluid passage; 1251-valve block; 1252-first spring; 1253-screw plug;

[0052] 131-second piston; 132-piston sleeve; 133-piston head; 134-elastic sealing assembly; 135-sealing joint; 136-second sealing rubber ring;

[0053] 1321-suction inlet; 1322-protrusion; 1323-fluid filling port; 1331-groove; 1341-inner pressure sealing ring; 1342-second spring; 1343-rubber plug. DETAILED DESCRIPTION

[0054] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0055] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "far", "near", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0057] The inventor found that the existing mechanical channeling tools at home and abroad have the problems of poor pipe string centering, poor cementing quality, easy breakthrough of the thin cement ring, and downward channeling into the underlying reservoir. Meanwhile, whether the commonly used external pipe packer is extruded or expanded, it may deform and lose the sealing ability under the action of long-term thermal alternating stress. In view of the above problems, on the basis of sufficient investigation of the present situation at home and abroad, the present application is proposed to provide a micro-lifting self-locking integrated water head prevention tool, tool string, system and application which overcomes the above problems or at least partially solves the above problems. The tool integrates the centralizing function of the completion pipe string and can also absorb the cement slurry from the outside of the casing and produce solid substances by chemical agent reaction in the rubber tube to realize formation sealing.

[0058] Referring to Figure 1 As shown in the drawings, the micro-lifting self-locking integrated water head prevention tool 1 provided in the embodiment of the present application can include a central pipe 11, a micro-lifting self-locking centralizing assembly 12, a reciprocating suction power assembly 13 and a sealing rubber tube 14 arranged outside the central pipe 11. The joint 121 of the micro-lifting self-locking centralizing assembly 12 is connected with the central pipe 11. The micro-lifting self-locking centralizing assembly 12 is used to lock the micro-lifting self-locking integrated water head prevention tool 1 on the well wall after wellhead pressing. The reciprocating suction power assembly 13 is used to suck the cement slurry outside the tool into the filling cavity (not shown in the figure) between the sealing rubber tube 14 and the central pipe 11, so as to make the sealing rubber tube 14 expand and realize sealing.

[0059] Referring to Figure 2As shown, the working process of the micro-lifting self-locking integrated top water channeling prevention tool provided in the embodiment of the present application is as follows, Figure 2 Fig. 1 (1) is a diagram of the righting body of the micro-lifting self-locking righting assembly in the original state and the unforced state of the sealing rubber tube in the original state; after the wellhead is started to be pressed, refer to Figure 2 Fig. 1 (2) shown, the righting body of the micro-lifting self-locking righting assembly is gradually lifted to Figure 2 Fig. 1 (3) shown, until the righting body locks the tool on the well wall; then continue to press the wellhead, and the cement slurry outside the tool is sucked into the pipe during the reciprocating suction process, so that the sealing rubber tube is expanded to realize setting.

[0060] It needs to be explained in the embodiment of the present application that the starting thrust of the micro-lifting self-locking righting assembly is less than the starting thrust of the reciprocating suction assembly, that is, the tool is first righted and locked by the wellhead pressure, and then the sealing rubber tube is expanded and set.

[0061] The above-mentioned micro-lifting self-locking integrated top water channeling prevention tool provided in the embodiment of the present application can not only play the role of sealing the formation, but also realize the righting of the pipe string, greatly reducing the length of the pipe string, improving the safety of the pipe string during running, and reducing the overall cost of the tool string, which is more economical and practical than the combined tool. The original top water channeling prevention tool only has the function of sealing, and cannot realize the righting of the pipe string. When the top water channeling prevention tool and the elastic righting device are combined to realize the sealing and righting function, the length of the entire tool string is too long, and the running risk exists in the wellbore with large dogleg angle.

[0062] In an optional embodiment, the existing pipe external packer righting tool is mostly dependent on a mechanical elastic righting device. The elastic mechanical righting device of this form has adjusted the outer diameter size before being lowered into the well, and there is a risk of encountering resistance during the lowering process. At the same time, the righting position cannot be adjusted during the lowering process or in the well, which leads to poor righting effect. In order to solve the above technical problems, the micro-lifting self-locking righting assembly is improved by the inventor. Refer to Figure 1 and Figure 3As shown, the micro-lift self-locking centralizing assembly 12 can include a joint 121, a centralizing seat 122, a centralizing body 123, a first piston 124, a valve assembly 125 and a cylinder sleeve 126; wherein the cylinder sleeve 126 is sleeved outside the joint 121 and the central pipe 11 and is threadedly connected with the joint 121; the centralizing seat 122 is fixed outside the joint 121 at a preset distance from the cylinder sleeve 126; one end of the centralizing body 123 is limited by the centralizing seat 122 and the other end is adjacent to the cylinder sleeve 126; the first piston 124 is located between the joint 121 and the cylinder sleeve 126, and one end of the first piston 124 is connected with the centralizing body 123; a fluid passage 1211 is arranged on the joint 121, and the valve assembly 125 is located in the fluid passage 1211; high-pressure fluid enters between the cylinder sleeve 126 and the joint 121 through the fluid passage 1211 to push the first piston 124 to drive the centralizing body 123 to slide, and the centralizing body 123 is lifted under the action of the centralizing seat 122.

[0063] The micro-lift self-locking centralizing assembly in the embodiment of the present application is a centralizing part of the whole tool and plays a centralizing function. The centralizing seat in the embodiment provides a fulcrum for the micro-lift of the centralizing body, and the centralizing seat is fixed on the joint and is located at a preset distance from the cylinder sleeve. Figure 4 and Figure 5 As shown, the centralizing body is slightly lifted under the extrusion of the first piston, and in combination with Figure 3 As shown, the centralizing body is slowly ridden on the centralizing seat during the lifting process, so that the centralizing body is equivalent to a centralizing tool, and the lifting amplitude of the centralizing body will become larger and larger as the pressure increases, so that the size of the pressure during the pressing can determine the size of the lifting height of the centralizing body, and the size-controllable centralizing is realized. For example, when the irregular wellbore or the wellbore of the large well section needs to be centered, by pressing twice the pressure, the centralizing of the large wellbore can be ensured, and when there is a mudstone shrinkage section, by pressing less pressure, the micro-lift and micro-centralizing are realized.

[0064] The micro-lift self-locking centralizing assembly in the embodiment of the present application realizes the centralizing function by the way that the pressure drives the piston (the first piston) and the piston drives the centralizing body to extend, so that the tool can be lowered into the well with a small size and will not be blocked during the lowering process, and at the same time, sufficient thrust is ensured to realize the centralizing of the completion string, solve the problem that the mechanical elastic centralizer is only relied on for the centralizing of the external packer, and the conventional mechanical centralizer has a size and a dimension which are adjusted on the ground, so that there is a risk of encountering resistance during the lowering process, the position of the centralizing cannot be adjusted in the well, and the centralizing effect is difficult to guarantee.

[0065] Further, the micro-lifting self-locking centralizing assembly can realize different size centralizing effects under different wellbore size conditions by applying different pressures at the wellhead, fully considering the centralizing problems of some large-belly wellbores and reduced-diameter wellbores, and the micro-lifting self-locking structure can realize automatic locking function, and after the centralizing reaches the size matching with the wellbore of the formation, the micro-lifting stops automatically, and locking is realized by the way that the centralizing blocks ride on the stepped centralizing seats, solving the problem that the current water-lifting and channel-preventing tool cannot automatically centralize and lock, and under different wellbore size conditions, different size centralizing sizes are needed, and the current centralizer only has the centralizing ability of fixed size. In summary, the tool is an automatically locking water-lifting and channel-preventing tool, and under different wellbore size conditions, different size centralizing sizes are needed, and through the micro-lifting self-locking structure, different size centralizing effects can be realized under different wellbore size conditions by applying different pressures at the wellhead. Not only the centralizing problems of some large-belly wellbores and reduced-diameter wellbores are fully considered, but also the micro-lifting self-locking structure can realize automatic locking function, and after the centralizing reaches the size matching with the wellbore of the formation, the micro-lifting stops automatically, and locking is realized by the way that the centralizing blocks ride on the centralizing seats.

[0066] In another optional embodiment, referring also to Figure 1 As shown in the figure, the valve assembly 125 can include a valve block 1251, a first spring 1252 and a plug 1253; the valve block 1251 and the first spring 1252 are located in the fluid passage 1211, and the plug 1253 is fixed on the fluid passage 1211 to limit the valve block 1251 and the first spring 1252; in the state of injecting high-pressure fluid into the center tube 11, the high-pressure fluid extrudes the valve block 1251 to compress the first spring 1252, and then the fluid passage 1211 is opened, so that the high-pressure fluid acts on the first piston 124; in the state of not injecting high-pressure fluid into the center tube 11, the first spring 1252 extrudes the valve block 1251 under the action of the rebound force, so that the valve block 1251 closes the fluid passage 1211.

[0067] The valve assembly in the embodiment is a single valve, and the valve block and the first spring are extruded to open the fluid passage during pressure injection, and the first spring is compressed; the first spring blocks the fluid passage under the action of the rebound force of the first spring when the pressure injection is stopped, and the valve assembly can be opened and closed at any time to form a stable pressure support environment for the centralizing body.

[0068] In another optional embodiment, referring also to Figure 1 and Figure 3As shown, the micro-lift self-locking centralizing assembly 12 can further include a blocking ring 127 between the first piston 124 and the cylinder sleeve 126, and the blocking ring 127 is connected with the cylinder sleeve 126. In a specific implementation, the blocking ring is provided with a first barb (not shown in the figure) on a contact surface of the first piston, and the first piston is provided with a second barb (not shown in the figure) matched with the first barb.

[0069] In the embodiment, the blocking ring functions as a fixing ring, and the lower end of the blocking ring is provided with a barb matched with the barb on the first piston to achieve the engagement and fixing. The first piston moves forward under the action of external pressure to push the centralizing body to move until the centralizing body is moved to the centralizing seat, and the pressing is stopped when the size of the wellbore is reached, at which time the centralizing body is just mounted on the centralizing seat, and the barb on the first piston and the barb of the blocking ring are engaged together to achieve the locking, so that the centralizing function is permanently achieved.

[0070] In another optional embodiment, further referring to Figure 1 As shown, the micro-lift self-locking centralizing assembly 12 can further include a plurality of first sealing rubber rings 128, part of the first sealing rubber rings 128 are located between the centralizing pipe 11 and the first piston 124, and part of the first sealing rubber rings 128 are located between the first piston 124 and the cylinder sleeve 126. The first sealing rubber rings can ensure the sealing performance between the components, and can be suitable for the high-pressure working environment in the well.

[0071] In another optional embodiment, the currently used water-lifting anti-channeling tool can only play a sealing role, but the sealing effect is short, the sealing rubber tube is easily damaged, and the water-lifting repeatedly occurs, which is difficult to effectively solve the problem. The embodiment of the present application can fully guarantee the quality and effect of the sealing by designing a structure of self-sucking cement slurry to complete the filling and expansion, and can prolong the service life of the oil and gas well. Referring to Figure 1 、 Figure 6 and Figure 7As shown, the reciprocating pumping power assembly 13 can include a second piston 131, a piston sleeve 132, a piston head 133, an elastic sealing assembly 134, and a sealing joint 135; the second piston 131 is located between the central pipe 11 and the cylinder sleeve 126 of the micro-lifting self-locking centralizing assembly 12; one end of the piston sleeve 132 is connected with the cylinder sleeve 126, and the other end is connected with the sealing joint 135; the other end of the sealing joint 135 is connected with the sealing rubber sleeve 14; one end of the second piston 131 close to the micro-lifting self-locking centralizing assembly 12 is adjacent to the joint 121 of the micro-lifting self-locking centralizing assembly 12, and the other end is connected with the piston head 133; the elastic sealing assembly is located between the central pipe 11 and the sealing joint 135, and one end is limited by the sealing joint 135, and the other end is abutted with the piston sleeve 132; the piston sleeve 132 is radially provided with a suction port 1321 for sucking the cement slurry outside the tool, and the inner wall of the piston sleeve 132 is provided with a protrusion 1322, and the piston head 133 is provided with a groove 1331 matched with the protrusion 1322; in the state of wellhead pressure, the second piston 131 drives the piston head 133 to slide, so that the protrusion 1322 and the groove 1331 are separated, the external cement slurry is sucked between the piston sleeve 132 and the central pipe 11, and the elastic sealing assembly 134 is opened under the extrusion of the piston head 133 to enter the sealing rubber sleeve 14 through the sealing joint 135; in the state of wellhead pressure, the second piston 131 rebounds, the protrusion 1322 and the groove 1331 are engaged, and the elastic sealing assembly 134 rebounds and abuts on the piston sleeve 132, so as to avoid the backflow of the cement slurry into the sealing rubber sleeve 14.

[0072] It should be noted that the sealing rubber sleeve in the embodiment is sleeved outside the central pipe, and a gap can be reserved between the sealing rubber sleeve and the central pipe, or the sealing rubber sleeve can be tightly attached. Since the sealing rubber sleeve in the embodiment of the application is a double-layer rubber sleeve, the inner rubber sleeve can be sharply expanded and enlarged after contacting water, and the outer rubber sleeve has good temperature resistance and pressure resistance. By sucking the cement slurry in the annulus outside the tool into the rubber sleeve, the water in the cement slurry in the inner rubber sleeve reacts with the inner rubber sleeve, and the volume is sharply increased, so as to start to compress the outer rubber sleeve, and after the cement slurry is lost, the cement stone becomes solid and stays in the rubber sleeve, thereby playing a supporting role.

[0073] The second piston in the embodiment of the present application provides thrust force through repeated wellhead pressurization, and under the repeated pressurization of the wellhead, the second piston repeatedly sucks the cement slurry outside the tool into the pipe and finally pushes it into the sealing rubber sleeve to achieve rubber sleeve inflation sealing. Under the action of pressure, the second piston drives the piston head to move forward, and at the beginning, the piston head is closed between the piston head and the piston sleeve, that is, the front end of the piston head is in a closed state. With the movement of the second piston, a pressure difference is formed inside the tool, and at this time, the front end of the piston head is opened, and under the action of the pressure difference, the external cement slurry is sucked in, and repeated suction makes the cement slurry enter the sealing rubber sleeve from the fluid filling port. It should be noted that after the wellhead stops pressurization, the thrust force applied to the second piston decreases. Since the second piston compresses the cement slurry in the closed space to generate pressure, the second piston is pushed back to the initial position to achieve repeated suction.

[0074] The embodiment of the present application can fully guarantee the quality and effect of the sealing, prolong the service life of the oil and gas well, and solve the problem that the currently used water-lifting anti-channeling tool can only play a sealing role, but the sealing effect is short, the sealing rubber sleeve is easily damaged, and water-lifting repeatedly occurs, which is difficult to effectively solve. The cement slurry sucked into the rubber sleeve reacts with the prefabricated chemical agent inside the rubber sleeve when the cement slurry loses water and solidifies, and the generated cement stone has strong hardness and dense texture, which can ensure that the cement stone does not crack and damage from the inside during long-term thermal production operation.

[0075] In another optional embodiment, referring also to Figure 1 As shown in the figure, the elastic plugging assembly 134 can include an inner suction pressure-bearing sealing ring 1341 and a second spring 1342. One end of the second spring 1342 is limited by the sealing joint 135, and the other end is connected with the inner suction pressure-bearing sealing ring 1341. One end of the inner suction pressure-bearing sealing ring 1341 is connected with the second spring 1342, and the other end is in abutment with the piston sleeve 132 to close the fluid filling port 1323 between the piston sleeve 132 and the center pipe 11.

[0076] In this embodiment, the cement slurry outside the tool is fully sucked into the pipe through several pressurization and pressure relief processes. The inner suction pressure-bearing sealing ring provides a liquid flow channel. When the second piston pushes the cement slurry in the filling channel to move towards the inside of the sealing rubber sleeve, the inner suction pressure-bearing sealing ring moves forward and leaks out of the filling port. At this time, the sucked cement slurry will enter the inside of the rubber sleeve from the filling port. When the inlet sealing piston moves reversely, the inner suction pressure-bearing sealing ring will block the filling port under the action of the suction force and the second spring, preventing the cement slurry entering the rubber sleeve from returning to the formation.

[0077] In another optional embodiment, referring also to Figure 1As shown, the elastic plugging assembly 134 can also include a rubber plug 1343 between the inner suction pressure-bearing sealing ring 1341 and the central pipe 11. The rubber plug is a long strip-shaped rubber plug, which can completely seal the sealing ring and the central pipe.

[0078] In another alternative embodiment, also referring to Figure 1 As shown, the reciprocating suction power assembly 13 can also include a plurality of second sealing rubber rings 136, part of which is located between the central pipe 11 and the second piston 131, and part of which is located between the second piston 131 and the cylinder sleeve 126. The second sealing rubber ring in this embodiment ensures the sealing between the parts, which can be better applied to the downhole high-pressure working environment.

[0079] In another alternative embodiment, also referring to Figure 1 、 Figure 8 and Figure 9 As shown, the sealing rubber tube 14 can include an inner rubber tube 141, a steel belt layer 142 and an outer rubber tube 143. The inner rubber tube 141 pre-stores chemical agents (not shown in the figure). The cement slurry is sucked into the sealing rubber tube 14 by the reciprocating suction power assembly 13, and the water in the cement slurry reacts with the chemical agents to increase the volume of the inner rubber tube 141 to generate a pushing force to push the steel belt layer 142 and the outer rubber tube 143 to seal the formation.

[0080] The embodiment of the present application separates the formation by using the high-temperature-resistant pressure-bearing sealing rubber tube. After the formation is sealed, the upper water layer will be difficult to channel from below the tool to the lower reservoir, and the lower steam will not channel upward to the upper formation. The high-temperature-resistant pressure-bearing sealing rubber tube is the core component, and its structural diagram is shown in Figure 8 As shown, the sealing rubber tube has a double-layer rubber tube structure, and a steel belt is sandwiched between the two layers of rubber tubes, and its structural section view is shown in Figure 9 It is the steel belt that provides the pressure-bearing capacity of the rubber tube, so that the rubber tube has a large pressure resistance and a large pushing force and sealing force for sealing hard formation. The inner rubber tube of the high-temperature-resistant pressure-bearing sealing rubber tube can react with water to expand, and the volume of the expanded rubber increases sharply to generate a large pushing force to push the outer rubber to seal the formation. At the same time, the cement slurry sucked into the rubber tube reacts with the pre-prepared chemical agents in the rubber tube when it is lost and solidified, and the generated cement stone has strong hardness and dense texture, so that the cement stone will not crack and damage from the inside during long-term thermal production operation.

[0081] The embodiment of the present application provides the double-layer rubber sleeve structure, a layer of steel belt is clamped between the two layers of rubber sleeves, the pressure bearing capacity of the rubber sleeve is provided through the steel belt, the rubber sleeve has large compression resistance, and the rubber sleeve has large pushing force and sealing force on the hard formation sealing, meanwhile, the inner layer rubber sleeve can be sharply expanded and enlarged after meeting water, and the outer layer rubber sleeve has good temperature resistance and pressure resistance.

[0082] The micro-lifting self-locking integrated water head anti-channeling tool has the functions of centralizing and sealing, the first piston is pushed by wellhead small pressure, the micro-lifting self-locking of the centralizing body is realized, the pressure is further increased, the second piston repeatedly sucks, the cement slurry outside the tool is sucked into the rubber sleeve, the cement slurry sucked into the rubber sleeve reacts with the chemical agent and the inner layer rubber sleeve pre-prepared in the rubber sleeve, the cement generates dense cement stone in the rubber sleeve, and large pushing force is applied to the outer layer rubber sleeve to complete sealing.

[0083] Based on the same inventive concept, the embodiment of the present application further provides a drilling tool string, which can include: a casing / screen pipe and the micro-lifting self-locking integrated water head anti-channeling tool; wherein the casing / screen pipe and the micro-lifting self-locking integrated water head anti-channeling tool are connected through a coupling (refer to the coupling 3 in Figure 1 ).

[0084] Based on the same inventive concept, the embodiment of the present application further provides a drilling system, which can include: a mud pump and the drilling tool string, and the mud pump repeatedly pumps high-pressure mud into the casing to make the micro-lifting self-locking integrated water head anti-channeling tool in the drilling tool string centralize and set.

[0085] Based on the same inventive concept, the embodiment of the present application further provides an application of the micro-lifting self-locking integrated water head anti-channeling tool in a drilling system.

[0086] The application process of the micro-lifting self-locking integrated water head anti-channeling tool in the embodiment of the present application is as follows: the tool is lowered into the well with the completion string → the size of the borehole is determined according to logging data, and then the pressure of centralizing is determined → the wellhead is pressed by 2-3 MPa in normal borehole, 4-6 MPa in large-belly borehole, and 1-2 MPa in reduced-diameter borehole → the pressure is determined according to the upper part, the wellhead is pressed, and the first piston is started → the wellhead pressing is completed, and the completion string is centralized → the wellhead is pressed to 15-17 MPa, the second piston is started to suck the cement slurry → the pressure is repeatedly pressed and released for 2-3 times → the cementing is cured for more than 24 hours, and the cement is fully cured → the construction is completed.

[0087] The micro-lifting self-locking integrated water channeling prevention tool provided by the embodiment of the present application is suitable for the case that an external casing packer needs to be added in a well completion pipe string to implement formation isolation, and is particularly suitable for the case that the external casing packer is used to isolate the formation in a thermal recovery well for heavy oil, so that the cement setting quality can be improved and the service life of the oil and gas well can be prolonged, and has a wide market application prospect. The specific example is as follows.

[0088] Wellbore preparation: the entire wellbore needs to be passed through before the tool is lowered into the well, so as to prevent the rubber tube of the high-temperature-resistant rubber tube from being scratched by sharp objects. Before the well completion pipe string is lowered, the wall protection mud needs to be repeatedly circulated for multiple times, so that the wellbore is smooth and has no collapse, and the well completion pipe string can be smoothly lowered.

[0089] Tool assembly: the three main parts of the micro-lifting self-locking integrated water channeling prevention tool, i.e., the micro-lifting self-locking centralizing assembly and the reciprocating suction power assembly, are assembled, indoor pressure test is performed, and the centralizing effect of the tool is verified before the tool is lowered into the well.

[0090] Formation pretreatment: after the well completion, the slick drill pipe is lowered to the bottom of the well, the mud pump is used to pump the prepared crosslinking agent, the weak formation is covered, 2 hours are interval, the crosslinking agent is continuously pumped to the top of the weak formation, 2 hours are interval again, and the pumping is repeated for several times, so that the weak formation is fully crosslinked.

[0091] Expansion and setting process: the mud pump is used to pump high-pressure mud into the casing, the cement plug is displaced downward, and the plugs are successively broken; the pressure is relatively small at the beginning, the centralizing function is completed, and then the pressure is continuously increased, the suction action is started, the high-pressure mud enters the piston cavity to push the piston to move downward, the pressure of the piston cavity is reduced due to the suction action, the mud in the external annulus is sucked, the high-pressure mud passes through the compression spring of the filling head to open the opening and closing hole, the cement slurry is filled into the rubber tube to complete the suction-filling process; the mud pumping at the wellhead is stopped, the spring pushes the filling head to reset under the action of the reaction force, the backflow of the filled mud is prevented, and one suction-filling-springback cycle is completed. After the expansion is completed, the set resin is broken under pressure to fill the micro cracks caused by the cement setting micro shrinkage, the above steps are repeated, the suction and filling are repeatedly performed, and finally the high-temperature-resistant rubber tube is expanded.

[0092] The detailed description and beneficial effects of the drilling tool string, system and application in the embodiment of the present application can be referred to the detailed introduction of the micro-lifting self-locking integrated water channeling prevention tool, and the embodiment of the present application will not be described here.

[0093] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. The present disclosure is not limited to the precise construction described above and shown in the accompanying drawings and various modifications and changes can be effected therein by those skilled in the art without departing from the scope of the application. The scope of the present disclosure is limited only by the claims appended hereto. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A micro-lifting, self-locking, integrated water-prevention tool, characterized in that, include: The central tube, and the micro-lifting self-locking and straightening assembly, the reciprocating suction power assembly, and the sealing rubber sleeve sleeved on the outside of the central tube; The connector of the micro-lift self-locking centralization assembly is connected to the central tube. The micro-lift self-locking centralization assembly is used to push the first piston in the assembly after applying a small pressure at the wellhead, thereby lifting and locking the centralizing body in the assembly to lock the micro-lift self-locking integrated water-blocking anti-channeling tool onto the well wall. Under increased pressure, the reciprocating suction power assembly uses the second piston to draw cement slurry from outside the tool into the filling cavity between the sealing sleeve and the central tube, causing the sealing sleeve to expand and achieve a seal. The sealing sleeve includes an inner sleeve, a steel strip layer, and an outer sleeve, with the steel strip layer located between the inner and outer sleeves. The inner sleeve contains pre-stored chemical agents. Cement slurry is drawn into the sealing sleeve via the reciprocating suction power assembly. The water in the cement slurry reacts with the chemical agents, causing the inner sleeve to increase in volume and generate thrust, thereby pushing the steel strip layer and the outer sleeve to seal the formation. The reciprocating suction power assembly includes a piston sleeve with a protrusion on its inner wall and a piston head with a groove that matches the protrusion.

2. The tool according to claim 1, characterized in that, The micro-lifting self-locking straightening assembly includes: a connector, a straightening seat, a straightening body, a first piston, a valve assembly, and a cylinder liner; The cylinder liner is sleeved on the outside of the joint and the central tube, and is threadedly connected to the joint; The straightening seat is fixed to the outside of the joint and at a predetermined distance from the cylinder liner; one end of the straightening body is limited by the straightening seat, and the other end is adjacent to the cylinder liner; The first piston is located between the joint and the cylinder liner, and one end of the first piston is connected to the centralizer; The connector is provided with a fluid channel, and the valve assembly is located in the fluid channel; High-pressure fluid enters from the joint through the fluid channel between the cylinder liner and the joint to push the first piston and drive the centralizer to slide, and under the action of the centralizer seat, the centralizer is lifted.

3. The tool according to claim 2, characterized in that, The valve assembly includes: a valve block, a first spring, and a plug; The valve block and the first spring are located in the fluid channel, and the plug is fixed on the fluid channel to limit the valve block and the first spring; When high-pressure fluid is injected into the central tube, the high-pressure fluid squeezes the valve block to compress the first spring, thereby opening the fluid passage so that the high-pressure fluid acts on the first piston; when high-pressure fluid is not injected into the central tube, the first spring squeezes the valve block under the action of the rebound force so that the valve block closes the fluid passage.

4. The tool according to claim 2, characterized in that, The micro-lift self-locking straightening assembly further includes a retaining ring located between the first piston and the cylinder liner, the retaining ring being connected to the cylinder liner.

5. The tool according to claim 4, characterized in that, The retaining ring has a first barb on its contact surface with the first piston, and the first piston has a second barb that cooperates with the first barb.

6. The tool according to any one of claims 2 to 5, characterized in that, The micro-lifting self-locking straightening assembly also includes: a plurality of first sealing rings; Specifically, a portion of the first sealing ring is located between the central tube and the first piston; another portion of the first sealing ring is located between the first piston and the cylinder liner.

7. The tool according to claim 1, characterized in that, The reciprocating suction power assembly includes: a second piston, a piston sleeve, a piston head, an elastic sealing assembly, and a sealing joint; The second piston is located between the central tube and the cylinder liner of the micro-lifting self-locking centering assembly; one end of the piston sleeve is connected to the cylinder liner, and the other end is connected to the sealing joint; the other end of the sealing joint is connected to the sealing rubber sleeve. The end of the second piston near the micro-lift self-locking straightening assembly is adjacent to the connector of the micro-lift self-locking straightening assembly, and the end away from the micro-lift self-locking straightening assembly is connected to the piston head; The elastic sealing assembly is located between the central tube and the sealing joint, with one end limited by the sealing joint and the other end abutting against the piston sleeve; The piston sleeve has a radially opening for sucking in cement slurry from outside the tool. Under wellhead pressurization, the second piston drives the piston head to slide, causing the protrusion and the groove to separate, and the external cement slurry is sucked into the space between the piston sleeve and the central tube. Under the pressure of the piston head, the elastic sealing assembly is opened to enter the sealing sleeve through the sealing joint. Under wellhead depressurization, the second piston rebounds, the protrusion and the groove engage, and the elastic sealing assembly rebounds and abuts against the piston sleeve to prevent the cement slurry entering the sealing sleeve from flowing back.

8. The tool according to claim 7, characterized in that, The elastic sealing assembly includes: an inner suction pressure-bearing sealing ring and a second spring; one end of the second spring is limited by the sealing joint, and the other end is connected to the inner suction pressure-bearing sealing ring; one end of the inner suction pressure-bearing sealing ring is connected to the second spring, and the other end abuts against the piston sleeve to close the fluid filling port between the piston sleeve and the central tube.

9. The tool according to claim 8, characterized in that, The resilient sealing assembly further includes a rubber plug located between the inner suction pressure-bearing sealing ring and the central tube.

10. The tool according to any one of claims 7 to 9, characterized in that, The reciprocating suction power assembly also includes: a number of second sealing rings; Specifically, a portion of the second sealing ring is located between the central tube and the second piston; a portion of the second sealing ring is located between the second piston and the cylinder liner.

11. A drilling tool string, characterized in that, include: The casing / screen pipe and the micro-lifting self-locking integrated top water anti-channeling tool as described in any one of claims 1 to 10; The sleeve / screen pipe is connected to the micro-lifting self-locking integrated top water anti-surge tool via a coupling.

12. A drilling system, characterized in that, include: The mud pump and the drilling tool string as described in claim 11, wherein the mud pump repeatedly pumps high-pressure mud into the casing to straighten and set the micro-lifting self-locking integrated top water anti-slip tool in the drilling tool string.

13. The application of a micro-lifting self-locking integrated top water anti-channeling tool as described in any one of claims 1 to 10 in a drilling system.

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