Micro-lifting self-locking integrated water jacking anti-channeling tool, tool string, system and application

Abstract

The invention discloses a micro-lifting self-locking integrated water jacking and channeling preventing tool, a tool string, a system and application. The tool can comprise a center pipe, a micro-lifting self-locking centralizing assembly, a reciprocating suction power assembly and a sealing rubber barrel, wherein the center pipe is sleeved with the micro-lifting self-locking centralizing assembly, the reciprocating suction power assembly and the sealing rubber barrel. Wherein a joint of the micro-lifting self-locking righting assembly is connected with the central pipe; the micro-lifting self-locking righting assembly is used for locking the micro-lifting self-locking integrated water jacking and channeling preventing tool on the well wall after a well mouth is pressed; the reciprocating suction power assembly is used for sucking cement paste outside the tool into a filling cavity between the sealing rubber sleeve and the center pipe, so that the sealing rubber sleeve expands to achieve sealing. By the adoption of the technical scheme, the aim of packing the stratum can be achieved, the pipe column centralizing can be achieved, the length of a pipe string is greatly reduced, and the problems that when the packing and centralizing functions are achieved through the combination mode of a water jacking anti-channeling tool and an elastic centralizer, the length of the whole tool string is too long, and the risk of encountering resistance in a well with the large dog leg degree exists are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of top water anti-channeling in drilling and completion, and in particular to a micro-lifting self-locking integrated top water anti-channeling tool, a tool string, a system and an application thereof. Background Art

[0002] After multiple rounds of steam injection production, the existing ultra-heavy oil wells are prone to local damage or detachment of the cement ring outside the casing due to repeated erosion of the cement ring by high-temperature hot and humid steam and the influence of the differences in expansion coefficients of cement, rock and casing. This creates gaps between the cement ring and the pipe wall, causing abnormal connectivity between formations, ultimately leading to unclear production strata, easy intrusion of water into the oil layer, low production well efficiency, and the inability to take effective measures.

[0003] For example, due to the complex oil-water relationship, some oilfields have super-heavy oil with side, top, bottom and interlayer water, and the oil wells have serious water problems. Among them, the water outflow from the outer channel is difficult to control and needs to be controlled. Before plugging the outer channel, it is necessary to determine whether there is a channel. There are many methods, which can be used to judge the production situation, mechanical methods during operation and construction, and logging methods to check the channel. At present, the methods for controlling top water channeling mainly include mechanical water plugging, overhaul casing compensation, and ash squeezing water plugging. Among them, mechanical water plugging and casing compensation are mainly for water-producing oil wells where the outer channel does not connect the oil layer with the water layer. Due to the constraints of well conditions and limited analysis and understanding, there are not many oil wells that are suitable. Ash squeezing water plugging generally includes perforating ash squeezing, abandoning part of the well section to squeeze ash, or re-cementing the well with an inner liner casing. Because the cement slurry is connected between the channel and the formation in the channel, there will be problems such as low cement squeezing pressure, large cement squeezing volume, and failure to test the pressure after drilling the cement plug, resulting in construction failure. In particular, after the cementing is squeezed, the cementing quality is tested without any problems, but during the production, the cement for sealing the channeling is heated by high-temperature steam and the channeling phenomenon reappears. The main reason for the low success rate and short validity period of the previous ash squeezing and water blocking measures is the lack of materials and construction technology. A survey was conducted on the causes of water production from super-heavy oil, the performance of plugging agents in the current domestic ash squeezing and water blocking, and the construction technology. It is believed that the success rate of top water treatment in super-heavy oil reservoirs can be effectively improved by compounding plugging agents and improving and perfecting the technology. The cement slurry plugging technology is widely used in the treatment of channeling problems outside the pipe during the mid- and late-stage development of oil fields, which is a powerful tool for oilfield oil stabilization and water control. According to the application in oil fields, the recommended methods for channeling treatment outside the pipe are the casing squeezing and pressure control method and the pre-plugging and segmented squeezing method, especially the deep adjustment and shallow plugging technology, which has a certain reference significance for improving the construction success rate. At present, to solve the problem of low success rate of channeling outside the pipe, it is necessary to work together to improve the performance of cement slurry, mechanical plugging, and chemical agents.

[0004] There are many studies on mechanical sealing at home and abroad. Most of the tools are external pipe packers. High-temperature resistant external pipe packers are used in non-reservoir layers to isolate the water layer from the lower formation. In this way, even if top water leakage occurs, it is difficult to leak down to the lower reservoir section. Summary of the invention

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

[0006] In a first aspect, an embodiment of the present invention provides a micro-lifting self-locking integrated water-preventing tool, which may include: a central tube, and a micro-lifting self-locking righting assembly, a reciprocating suction power assembly, and a sealing rubber cylinder sleeved outside the central tube;

[0007] Among them, the joint of the micro-lifting self-locking righting assembly is connected to the central tube; the micro-lifting self-locking righting assembly is used to lock the micro-lifting self-locking integrated top water anti-channeling tool on the well wall after wellhead pressure is applied; 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 tube, so that the sealing rubber tube expands to achieve sealing.

[0008] Optionally, the micro-lift self-locking righting assembly may include: a joint, a righting seat, a righting body, a first piston, a valve assembly and a cylinder sleeve;

[0009] The cylinder sleeve is sleeved on the outside of the joint and the center pipe, and is threadedly connected to the joint;

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

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

[0013] The high-pressure fluid enters from the joint into between the cylinder sleeve and 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 may include: a valve block, a first spring and a wire plug;

[0015] 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;

[0016] 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 channel, 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 channel.

[0017] Optionally, the slightly-lifting self-locking righting assembly may further include: a retaining ring located between the first piston and the cylinder liner, the retaining ring being connected to the cylinder liner.

[0018] Optionally, a first barb is provided on the contact surface between the retaining ring and the first piston, and a second barb cooperating with the first barb is provided on the first piston.

[0019] Optionally, the micro-lifting self-locking righting assembly may further include: a plurality of first sealing rubber rings;

[0020] Part of the first sealing rubber ring is located between the central tube and the first piston; part of the first sealing rubber ring is located between the first piston and the cylinder sleeve.

[0021] Optionally, the reciprocating suction power assembly may include: a second piston, a piston sleeve, a piston head, an elastic sealing component and a sealing joint;

[0022] Wherein, the second piston is located between the central tube and the cylinder sleeve of the micro-lifting self-locking and straightening assembly; one end of the piston sleeve is connected to the cylinder sleeve, and the other end is connected to the sealing joint; the other end of the sealing joint is connected to the sealing rubber cylinder;

[0023] One end of the second piston close to the micro-lift self-locking righting assembly is adjacent to the joint of the micro-lift self-locking righting assembly, and one end away from the micro-lift self-locking righting assembly is connected to the piston head;

[0024] The elastic sealing component is located between the central tube and the sealing joint, one end of which is limited by the sealing joint and the other end of which is in contact with the piston sleeve;

[0025] The piston sleeve is radially provided with a suction port for sucking cement slurry outside the tool, and a protrusion is provided on the inner wall of the piston sleeve, and a groove matching the protrusion is provided on the piston head; when the wellhead is pressurized, the second piston drives the piston head to slide so that the protrusion and the groove are separated, and the external cement slurry is sucked into between the piston sleeve and the center pipe, and the elastic blocking component is opened under the squeezing of the piston head to enter the sealing rubber cylinder through the sealing joint; when the wellhead is not pressurized, the second piston rebounds, the protrusion and the groove are engaged, and the elastic sealing component rebounds and abuts against the piston sleeve to prevent the cement slurry that has entered the sealing rubber cylinder from flowing back.

[0026] Optionally, the elastic sealing assembly may include: an internal 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 internal suction pressure-bearing sealing ring; one end of the internal 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 center tube.

[0027] Optionally, the elastic sealing assembly may further include: a rubber plug located between the internal suction pressure-bearing sealing ring and the central tube.

[0028] Optionally, the reciprocating suction power assembly may further include: a plurality of second sealing rubber rings;

[0029] Part of the second sealing rubber ring is located between the central tube and the second piston; part of the second sealing rubber ring is located between the second piston and the cylinder sleeve.

[0030] Optionally, the sealing rubber sleeve may include: an inner rubber sleeve, a steel belt layer and an outer rubber sleeve; the inner rubber sleeve is pre-stored with chemical agents;

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

[0032] In the second aspect, an embodiment of the present invention provides a drilling tool string, which may include: casing / screen and the micro-lifting, self-locking, integrated top water anti-channeling tool described in the first aspect; wherein the casing / the screen is connected to the micro-lifting, self-locking, integrated top water anti-channeling tool via a coupling.

[0033] In a third aspect, an embodiment of the present invention provides a drilling system, which may include: a mud pump and the drilling tool string described in the second aspect, wherein the mud pump repeatedly pumps high-pressure mud into the casing to straighten and seal the micro-lifting, self-locking, integrated top water anti-channeling tool in the drilling tool string.

[0034] In a fourth aspect, an embodiment of the present invention provides an application of a micro-lifting, self-locking, integrated top water anti-channeling tool as described in the first aspect in a drilling system.

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

[0036] The embodiment of the present invention provides a micro-lifting self-locking integrated top water anti-channeling tool, tool string, system and application, which can not only isolate the formation but also realize the straightening of the pipe string, greatly reducing the length of the pipe string, improving the safety of the pipe string, and greatly reducing the overall cost of the tool string, which is more economical and practical than the combination tool. It solves the problem that the original top water anti-channeling tool only has the isolation function and cannot realize the straightening of the pipe string, and when the top water anti-channeling tool and the elastic straightener are combined to realize the isolation and straightening functions, the length of the entire tool string is too long, and there is a risk of encountering obstacles when running into a wellbore with a large dogleg degree.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 1 It is a structural diagram of a micro-lifting self-locking integrated water-preventing tool provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the working principle of the top water anti-channeling tool provided in an embodiment of the present invention;

[0042] Figure 3 It is an enlarged structural diagram of the micro-lifting self-locking righting assembly provided in an embodiment of the present invention;

[0043] Figure 4 A structural diagram of a righting seat provided in an embodiment of the present invention;

[0044] Figure 5 A structural diagram of a centralizing body provided in an embodiment of the present invention;

[0045] Figure 6An enlarged structural diagram of a reciprocating suction power assembly provided in an embodiment of the present invention;

[0046] Figure 7 A structural diagram of a piston sleeve and a piston head provided in an embodiment of the present invention;

[0047] Figure 8 A structural diagram of a sealing rubber cartridge provided in an embodiment of the present invention;

[0048] Fig. 9 for Figure 8 Cross-sectional structural diagram;

[0049] Among them, 1-slightly lifted self-locking integrated water-preventing tool; 2-casing / screen; 3-coupling;

[0050] 11-center tube; 12-slightly lifting self-locking righting assembly; 13-reciprocating suction power assembly; 14-sealing rubber cylinder;

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

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

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

[0054] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] The inventors found that the problems with existing mechanical sealing tools at home and abroad are that the pipe string is poorly centered, the cement sealing quality is poor, and the top water easily breaks through the thin cement ring and flows down to the reservoir below. At the same time, the commonly used external pipe sealers, whether extrusion type or expansion type, may deform and lose their sealing ability under the action of long-term thermal alternating stress. In view of the above problems, based on a full investigation of the current situation at home and abroad, the present invention is proposed to provide a micro-lifting self-locking integrated top water anti-channeling tool, tool string, system and application that overcomes the above problems or at least partially solves the above problems. The tool integrates the straightening function of the completion pipe string, and can absorb cement slurry from the outside of the casing and the chemical agent in the rubber tube to react to produce solid matter to achieve formation isolation.

[0058] Reference Figure 1 As shown, in an embodiment of the present invention, there is provided a micro-lifting self-locking integrated top water anti-channeling tool 1, which may include: a central tube 11, and a micro-lifting self-locking straightening assembly 12, a reciprocating suction power assembly 13, and a sealing rubber tube 14 which are sleeved on the outside of the central tube 11; wherein, the joint 121 of the micro-lifting self-locking straightening assembly 12 is connected to the central tube 11; the micro-lifting self-locking straightening assembly 12 is used to lock the micro-lifting self-locking integrated top water anti-channeling tool 1 on the well wall after wellhead pressure is applied; the reciprocating suction power assembly 13 is used to suck cement slurry outside the tool into a filling cavity (not shown in the figure) between the sealing rubber tube 14 and the central tube 11, so that the sealing rubber tube 14 expands to achieve sealing.

[0059] Reference Figure 2As shown, the working process of the micro-lifting self-locking integrated water-preventing tool provided in the embodiment of the present invention is as follows: Figure 2 (1) is a diagram of the original state of the slightly lifted self-locking straightening assembly and the unstressed state of the sealing rubber tube; after the wellhead begins to be pressurized, refer to Figure 2 As shown in (2), the slightly lifted self-locking straightening assembly straightens the straightening body gradually to Figure 2 As shown in (3) in the figure, the tool is locked on the well wall by the stabilizing body; then the wellhead is pressurized continuously, and the cement slurry outside the tool is sucked into the pipe during the reciprocating pumping process, so that the sealing rubber tube expands to achieve sealing.

[0060] It should be noted in the embodiment of the present invention that the starting thrust of the above-mentioned micro-lifting self-locking righting assembly is smaller than the starting thrust of the reciprocating suction assembly, that is, the tool is first righted and self-locked by wellhead pressure before the sealing rubber cylinder can be expanded and sealed.

[0061] The above-mentioned micro-lifting self-locking integrated top water anti-channeling tool provided in the embodiment of the present invention can not only isolate the formation but also realize the straightening of the pipe string, greatly reducing the length of the pipe string, improving the safety of the pipe string when running, and at the same time reducing the overall cost of the tool string, which is more economical and practical than the combination tool. It solves the problem that the original top water anti-channeling tool only has the isolation function and cannot realize the straightening of the pipe string, and when the top water anti-channeling tool and the elastic straightener are combined to realize the isolation and straightening functions, the length of the entire tool string is too long, and there is a risk of encountering obstacles when running into a wellbore with a large dogleg degree.

[0062] In an optional embodiment, the existing external packer straightening tools mostly rely on mechanical elastic straighteners. This type of elastic mechanical straightener has its outer diameter adjusted before being lowered into the well, and there is a risk of encountering resistance during the lowering process. At the same time, the straightening position cannot be adjusted during the lowering process or underground, resulting in poor straightening effect. In order to solve the above technical problems, the inventor has improved the micro-lift self-locking straightening assembly. Figure 1 and Figure 3As shown, the micro-lifting self-locking straightening assembly 12 may include: a joint 121, a straightening seat 122, a straightening body 123, a first piston 124, a valve assembly 125 and a cylinder sleeve 126; wherein the cylinder sleeve 126 is sleeved on the outside of the joint 121 and the center tube 11, and is threadedly connected to the joint 121; the straightening seat 122 is fixed on the outside of the joint 121 and is at a preset distance from the cylinder sleeve 126; one end of the straightening body 123 is limited by the straightening 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 to the straightening body 123; a fluid channel 1211 is provided on the joint 121, and the valve assembly 125 is located in the fluid channel 1211; high-pressure fluid enters from the joint 121 to between the cylinder sleeve 126 and the joint 121 through the fluid channel 1211, so as to push the first piston 124 to drive the straightening body 123 to slide, and the straightening body 123 is lifted under the action of the straightening seat 122.

[0063] In the embodiment of the present invention, the above-mentioned micro-lifting self-locking straightening assembly is the straightening part of the entire tool, which plays the straightening function. The above-mentioned straightening seat in this embodiment provides a fulcrum when the straightening body is slightly lifted, referring to Figure 4 and Figure 5 As shown, the straightening body is slightly lifted under the squeezing action of the first piston, combined with Figure 3 As shown in the figure, the straightening body is slowly mounted on the straightening seat during the lifting process, so that the straightening body is equivalent to a straightening tool, and as the pressure increases, the lifting amplitude of the straightening body will also increase. In this way, the pressure of the pressure injection can determine the lifting height of the straightening body, and the straightening size can be controlled. For example, when straightening is required in an irregular wellbore or a well section with a relatively large wellbore, by injecting more than twice the pressure, the straightening of the large wellbore can be guaranteed. When there is a mudstone shrinkage section, less pressure injection can be used to achieve micro-lifting and micro-straightening.

[0064] The above-mentioned micro-lifting self-locking righting assembly in the embodiment of the present invention pushes the piston (the first piston) through pressure, and realizes the righting function by the piston pushing the righting body to extend. In this way, it can be ensured that a smaller size can be entered into the well, and no resistance will occur during the lowering process. At the same time, there is sufficient thrust to realize the righting of the completion tubing, and solves the problem that the righting of the external pipe packer currently relies solely on mechanical elastic righting devices, while conventional mechanical righting devices have the risk of encountering resistance during the lowering process because the outer diameter size has been adjusted on the ground. At the same time, the righting position cannot be adjusted underground, and the righting effect is difficult to guarantee.

[0065] Furthermore, the above-mentioned micro-lift self-locking righting assembly can achieve different sizes of righting effects by applying different pressures at the wellhead under different borehole size conditions, which fully considers the righting problems of some large-bellied wellbores and reduced-diameter wellbores. At the same time, the micro-lift self-locking structure can realize the automatic locking function. After the righting reaches the size that matches the formation borehole, the micro-lifting stops automatically, and the righting is achieved by the righting block riding on the stepped righting seat, which solves the problem that there is currently no top water anti-channeling tool that can automatically righting and automatically locking, and different sizes of righting dimensions are required under different borehole size conditions, while the current righting device only has the righting capacity of fixed dimensions. In summary, this tool is an automatically locked top water anti-channeling tool. Different sizes of righting dimensions are required under different borehole size conditions. Through the micro-lift self-locking structure, different sizes of righting effects can be achieved by applying different pressures at the wellhead under different borehole size conditions. Not only does it fully consider the problem of straightening some large-bellied wellbores and reduced-diameter wellbores, but the micro-lift self-locking structure can also realize the automatic locking function. After the straightening is matched with the formation wellbore size, the micro-lifting stops automatically and the locking is achieved by the straightening block riding on the straightening seat.

[0066] In another optional embodiment, also refer to Figure 1 As shown, the valve assembly 125 may 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 channel 1211, and the plug 1253 is fixed on the fluid channel 1211 to limit the valve block 1251 and the first spring 1252; when high-pressure fluid is injected into the central tube 11, the high-pressure fluid squeezes the valve block 1251 to compress the first spring 1252 to open the fluid channel 1211, so that the high-pressure fluid acts on the first piston 124; when high-pressure fluid is not injected into the central tube 11, the first spring 1252 squeezes the valve block 1251 under the action of the rebound force, so that the valve block 1251 closes the fluid channel 1211.

[0067] The valve assembly in this embodiment is a one-way valve. When pressurizing, the valve block and the first spring are squeezed to open the fluid channel, and the first spring is compressed. When pressurizing stops, the first spring rebounds and blocks the liquid flow channel under the reverse thrust of the first spring. The valve assembly can be opened and closed at any time when the wellhead is pressurized to form a stable pressure support environment for the straightening body.

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

[0069] In this embodiment, the retaining ring plays a fixing role, and the lower end of the retaining ring has a barb that can cooperate with the barb on the first piston to achieve bite fixation. Under the action of external pressure, the first piston moves forward and pushes the straightening body to move until the straightening body moves to the straightening seat. When the wellbore size to be straightened is reached, the pressure is stopped, and the straightening body just rides on the straightening seat. At the same time, the barb on the first piston and the barb of the retaining ring bite together to achieve locking, so that the straightening function can be permanently achieved.

[0070] In another optional embodiment, also refer to Figure 1 As shown, the micro-lift self-locking and straightening assembly 12 may further include: a plurality of first sealing rubber rings 128; wherein, some of the first sealing rubber rings 128 are located between the central tube 11 and the first piston 124; and some of the first sealing rubber rings 28 are located between the first piston 124 and the cylinder sleeve 126. The first sealing rubber rings can ensure the sealing performance between various components and can be suitable for underground high-pressure working environments.

[0071] In another optional embodiment, the top water anti-channeling tools currently used can only play a sealing role, but the sealing effect is short, the sealing rubber tube is easily damaged, and the top water occurs repeatedly, which is difficult to effectively solve the problem. The embodiment of the present invention designs a structure that completes the filling and expansion of self-priming cement slurry, which can fully guarantee the quality and effect of the sealing and extend the service life of the oil and gas well. Figure 1 , Figure 6 and Figure 7As shown, the reciprocating suction power assembly 13 may include: a second piston 131, a piston sleeve 132, a piston head 133, an elastic sealing assembly 134 and a sealing joint 135; wherein the second piston 131 is located between the center tube 11 and the cylinder sleeve 126 of the micro-lift self-locking righting assembly 12; one end of the piston sleeve 132 is connected to the cylinder sleeve 126, and the other end is connected to the sealing joint 135; the other end of the sealing joint 135 is connected to the sealing rubber tube 14; the end of the second piston 131 close to the micro-lift self-locking righting assembly 12 is adjacent to the joint 121 of the micro-lift self-locking righting assembly 12, and the end away from the micro-lift self-locking righting assembly 12 is connected to the piston head 133; the elastic sealing assembly is located between the center tube 11 and the sealing joint 135, one end of which is limited by the sealing joint 135, and the other end is pressed against the piston sleeve 132 The piston sleeve 132 is radially provided with a suction port 1321 for sucking cement slurry outside the tool, and a protrusion 1322 is provided on the inner wall of the piston sleeve 132, and a groove 1331 matching the protrusion 1322 is provided on the piston head 133; when the wellhead is pressurized, the second piston 131 drives the piston head 133 to slide, so that the protrusion 1322 and the groove 1331 are separated, and the external cement slurry is sucked between the piston sleeve 132 and the central pipe 11, and the elastic blocking component 134 is opened under the pressure of the piston head 133 to enter the sealing rubber cylinder 14 through the sealing joint 135; when the wellhead is not pressurized, the second piston 131 rebounds, the protrusion 1322 and the groove 1331 are engaged, and the elastic blocking component 134 rebounds and abuts against the piston sleeve 132 to prevent the cement slurry entering the sealing rubber cylinder 14 from flowing back.

[0072] It should be noted that in this embodiment, the sealing rubber sleeve is sleeved on the outside of the central tube, and a certain distance of gap can be reserved between the sealing rubber sleeve and the central tube, and of course, they can also fit tightly. Since the above-mentioned sealing rubber sleeve in the embodiment of the present invention is a double-layer rubber sleeve, the inner rubber sleeve can expand rapidly after contacting water, and the outer rubber sleeve has good temperature and pressure resistance. By sucking the cement slurry in the annulus outside the tool into the rubber sleeve, the water in the cement slurry sucked inside reacts with the inner rubber sleeve, and the volume increases rapidly, and the outer rubber sleeve begins to be compressed. After the cement slurry loses water, it becomes a solid cement stone and remains inside the rubber sleeve, playing a supporting role.

[0073] The second piston in the embodiment of the present invention provides thrust by repeatedly pressurizing the wellhead. Under the action of repeated pressurization at the wellhead, the second piston repeatedly sucks the cement slurry outside the tool into the tube, and finally pushes it into the inside of the sealing rubber tube to achieve the expansion seal of the rubber tube. Under the action of pressure, the second piston drives the piston head to move forward together. At the beginning, the piston head and the piston sleeve are closed, that is, the front end of the piston head is in a closed state. As the second piston moves, a pressure difference is formed inside the tool. At this time, the front end of the piston head opens, and the external cement slurry is sucked in under the action of the pressure difference. The cement slurry is repeatedly sucked into the sealing rubber tube from the fluid filling port. It should be noted here that after the wellhead stops pressurizing, the thrust to the second piston is reduced. Since the second piston compresses the cement slurry in the confined space, pressure is generated, and the second piston is pushed back to the initial state to achieve repeated suction.

[0074] The embodiment of the present invention can fully guarantee the quality and effect of isolation by designing a structure that completes the filling and expansion with self-priming cement slurry, extend the service life of oil and gas wells, and solve the problem that the top water anti-channeling tools currently used can only play the role of isolation, but the isolation effect is short, the sealing rubber tube is easy to be damaged, and the top water occurs repeatedly, which is difficult to effectively cure. The cement slurry sucked into the rubber tube reacts with the prefabricated chemical agent inside the rubber tube when it loses water and solidifies, and the generated cement stone has a strong hardness and a denser texture, so that it can be ensured that the cement stone inside the rubber tube will not be thermally cracked during the long-term thermal recovery operation, resulting in cracks and damage from the inside.

[0075] In another optional embodiment, also refer to Figure 1 As shown, the elastic sealing assembly 134 may include: an internal 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 to the internal suction pressure-bearing sealing ring 1341; one end of the internal suction pressure-bearing sealing ring 1341 is connected to the second spring 1342, and the other end abuts against the piston sleeve 132 to close the fluid filling port 1323 between the piston sleeve 132 and the center tube 11.

[0076] In this embodiment, the cement slurry outside the tool is fully sucked into the tube through several times of pressure injection and pressure relief. The function of the internal suction pressure-bearing sealing ring is to provide a liquid flow channel. When the second piston pushes the cement slurry in the filling channel to move into the sealing rubber tube, the internal suction pressure-bearing sealing ring moves forward and leaks out of the filling port. At this time, the sucked cement slurry will enter the rubber tube from the filling port. When the liquid inlet sealing piston moves in the opposite direction, the internal suction pressure-bearing sealing ring will block the filling port under the action of the suction force and the second spring to prevent the cement slurry that has entered the rubber tube from returning to the formation.

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

[0078] In another optional embodiment, also refer to Figure 1 As shown, the reciprocating suction power assembly 13 may further include: a plurality of second sealing rubber rings 136; wherein, part of the second sealing rubber rings 136 are located between the central tube 11 and the second piston 131; and part of the second sealing rubber rings 136 are located between the second piston 131 and the cylinder sleeve 126. The second sealing rubber rings in this embodiment ensure the sealing between various components and can be better applied to the underground high-pressure working environment.

[0079] In another optional embodiment, also refer to Figure 1 , Figure 8 and Fig. 9 As shown, the sealing rubber tube 14 may include: an inner rubber tube 141, a steel belt layer 142 and an outer rubber tube 143; chemical agents are pre-stored in the inner rubber tube 141 (not shown in the figure); cement slurry is sucked into the sealing rubber tube 14 through 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 and generate thrust to push the steel belt layer 142 and the outer rubber tube 143 to seal the formation.

[0080] The embodiment of the present invention separates the strata by means of a high temperature resistant and pressure bearing sealing rubber tube. After the strata are separated, the upper water layer will be difficult to flow down from the tool to the lower reservoir, and at the same time, the lower steam will not flow up to the upper strata. The high temperature resistant and pressure bearing sealing rubber tube is its core component, and its structure diagram is shown in FIG. Figure 8 It has a double-layer rubber tube structure, with a layer of steel belt sandwiched between the two layers of rubber tubes. Its structural cross-section is shown in Fig. 9 As shown in the figure, it is through this steel belt that the pressure bearing capacity of the rubber tube is provided, so that the rubber tube has a greater pressure resistance and has greater thrust and sealing force on the isolation of hard formations. The inner rubber tube of the high temperature and pressure-resistant sealing rubber tube can react with water to expand. The volume of the expanded rubber increases sharply, generating a large thrust to push the outer rubber layer to isolate the formation. At the same time, the cement slurry sucked into the rubber tube reacts with the prefabricated chemical agent inside the rubber tube when it loses water and solidifies. The generated cement stone has a stronger hardness and a denser texture. This can ensure that the cement stone inside the rubber tube will not be thermally cracked during the long-term thermal recovery operation, resulting in cracks and damage from the inside.

[0081] The embodiment of the present invention designs a double-layer rubber tube structure, with a steel belt sandwiched between the two layers of rubber tubes. The steel belt provides the rubber tube with pressure bearing capacity, so that the rubber tube has a greater pressure resistance, and has greater thrust and sealing force on the isolation of hard formations. At the same time, the inner rubber tube can expand rapidly after encountering water, and the outer rubber tube has good temperature and pressure resistance. By sucking the cement slurry in the annulus outside the packer into the rubber tube, the water in the sucked cement slurry reacts with the inner rubber tube, and the volume increases rapidly, and the outer rubber tube begins to be compressed. After the cement slurry loses water, it becomes a solid cement stone and remains in the rubber tube, playing a supporting role.

[0082] The above-mentioned micro-lifting self-locking integrated water-blocking anti-channeling tool provided in the embodiment of the present invention has both straightening and sealing functions. A small pressure is applied at the wellhead to push the first piston to achieve micro-lifting and self-locking of the straightening body. The pressure is then increased to achieve repeated suction by the second piston to suck the cement slurry outside the tool into the rubber cylinder. The cement slurry sucked into the rubber cylinder reacts with the prefabricated chemical agents inside the rubber cylinder and the inner layer of the rubber cylinder to achieve the formation of dense cement stone inside the rubber cylinder. At the same time, a large thrust is applied to the outer layer of the rubber cylinder to complete the sealing.

[0083] Based on the same inventive concept, an embodiment of the present invention further provides a drilling tool string, which may include: a casing / screen and a micro-lifting self-locking integrated top water anti-channeling tool as described above; wherein the casing / screen is connected to the micro-lifting self-locking integrated top water anti-channeling tool through a coupling (refer to Figure 1 The coupling 3).

[0084] Based on the same inventive concept, a drilling system is also provided in an embodiment of the present invention, which may include: a mud pump and the above-mentioned drilling tool string, the mud pump repeatedly pumps high-pressure mud into the casing to straighten and seal the micro-lifting, self-locking, integrated top water anti-channeling tool in the drilling tool string.

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

[0086] The application process of the micro-lifting self-locking integrated top water anti-channeling tool in the embodiment of the present invention is as follows: the tool is lowered into the well along with the completion string → the wellbore size is determined according to the logging data, and then the straightening pressure is determined → the normal wellbore is pressurized at the wellhead at 2-3MPa, the large-bellied wellbore is 4-6MPa, and the reduced-diameter wellbore is 1-2MPa → the pressure is determined according to the upper part, the wellhead is pressurized, and the first piston is started → the wellhead is pressurized, and the completion string is straightened → the wellhead is pressurized to 15-17MPa, and the second piston is started to suck cement slurry → repeatedly pressurize and release the pressure 2-3 times → cementing waits for more than 24 hours to fully solidify → construction is completed.

[0087] The micro-lifting self-locking integrated anti-water channeling tool provided by the embodiment of the present invention is suitable for the situation where an external packer needs to be added to the completion pipe string to implement formation isolation during the completion operation of oil and gas wells, and is particularly suitable for the situation where the formation is isolated outside the thermal production pipe of heavy oil thermal production wells. It can improve the sealing quality of cement stone and extend the service life of oil and gas wells, and has broad market application prospects. Specific examples are as follows:

[0088] Wellbore preparation: Before the tool is lowered into the well, the entire wellbore needs to be cleared to prevent sharp objects from scratching the rubber part of the high-temperature resistant rubber tube. Before lowering the completion string, the wall protection mud needs to be repeatedly circulated several times to keep the wellbore smooth and without collapse, so as to facilitate the smooth lowering of the completion string.

[0089] Tool assembly: Assemble the three main parts of the micro-lifting self-locking integrated water-preventing tool, including the micro-lifting self-locking righting assembly and the reciprocating suction power assembly, and conduct an indoor pressure test to verify the righting effect of the tool before it can be lowered into the well.

[0090] Formation pretreatment: After the well is dredged, lower the bare drill pipe to the bottom of the well, use a mud pump to pump in the configured cross-linking agent to cover the weak formations. After an interval of 2 hours, continue to pump the cross-linking agent to the top of the weak formation, and then after an interval of 2 hours, repeat the pumping several times to ensure that the weak formations are fully cross-linked.

[0091] Expansion sealing process: Use a mud pump to pump high-pressure mud into the casing, and the cementing plug moves downward to break the plugs in turn; the pressure is relatively small at the beginning, completing the righting function, and then continue to increase the pressure to start the suction action. The high-pressure mud enters the piston chamber to push the piston downward. Due to the suction effect, the pressure in the piston chamber decreases, sucking in the mud in the external annulus. The high-pressure mud compresses the spring through the filling head, opens the opening and closing channel, and the cement slurry is filled into the rubber cylinder to complete the suction-filling process; the mud pumping is stopped at the wellhead, and the spring pushes the filling head to reset under the action of the reaction force to prevent the filled mud from flowing back, completing a suction-filling-rebound cycle. After the expansion is completed, the solidified resin is compressed and ruptured and released, filling the tiny cracks formed by the micro-contraction of cement solidification. Repeat the above steps, repeatedly perform suction and filling, and finally achieve the expansion of the high-temperature resistant rubber cylinder.

[0092] The detailed description and beneficial effects of the above-mentioned drilling tool string, system and application in the embodiments of the present invention can be referred to the detailed description of the above-mentioned micro-lifting self-locking integrated top water anti-channeling tool, and the embodiments of the present invention will not be repeated here.

[0093] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A micro-lifting self-locking integrated water-preventing tool, characterized in that: include: A central tube, and a slightly lifting self-locking righting assembly, a reciprocating suction power assembly, and a sealing rubber cylinder sleeved on the outer side of the central tube; Among them, the joint of the micro-lifting self-locking righting assembly is connected to the central tube; the micro-lifting self-locking righting assembly is used to lock the micro-lifting self-locking integrated top water anti-channeling tool on the well wall after wellhead pressure is applied; 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 tube, so that the sealing rubber tube expands to achieve sealing.

2. The tool according to claim 1, characterized in that The micro-lifting self-locking righting assembly comprises: a joint, a righting seat, a righting body, a first piston, a valve assembly and a cylinder sleeve; The cylinder sleeve is sleeved on the outside of the joint and the center pipe, and is threadedly connected to the joint; The straightening seat is fixed on the outside of the joint and is at a preset distance from the cylinder sleeve; one end of the straightening body is limited by the straightening seat, and the other end is adjacent to the cylinder sleeve; The first piston is located between the joint and the cylinder sleeve, and one end of the first piston is connected to the centralizing body; The joint is provided with a fluid channel, and the valve assembly is located in the fluid channel; The high-pressure fluid enters from the joint into between the cylinder sleeve and 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.

3. The tool according to claim 2, characterized in that The valve assembly comprises: a valve block, a first spring and a wire 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 channel, 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 channel.

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

5. The tool according to claim 4, characterized in that A first barb is provided on the contact surface between the retaining ring and the first piston, and a second barb matched with the first barb is provided on the first piston.

6. The tool according to any one of claims 2 to 5, characterized in that The micro-lifting self-locking righting assembly further includes: a plurality of first sealing rubber rings; Part of the first sealing rubber ring is located between the central tube and the first piston; part of the first sealing rubber ring is located between the first piston and the cylinder sleeve.

7. The tool according to claim 1, characterized in that The reciprocating suction power assembly comprises: a second piston, a piston sleeve, a piston head, an elastic sealing component and a sealing joint; Wherein, the second piston is located between the central tube and the cylinder sleeve of the micro-lifting self-locking and straightening assembly; one end of the piston sleeve is connected to the cylinder sleeve, and the other end is connected to the sealing joint; the other end of the sealing joint is connected to the sealing rubber cylinder; One end of the second piston close to the micro-lift self-locking righting assembly is adjacent to the joint of the micro-lift self-locking righting assembly, and one end away from the micro-lift self-locking righting assembly is connected to the piston head; The elastic sealing component is located between the central tube and the sealing joint, one end of which is limited by the sealing joint and the other end of which is in contact with the piston sleeve; The piston sleeve is radially provided with a suction port for sucking cement slurry outside the tool, and a protrusion is provided on the inner wall of the piston sleeve, and a groove matching the protrusion is provided on the piston head; when the wellhead is pressurized, the second piston drives the piston head to slide so that the protrusion and the groove are separated, and the external cement slurry is sucked into between the piston sleeve and the center pipe, and the elastic blocking component is opened under the squeezing of the piston head to enter the sealing rubber cylinder through the sealing joint; when the wellhead is not pressurized, the second piston rebounds, the protrusion and the groove are engaged, and the elastic sealing component rebounds and abuts against the piston sleeve to prevent the cement slurry that has entered the sealing rubber cylinder from flowing back.

8. The tool according to claim 7, characterized in that The elastic sealing assembly includes: an internal 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 internal suction pressure-bearing sealing ring; one end of the internal 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 center tube.

9. The tool according to claim 8, characterized in that The elastic sealing assembly also 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 further includes: a plurality of second sealing rubber rings; Part of the second sealing rubber ring is located between the central tube and the second piston; part of the second sealing rubber ring is located between the second piston and the cylinder sleeve.

11. The tool according to any one of claims 1 to 5 and 7 to 9, characterized in that: The sealing rubber sleeve comprises: an inner rubber sleeve, a steel belt layer and an outer rubber sleeve; the inner rubber sleeve is pre-stored with chemical agents; The cement slurry is sucked into the sealing rubber cylinder through the reciprocating suction power assembly, and the water in the cement slurry reacts with the chemical agent to increase the volume of the inner rubber cylinder to generate thrust, so as to push the steel belt layer and the outer rubber cylinder to seal the formation.

12. A drilling tool string, characterized in that: include: Casing / screen pipe and a micro-lifting self-locking integrated top water anti-channeling tool as described in any one of claims 1 to 11; Wherein, the casing / the screen pipe is connected to the slightly lifted self-locking integrated water-preventing tool through a coupling.

13. A drilling system, characterized in that: include: A mud pump and a drilling tool string as claimed in claim 12, wherein the mud pump repeatedly pumps high-pressure mud into the casing to straighten and seal the micro-lifting self-locking integrated top water anti-channeling tool in the drilling tool string.

14. Use of the micro-lifting self-locking integrated top water anti-channeling tool as claimed in any one of claims 1 to 11 in a drilling system.

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