Drilling liner hanger system and related method

Abstract

The invention discloses a drilling liner hanger system and a related method. The system comprises a drilling liner hanger and a setting tool, in the drilling liner hanger, a packer is connected between a mandrel and a tie-back barrel, a flowing channel is formed in the tie-back barrel and the mandrel, a lower slip is arranged on the mandrel, a taper sleeve is fixed to the mandrel, a setting piston is connected with the mandrel in a sealed mode, and a hydraulic cavity is formed between the mandrel and the setting piston. The setting tool is arranged in the flowing channel; in the setting tool, a floating valve mechanism is in sealing fit with a body and a tie-back barrel, and a first space is formed among the floating valve mechanism, the tie-back barrel, a mandrel and the body; cleaning liquid is contained in the first space; the packer executing mechanism and the releasing mechanism are arranged in the first space; a second space is formed between the thrust mechanism and the body; the packing mechanism is in sealing fit with the body and the mandrel. The second space is communicated with the hydraulic cavity; the pressure balance mechanism communicates with the first space and the second space and is used for transporting the cleaning liquid in the first space to the second space and the hydraulic cavity.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas well cementing, and in particular to a tail pipe hanger system and related methods. Background Art

[0002] The liner hanger is a downhole tool for completion. During the completion operation, the liner hanger is used to connect the liner, and the setting tool is connected to the running pipe string and lowered into the well together. The liner hanger is hung on the upper casing through slips to support the liner connected at the bottom. The current general liner hanger sitting method is to lower the running pipe string to the sitting position, and then, by throwing a ball to hold the pressure, using the pressure difference of the liquid column inside and outside the pipe, the setting tool, including the packer actuator and the release mechanism, etc., works together, and uses drilling fluid as the driving liquid to activate the liner hanger's setting mechanism to drive the slips to move, sit on the upper casing, and extend the liner into the wellbore. Summary of the invention

[0003] In order to better realize the hanging of the liner hanger, the present invention provides a liner hanger system and related methods.

[0004] In a first aspect, an embodiment of the present invention provides a liner hanger system, including a liner hanger 100 and a setting tool 200;

[0005] The liner hanger 100 includes a tie-back tube 101, a lower slip 102, a cone sleeve 103, a packer 104, a setting piston 105, a mandrel 106, a flow channel 108 and a hydraulic chamber 109;

[0006] The packer 104 is connected between the core shaft 106 and the tie-back tube 101, the flow channel 108 is formed in the tie-back tube 101 and the core shaft 106, the lower slip 102 is arranged on the core shaft 106, the taper sleeve 103 is fixed to the core shaft 106, the setting piston 105 is sealed and connected to the core shaft 106, the hydraulic chamber 109 is formed between the core shaft 106 and the setting piston 105, and under the hydraulic action of the hydraulic chamber 109, the setting piston 105 can push the lower slip 102 to move along the taper sleeve 103 and expand radially;

[0007] The setting tool 200 is placed in the flow channel 108;

[0008] The setting tool 200 includes a body 201, and a floating valve mechanism 220, a packer actuator 230, a release mechanism 210, a pressure balance mechanism 270, a thrust mechanism 250 and a packing mechanism 260 which are sequentially arranged on the body 201 from top to bottom;

[0009] The floating valve mechanism 220 is sealed with the body 201 and the tie-back tube 101 respectively, and a first space 2001 is formed between the floating valve mechanism 220, the tie-back tube 101, the core shaft 106 and the body 201; the first space 2001 contains a cleaning liquid;

[0010] The packer actuator 230 and the release mechanism 210 are placed in the first space 2001;

[0011] A second space 2002 is formed between the thrust mechanism 250 and the body 201;

[0012] The sealing mechanism 260 is respectively in sealing cooperation with the body 201 and the core shaft 106;

[0013] The second space 2002 is in communication with the hydraulic chamber 109;

[0014] The pressure balancing mechanism 270 connects the first space 2001 and the second space 2002 , and is used to move the cleaning liquid in the first space 2001 to the second space 2002 and the hydraulic chamber 109 .

[0015] In one or some optional embodiments, the pressure balancing mechanism 270 includes a one-way check valve mechanism;

[0016] The floating valve mechanism 220 can drive the cleaning liquid in the first space 2001 to move to the second space 2002 and the hydraulic chamber 109 through the one-way check valve mechanism under the hydrostatic pressure of the drilling fluid.

[0017] In one or some optional embodiments, the one-way check valve mechanism includes a piston chamber 271, a chamber seat 272, a balance piston 273, an outer annular seal 274 and a pressure balance spring 275;

[0018] The piston chamber 271 is formed between the balance piston 273 and the chamber seat 272;

[0019] The bottom of the balancing piston is connected to the pressure balancing spring 275, and the outer annular seal 274 is provided on the balancing piston 273;

[0020] If the hydraulic pressure of the first space and the second space is balanced, under the action of the pressure balance spring 275, the outer annular seal 274 on the balance piston 273 is engaged and sealed with the cavity seat 272;

[0021] If the hydraulic pressure of the first space is greater than that of the second space, the balance piston 273 moves relative to the chamber seat 272 under the pressure difference, so that the cleaning liquid flows from the first space 2001 to the second space 2002 and the hydraulic chamber 109 .

[0022] In one or some optional embodiments, the pressure balancing mechanism 270 further includes an inner annular seal 276;

[0023] The inner annular seal 276 is in sealing cooperation with the balancing piston 273 and the body 201 .

[0024] In one or some optional embodiments, the thrust mechanism includes a driving ball seat 251 and a thrust piston 252;

[0025] The driving ball seat 251 is sealedly connected to the thrust piston 252, and the second space 2002 is formed between the thrust piston 252 and the body 201;

[0026] The driving ball seat 251 is used to carry the setting ball B.

[0027] In one or some optional embodiments, the setting tool further includes a locking mechanism 240;

[0028] The locking mechanism 240 is disposed on the body 201 and locks the thrust piston 252;

[0029] After the driving ball seat 251 is pressed to a first pressure after the ball is thrown, the locking mechanism can unlock the thrust piston 252 .

[0030] In one or some optional embodiments, the locking mechanism includes a locking shear pin 241, and the locking shear pin 241 is disposed between the thrust piston 252 and the body 201;

[0031] The locking shear pin 241 is configured to be sheared when the driving ball seat 251 is pressed to a first pressure.

[0032] In one or some optional embodiments, the thrust mechanism further includes a thrust shear pin 254, and the thrust shear pin 254 is disposed between the thrust piston 252 and the body 201;

[0033] The thrust shear pin 254 is configured to be sheared when the driving ball seat 251 is pressed to a second pressure.

[0034] The thrust piston 252 can move a first distance relative to the thrust shear pin 254 to pressurize the second space 2002 and the hydraulic chamber 109, and drive the setting piston 105 to move to a second distance;

[0035] When the driving ball seat 251 is pressed to the second pressure, the thrust shear pin 254 is sheared off, and the thrust piston 252 can move relative to the body 201 to increase the pressure of the second space 2002 and the hydraulic chamber 109, driving the setting piston 105 to move to a third distance;

[0036] The second pressure is greater than the first pressure; and the third distance is greater than the second distance.

[0037] In one or some optional embodiments, the isolation mechanism includes a valve body 261; the valve body 261 is sealed and cooperates with the core shaft 106;

[0038] The main body is provided with a first port 202 , the valve body is provided with a second port 262 , and the core shaft 106 is provided with a third port 107 ;

[0039] The hydraulic chamber 109 is in communication with the second space 2002 through the first port 202 , the second port 262 and the third port 107 .

[0040] In one or some optional embodiments, the isolation mechanism 260 further includes an isolation seal 263 , and the isolation seal 263 is sealingly matched with the valve body 261 and the core shaft 106 .

[0041] In one or some optional embodiments, the setting tool 200 further includes an overpressure relief mechanism 280;

[0042] The overpressure relief mechanism 280 is disposed on the body 201 and is used to release the cleaning liquid in the second space 2002 into the first space 2001 .

[0043] In one or some optional embodiments, the overpressure relief mechanism 280 includes a piston chamber 281, a pressure relief shear pin 283, a floating piston 284 and a pressure relief spring 286;

[0044] The body 201 is provided with a pressure relief port 282, and the pressure relief shear pin 283 is provided at the pressure relief port 282;

[0045] The bottom of the floating piston 284 is connected to the pressure relief spring 286;

[0046] If the pressure difference between the second space 2002 and the first space 2001 is less than a predetermined pressure difference threshold, under the action of the pressure relief spring 286, the floating piston 284 may move a fourth distance relative to the pressure relief shear pin 283;

[0047] If the pressure difference between the second space 2002 and the first space 2001 is greater than the predetermined pressure difference threshold, the floating piston 284 can drive the pressure relief spring 286 to contract and shear the pressure relief shear pin 283 to open the pressure relief port 282 to connect the second space 2002 and the first space 2001.

[0048] In one or some optional embodiments, the liner hanger 100 further includes an upper slip 110 disposed on the mandrel 106;

[0049] The upper slip is located between the packer 104 and the cone sleeve 103;

[0050] Under the pressure of the release mechanism 210 , the packer 104 can push the upper slip to move along the cone sleeve 103 and expand radially.

[0051] In a second aspect, an embodiment of the present invention provides an operating method of a liner hanger system according to any one of claims 1 to 13, comprising:

[0052] Connect the running string 13, the setting tool 200 and the liner hanger 100, and run them into the wellbore;

[0053] During the lowering of the liner hanger 100 , the gravity of the drilling fluid in the wellbore acts on the floating valve mechanism 220 to move the clean liquid from the first space 2001 to the second space 2002 and the hydraulic chamber 109 ;

[0054] After the liner hanger 100 is lowered to a predetermined position, a setting ball B is inserted into the thrust mechanism 250 and hydraulic pressure is applied to unlock the thrust mechanism 250;

[0055] The hydraulic pressure is continuously applied to drive the thrust mechanism 250 to pressurize the second space 2001 and the hydraulic chamber 109 , so that under the hydraulic pressure of the hydraulic chamber 109 , the setting piston 105 pushes the lower slip 102 to move and radially expand along the cone sleeve 103 .

[0056] In one or some optional embodiments, the operating method of the liner hanger system further includes:

[0057] After the lower slip 102 sets the casing 11, the setting tool 200 is released from the liner hanger 100, and the running tool and the setting tool 200 are taken out of the wellbore.

[0058] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0059] The liner hanger system provided by the embodiment of the present invention adopts the first space group as the reserve space of the driving liquid, and the clean liquid is transferred from the first space to the second space and the hydraulic chamber through the pressure balance valve mechanism. The driving fluid required for the liner hanger to be set is transferred in a sealed state, and is not affected by the drilling fluid containing debris. The debris is not easy to be deposited on the setting tool and the liner hanger, which reduces the interference of the drilling fluid containing debris on the setting of the liner hanger, thereby avoiding affecting the driving of the setting piston; and when the hydraulic chamber is pressurized to set the slip, the debris will not enter the fluid channel between the first space, the second space and the hydraulic chamber, avoiding blocking the setting tool and the setting piston of the liner hanger, therefore, it will not affect the pressure effect of the driving liquid on the slip, and can achieve safe setting of the liner hanger. It can be applied to the completion operation of high-cuttings ratio wells with drilling fluid containing a large amount of debris in the downhole environment, has reliable performance, strong applicability, is easy to promote and apply on a large scale, and is conducive to improving economic benefits. It is particularly suitable for the completion operation of deep wells, high-density wells, and high-pressure wells.

[0060] In the liner hanger system provided by the embodiment of the present invention, the pressure balance mechanism of the setting tool is provided with a one-way check valve mechanism, and the one-way check valve mechanism can prevent the reverse delivery of the clean liquid. During the process of lowering the pipe and completing the well, the static pressure of the drilling fluid acts on the floating valve mechanism, so that the clean liquid is transferred from the first space to the second space and the hydraulic chamber through the pressure balance mechanism, and the pressure in the setting tool will be balanced with the static pressure of the drilling fluid in the annulus, balancing the influence of the static pressure of the drilling fluid column, which ensures that only the relative pressure higher than the static pressure reference of the drilling fluid can be used to set the liner hanger, avoiding the liner hanger from being set prematurely.

[0061] In the liner hanger system provided by the embodiment of the present invention, the driving ball seat and the thrust piston of the thrust mechanism of the setting tool are linked to each other and configured to engage with the deployed setting ball. During the cementing operation of the liner hanger, the thrust piston acts as a sealing sleeve to provide drilling fluid debris and pressure isolation, thereby preventing the drilling fluid from contaminating the clean liquid in the second space.

[0062] In the liner hanger system provided by the embodiment of the present invention, the locking mechanism of the sealing tool locks the thrust piston, and the locking mechanism can prevent any unintentional movement of the thrust piston. Since the drilling fluid needs to circulate during the process of lowering the pipe string, the locking mechanism allows a high flow rate and a high circulation rate of the drilling fluid, and the sealing tool can withstand the open hole isolation situation where the circulation flow suddenly stops and the wellbore pressure increases. In addition, when the locking mechanism is locked, the internal pressure of the thrust piston is much higher than the pressure generated by the fluctuation of the drilling fluid, thereby preventing the thrust piston from starting prematurely.

[0063] In the liner hanger system provided by the embodiment of the present invention, a thrust shear pin is arranged on the thrust mechanism of the setting tool, and multi-level pressure is set on the setting ball to shear the thrust shear pin, thereby converting the pressure applied to the setting ball into the pressure of the driving fluid, so that the thrust piston further compresses the clean liquid in the second space, allowing more of it to enter the hydraulic chamber of the setting piston, and transmitting the converted hydraulic pressure to the setting piston to achieve a pressurization effect, so as to set the lower slip and eliminate the influence of the debris environment in the drilling fluid that may cause the liner hanger moving component to achieve a greater force to achieve setting.

[0064] In the liner hanger system provided by the embodiment of the present invention, the overpressure relief mechanism of the sealing tool can respond to the enhanced pressure difference to prevent the pressure in the system from being too high during sealing. When the preset pressure difference threshold is exceeded, the pressure relief pin can be sheared to achieve communication between the second space and the first space, and the floating piston can relieve the static fluid pressure under the action of the pressure relief spring.

[0065] In the liner hanger system provided by the embodiment of the present invention, the overpressure relief mechanism of the setting tool can also cope with the increase of downhole temperature through the corresponding movement of the floating piston during the process of maintaining pressure balance.

[0066] 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.

[0067] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] 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:

[0069] Figure 1 The working principle of the liner hanger system provided in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0070] Figure 2 The working principle of the liner hanger system provided in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0071] Figure 3 A schematic diagram of the structure of a liner hanger system provided in an embodiment of the present invention;

[0072] Figure 4 Schematic diagram of the working of the setting tool provided in the embodiment of the present invention Figure 1 ;

[0073] Figure 5 Schematic diagram of the working of the setting tool provided in the embodiment of the present invention Figure 2 ;

[0074] Figure 6 A schematic diagram of a pressure balancing mechanism provided in an embodiment of the present invention;

[0075] Figure 7 The working diagram of the thrust mechanism provided in the embodiment of the present invention is as follows Figure 1 ;

[0076] Figure 8 The working diagram of the thrust mechanism provided in the embodiment of the present invention is as follows Figure 2 ;

[0077] Fig. 9 The working diagram of the thrust mechanism provided in the embodiment of the present invention is as follows Figure 3 ;

[0078] Fig.10 Schematic diagram of the working of the overpressure relief mechanism provided in the embodiment of the present invention Figure 1 ;

[0079] Fig.11 Schematic diagram of the working of the overpressure relief mechanism provided in the embodiment of the present invention Figure 2 .

[0080] In the attached figure:

[0081] 11. Casing, 12. Tail pipe, 13. Running string, B. Setting ball.

[0082] 100: liner hanger, 101. tie-back tube, 102. lower slip, 103. cone sleeve, 104. packer, 105. setting piston, 106. mandrel, 107. third port, 108. flow channel, 109. hydraulic chamber, 110. upper slip.

[0083] 200: Setting tool, 201. Body, 202. First port, 210. Release mechanism, 211. Setting ball seat, 220. Floating valve mechanism, 230. Packer actuator, 240. Locking mechanism, 241. Locking shear pin, 250. Thrust mechanism, 251. Driving ball seat, 252. Thrust piston, 253. Thrust seal, 254. Thrust shear pin, 260. Packing mechanism, 261. Valve body, 262. Second port, 26 3. Sealing seal, 270. Pressure balancing mechanism, 271. Piston chamber, 272. Chamber seat, 273. Balancing piston, 274. Outer annular seal, 275. Pressure balancing spring, 276. Inner annular seal, 280. Overpressure relief mechanism, 281. Piston chamber, 282. Pressure relief port, 283. Pressure relief shear pin, 284. Floating piston, 285. Pressure relief seal, 286. Pressure relief spring, 2001. First space, 2002. Second space. DETAILED DESCRIPTION

[0084] 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.

[0085] 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.

[0086] 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.

[0087] The inventors found that in some downhole environments, the drilling fluid density can reach 2.0 g / cm 3As mentioned above, the main weighting component in the drilling fluid is barite. Under low flow rate and low pressure gradient, barite and other debris have the phenomenon of deposition. When the tail tube hanger is lowered into the tail tube hanger under such fluid environment, the drilling fluid containing debris is easy to deposit the debris into the tail tube hanger sealing mechanism, thereby affecting the drive of the sealing mechanism, causing the sealing mechanism to be blocked or unable to operate. When using such a drilling fluid containing debris as a driving liquid and pressurizing the sealing fluid cylinder of the tail tube hanger to seal the slip, the debris may enter the internal pressure space of the sealing tool and the tail tube hanger, blocking the fluid channel, causing the slip sealing pressure to increase, and even causing the pressure of the driving liquid to be unable to act on the slip, resulting in the tail tube hanger being unable to be sealed. Based on this, an embodiment of the present invention provides a tail tube hanger system and related methods, which are described in detail through specific embodiments below.

[0088] Embodiment 1

[0089] The embodiment of the present invention provides a liner hanger system, referring to Figure 1-Figure 11 As shown, the liner hanger system includes a liner hanger 100 and a setting tool 200;

[0090] The liner hanger comprises a tie-back tube 101, a lower slip 102, a cone sleeve 103, a packer 104, a setting piston 105, a mandrel 106, a flow channel 108 and a hydraulic chamber 109;

[0091] The packer 104 is connected between the core shaft 106 and the tie-back tube 101, the flow channel 108 is formed in the tie-back tube 101 and the core shaft 106, the lower slip 102 is arranged on the core shaft 106, the taper sleeve 103 is fixed to the core shaft 106, the setting piston 105 is sealed and connected to the core shaft 106, the hydraulic chamber 109 is formed between the core shaft 106 and the setting piston 105, and under the hydraulic action of the hydraulic chamber 109, the setting piston 105 can push the lower slip 102 to move along the taper sleeve 103 and expand radially;

[0092] The setting tool 200 is placed in the flow channel 108;

[0093] The setting tool 200 includes a body 201, and a floating valve mechanism 220, a packer actuator 230, a release mechanism 210, a pressure balance mechanism 270, a thrust mechanism 250 and a packing mechanism 260 which are sequentially arranged on the body 201 from top to bottom;

[0094] The floating valve mechanism 220 is sealed with the body 201 and the tie-back tube 101 respectively, and a first space 2001 is formed between the floating valve mechanism 220, the tie-back tube 101, the core shaft 106 and the body 201; the first space 2001 contains a cleaning liquid;

[0095] The packer actuator 230 and the release mechanism 210 are placed in the first space 2001;

[0096] A second space 2002 is formed between the thrust mechanism 250 and the body 201;

[0097] The sealing mechanism 260 is respectively in sealing cooperation with the body 201 and the core shaft 106;

[0098] The second space 2002 is in communication with the hydraulic chamber 109;

[0099] The pressure balancing mechanism 270 connects the first space 2001 and the second space 2002 , and is used to move the cleaning liquid in the first space 2001 to the second space 2002 and the hydraulic chamber 109 .

[0100] Reference Figure 1 and Figure 2 The schematic diagram of the operation of the liner hanger shown in the figure shows that the wellbore has a casing 11. In the casing 11, the liner hanger 100 of the liner hanger system provided by the embodiment of the present invention is lowered into the liner 12 together with the setting tool 200. The setting tool 200 is connected to the running pipe string 13. When reaching a suitable depth, that is, reaching the hanging position, the setting tool 200 activates the liner hanger 100 through the lower slip 102, so that the liner 12 extends into the open hole wellbore.

[0101] Specifically, refer to Figure 3-Figure 11 As shown, a first space 2001 is formed between the floating valve mechanism 220, the tie-back tube 101, the core shaft 106 and the body 201, and clean liquid is stored in the first space 2001 as a driving liquid. The floating valve mechanism 220 can prevent the drilling fluid in the wellbore from entering the first space 2001. The thrust piston 252 and the body 201 form a second space 2002, and the pressure balance mechanism 270 provided on the body 201 is configured to transport the clean liquid in the first space 2001 to the second space 2002 and the hydraulic chamber 109. When the hydraulic chamber 109 of the liner hanger is pressurized to seal the lower slip 102, the clean liquid enters the first space 2002 and the hydraulic chamber 109 from the first space through the pressure balance mechanism 270. Under the hydraulic action of the hydraulic chamber 109, the sealing piston 105 can push the lower slip 102 to move and expand radially along the cone sleeve 103, and hang on the casing 11, so that the liner extends into the wellbore. As shown in FIG. Figure 2As shown, after setting the liner 12 and liner hanger 100, the setting tool 200 is released from the liner hanger system so that other cementing operations can be performed.

[0102] In the embodiment of the present invention, although the liner hanger 100 is exposed to the drilling fluid, the clean liquid in the first space 2001, the second space 2002 and the hydraulic chamber 109 will not be contaminated or affected by the debris in the drilling fluid, thereby minimizing the contact with the drilling fluid and reducing the operational risk of sealing the liner hanger 100.

[0103] In the embodiment of the present invention, the process of the clean liquid moving from the first space 2001 to the second space 2002 and the hydraulic chamber 109 connected to the second space 2002 are all moved in a sealed state, and the internal working parts of the sealing tool 200, the sealing actuator 230, the release mechanism 210, the pressure balance mechanism 270 and the thrust mechanism 250 are all kept in a sealed state and are not affected by the drilling fluid containing debris, so as to reduce the interference of the drilling fluid on the sealing of the tail pipe hanger 100, and avoid clogging the sealing tool 200 and the sealing piston 105 of the tail pipe hanger 100.

[0104] The liner hanger system provided by the embodiment of the present invention adopts the first space group as the reserve space of the driving liquid, and the clean liquid is transferred from the first space to the second space and the hydraulic chamber through the pressure balance valve mechanism. The driving fluid required for the liner hanger to be set is transferred in a sealed state, and is not affected by the drilling fluid containing debris. The debris is not easy to be deposited on the setting tool and the liner hanger, which reduces the interference of the drilling fluid containing debris on the setting of the liner hanger, thereby avoiding affecting the driving of the setting piston; and when the hydraulic chamber is pressurized to set the slip, the debris will not enter the fluid channel between the first space, the second space and the hydraulic chamber, avoiding blocking the setting tool and the setting piston of the liner hanger, therefore, it will not affect the pressure effect of the driving liquid on the slip, and can achieve safe setting of the liner hanger. It can be applied to the completion operation of high-cuttings ratio wells with drilling fluid containing a large amount of debris in the downhole environment, has reliable performance, strong applicability, is easy to promote and apply on a large scale, and is conducive to improving economic benefits. It is particularly suitable for the completion operation of deep wells, high-density wells, and high-pressure wells.

[0105] In one embodiment, the pressure balancing mechanism 270 includes a one-way check valve mechanism (not shown in the figure);

[0106] The floating valve mechanism 220 can drive the cleaning liquid in the first space 2001 to move to the second space 2002 and the hydraulic chamber 109 through the one-way check valve mechanism under the hydrostatic pressure of the drilling fluid.

[0107] In the liner hanger system provided by the embodiment of the present invention, the pressure balance mechanism 270 is provided with a one-way check valve mechanism, which can prevent the reverse delivery of the clean liquid. During the process of lowering the pipe and completing the well, the static pressure of the drilling fluid acts on the floating valve mechanism 220, so that the clean liquid is transferred from the first space 2001 to the second space 2002 and the hydraulic chamber 109 through the pressure balance mechanism 270, and the pressure in the setting tool 200 will be balanced with the static pressure of the drilling fluid in the annulus, balancing the influence of the static pressure of the drilling fluid column, which ensures that only the relative pressure higher than the static pressure reference of the drilling fluid can be used to set the liner hanger 100, avoiding the liner hanger 100 from being set prematurely.

[0108] In a specific embodiment, referring to Figure 6 As shown, the one-way check valve mechanism includes a piston chamber 271, a chamber seat 272, a balance piston 273, an outer annular seal 274 and a pressure balance spring 275;

[0109] The piston chamber 271 is formed between the balance piston 273 and the chamber seat 272;

[0110] The bottom of the balancing piston is connected to the pressure balancing spring 275, and the outer annular seal 274 is provided on the balancing piston 273;

[0111] If the hydraulic pressure of the first space and the second space is balanced, under the action of the pressure balance spring 275, the outer annular seal 274 on the balance piston 273 is engaged and sealed with the cavity seat 272 to isolate the first space 2001 and the second space 2002;

[0112] If the hydraulic pressure of the first space is greater than that of the second space, the balance piston 273 moves relative to the chamber seat 272 under the pressure difference, so that the cleaning liquid flows from the first space 2001 to the second space 2002 and the hydraulic chamber 109 .

[0113] In the liner hanger system provided by the embodiment of the present invention, in the one-way check valve mechanism of the pressure balancing mechanism 270 , the piston chamber 271 may be a cylindrical chamber, and the balancing piston 273 is a cylinder and is disposed in the piston chamber 271 .

[0114] In the embodiment of the present invention, the balancing piston 273 can move relative to the cavity seat 272 in the piston cavity 271 in response to the pressure difference. The balancing piston 273 has an outer annular seal 274, and a pressure balancing spring 275 arranged in the piston cavity 271 biases the balancing piston 273 toward the cavity seat 272 to balance the pressure difference between the first space 2001 and the second space 2002. The outer annular seal 274 engages with the cavity seat 272 and seals to form a one-way valve structure. If the hydraulic pressure of the first space 2001 and the second space 2002 is balanced, the balancing piston 273 in the closed position has the outer annular seal 274 engaged with the cavity seat 272, which prevents reverse fluid communication from the second space 2002 to the first space 2001, and prevents the cleaning liquid from returning from the second space 2002 to the first space 2001 through the one-way valve structure of the pressure balancing mechanism 270. If the hydraulic pressure of the first space 2001 is greater than the hydraulic pressure of the second space 2002 , the balance piston 273 in the open state is separated from the chamber seat 272 , so that the fluid can flow from the first space 2001 to the second space 2002 and the hydraulic chamber 109 .

[0115] In a specific embodiment, referring to Figure 6 As shown, the pressure balancing mechanism 270 further includes an inner annular seal 276;

[0116] The inner annular seal 276 is in sealing cooperation with the balancing piston 273 and the body 201 .

[0117] In the liner hanger system provided by the embodiment of the present invention, the inner annular seal 276 of the pressure balance mechanism 270 can further prevent reverse fluid communication from the second space 2002 to the first space 2001 .

[0118] In one embodiment, referring to Figure 3-Figure 9 As shown, the thrust mechanism 250 includes a driving ball seat 251 and a thrust piston 252;

[0119] The driving ball seat 251 is sealedly connected to the thrust piston 252, and the second space 2002 is formed between the thrust piston 252 and the body 201;

[0120] The driving ball seat 251 is used to carry the setting ball B.

[0121] In a specific embodiment, referring to Figure 3-Figure 9 As shown, the thrust mechanism 250 further includes a thrust seal 253 , and the thrust piston 252 and the body 201 are sealed together via the thrust seal 253 .

[0122] In the liner hanger system provided by the embodiment of the present invention, the driving ball seat 251 and the thrust piston 252 are linked to each other and configured to engage with the deployed setting ball B. During the cementing operation of the liner hanger 100, the thrust piston 252 acts as a sealing sleeve to provide drilling fluid debris and pressure isolation, thereby preventing the drilling fluid from contaminating the clean liquid in the second space 2002.

[0123] During the setting operation, a ball is thrown into the setting tool 200. When the setting ball B is located at the driving ball seat 251, the setting tool 200 moves the thrust piston 252 by increasing the pressure in the tube of the setting ball B, compressing the clean liquid in the second space 2002. Since the second space 2002 is connected to the hydraulic chamber 109, the setting piston 105 is driven by hydraulic pressure to achieve the setting of the lower slip 102. Since the means of pressurizing and driving the fluid by the setting tool 200 is not contaminated or affected by the debris in the drilling fluid, during the operation, only the clean liquid enters the hydraulic chamber 109 of the liner hanger, which minimizes the contact with the drilling fluid, thereby reducing the operation risk of setting the liner hanger 100.

[0124] In one embodiment, referring to Figure 3 and Figure 4 As shown, the setting tool 100 further includes a locking mechanism 240;

[0125] The locking mechanism 240 is disposed on the body 201 and locks the thrust piston 252;

[0126] After the driving ball seat 251 is pressed to a first pressure after the ball is thrown, the locking mechanism can unlock the thrust piston 252 .

[0127] The inventor found that due to the difference in the surface of the thrust piston 252 of the thrust mechanism 250, during the large displacement and high rate of drilling fluid circulation, the pressure increase may cause the thrust piston 252 to start, causing the slip to move in advance, resulting in the problem of premature sitting of the tail pipe hanger. Based on this, the inventor proposed to use the locking mechanism 240 to lock the thrust piston 252. The locking mechanism 240 can prevent any unintentional movement of the thrust piston 252. Since the drilling fluid needs to circulate during the lowering of the pipe string, the locking mechanism 240 allows a high flow rate and a high circulation rate of the drilling fluid. The setting tool 200 can withstand the open hole isolation situation where the circulation flow suddenly stops and the wellbore pressure increases. In addition, due to the difference in the surface of the thrust piston 252 of the thrust mechanism 250, the pressure increase may cause the thrust piston 252 to start. When the locking mechanism 240 is locked, the internal pressure of the thrust piston 252 is much higher than the pressure generated by the fluctuation of the drilling fluid, thereby preventing the thrust piston 252 from starting in advance. Until the lowered tubing reaches the sealing position and a sealing system is needed, a ball is thrown into the sealing tool 200. When the sealing ball B is located at the driving ball seat 251 for holding pressure, the sealing tool 200 moves the thrust piston 252 by increasing the pressure in the pipe caused by the sealing ball B to unlock the locking mechanism 240.

[0128] In a specific embodiment, it can be, referring to Figure 4 As shown, the locking mechanism 240 includes a locking shear pin 241, and the locking shear pin 241 is arranged between the thrust piston 252 and the body 201;

[0129] The locking shear pin 241 is configured to be sheared when the driving ball seat 251 is pressed to a first pressure.

[0130] The liner hanger system provided by the embodiment of the present invention requires a setting system when the tubing is lowered into the setting position. A ball is thrown into the setting tool 200, and the setting ball B is located on the driving ball seat 251 to hold the pressure. As the pressure in the pipe increases to the first pressure, the setting tool 200 pushes the thrust piston 252 to shear the locking shear pin 241, thereby unlocking the pipe.

[0131] In a specific embodiment, referring to Figure 3-Figure 9 As shown, the thrust mechanism 250 further includes a thrust shear pin 254, and the thrust shear pin 254 is disposed between the thrust piston 252 and the body 201;

[0132] The thrust shear pin 254 is configured to be sheared when the driving ball seat 251 is pressed to a second pressure.

[0133] The thrust piston 252 is configured to move a first distance relative to the thrust shear pin 254 to pressurize the second space 2002 and the hydraulic chamber 109 and drive the setting piston 105 to move to a second distance;

[0134] When the driving ball seat 251 is pressed to the second pressure, the thrust shear pin 254 is sheared off, and the thrust piston 252 can move relative to the body 201 to increase the pressure of the second space 2002 and the hydraulic chamber 109, driving the setting piston 105 to move to a third distance;

[0135] The second pressure is greater than the first pressure; the third distance is greater than the second distance.

[0136] The inventors found that due to the debris environment in the drilling fluid, the deposited debris tends to gather in the hydraulic chamber 109 of the liner hanger and the area around the lower slip 102. The accumulation of debris may increase the driving pressure required for the movement of the sealing tool and the slip of the liner hanger. Based on this, the inventors proposed that the thrust piston 252 can achieve differential pressurization. The thrust piston 252 and the tool body 201 can be limited by the thrust shear pin 254. The pressure of the sealing ball B increases to the first pressure, and the locking shear pin 241 of the locking mechanism 240 is sheared off. The thrust piston 252 can move a first distance L1 before being released. The movement of the thrust piston 252 increases the pressure of the clean liquid in the second space 2002, which can move the sealing piston 105 a second distance L2. If the initial distance L2 of the sealing piston 105 is not enough to drive the lower slip 102 to sit on the outside, the pressure of the cleaning liquid in the second space 2002 can be increased. On the layer casing 11, a higher pressure is applied to the sealing ball B to shear the thrust shear pin 254, and the thrust piston 252 continues to move, further compressing the clean liquid in the second space 2002, so that more clean liquid enters the hydraulic chamber 109. When the thrust piston 252 moves a larger distance, the sealing piston 105 will also move a larger distance to reach the third distance L3, so that the lower cava 102 can get rid of the cone sleeve 103 and contact the casing 11, and finally the lower cava 102 is sealed by the boosting effect.

[0137] The liner hanger system provided in the embodiment of the present invention sets multi-level pressure for the sealing ball B to shear the thrust shear pin 254, thereby converting the pressure applied to the sealing ball B into the pressure of the driving fluid, so that the thrust piston 252 further compresses the clean liquid in the second space 2002, allowing more of the clean liquid to enter the hydraulic chamber 109 of the sealing piston 105, and transmits the converted hydraulic pressure to the sealing piston 105 to achieve a pressurization effect, so as to seal the lower slip 102 and eliminate the influence of the debris environment in the drilling fluid that may cause the moving components of the liner hanger 100 to achieve a greater force for sealing.

[0138] In one embodiment, referring to Figure 3-Figure 9As shown, the sealing mechanism includes a valve body 261; the valve body 261 is sealed and matched with the core shaft 106;

[0139] The main body is provided with a first port 202 , the valve body is provided with a second port 262 , and the core shaft 106 is provided with a third port 107 ;

[0140] The hydraulic chamber 109 is in communication with the second space 2002 through the first port 202 , the second port 262 and the third port 107 .

[0141] The liner hanger system provided by the embodiment of the present invention is sealed and matched with the core shaft 106 by the valve body 261 to isolate the clean liquid in the second space 2002 from the external drilling fluid. The hydraulic chamber 109 is connected with the second space 2002 through the first port 202, the second port 262 and the third port 107. The second space 2002 is compressed by the thrust piston 252, and the pressure applied to the setting ball B is converted into the pressure of the driving fluid, and the converted pressure is transmitted to the setting piston 105 of the liner hanger. The lower slip 102 is pushed by the setting piston 105 to move and radially expand along the cone sleeve 103, and is hung on the casing 11, so that the liner extends into the wellbore.

[0142] In a specific embodiment, referring to Figure 3-Figure 9 As shown, the isolation mechanism 260 further includes an isolation seal 263, which is sealed with the valve body 261 and the core shaft 106. The isolation seal 263 isolates the third port 107 to prevent the drilling fluid entering from the third port 107 from mixing with the clean liquid in the second space 2002.

[0143] In the embodiment of the present invention, the fluid above the isolation mechanism 260 is isolated from the drilling fluid by the floating valve mechanism 220, and the isolation seal 263 on the valve body 261 of the isolation mechanism 260 isolates the third port 107, so that the setting tool 200 can achieve debris isolation.

[0144] In the embodiment of the present invention, the thrust mechanism 250 is sealed in the flow channel 108 of the liner hanger 100 using the isolation mechanism 260 , and at least one port ( 262 , 202 ) of the body 201 and the isolation mechanism 260 is connected to at least one third port 107 of the liner hanger 100 .

[0145] In one embodiment, referring to Fig.10 and Fig.11 As shown, the setting tool 200 further includes an overpressure relief mechanism 280;

[0146] The overpressure relief mechanism 280 is disposed on the body 201 and is used to release the cleaning liquid in the second space 2002 into the first space 2001 .

[0147] In a specific embodiment, referring to Fig.10 and Fig.11 As shown, the overpressure relief mechanism 280 includes a piston chamber 281, a pressure relief shear pin 283, a floating piston 284 and a pressure relief spring 286;

[0148] The body 201 is provided with a pressure relief port 282, and the pressure relief shear pin 283 is provided at the pressure relief port 282;

[0149] The bottom of the floating piston 284 is connected to the pressure relief spring 286;

[0150] If the pressure difference between the second space 2002 and the first space 2001 is less than a predetermined pressure difference threshold, under the action of the pressure relief spring 286, the floating piston 284 may move a fourth distance relative to the pressure relief shear pin 283;

[0151] If the pressure difference between the second space 2002 and the first space 2001 is less than the predetermined pressure difference threshold, the floating piston 284 can drive the pressure relief spring 286 to contract and shear the pressure relief shear pin 283 to open the pressure relief port 282 to connect the second space 2002 and the first space 2001.

[0152] In the liner hanger system provided by the embodiment of the present invention, the pressure relief port 282 of the overpressure relief mechanism 280 can be opened to connect the second space 2002 with the first space 2001, and a pressure relief shear pin 283 is provided in the pressure relief port 282. The floating piston 284 moves relative to the pressure relief shear pin 283 in the piston chamber 281 in response to the pressure difference change. When the pressure difference between the second space 2002 and the first space 2001 is less than the predetermined pressure difference threshold, the floating piston 284 interacts with the pressure relief shear pin 283 to prevent the first space 2002 from being opened. The second space 2001 and 2002 are connected via the pressure relief port 282 to prevent the cleaning fluid from entering the first space 2001 from the second space 2002. When the pressure difference between the second space 2002 and the first space 2001 is greater than the predetermined pressure difference threshold, the floating piston 284 shears the pressure relief shear pin 283, connects with the pressure relief port 282, and allows the driving fluid to flow from the second space 2002 to the pressure relief port 282, thereby releasing the cleaning liquid in the second space 2002 into the first space 2001.

[0153] In a specific embodiment, referring to Fig.10 and Fig.11As shown, the overpressure relief mechanism 280 further includes a pressure relief seal 285 , and the floating piston 284 is sealedly matched with the valve body 261 of the isolation mechanism 260 through the pressure relief seal 285 .

[0154] During the completion operation, the floating piston 284 of the overpressure relief mechanism 280 moves, and the second space 2002 can be expanded when the pressure is increased. The gap between the floating piston 284 and the pressure relief shear pin 283 can relieve the static fluid pressure. In the process of maintaining pressure balance, the overpressure relief mechanism 280 can also respond to the increase in downhole temperature through corresponding movement. During the slip setting process, due to the unidirectional migration of the clean liquid in the first space 2001 to the second space 2002 and the hydraulic chamber 109, the pressure in the second space 2002 will be greater than the pressure in the first space 2001. Once the pressure of the second space and the first space 2001 exceeds the rated pressure difference threshold, the floating piston 284 will shear the pressure relief shear pin 283 under the action of hydraulic pressure, and release the pressure from the second space 2002 to the first space 2001. In the first space 2001, the floating valve mechanism 220 can respond to the increase in pressure by expanding the volume upward. At this time, due to the action of the pressure relief spring 286, the system will balance and return to its original position. The overpressure relief mechanism 280 can protect the setting piston 105 and its seals from overpressure, and prevent any pressure exceeding the rated pressure from being transmitted to the liner hanger 100 , so that the liner hanger 100 is not affected by overpressure.

[0155] In one embodiment, referring to Figure 3 As shown, the liner hanger 100 further includes an upper slip 110 disposed on the mandrel 106;

[0156] The upper slip is located between the packer 104 and the cone sleeve 103;

[0157] Under the pressure of the release mechanism 210 , the packer 104 can push the upper slip to move along the cone sleeve 103 and expand radially.

[0158] The liner hanger system provided by the embodiment of the present invention can be a liner hanger with double slips. When the running pipe string 13 reaches a suitable depth, that is, reaches the sitting position, the setting tool 200 activates the liner hanger 100 through the packer 104. Specifically, after the ball is thrown into the setting tool 200, the setting ball B first reaches the setting ball seat 211 of the release mechanism 210. By holding the pressure at the wellhead, the setting tool 200 increases the pressure in the pipe by the setting ball B to push the release mechanism 210 and the packer actuator 230. Under the pressure of the release mechanism 210 and the packer actuator 230, the packer 104 pushes the upper slip 110 to move downward along the cone sleeve 103 and expand radially, so as to set the upper slip 110. The setting of the upper slip 110 ensures that the liner hanger 100 cannot be lifted.

[0159] In the embodiment of the present invention, the floating valve mechanism 220 of the setting tool 200 is an annular structure, which is sleeved on the body 201 and is sealed with the tie-back tube 101 through a seal, so that the clean liquid inside the first space 2001 is isolated from the drilling fluid above the floating valve mechanism 220. As the depth of the pipe string increases, the floating valve mechanism 220 moves downward under the gravity of the drilling fluid above the floating valve mechanism 220 to compress the clean liquid in the first space 2001 and move it to the second space 2002 and the hydraulic chamber 109. The specific structural form of the floating valve mechanism 220 is not specifically limited here.

[0160] The body 201 of the setting tool 200 in the embodiment of the present invention is a multi-section structure. The implementation method of connecting the multi-section structure can refer to the detailed description of the prior art, which will not be repeated here.

[0161] The specific structures of the release mechanism 210 and the packer actuator 230 of the setting tool 200 and the packer 104 of the liner hanger 100 in the embodiment of the present invention can refer to the detailed description of the prior art, and will not be repeated here.

[0162] The liner hanger system provided in the embodiment of the present invention lowers the liner hanger 100 and the connected liner into the wellbore by using a setting tool 200 installed on the running pipe string 13. The setting tool 200 is arranged in the liner hanger 100 (sealed and locked), and the first space 2001 is filled with clean liquid.

[0163] During the lowering process, the hydrostatic pressure of the drilling fluid in the wellbore will act on the driving floating valve mechanism 220 to transfer the clean liquid in the first space 2001 to the second space 2002 through the pressure balancing mechanism 270. The pressure in the second space 2002 is balanced with the hydrostatic pressure of the drilling fluid in the wellbore. The one-way valve mechanism in the pressure balancing mechanism 270 can prevent the driving fluid in the second space 2002 from returning to the first space 2001.

[0164] When the liner hanger 100 is lowered to the designed depth and reaches the setting position, the operator drops the setting ball B into the release mechanism 210 of the setting tool 200, applies hydraulic pressure behind the setting ball B, and unlocks the setting tool 200; under the pressure of the release mechanism 210, the packer 104 pushes the upper slips to move and radially expand along the cone sleeve 103 to achieve the setting of the upper slips. The upper slips are used to ensure that the liner hanger 100 cannot be lifted.

[0165] As the wellhead continues to build up pressure, the sealing ball B is discharged from the release mechanism 210, and the sealing ball B reaches the driving ball seat 251 of the thrust mechanism 250, and continues to apply pressure to unlock the locking mechanism 240. When the driving ball seat 251 is unlocked, the hydraulic pressure of the sealing ball B in the driving ball seat 251 can push the thrust piston 252 of the thrust mechanism 250 to move downward a first distance relative to the thrust shear pin 254, so as to increase the pressure in the second space 2002 and the hydraulic chamber 109, drive the sealing piston 105 to move to a second distance, and drive the lower cava 102 to move and expand radially along the cone sleeve 103. When the lower cava 102 is fully engaged with the casing 11 and sealing is achieved, the pressure build-up stops.

[0166] If the lower cava 102 has not been completely sealed, the hydraulic pressure of the sealing ball B is continuously applied to further compress the second space 2002, so that the clean liquid enters the hydraulic chamber 109 of the liner hanger 100, and the ball is dropped into the ball seat 251 to hold the pressure to the second pressure. The thrust shear pin 254 is sheared off, and the thrust piston 252 can move relative to the body 201 to increase the pressure of the second space 2002 and the hydraulic chamber 109, drive the sealing piston 105 to move to a third distance, drive the lower cava 102 to move and radially expand along the cone sleeve 103, and make the lower cava 102 fully mesh with the casing 11.

[0167] After the operation is completed, the setting tool 200 is released from the interior of the liner hanger 100 , and the setting tool 200 is taken out from the liner hanger 100 in the casing 11 .

[0168] It should be noted that, after the operation is completed, releasing the setting tool 200 from the interior of the liner hanger 100 may refer to releasing a releasable joint (not shown in the figure) of the setting tool 200 from the interior of the liner hanger 100 .

[0169] It should be noted that during the well completion operation, the floating piston 284 of the overpressure relief mechanism 280 moves, and the second space 2002 can be expanded when the pressure is increased, and the gap between the floating piston 284 and the pressure relief shear pin 283 can relieve the static fluid pressure. In the process of maintaining pressure balance, the overpressure relief mechanism 280 can also respond to the increase of downhole temperature through corresponding movement.

[0170] During the slip setting process, due to the unidirectional migration of the clean liquid in the first space 2001 to the second space 2002 and the hydraulic chamber 109, the pressure in the second space 2002 will be greater than the pressure in the first space. Once the pressure between the second space and the first space 2001 exceeds the rated pressure difference threshold, the floating piston 284 will shear the pressure relief shear pin 283 under the action of hydraulic pressure, and release the pressure from the second space 2002 to the first space 2001. In the first space 2001, the floating valve mechanism 220 can respond to the increase in pressure by expanding the volume upward. At this time, due to the action of the pressure relief spring 286, the system will balance and return to its original position. The overpressure relief mechanism 280 can protect the tail pipe hanger 100 from overpressure.

[0171] Embodiment 2

[0172] Based on the same inventive concept, an embodiment of the present invention further provides an operating method of the liner hanger system described in the first embodiment, comprising:

[0173] Connect the running string 13, the setting tool 200 and the liner hanger 100, and run them into the wellbore;

[0174] During the lowering of the liner hanger 100 , the gravity of the drilling fluid in the wellbore acts on the floating valve mechanism 220 to move the clean liquid from the first space 2001 to the second space 2002 and the hydraulic chamber 109 ;

[0175] After the liner hanger 100 is lowered to a predetermined position, a setting ball B is inserted into the thrust mechanism 250 and hydraulic pressure is applied to unlock the thrust mechanism;

[0176] The hydraulic pressure is continuously applied to drive the thrust mechanism 250 to pressurize the second space 2001 and the hydraulic chamber 109 , so that under the hydraulic pressure of the hydraulic chamber 109 , the setting piston 105 pushes the lower slip 102 to move and radially expand along the cone sleeve 103 .

[0177] In a specific embodiment, the operating method of the liner hanger system further includes: after the lower slip 102 sets the casing 11, releasing the setting tool 200 from the liner hanger 100, and removing the running tool and the setting tool 200 from the wellbore.

[0178] The detailed implementation of the operating method of the liner hanger system of the embodiment of the present invention can refer to the detailed description of the liner hanger system in the above-mentioned embodiment 1, and will not be repeated here.

[0179] 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 liner hanger system, characterized in that: It comprises a liner hanger (100) and a setting tool (200); The liner hanger (100) comprises a tie-back tube (101), a lower slip (102), a cone sleeve (103), a packer (104), a setting piston (105), a mandrel (106), a flow channel (108) and a hydraulic chamber (109); The packer (104) is connected between the core shaft (106) and the tie-back tube (101), the flow channel (108) is formed in the tie-back tube (101) and the core shaft (106), the lower slip (102) is arranged on the core shaft (106), the cone sleeve (103) is fixed on the core shaft (106), the setting piston (105) is sealed and connected to the core shaft (106), the hydraulic chamber (109) is formed between the core shaft (106) and the setting piston (105), and under the hydraulic action of the hydraulic chamber (109), the setting piston (105) can push the lower slip (102) to move along the cone sleeve (103) and expand radially; The setting tool (200) is placed in the flow channel (108); The setting tool (200) comprises a body (201), and a floating valve mechanism (220), a packer actuator (230), a release mechanism (210), a pressure balance mechanism (270), a thrust mechanism (250) and a packing mechanism (260) which are sequentially arranged on the body (201) from top to bottom; The floating valve mechanism (220) is respectively sealed with the body (201) and the tie-back cylinder (101), and a first space (2001) is formed between the floating valve mechanism (220), the tie-back cylinder (101), the core shaft (106) and the body (201); the first space (2001) contains a cleaning liquid; The packer actuator (230) and the release mechanism (210) are placed in the first space (2001); A second space (2002) is formed between the thrust mechanism (250) and the body (201); The sealing mechanism (260) is respectively in sealing cooperation with the body (201) and the core shaft (106); The second space (2002) is in communication with the hydraulic chamber (109); The pressure balancing mechanism (270) is connected to the first space (2001) and the second space (2002), and is used to move the cleaning liquid in the first space (2001) to the second space (2002) and the hydraulic chamber (109).

2. The liner hanger system according to claim 1, characterized in that: The pressure balancing mechanism (270) comprises a one-way check valve mechanism; The floating valve mechanism (220) can drive the clean liquid in the first space (2001) to move to the second space (2002) and the hydraulic chamber (109) through the one-way check valve mechanism under the action of the hydrostatic pressure of the drilling fluid.

3. The liner hanger system according to claim 2, characterized in that: The one-way check valve mechanism comprises a piston chamber (271), a chamber seat (272), a balancing piston (273), an outer annular seal (274) and a pressure balancing spring (275); The piston chamber (271) is formed between the balancing piston (273) and the chamber seat (272); The bottom of the balancing piston (273) is connected to the pressure balancing spring (275), and the outer annular seal (274) is arranged on the balancing piston (273); If the hydraulic pressure of the first space (2001) and the second space (2002) is balanced, under the action of the pressure balance spring (275), the outer annular seal (274) on the balance piston (273) is engaged and sealed with the cavity seat (272); If the hydraulic pressure of the first space (2001) is greater than the hydraulic pressure of the second space (2002), the balance piston (273) moves relative to the chamber seat (272) under the action of the pressure difference, so that the cleaning liquid flows from the first space (2001) to the second space (2002) and the hydraulic chamber (109).

4. The liner hanger system according to claim 3, characterized in that: The pressure balancing mechanism (270) further includes an inner annular seal (276); The inner annular seal (276) is sealingly matched with the balancing piston (273) and the body (201).

5. The liner hanger system according to claim 1, characterized in that: The thrust mechanism (250) comprises a driving ball seat (251) and a thrust piston (252); The driving ball seat (251) is sealedly connected to the thrust piston (252), and the second space (2002) is formed between the thrust piston (252) and the body (201); The driving ball seat (251) is used for carrying the setting ball.

6. The liner hanger system according to claim 5, characterized in that: The setting tool (200) further comprises a locking mechanism (240); The locking mechanism (240) is disposed on the body (201) and locks the thrust piston (252); After the driving ball seat (251) is pressed to a first pressure after the ball is thrown, the locking mechanism (240) can unlock the thrust piston (252).

7. The liner hanger system according to claim 6, characterized in that: The locking mechanism (240) comprises a locking shear pin (241), and the locking shear pin (241) is arranged between the thrust piston (252) and the body (201); The locking shear pin (241) is configured to be sheared when the driving ball seat (251) is pressed to a first pressure.

8. The liner hanger system according to claim 7, characterized in that: The thrust mechanism (250) further comprises a thrust shear pin (254), wherein the thrust shear pin (254) is arranged between the thrust piston (252) and the body (201); The thrust shear pin (254) is configured to be shearable when the driving ball seat (251) is pressed to a second pressure. The thrust piston (252) can move a first distance L1 relative to the thrust shear pin (254) to increase the pressure of the second space (2002) and the hydraulic chamber (109), thereby driving the setting piston (105) to move to a second distance L2; When the driving ball seat (251) is pressed to a second pressure, the thrust shear pin (254) is sheared off, and the thrust piston (252) can move relative to the body (201) to increase the pressure in the second space (2002) and the hydraulic chamber (109), thereby driving the setting piston (105) to move to a third distance L3; The second pressure is greater than the first pressure; the third distance L3 is greater than the second distance L2.

9. The liner hanger system according to claim 1, characterized in that: The sealing mechanism (260) comprises a valve body (261); the valve body (261) is in sealing cooperation with the core shaft (106); The body (201) is provided with a first port (202), the valve body (261) is provided with a second port (262), and the core shaft (106) is provided with a third port (107); The hydraulic chamber (109) is in communication with the second space (2002) via the first port (202), the second port (262) and the third port (107).

10. The liner hanger system according to claim 9, characterized in that: The sealing mechanism (260) further comprises a sealing seal (263), wherein the sealing seal (263) is sealingly matched with the valve body (261) and the core shaft (106).

11. The liner hanger system according to claim 1, characterized in that: The setting tool (200) further comprises an overpressure relief mechanism (280); The overpressure relief mechanism (280) is arranged on the body (201) and is used to release the cleaning liquid in the second space (2002) into the first space (2001).

12. The liner hanger system according to claim 11, characterized in that: The overpressure relief mechanism (280) comprises a piston chamber (281), a pressure relief shear pin (283), a floating piston (284) and a pressure relief spring (286); The body (201) is provided with a pressure relief port (282), and the pressure relief shear pin (283) is provided at the pressure relief port (282); The bottom of the floating piston (284) is connected to the pressure relief spring (286); If the pressure difference between the second space (2002) and the first space (2001) is less than a predetermined pressure difference threshold, under the action of the pressure relief spring (286), the floating piston (284) can move a fourth distance relative to the pressure relief shear pin (283); If the pressure difference between the second space (2002) and the first space (2001) is greater than the predetermined pressure difference threshold, the floating piston (284) can drive the pressure relief spring (286) to contract and shear the pressure relief shear pin (283) to open the pressure relief port (282) to connect the second space (2002) and the first space (2001).

13. The liner hanger system according to claim 1, wherein: The liner hanger (100) further includes an upper slip (110) disposed on the mandrel (106); The upper slip (110) is located between the packer (104) and the cone sleeve (103); Under the pressure of the release mechanism (210), the packer (104) can push the upper slip (110) to move and radially expand along the cone sleeve (103).

14. An operating method of a liner hanger system according to any one of claims 1 to 13, characterized in that: include: Connecting a running pipe string (13), a setting tool (200) and the liner hanger (100), and lowering them into a wellbore; During the lowering process of the liner hanger (100), the gravity of the drilling fluid in the wellbore acts on the floating valve mechanism (220), so that the clean liquid is transferred from the first space (2001) to the second space (2002) and the hydraulic chamber (109); After the liner hanger (100) is lowered to a predetermined position, a hydraulic pressure is applied to the thrust mechanism (250) after a setting ball is inserted therein, thereby unlocking the thrust mechanism (250); The hydraulic pressure is continued to be applied to drive the thrust mechanism (250) to increase the pressure of the second space (2001) and the hydraulic chamber (109), so that under the hydraulic action of the hydraulic chamber (109), the sealing piston (105) pushes the lower slip (102) to move and expand radially along the cone sleeve (103).

15. The method for operating a liner hanger system according to claim 14, wherein: Also includes: After the lower slip (102) sets the casing (11), the setting tool (200) is released from the liner hanger (100), and the running string (13) and the setting tool (200) are taken out of the wellbore.

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