Tail pipe suspension system and using method thereof

Abstract

The invention relates to a tail pipe suspension system and a using method thereof. The system comprises a tail pipe hanger, a suspension mechanism, a tripping-in pipe column, a pre-locking module, a packer assembly, at least one hydraulic mechanism and a ball seat arranged at the tail end of the tripping-in pipe column. The drilling liner hanger is connected with the feeding tool assembly; the feeding tool assembly is connected with the mandrel assembly; the suspension mechanism is locked on the drilling liner hanger through the pre-locking module, a medium-pressure area is arranged between the mandrel assembly and the drilling liner hanger, and the internal channel extends downwards to penetrate through the mandrel assembly to be communicated with the medium-pressure area. The inner pressure area is communicated with the medium pressure area through a plurality of channels arranged on the mandrel assembly; the suspension mechanism comprises a cone with an inclined surface and a slip connected with the hydraulic mechanism, and the slip can move relative to the inclined surface of the cone. The pre-locking module is arranged in the drilling liner hanger, so that the risk that the drilling liner hanger is set and released in advance due to overlarge fluctuation of external pressure when the drilling liner hanger is put down is overcome.

Description

Technical Field

[0001] The invention relates to a tail pipe suspension system and a use method thereof. Background Art

[0002] A liner suspension system can be used in a well completion to suspend the liner / casing in the casing string via a liner hanger. The liner suspension system can be either mechanically or hydraulically operated. However, hydraulically operated systems generally offer greater versatility and allow the liner to be rotated during the running process in the well. During the running process, fluid is circulated downhole under pressure to facilitate the running of the liner. However, higher flow rates of circulating fluid can create high circulating pressures, which can cause the liner hanger to prematurely release the running tool used to lower the liner hanger. Summary of the invention

[0003] In order to enrich the types of liner suspension systems in the prior art and prevent the liner hanger from starting prematurely, the present invention proposes a liner suspension system and a method for using the liner suspension system. The technical solution proposed by the present invention is as follows:

[0004] In a first aspect, the present invention provides a liner suspension system, comprising: a liner hanger, a suspension mechanism, a running string, a pre-locking module, a packer assembly, at least one hydraulic mechanism, and a ball seat disposed at the tail end of the running string;

[0005] The running pipe string includes a mandrel assembly, and the liner hanger includes a running tool assembly, and the running tool assembly is connected to the mandrel assembly;

[0006] The hanging mechanism is locked on the liner hanger by the pre-locking module, the pre-locking module comprises a locking mechanism mounted on the liner hanger and an outer sleeve mounted on the running tool assembly, the locking mechanism is fixed at a preset position by the sleeve;

[0007] The inner passage of the mandrel assembly forms an inner pressure zone;

[0008] A medium-pressure zone is provided between the mandrel assembly and the liner hanger, and the internal passage extends downward through the mandrel assembly and communicates with the medium-pressure zone;

[0009] The inner pressure zone is connected to the medium pressure zone through a plurality of channels arranged on the mandrel assembly; the packer assembly is used to form a pressure difference between the inner pressure zone and the medium pressure zone;

[0010] The running tool assembly and the at least one hydraulic mechanism are disposed in the medium pressure zone;

[0011] The suspension mechanism comprises a cone having an inclined surface and slips connected to the hydraulic mechanism, and the slips can move relative to the inclined surface of the cone;

[0012] In the ball seat blocking state: the running tool assembly can move relative to the core shaft assembly under the action of the pressure difference between the inner pressure zone and the medium pressure zone, releasing the locking mechanism to unlock the pre-locking module; the hydraulic mechanism can drive the cava to move radially outward along the inclined surface of the cone and engage with the casing under the action of the pressure difference between the inner pressure zone and the medium pressure zone.

[0013] In some embodiments, the mandrel assembly includes a first mandrel;

[0014] The pre-locking module includes a third sealing assembly and a second piston mechanism slidably mounted around the first spindle;

[0015] A third sealing assembly is provided between the first spindle and the second piston mechanism to form a second driving chamber;

[0016] The first core shaft is provided with a third channel, and the second driving chamber is communicated with the internal pressure zone through the third channel.

[0017] In some embodiments, the suspension mechanism includes a hanger body;

[0018] The locking mechanism is mounted on the hanger body.

[0019] In some embodiments, the second piston mechanism comprises an upper sleeve, a lower sleeve and a piston;

[0020] The upper sleeve and the lower sleeve are respectively arranged at two ends of the piston;

[0021] The lower sleeve and the first core shaft are connected via a first pin, and the upper sleeve and the first core shaft are connected via a second pin.

[0022] In some embodiments, the locking mechanism includes a spring component and a plurality of limit lock blocks installed in the suspension mechanism;

[0023] One end of the spring component abuts against the upper sleeve, and the other end is connected to the limit lock block;

[0024] The hanger body is radially formed with a first groove corresponding to the limit lock block, and the limit lock block is embedded in the first groove under the action of the spring component.

[0025] In some embodiments, a second groove corresponding to the limit lock block is provided inside the hydraulic mechanism;

[0026] The limiting locking block can move into the second groove after being unlocked, and is embedded in the second groove under the action of the spring component.

[0027] In some embodiments, the spindle assembly has a bypass module, and the bypass module is disposed in the hydraulic mechanism;

[0028] A second sealing assembly is disposed between the bypass module and the hanger body.

[0029] In some embodiments, the bypass module includes a longitudinal channel extending axially through the second sealing assembly to achieve pressure balance between the inner pressure area and the middle pressure area above and below the second sealing assembly.

[0030] In some embodiments, the bypass module further comprises a radial channel extending between the inner pressure region and the intermediate pressure region, wherein the radial channel is located isolated from the longitudinal channel;

[0031] A first driving chamber is provided in the hydraulic mechanism;

[0032] The hanger body is provided with a second passage communicating with the radial passage and the first drive cavity.

[0033] In some embodiments, the packer assembly includes a packer drive assembly and a packer connected to each other, wherein the packer drive assembly is located in a medium pressure zone above the packer;

[0034] The liner hanger comprises an outer body, and the mandrel assembly is arranged in the outer body;

[0035] A retaining ring is provided at the upper end of the first piston mechanism, and the retaining ring is fixed to the outer sleeve through a shearing mechanism;

[0036] The packer is arranged in the outer body, and the packer is connected to the core shaft assembly and the outer body respectively.

[0037] In some embodiments, the running tool assembly includes a clamping mechanism, a connecting mechanism, and a first piston mechanism slidably mounted about a first mandrel;

[0038] The driving chamber of the first piston mechanism is in communication with the radial channel via a first channel provided on the first spindle;

[0039] The first piston mechanism is connected to the packer through the clamping mechanism and the connecting mechanism.

[0040] In some embodiments, the core shaft assembly further includes a second core shaft disposed at an upper end of the first core shaft, and a first sealing assembly is disposed between the second core shaft and the outer body.

[0041] In a second aspect, the present invention provides a method for using the tail pipe suspension system according to the first aspect, comprising:

[0042] deploying a liner hanger downhole by running a tool assembly;

[0043] Throwing the ball onto the tee, pressure is applied to the internal channel, creating a pressure difference between the internal pressure area and the intermediate pressure area;

[0044] When the pressure difference reaches the first preset value, the locking mechanism is released and the pre-locking module is unlocked; at the same time, the increased pressure in the internal pressure zone acts on the hydraulic mechanism, and the hydraulic mechanism moves upward to drive the slips to move relative to the inclined surface of the cone, so that the slips move radially outward and engage with the surrounding casing, and the tail pipe hanger is sealed on the casing.

[0045] In some embodiments, the method further includes: continuing to apply pressure to the internal channel, and when the pressure difference reaches a second preset value, the first piston mechanism moves, releasing the clamping mechanism, and the packer is separated from the lower string; wherein the second preset value is greater than the first preset value.

[0046] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0047] The liner suspension system provided by the present invention has an internal pressure zone formed in the internal channel of the mandrel assembly, a medium pressure zone is arranged between the mandrel assembly and the liner hanger, and the internal channel extends downward through the mandrel assembly to communicate with the medium pressure zone; the internal pressure zone is communicated with the medium pressure zone through a plurality of channels arranged on the mandrel assembly, so as to realize pressure balance between the area in the lowered pipe column, i.e., the internal pressure zone, and the area between the lowered pipe column and the liner hanger, i.e., the medium pressure zone, to prevent pressure imbalance when starting the liner hanger, and to facilitate fluid circulation at a relatively high rate and pressure during the lowering of the liner and the liner hanger. By connecting the running tool assembly with the mandrel assembly, the running tool assembly can move relative to the mandrel assembly under the action of the pressure difference between the internal pressure zone and the medium pressure zone in the state of ball seat blocking, and the liner hanger can generate a pressure difference between the internal pressure zone and the medium pressure zone by throwing a ball in the running tool, and by relatively increasing the pressure in the internal pressure zone, the locking mechanism is released, so that the pre-locking module is unlocked, and the liner hanger can be driven. Furthermore, under the action of the pressure difference between the inner pressure zone and the medium pressure zone, the hydraulic mechanism can drive the slip to move relative to the inclined surface of the cone, so that the slip moves radially outward along the inclined surface of the cone and engages with the surrounding casing to seal the tail tube hanger on the casing. By arranging a pre-locking module in the tail tube hanger, the risk of premature sealing and release of the tail tube hanger due to excessive external pressure fluctuations when the tail tube hanger is lowered is overcome. The pre-locking module can be used in conjunction with the tail tube hanger to prevent the tail tube hanger from starting prematurely, thereby improving the reliability of the tail tube hanger in deep wells and ultra-deep wells.

[0048] 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 are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 is a schematic diagram of the liner suspension system being deployed into the wellbore;

[0052] Figure 2 is a schematic cross-sectional view of the packer connection portion AA of the liner suspension system;

[0053] Figure 3 is a schematic cross-sectional view of a running tool assembly BB of a tail pipe suspension system;

[0054] Figure 4 is a schematic cross-sectional view of a tail pipe suspension portion CC of the tail pipe suspension system;

[0055] Figure 5 This is an example diagram of a bypass module for a tail pipe suspension system;

[0056] Figure 6 is a schematic cross-sectional view of a bypass module of a tail pipe suspension system;

[0057] Fig. 7A It is a schematic diagram of the pre-locking module DD of the tail pipe suspension system;

[0058] Figure 7B is a cross-sectional view of the pre-locking module after the liner hanger is set;

[0059] Figure 8 is a cross-sectional view of a locking mechanism E of a pre-locking module of a liner hanger;

[0060] Fig.9A is a schematic diagram of the suspension mechanism of the tail tube hanger system;

[0061] Fig. 9BIt is a schematic diagram of the suspension mechanism after the tail tube hanger system is sealed.

[0062] In the figure: 100, wellbore; 101, casing; 102, tail pipe hanger; 103, hanging mechanism; 104, running string; 105, pre-locking module; 106, running tool assembly; 107, packer drive assembly; 108, packer; 109, cone; 110, slip; 111, hydraulic mechanism; 112, mandrel assembly; 113, outer body; 114, first mandrel; 115, packing structure; 116, second mandrel; 117, first sealing assembly; 118, internal pressure zone; 119, internal channel; 120, medium pressure zone; 121, first piston mechanism; 122, clamping mechanism; 123, connecting mechanism; 124, first channel; 125, shearing machine structure; 126, bypass module; 127, hanger body; 128, second sealing assembly; 129, longitudinal channel; 130, radial channel; 131, second channel; 132, first drive chamber; 133, piston; 134, third sealing assembly; 135, second drive chamber; 136, third channel; 137, lower sleeve; 138, first pin; 139, first limiting groove; 140, upper sleeve; 141, second pin; 142, second limiting groove; 143, locking mechanism; 144, limiting lock block; 145, first groove; 146, spring component; 147, ball; 148, ball seat; 149, second groove; 150, retaining ring; 151, outer sleeve. DETAILED DESCRIPTION

[0063] 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.

[0064] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0065] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the 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.

[0066] 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.

[0067] In the completion, a liner suspension system can be used to suspend the liner / casing in the casing string through the liner hanger. The liner suspension system can be a mechanical operating system or a hydraulic operating system. The hydraulic operating system generally has greater versatility and allows the liner to rotate during the running process in the well. During the running process, the fluid circulates under pressure downhole to facilitate the running of the liner. The inventor found in his work that a higher flow rate circulating fluid will produce a high circulating pressure, which may cause the liner hanger to release the running tool used to lower the liner hanger prematurely. People have tried to limit this premature start, but the current system may not be able to protect the liner suspension system from the impact of premature hydraulic start, which cannot meet the inventor's expectations. In order to overcome the shortcomings of the prior art, a liner suspension system and method without pressure sensitive drive are provided to solve the problems of low reliability, easy premature setting, and easy failure of the liner hanger encountered in deep wells and ultra-deep wells. After further research and development, the inventor made the present invention to reduce or eliminate the risk of premature start of the liner suspension system and / or premature release of the running tool.

[0068] Embodiment 1

[0069] The embodiment of the present invention provides a tail pipe suspension system, referring to Figure 1 As shown, it includes: a tail pipe hanger 102, a hanging mechanism 103, a running pipe string 104, a pre-locking module 105, a running tool assembly 106, a packer assembly, at least one hydraulic mechanism 111 and a ball seat 148 arranged at the tail end of the running pipe string 104; the ball seat 148 is used to receive the dropped ball, block the communication between the inner pressure zone 118 and the medium pressure zone 120, and generate a sufficient pressure difference.

[0070] The running string 104 includes a mandrel assembly 112, and the liner hanger 102 includes a running tool assembly 106, and the running tool assembly 106 is connected to the mandrel assembly 112 and is used to transport the liner hanger 102 to a desired position in the wellbore 100;

[0071] The hanging mechanism 103 is locked on the liner hanger 102 through the pre-locking module 105, and the pre-locking module 105 includes a locking mechanism 143 installed on the liner hanger 102 and a sleeve installed on the running tool assembly 106, and the locking mechanism 143 is fixed at a preset position by the sleeve; the locking mechanism is fixed at a preset position by the sleeve; the locking mechanism is fixed at a preset position by the sleeve to lock the liner hanger 102 to prevent premature action, and the sleeve can move under the action of sufficient pressure difference to release the locking mechanism.

[0072] The inner passage 119 of the mandrel assembly 112 is formed with an inner pressure zone 118;

[0073] A medium pressure zone 120 is provided between the mandrel assembly 112 and the liner hanger 102. The internal passage 119 extends downward through the mandrel assembly 112 and communicates with the medium pressure zone 120. The internal passage 119 extends downward through the mandrel assembly 112 and allows the fluid to circulate at a relatively high pressure during the process of being lowered into the well. The packer assembly is used to form a pressure difference between the internal pressure zone 118 and the medium pressure zone 120. The packer assembly can drive the liner hanger 102 to be set by applying a sufficient pressure difference between the internal pressure zone 118 and the medium pressure zone 120.

[0074] The inner pressure zone 118 is connected to the intermediate pressure zone 120 through a plurality of channels provided on the mandrel assembly 112; the inner channel 119 is also connected to the intermediate pressure zone 120 located outside the mandrel assembly 112 and inside the liner hanger 102. The pressure zones, i.e., the inner pressure zone 118 and the intermediate pressure zone 120, can be connected to each other through ports surrounding the mandrel assembly 112. This allows the inner pressure zone 118 to maintain a basic pressure balance with the intermediate pressure zone 120 below the isolation structure 115 during the running process, and the pressure balance helps to avoid the possibility of prematurely releasing the running string 104 on the liner hanger 102.

[0075] The running tool assembly 106 and the at least one hydraulic mechanism 111 are disposed in the medium-pressure zone 120 .

[0076] The suspension mechanism 103 includes a cone 109 having an inclined surface and slips 110 connected to the hydraulic mechanism 111, and the slips 110 can move relative to the inclined surface of the cone 109; the suspension mechanism 103 works in conjunction with the pre-locking module 105 to prevent the suspension mechanism 103 from being prematurely activated and set with the casing 101. Once the pre-locking module 105 releases the suspension mechanism 103, the pressure applied downward by the running string 104 can be used to drive at least one hydraulic mechanism 111 to move the slips 110 relative to the cone 109. The relative movement of the slips 110 on the inclined surface of the cone 109 effectively forces the slips 110 to move radially outward and eventually engage with the surrounding casing 101.

[0077] When the ball seat 148 is in the blocked state: the running tool assembly 106 can move relative to the core shaft assembly 112 under the action of the pressure difference between the inner pressure zone 118 and the medium pressure zone 120, so that the pre-locking module 105 is unlocked; the hydraulic mechanism 111 can drive the cava 110 to move radially outward along the inclined surface of the cone 109 under the action of the pressure difference between the inner pressure zone 118 and the medium pressure zone 120, and engage with the casing 101, so as to seat the tail pipe hanger 102 on the casing 101.

[0078] The present invention relates to the field of oil and gas cementing tools, and in particular to a liner suspension system and method without pressure sensitive drive. By setting a pre-locking module 105 in the liner hanger 102, the risk of premature setting and release of the liner hanger 102 due to excessive external pressure fluctuations when the liner hanger 102 is lowered is overcome. The present invention utilizes a liner hanger system having a running string 104 and a liner hanger 102. The liner hanger 102 can be started at a desired position to hang the liner / casing on the surrounding casing string. The liner suspension system utilizes a pre-locking module 105, which can be used in conjunction with the liner hanger 102 to prevent the liner hanger 102 from starting too early. The pre-locking module 105 can achieve pressure balance between the area in the running string 104 and the area between the running string 104 and the liner hanger 102 to prevent the liner hanger 102 from starting due to pressure imbalance. Specifically, an internal pressure zone 118 is formed in the internal channel of the mandrel assembly 112, a medium pressure zone 120 is arranged between the mandrel assembly 112 and the liner hanger 102, and an internal channel 119 extends downward through the mandrel assembly 112 to communicate with the medium pressure zone 120; the internal pressure zone 118 is communicated with the medium pressure zone 120 through a plurality of channels arranged on the mandrel assembly 112, so as to achieve pressure balance between the area inside the lowering string 104, i.e., the internal pressure zone 118, and the area between the lowering string 104 and the liner hanger 102, i.e., the medium pressure zone 120, thereby preventing pressure imbalance when starting the liner hanger 102 and facilitating fluid circulation at a relatively high rate and pressure during the lowering of the liner and the liner hanger. By connecting the running tool assembly 106 with the core shaft assembly 112, the running tool assembly 106 can move relative to the core shaft assembly 112 under the action of the pressure difference between the internal pressure zone 118 and the medium pressure zone 120 when the ball seat 148 is blocked, so that the locking mechanism 143 is unlocked, and the tail pipe hanger can generate a pressure difference between the internal pressure zone and the medium pressure zone by throwing a ball into the running tool. By relatively increasing the pressure in the internal pressure zone, the locking mechanism is released, allowing the tail pipe hanger to be driven. Furthermore, under the action of the pressure difference between the inner pressure zone 118 and the medium pressure zone 120, the hydraulic mechanism 111 can drive the slip 110 to move relative to the inclined surface of the cone 109, so that the slip 110 moves radially outward along the inclined surface of the cone 109 and engages with the surrounding casing 101 to seal the tail tube hanger 102 on the casing 101. By arranging a pre-locking module in the tail tube hanger, the risk of premature sealing and release of the tail tube hanger due to excessive external pressure fluctuations when the tail tube hanger is lowered is overcome. The pre-locking module can be used in conjunction with the tail tube hanger to prevent the tail tube hanger from starting prematurely, thereby improving the reliability of the tail tube hanger in deep wells and ultra-deep wells.

[0079] Reference Figure 2, which shows a cross-sectional view of the connection portion of the packer 108. The mandrel assembly 112 is arranged in the outer body 113 of the entire liner hanger 102;

[0080] The mandrel assembly 112 further includes a second mandrel 116 disposed at the upper end of the first mandrel 114, and a first sealing assembly 117 is disposed between the second mandrel 116 and the outer body 113. The first sealing assembly 117 surrounds the second mandrel 116, and the function of the first sealing assembly 117 is to form a seal between the second mandrel 116 and the surrounding outer body 113.

[0081] Reference Figure 3 As shown, the mandrel assembly 112 of the running string 104 is coupled to the running tool assembly 106 of the liner hanger 102, thereby connecting the running string 104 and the liner hanger 102. The running tool assembly 106 includes a clamping mechanism 122, a connecting mechanism 123, and a first piston mechanism 121 slidably mounted around the first mandrel 114;

[0082] The driving chamber of the first piston mechanism 121 is connected to the radial channel 130 through a first channel provided on the first core shaft 114;

[0083] A retaining ring 150 is disposed at the upper end of the first piston mechanism 121 . The retaining ring 150 is fixed to the outer sleeve 151 through a shearing mechanism 125 . The retaining ring 150 defines the initial state of the first piston mechanism 121 .

[0084] The first piston mechanism 121 is connected to the packer 108 through the clamping mechanism 122 and the connecting mechanism 123. The present invention uses a pressure difference to release the running tool assembly 106 from the tail pipe hanger assembly. Specifically, when the internal pressure zone 118 is connected, the pressure cannot form and cannot move the first piston mechanism 121. Therefore, the running string 104 and the packer 108 will not be released prematurely. In fact, the structure of the first piston mechanism 121 and the entire running tool assembly 106 allows the pressure to be transmitted upward along the medium pressure zone 120 to the isolation structure 115 of the packer 108. This allows the internal pressure zone 118 and the medium pressure zone 120 to communicate with each other to achieve pressure balance, thereby preventing the packer 108 and the running string 104 from being released prematurely. However, once the internal pressure zone 118 is blocked (for example, by throwing a ball), a greater pressure can be applied through the internal pressure zone 118 relative to the medium pressure zone 120. The increased pressure acts on the first piston mechanism 121 through the first passage 124. Sufficient pressure in the inner pressure zone 118 relative to the medium pressure zone 120 causes the first piston mechanism 121 to move axially along the first mandrel 114, and the first piston mechanism 121 pushes the connecting mechanism 123 to move axially, and the clamping mechanism 122 is moved to the release position through the connecting mechanism 123. Moving the clamping mechanism 122 to the release position also releases the connection between the packer 108 and the running string 104. After the connection between the packer 108 and the running string 104 is released, the packer 108 can be set mechanically.

[0085] Reference Figure 4 As shown, the spindle assembly 112 has a bypass module 126, and the bypass module 126 is disposed in the hydraulic mechanism 111;

[0086] The suspension mechanism 103 includes a hanger body 127, and a second sealing assembly 128 is disposed between the bypass module 126 and the hanger body 127. The bypass module 126 is sealed and engaged with the hanger body 127 of the suspension mechanism 103 through the second sealing assembly 128, and the hanger body 127 is positioned by the internal structure of the hydraulic mechanism 111.

[0087] Reference Figure 4 As shown, the bypass module 126 includes a longitudinal channel 129 that extends axially through the second sealing assembly 128 to achieve pressure balance between the inner pressure area 118 and the middle pressure area 120 above and below the second sealing assembly 128 .

[0088] Reference Figure 4 , Figure 5 and Figure 6As shown, the bypass module 126 further includes a radial passage 130 extending between the inner pressure region 118 and the intermediate pressure region 120 , and the position of the radial passage 130 is kept isolated from the longitudinal passage 129 ;

[0089] The hydraulic mechanism 111 is provided with a first driving chamber 132;

[0090] The hanger body 127 is provided with a second channel 131, which is in communication with the radial channel 130 and the first drive chamber 132. The corresponding second channel 131 is formed by the hanger body 127, so that the medium pressure area 120 can be connected with the drive chamber of at least one corresponding hydraulic mechanism 111, that is, the first drive chamber 132. Once the flow along the internal pressure area 118 is blocked, the pressure in the internal pressure area 118 will increase, and this relatively increased pressure passes through the radial channel 130 and then through the second channel 131 to enter the first drive chamber 132. Sufficient pressure can cause the corresponding hydraulic mechanism 111 to axially displace relative to the hanger body of the suspension mechanism 103, and then drive the slips 110 to seal the liner hanger 102.

[0091] Reference Fig. 7A As shown, the spindle assembly 112 includes a first spindle 114;

[0092] The pre-locking module 105 includes a third sealing assembly 134 and a second piston mechanism slidably mounted around the first spindle 114;

[0093] A third sealing assembly 134 is disposed between the first core shaft 114 and the second piston mechanism to form a second driving chamber 135;

[0094] The first core shaft 114 is provided with a third channel 136, and the second driving chamber 135 is in communication with the internal pressure zone 118 through the third channel 136. The third sealing assembly 134 is located between the piston 133 and the first core shaft 114 to form a second driving chamber 135, and the second driving chamber 135 is in fluid communication with the internal pressure zone 118 through at least one third channel 136. The second piston mechanism includes an upper sleeve 140, a lower sleeve 137 and a piston 133;

[0095] The upper sleeve 140 and the lower sleeve 137 are respectively arranged at both ends of the piston 133; the upper sleeve 140 and the lower sleeve 137 are coupled with the movable piston 133, the piston 133 is installed around the first core shaft 114, and the piston 133 is prevented from rotating relative to the first core shaft and can only move axially.

[0096] The lower sleeve 137 and the first mandrel 114 are connected by a first pin 138, and the upper sleeve 140 and the first mandrel 114 are connected by a second pin 141. The first pin 138 is used to limit the position of the lower sleeve 137, and the second pin 141 is used to limit the position of the upper sleeve 140, so that it can only move axially within a specified area. The first mandrel 114 is provided with a first limiting groove 139 corresponding to the position of the lower sleeve 137, and the first limiting groove 139 is used to limit the axial movement area of ​​the lower sleeve 137. The first mandrel 114 is provided with a second limiting groove 142 corresponding to the position of the upper sleeve 140, and the second limiting groove 142 is used to limit the axial movement area of ​​the upper sleeve 140.

[0097] Reference Fig. 7A and Figure 7B As shown, a locking mechanism 143 may be used to lock the liner hanger 102 to prevent premature activation.

[0098] The liner hanger 102 includes a hanger body 127;

[0099] The locking mechanism 143 is mounted on the hanger body 127 .

[0100] Reference Figure 7B and Figure 8 As shown, the locking mechanism 143 locks the suspension mechanism 103 when it is lowered into the wellbore so that it is not driven. The locking mechanism 143 includes a spring component 146 and a plurality of limit lock blocks 144 installed in the suspension mechanism 103;

[0101] One end of the spring component 146 abuts against the upper sleeve 140, and the other end is connected to the limit lock block 144; a plurality of limit lock blocks 144 are installed in the suspension mechanism 103 and retained in the suspension mechanism 103. The plurality of limit lock blocks 144 are maintained in a radially outward locking position by the upper sleeve 140 and the lower sleeve 137, and the plurality of limit lock blocks 144 are supported in a radially outward direction by the spring force of the spring component 146, so that the liner hanger 102 is in an initial locking state. The locking mechanism 143 includes a sleeve coupled to the piston 133, and the plurality of limit lock blocks 144 are engaged with the inner surface of the corresponding hydraulic mechanism 111 of the liner hanger 102.

[0102] The hanger body 127 of the suspension mechanism 103 is radially formed with a first groove 145 corresponding to the limit lock block 144. The limit lock block 144 can be installed in the corresponding first groove 145 formed along the outside of the hanger body 127. The limit lock block 144 is embedded in the first groove 145 under the action of the spring component 146.

[0103] When the suspension mechanism 103 is in the position required for the slip 110 to be hung, the ball 147 is lowered through the internal channel 119 of the lower pipe string 104 and the mandrel assembly 112 until it contacts the corresponding ball seat 148. When the ball 147 contacts the ball seat 148, the pressure can be increased along the internal pressure zone 118 to establish a pressure difference between the internal pressure zone 118 and the medium pressure zone 120. The increased pressure in the internal pressure zone 118 acts on the piston 133 through the third channel 136. After the set pressure is increased, the piston 133 moves relative to the hanger body 127 of the suspension mechanism 103, driving the upper sleeve 140 to move downward. Under the action of the spring component 146, the limit lock block 144 is separated from the hydraulic mechanism 111, and the pre-locking module 105 is unlocked. At the same time, the increased pressure in the internal pressure zone 118 can act on the corresponding hydraulic mechanism 111 through the radial channel 130 and the second channel 131. Because the corresponding limit lock block 144 no longer locks the hydraulic mechanism 111 in the initial position relative to the hanger body 127, the sufficient increase in pressure can cause at least one hydraulic mechanism 111 to move upward along the hanger body 127. The upward movement of the hydraulic mechanism 111 causes the slips 110 to transition from a radially contracted position to a radially expanded position, thereby engaging the surrounding casing 101 support. Fig.9A , which is a schematic diagram of the structure of the slip 110 when it is radially contracted; Fig. 9B , which is a schematic diagram of the structure of the slip 110 when it is radially expanded.

[0104] In some embodiments, Figure 8 As shown, a second groove 149 corresponding to the limit locking block 144 may also be provided inside the corresponding hydraulic mechanism 111 surrounding the limit locking block 144;

[0105] The limit lock block 144 can move into the second groove 149 after being unlocked, and be embedded in the second groove 149 under the action of the spring component 146. The spring component 146 can bias the limit lock block 144 radially outward again after driving the suspension mechanism 103, and the limit lock block 144 is embedded in the second groove 149.

[0106] In some embodiments, the packer assembly includes a packer drive assembly 107 and a packer 108 connected to each other, wherein the packer drive assembly 107 is located in a medium pressure zone 120 above the packer 108, and is used to ensure an initial pressure balance between the internal pressure zone 118 and the medium pressure zone 120, so as to prevent the packer 108 and the running tool assembly 106 from being released prematurely;

[0107] The liner hanger 102 includes an outer body 113, and the mandrel assembly 112 is arranged in the outer body 113;

[0108] The packer 108 is disposed in the outer body 113, and the packer 108 is connected to the mandrel assembly 112 and the outer body 113, respectively. The packer 108 is released by increasing the pressure difference between the inner pressure zone 118 and the middle pressure zone 120, and after the dropped ball 147 contacts the ball seat 148, the pressure accumulation in the inner pressure zone 118 causes the liner hanger 102 to be set, and then the packer 108 is set and the running tool assembly 106 is released.

[0109] Embodiment 2

[0110] An embodiment of the present invention provides a method for using the tail pipe suspension system as described in Embodiment 1, comprising:

[0111] S101, deploying a liner hanger 102 downhole by running a tool assembly 106; locking the liner hanger 102 of the liner hanger assembly in a radially contracted state by a locking mechanism 143 installed in the liner hanger 102 and retained by the liner hanger 102;

[0112] S102, the ball 147 is delivered to the ball seat 148, and pressure is applied to the internal channel 119, so as to generate a pressure difference between the internal pressure area 118 and the intermediate pressure area 120, that is, a pressure difference is generated between the internal pressure area of ​​the running tool assembly 106 and the intermediate pressure area around the running tool assembly 106, and the piston of the running tool assembly 106 is moved by using the pressure difference to release the locking mechanism;

[0113] S103. When the pressure difference reaches the first preset value, the second piston mechanism moves upward and the pre-locking module 105 is unlocked; at the same time, the increased pressure in the internal pressure zone 118 acts on the hydraulic mechanism 111, and the hydraulic mechanism 111 moves upward to drive the cava 110 to move relative to the inclined surface of the cone 109, so that the cava 110 moves radially outward and engages with the surrounding casing 101, and the liner hanger 102 is seated on the casing 101, thereby using the pressure difference to drive the liner hanger 102 to be seated at the set position in the wellbore.

[0114] In a specific embodiment, the method further comprises:

[0115] S104, continue to apply pressure to the internal channel 119, when the pressure difference reaches a second preset value, the first piston mechanism 121 moves, releases the clamping mechanism 122, and the packer 108 is separated from the running pipe string 104; wherein the second preset value is greater than the first preset value.

[0116] Specifically, the operating method of the liner suspension system provided by the embodiment of the present invention is as follows: after the liner hanger 102 is sent to the designated position, the ball 147 is dropped from the wellhead, and after the ball 147 falls into the ball seat 148, pressure is applied along the internal channel 119, so that the ball 147 can form a pressure difference between the internal pressure zone 118 and the medium pressure zone 120, and the increased pressure in the internal pressure zone 118 acts on the piston 133 through the third channel 136. When the pressure difference reaches the set value, the piston 133 moves downward to make the upper sleeve 140 away from the limit lock block 144, thereby releasing the limit lock block 144, the pre-locking module 105 is unlocked, and the limit lock block 144 no longer locks the hydraulic mechanism 111 in the initial position. At the same time, the increased pressure in the internal pressure zone 118 acts on the hydraulic mechanism 111 through the radial channel 130 and the second channel 131, and the hydraulic mechanism 111 moves upward to drive the slips 110, and the slips 110 engage with the casing 101, thereby achieving the setting of the liner hanger 102. The pressure is continuously applied along the internal passage 119, and the first piston mechanism 121 moves downward, releasing the clamping mechanism 122, thereby releasing the connection between the packer 108 and the running string 104. After the packer 108 is released, the packer 108 can be set by applying the weight of the drill string, etc., to achieve the use of differential pressure to release the packer of the liner hanger assembly, and to achieve the setting of the packer by releasing the weight on the packer.

[0117] Subsequently, the ball 147 and the ball seat 148 may be removed from the internal passage 119 by continuing to apply pressure to shear the ball seat 148. In addition, the mandrel assembly 112 and the entire running string 104 may also be removed from the liner hanger 102 and recovered to the surface.

[0118] In the embodiment of the present invention, the method of using the tail pipe suspension system corresponds to the tail pipe suspension system described in the above embodiment 1. The specific implementation process can refer to the description of the tail pipe suspension system in the above embodiment 1, and the repeated parts will not be repeated here.

[0119] In this document, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The orientation or position relationship indicated by the terms "upper", "lower", etc. is based on the orientation or position relationship shown in the accompanying drawings, and is 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 operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0120] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. The present invention is not limited to any single aspect, any single embodiment, or any combination and / or permutation of these aspects and / or embodiments. Each aspect and / or embodiment of the present invention can be used alone, or in combination with one or more other aspects and / or other embodiments.

[0121] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A tail pipe suspension system, characterized in that: include: A liner hanger (102), a suspension mechanism (103), a running string (104), a pre-locking module (105), a packer assembly, at least one hydraulic mechanism (111), and a ball seat (148) arranged at the rear end of the running string (104); The running pipe string (104) includes a mandrel assembly (112), and the liner hanger (102) includes a running tool assembly (106), and the running tool assembly (106) is connected to the mandrel assembly (112); The hanging mechanism (103) is locked on the liner hanger (102) through the pre-locking module (105), the pre-locking module (105) comprises a locking mechanism (143) mounted on the liner hanger (102) and an outer sleeve (151) mounted on the running tool assembly (106), the locking mechanism (143) being fixed at a preset position by the sleeve; The inner passage (119) of the mandrel assembly (112) is formed with an inner pressure zone (118); A medium-pressure area (120) is provided between the mandrel assembly (112) and the liner hanger (102), and the internal channel (119) extends downward through the mandrel assembly (112) and communicates with the medium-pressure area (120); The internal pressure zone (118) is connected to the medium pressure zone (120) through a plurality of channels arranged on the mandrel assembly (112); the packer assembly is used to form a pressure difference between the internal pressure zone (118) and the medium pressure zone (120); The running tool assembly (106) and the at least one hydraulic mechanism (111) are arranged in the medium pressure zone (120); The suspension mechanism (103) comprises a cone (109) having an inclined surface and a slip (110) connected to the hydraulic mechanism (111), wherein the slip (110) can move relative to the inclined surface of the cone (109); When the ball seat (148) is in the blocked state: the delivery tool assembly (106) can move relative to the core shaft assembly (112) under the action of the pressure difference between the inner pressure zone (118) and the medium pressure zone (120), releasing the locking mechanism (143) so that the pre-locking module (105) is unlocked; the hydraulic mechanism (111) can drive the slip (110) to move radially outward along the inclined surface of the cone (109) and engage with the casing (101) under the action of the pressure difference between the inner pressure zone (118) and the medium pressure zone (120).

2. The tail pipe suspension system according to claim 1, characterized in that: The mandrel assembly (112) includes a first mandrel (114); The pre-locking module (105) includes a third sealing assembly (134) and a second piston mechanism slidably mounted around the first spindle (114); A third sealing assembly (134) is provided between the first core shaft (114) and the second piston mechanism to form a second driving chamber (135); The first core shaft (114) is provided with a third channel (136), and the second driving chamber (135) is connected to the internal pressure zone (118) through the third channel (136).

3. The tail pipe suspension system according to claim 2, characterized in that: The suspension mechanism (103) comprises a hanger body (127); The locking mechanism (143) is mounted on the hanger body (127).

4. The tail pipe suspension system according to claim 3, characterized in that: The second piston mechanism comprises an upper sleeve (140), a lower sleeve (137) and a piston (133); The upper sleeve (140) and the lower sleeve (137) are respectively arranged at two ends of the piston (133); The lower sleeve (137) and the first core shaft (114) are connected via a first pin (138), and the upper sleeve (140) and the first core shaft (114) are connected via a second pin (141).

5. The tail pipe suspension system according to claim 4, characterized in that: The locking mechanism (143) comprises a spring component (146) and a plurality of limiting locking blocks (144) installed in the suspension mechanism (103); One end of the spring component (146) abuts against the upper sleeve (140), and the other end is connected to the limiting lock block (144); The hanger body (127) is formed with a first groove (145) corresponding to the limiting locking block (144) along the outer radial direction, and the limiting locking block (144) is embedded in the first groove (145) under the action of the spring component (146).

6. The tail pipe suspension system according to claim 5, characterized in that: A second groove (149) corresponding to the limiting locking block (144) is arranged inside the hydraulic mechanism (111); The limiting lock block (144) can move into the second groove (149) after being unlocked, and is embedded in the second groove (149) under the action of the spring component (146).

7. The tail pipe suspension system according to claim 1, characterized in that: The spindle assembly (112) has a bypass module (126), and the bypass module (126) is arranged in the hydraulic mechanism (111); A second sealing assembly (128) is disposed between the bypass module (126) and the hanger body (127).

8. The tail pipe suspension system according to claim 7, characterized in that: The bypass module (126) includes a longitudinal passage (129) extending axially through the second sealing assembly (128) to achieve pressure balance between the inner pressure area (118) and the intermediate pressure area (120) above and below the second sealing assembly (128).

9. The tail pipe suspension system according to claim 8, characterized in that: The bypass module (126) further includes a radial channel (130) extending between the internal pressure region (118) and the medium pressure region (120), wherein the radial channel (130) is located so as to be isolated from the longitudinal channel (129); A first driving chamber (132) is provided in the hydraulic mechanism (111); The hanger body (127) is provided with a second passage (131), and the second passage (131) is communicated with the radial passage (130) and the first driving chamber (132).

10. The tail pipe suspension system according to claim 2, characterized in that: The packer assembly comprises a packer drive assembly (107) and a packer (108) connected to each other, wherein the packer drive assembly (107) is located in a medium pressure zone (120) above the packer (108); The liner hanger (102) comprises an outer body (113), and the mandrel assembly (112) is arranged in the outer body (113); The packer (108) is arranged in the outer body (113), and the packer (108) is connected to the core shaft assembly (112) and the outer body (113) respectively.

11. The tail pipe suspension system according to claim 10, characterized in that: The running tool assembly (106) includes a clamping mechanism (122), a connecting mechanism (123) and a first piston mechanism (121) slidably mounted around a first mandrel (114); The driving chamber of the first piston mechanism (121) is in communication with the radial channel (130) via a first channel provided on the first core shaft (114); A retaining ring (150) is provided at the upper end of the first piston mechanism (121), and the retaining ring (150) is fixed to the outer sleeve (151) through a shearing mechanism (125); The first piston mechanism (121) is connected to the packer (108) via the clamping mechanism (122) and the connecting mechanism (123).

12. The tail pipe suspension system according to claim 10, characterized in that: The core shaft assembly (112) further comprises a second core shaft (116) arranged at the upper end of the first core shaft (114), and a first sealing component (117) is arranged between the second core shaft (116) and the outer body (113).

13. A method for using the tail pipe suspension system according to any one of claims 1 to 12, characterized in that: include; Deploying a liner hanger (102) downhole via a running tool assembly (106); Throwing the ball (147) onto the ball seat (148), applying pressure to the inner channel (119), and generating a pressure difference between the inner pressure area (118) and the medium pressure area (120); When the pressure difference reaches a first preset value, the locking mechanism (143) is released and the pre-locking module (105) is unlocked; at the same time, the increased pressure in the internal pressure zone (118) acts on the hydraulic mechanism (111), and the hydraulic mechanism (111) moves upward to drive the slip (110) to move relative to the inclined surface of the cone (109), so that the slip (110) moves radially outward and engages with the surrounding casing (101), and the tail pipe hanger (102) is sealed on the casing (101).

14. The method for using the tail pipe suspension system according to claim 13, characterized in that: The method further comprises: continuing to apply pressure to the internal channel (119); when the pressure difference reaches a second preset value, the first piston mechanism (121) moves, releasing the clamping mechanism (122), and the packer (108) is separated from the running pipe string (104); wherein the second preset value is greater than the first preset value.

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