Drilling liner suspension system for upper well cementation

Abstract

The invention belongs to the field of petroleum and natural gas well cementation tools, particularly relates to a tail pipe suspension system for upper well cementation, and aims to solve the problems that in the prior art, cement is pumped into an outer annulus of a tail pipe from a drill floor, a large amount of cement is left in the tail pipe, and time and labor are wasted for later operation. According to the drilling liner hanger, the drilling liner is subjected to well cementation in the borehole by using the tripping-in tool, and the drilling liner hanger is fixed in the borehole by using the bridge plug to transfer hydraulic pressure. The bypass port is opened by deploying another bridge plug onto the opening valve seat and driving movement of the control unit that is open relative to the bypass port. When the packer of the tool remains sealed in the hanger, cement pumped from the bypass port is pressed into the drilling liner and the outer annulus of the wellbore. After well cementation is completed, the bypass port is closed by deploying the other bridge plug onto the closing valve seat and moving the other bridge plug. According to the invention, the risk that cement is left in the tail pipe assembly can be reduced, and additional equipment does not need to be tripped above the tripping-in tool.

Description

Technical Field

[0001] The present invention belongs to the field of oil and gas cementing tools, and particularly relates to a liner hanger system for upper cementing. Background Art

[0002] For traditional liner cementing in horizontal wells, in order to cement the liner in place, cement is pumped into the running string, through the liner and into the annulus outside the liner. In contrast, in some types of liner cementing processes, it is not necessary to cement around the liner in the horizontal section of the wellbore, but only to cement at the top of the liner in the vertical section of the wellbore.

[0003] Traditionally, the cementing operation is completed by closing the liner and removing the running tool from the liner, and circulating the cement from the end of the liner assembly to the annulus behind the liner. However, pumping cement from the drill floor into the annulus outside the liner. This causes a large amount of cement to remain in the liner, which is time-consuming and laborious for later operations.

[0004] Based on this, the present invention proposes a liner hanger system for upper cementing. Summary of the Invention

[0005] In order to solve the above problems in the prior art, that is, in the prior art, pumping cement from the drill floor into the annulus outside the liner causes a large amount of cement to remain in the liner, which is time-consuming and laborious for later operations. The present invention provides a liner hanger system for upper cementing, which system includes a running tool, a liner assembly and a plug assembly;

[0006] The running tool includes a tool body, and the tool body includes a cementing assembly; the main body of the cementing assembly is a housing, and a first channel is opened along the axial direction of the housing, and the first channel communicates with a bypass port, and the bypass port is opened on the outer circumferential surface of the housing;

[0007] A control unit is arranged in the first channel, a control port is opened on the outer circumferential surface of the control unit, the control port is connected with a control channel, the control channel is opened in the axial direction of the control unit, and an opening unit and a closing unit are arranged in the control channel. The opening unit moves from a closed state to an open state relative to the control port in the control unit; the closing unit is used to release the control unit, so that the control port moves relative to the bypass port and closes;

[0008] The liner assembly includes a liner hanger system and a liner string. The liner hanger system includes a setting mechanism and a hydraulic mechanism. The hydraulic mechanism is sleeved on the outer surface of the body of the liner hanger system. The setting mechanism is disposed in the casing of the wellbore through the hydraulic mechanism. A second channel is coaxially formed on the body of the liner hanger system, and the hydraulic mechanism has a driving port in the second channel. The liner string is supported in the wellbore by the liner hanger system.

[0009] The bridge plug assembly is disposed on and moves along the opening unit and the closing unit, and is configured to open or close the bypass port.

[0010] In some preferred embodiments, the liner assembly further includes a float shoe assembly, a tieback string, and a liner top packer. The float shoe assembly is connected to the distal end of the liner string. The liner top packer is configured to be set by compression in the casing of the wellbore. The tieback string is connected to the upper end of the liner top packer. The liner top packer includes additional slips, and the additional slips engage with the casing to keep the liner top packer in a compressed state.

[0011] In some preferred embodiments, the main body of the control unit is of a cylindrical structure. The control unit is sealingly connected to the first channel through a first seal. First and second chucks are respectively disposed at both ends of the cylindrical structure of the control unit. The first chuck is used to support the opening unit, and the second chuck is used to support the closing unit.

[0012] The first chuck is fixed on the inner circumferential surface of the housing, and a plurality of the first chucks are uniformly arranged along the circumferential direction at one end of the control unit. The second chuck engages with a groove, and the groove is circumferentially formed on the inner circumferential surface of the housing.

[0013] The first chuck can be disposed in a first slot, and the first slot is formed on the surface of the first channel. The second chuck can be disposed in a second slot, and the second slot is formed on the surface of the first channel.

[0014] In some preferred embodiments, the running tool includes an opening unit at least partially disposed in the control unit, which has a movable opening valve seat. The opening unit moves from an initial closed position to an open state relative to the bypass port in the control unit in response to hydraulic pressure applied to the opening bridge plug on the opening valve seat. The control unit includes a first chuck configured to capture the opening unit in a second closed position. The first chuck is configured to release the opening unit in response to a predetermined pressure.

[0015] In some preferred embodiments, the opening unit is hermetically connected to the control unit through a second seal. An opening through-hole and an opening valve seat are successively formed in the main body of the opening unit. The opening plug in the bridge plug assembly can be installed on the opening valve seat through the opening through-hole.

[0016] The main body of the opening unit is fixed to the control unit by a first pin. In an initial state, the main body of the opening unit is configured to close the control port and the bypass port.

[0017] In some preferred embodiments, the running tool includes a closing unit at least partially disposed in the control unit and having a movable closing valve seat therein. The closing unit can move from an engaged state to a disengaged state relative to a second collet on the control unit in response to hydraulic pressure applied to the closing plug, and the disengaged state is achieved by the closing unit.

[0018] In some preferred embodiments, the closing unit is hermetically connected to the inner circumferential surface of the housing through a third seal. A preset distance is reserved between one end of the closing unit close to the opening unit and the opening unit. The other end of the closing unit far from the opening unit is fixed to the housing by a second pin.

[0019] A closing through-hole and a closing valve seat are successively formed in the interior of the main body of the closing unit along its axial direction. The closing plug in the bridge plug assembly can be disposed in the closing valve seat through the closing through-hole. The second pin is released by a predetermined force generated by the hydraulic pressure on the closing plug, so that the outer circumferential surface of the closing valve seat closes the control port and the bypass port.

[0020] A base is fixed to the main body of the closing unit, and the base is supported by the second collet.

[0021] In some preferred embodiments, the tool body further includes a setting assembly connected to the lower end of the cementing assembly. The setting assembly includes an engaging mechanism that engages and fixes with the inner circumferential surface of the second channel to realize the releasable engagement of the liner hanger assembly. A seal packer is provided between the engaging mechanism and the cementing assembly. The seal packer is sealed in the liner hanger system and seals the tie-back casing through a seal actuator.

[0022] In some preferred embodiments, the lower end of the setting assembly is connected to an isolation assembly. The isolation assembly includes a pressure port and a setting seat. The pressure port is formed on the outer circumferential surface of the isolation assembly body and communicates with the first channel and the second channel. The pressure port is opened or closed through the setting seat. The setting seat is disposed on the inner circumferential surface of the isolation assembly body and can slide along it.

[0023] Sealing partitions are provided at both the upper and lower ends of the pressure port. The sealing partitions are used to seal off the second channel and the hydraulic ports in the hydraulic mechanism. The hydraulic ports are opened on the hydraulic mechanism and the body of the liner hanger system and are in communication with the second channel. Liquid can push the slips of the setting mechanism to actuate through the hydraulic ports to achieve setting and hanging.

[0024] In some preferred embodiments, the upper end of the cementing assembly in the running tool is connected to the running string. The running tool is at least partially disposed within the liner hanger system. The running string is used to lower the liner assembly from surface equipment.

[0025] Advantages of the present invention:

[0026] The present invention uses a running tool to cement the liner in the wellbore. When the bypass port of the tool is closed, the bridge plug of the running tool transfers hydraulic pressure to fix the liner hanger in the wellbore. By deploying another bridge plug onto the open valve seat and driving the control unit that is open relative to the bypass port to move, the bypass port is opened. When the packer of the tool maintains a seal in the hanger, the cement pumped out from the bypass port is pressed into the annulus between the liner and the wellbore. After cementing is completed, by deploying another bridge plug onto the closed valve seat and moving the control sleeve that is closed relative to the bypass port, the bypass port is closed. By allowing fluid to flow through the bridge plug in the tool, fluid communication between the tool and the liner is re-established. The present invention can reduce the risk of leaving cement within the liner assembly without the need to run additional equipment above the running tool. Before performing a liner top squeeze operation using the present invention, it is not necessary to pump cement into the liner annulus. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects, and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings:

[0028] Figure 1 is a schematic diagram of the principle of a liner hanger system for upper cementing according to the present invention;

[0029] Figure 2 is a schematic diagram of the structure of the bridge plug assembly and the running tool of a liner hanger system for upper cementing according to the present invention;

[0030] Figure 3 is a schematic diagram of the structure of the liner hanger system of a liner hanger system for upper cementing according to the present invention;

[0031] Figure 4A is a schematic diagram of the first state of the cementing assembly in the initial stage of a liner hanger system for upper cementing according to the present invention;

[0032] Figure 4B It is a schematic diagram of the second state of the cementing assembly in the initial stage of a liner hanger system for upper cementing according to the present invention;

[0033] Figure 5A It is a schematic diagram of the first state of the cementing assembly in the opening stage of a liner hanger system for upper cementing according to the present invention;

[0034] Figure 5B It is a schematic diagram of the first state of the cementing assembly in the opening stage of a liner hanger system for upper cementing according to the present invention;

[0035] Figure 6A It is a schematic diagram of the first state of the cementing assembly in the closing stage of a liner hanger system for upper cementing according to the present invention;

[0036] Figure 6B It is a schematic diagram of the second state of the cementing assembly in the closing stage of a liner hanger system for upper cementing according to the present invention;

[0037] Figure 6C It is a schematic diagram of the third state of the cementing assembly in the closing stage of a liner hanger system for upper cementing according to the present invention. Detailed implementation manners

[0038] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention and are not intended to limit the invention. Additionally, it should be noted that for the sake of description, only parts related to the relevant invention are shown in the drawings.

[0039] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0040] As Figures 1 - 6C shown, referring to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4A , the present invention provides a liner hanger system for upper cementing, which system includes a running tool 100, a liner assembly 20 and a plug assembly 60;

[0041] The running tool 100 includes a tool body 102, and the tool body 102 includes a cementing assembly 110; the main body of the cementing assembly 110 is a housing 112, and a first channel 114 is provided along the axial direction of the housing 112, and the first channel 114 communicates with a bypass port 116, and the bypass port 116 is provided on the outer circumferential surface of the housing 112;

[0042] A control unit 140 is provided in the first channel 114. Control ports 146 are formed on the outer circumferential surface of the control unit 140. The control ports 146 are connected to a control channel 142. The control channel 142 is formed in the axial direction of the control unit 140. An opening unit 130 and a closing unit 150 are provided in the control channel 142. The opening unit 130 moves from a closed state to an open state relative to the control ports 146 in the control unit 140; the closing unit 150 is configured to release the control unit 140, such that the control ports 146 move relative to the bypass ports 116 to close.

[0043] The liner assembly 20 includes a liner hanger system 30 and a liner string 22. The liner hanger system 30 includes a setting mechanism 32 and a hydraulic mechanism 34; the hydraulic mechanism 34 is sleeved on the outer surface of the body of the liner hanger system 30. The setting mechanism 32 is disposed in the casing 14 of the wellbore 12 through the hydraulic mechanism 34; a second channel 31 is coaxially formed on the body of the liner hanger system 30. The hydraulic mechanism 34 has a driving port in the second channel 31; the liner string 22 is supported in the wellbore 12 by the liner hanger system 30.

[0044] The bridge plug assembly 60 is disposed on and moves along the opening unit 130 and the closing unit 150. The bridge plug assembly 60 is configured to open or close the bypass ports 116.

[0045] Wherein, the liner hanger system 30 is installed on the casing 14 by using the hydraulic pressure of the running string 52.

[0046] Wherein, the hydraulic mechanism 34 may be a hydraulic piston. The hydraulic piston communicates with the second channel 31 through a hydraulic port 36. Under hydraulic drive, the hydraulic cylinder 34 pushes the setting mechanism 32 against the setting cone on the liner hanger system 30, such that the setting mechanism 32 engages with the inner wall of the wellbore casing 14 during downhole setting.

[0047] Wherein, the tool body 102 has a lower end 104 in the well, an upper end 106 in the well, and a tool channel 105. Generally, the tool body 102 may be composed of a plurality of interconnected components, a cementing tool 110, a setting assembly 160, and an isolation assembly 180, such that the tool channel 105 extends through the running tool 100. The upper end 106 of the running tool 100 is configured to be connected to the running string 52. The tool body 102 is installed in the interior 31 of the liner hanger 30 for running and setting the liner assembly 20.

[0048] Preferably, refer to Figure 3The liner assembly 20 further includes a float shoe assembly 40, a tieback cylinder 35, and a liner top packer 38; the float shoe assembly 40 is connected to the distal end of the liner string 22; the liner top packer 38 is configured to be set in the casing 14 of the wellbore 12 by compression; the tieback cylinder 35 is connected to the upper end of the liner top packer 38, and the liner top packer 38 includes an additional slip 39, and the additional slip 39 engages with the casing 14 to keep the liner top packer 38 in a compressed state.

[0049] Among them, the float shoe assembly 40 may include a float shoe 44, a float collar 46, and a bumping collar 48.

[0050] Preferably, referring to Figure 4A , Figure 4B , Figure 5A , Figure 5B , Figure 6A , Figure 6B , Figure 6C , the main body of the control unit 140 is of a cylindrical structure. The control unit 140 is hermetically connected to the first channel 114 through a first seal 141. First chucks 145a and second chucks 145b are respectively arranged at both ends of the cylindrical structure of the control unit 140. The first chuck 145a is used to support the opening unit 130, and the second chuck 145b is used to support the closing unit;

[0051] The first chuck 145a is fixed on the inner circumferential surface of the housing 112, and a plurality of the first chucks 145a are uniformly arranged along the circumferential direction at one end of the control unit 140; the second chuck 145b engages with the groove 115b, and the groove 115b is circumferentially opened on the inner circumferential surface of the housing 112;

[0052] The first chuck 145a can be arranged in the first slot 115a, and the first slot 115a is opened on the surface of the first channel 114. The second chuck 145b can be arranged in the second slot 115c, and the second slot 115c is opened on the surface of the first channel 114.

[0053] Preferably, the running tool 100 includes an opening unit 130 at least partially disposed in the control unit 140, which has a movable opening valve seat 134. The opening unit 130 moves from an initial closed position to an open state relative to the bypass port 116 in the control unit 140 in response to the hydraulic pressure applied to the opening bridge plug 64 of the opening valve seat 134. Among them, the control unit 140 includes a first chuck 145a configured to capture the opening unit 130 in a second closed position; the first chuck 145a is configured to release the opening unit 130 in response to a predetermined pressure.

[0054] Preferably, referring to Figure 4A , Figure 4B , Figure 5A , Figure 5B , Figure 6A , Figure 6B , Figure 6C , the opening unit 130 is hermetically connected to the control unit 140 through a second seal 131. An opening through-hole 132 and an opening valve seat 134 are successively formed on the main body of the opening unit 130. The opening bridge plug 64 in the bridge plug assembly 60 can be installed on the opening valve seat 134 through the opening through-hole 132;

[0055] The main body of the opening unit 130 is fixed on the control unit 140 through a first pin 133. The main body of the opening unit 130 is used to close the control port 146 and the bypass port 116 in the initial state.

[0056] Among them, when the present invention is in use, by installing the opening bridge plug 64 on the opening valve seat 134 of the running-in tool, using the hydraulic pressure of the running-in string 52 behind the opening bridge plug 64 on the opening valve seat 134, the opening valve seat 134 is opened relative to the bypass port 116 in the running-in tool 100, and the cement is pressed into the annulus between the liner 20 and the wellbore 12 through the bypass port 116.

[0057] Among them, the first pin 133 is a hydraulic pin.

[0058] Among them, the opening unit 130 can move from the closed position to the open state relative to the control port 146 in response to the hydraulic pressure applied to the fixed opening bridge plug 64 by the control unit 140. The control unit 140 includes a catcher configured to capture the opening unit 130 in the second closed position, and the catcher is configured to release the opening unit 130 in response to a predetermined force.

[0059] Preferably, the running-in tool 100 includes a closing unit 150 at least partially disposed in the control unit 140, and has a movable closing valve seat 154 therein. The closing unit 150 can move from the engaged state to the disengaged state relative to the second chuck 145b on the control unit 140 in response to the hydraulic pressure applied to the closing bridge plug 66, and the disengaged state is achieved through the closing unit 150.

[0060] Preferably, referring to Figure 4A , Figure 4B , Figure 5A , Figure 5B , Figure 6A , Figure 6B , Figure 6C, the closing unit 150 is sealingly connected to the inner circumferential surface of the housing 112 through a third seal 151; one end of the closing unit 150 close to the opening unit 130 is reserved a set distance from the opening unit 130; the end of the closing unit 150 far from the opening unit 130 is fixed to the housing 112 through a second pin 156;

[0061] Inside the main body 153 of the closing unit 150, a closing through-hole 152 and a closing valve seat 154 are successively opened along its axial direction; the closing plug 66 in the bridge plug assembly 60 can be arranged in the closing valve seat 154 through the closing through-hole 152, and the second pin 156 is released by a predetermined force generated by the hydraulic pressure on the closing plug 66, so that the outer circumferential surface of the closing valve seat 154 closes the control port 146 and the bypass port 116;

[0062] A base 155 is fixed on the main body 153 of the closing unit 150, and the base 155 is supported by the second chuck 145b.

[0063] Wherein, the closing unit 150 moves from an engaged state to a disengaged state relative to the catcher on the control unit 140 in response to the hydraulic pressure applied to the fixed closing plug 66. In the disengaged state, the catcher is released by the closing unit 150; the control unit 140 moves from an open position to a closed position in response to the released catcher.

[0064] Wherein, the closing unit 150 is held in an initial state in the first channel 114 by a pin 156. A part of the closing unit 150 cooperates with the control unit 140, so that the base 155 of the closing unit 150 engages with the chuck 145b of the control unit 140 to fix the control unit 140 in place;

[0065] The size of the setting plug 62 can pass through the opening valve seat 134 of the opening unit 130 and the closing valve seat 154 of the closing unit 150. Once the setting step is completed as described above, the running tool 100 can be held in place in the liner hanger system 30, so that the bypass port 116 communicates with the liner, and cementing can be carried out.

[0066] The opening plug 64 sits in the opening valve seat 134 of the opening unit 130, and the first pin 133 transmitted through the first channel 114 opens the opening unit 130 in the control unit 140 relative to the control port 146. The opening unit 130 is finally clamped by the lower chuck 145a of the control unit 140 retracted in the channel 114.

[0067] The open state of the opening unit 130 relative to the control port 146 allows fluid to pass from the first channel 114 of the housing through the control port 146 and out of the aligned bypass port 116 to start the cementing operation. The fluid flow can now be diverted from the control port 146, the bypass port 146, and the first channel 116, so that the cement can be lapped with the liner for top-down cementing.

[0068] Meanwhile, the closing unit 150 remains engaged with the control unit 140 through the base 155 that engages with the second chuck 145b. The closing unit 150 is configured to release the control unit 140 when activated. When the cementing operation is completed, the control unit 140 is released in the first channel 114 of the housing 112 so that the control port 146 moves relative to the bypass port 116 to close. Finally, the fluid communication through the wellbore of the running tool can be re-established.

[0069] After cementing is completed, the closing plug 66 is pumped into the running tool 100 and engages with the closing valve seat 154 of the closing unit 150. The pressure applied behind the closing plug 66 eventually causes the bottom second pin 156 of the closing unit 150 to disengage from the housing 112, causing the closing unit 150 to move relative to the control unit 140. The base 155 disengages from the chuck 145b of the control unit 140, and the chuck 145b is not supported by the closing unit 150.

[0070] When the fluid pressure overcomes the control of the first chuck 145a and the second chuck 145b, the closing unit 150, the control unit 140, and the opening unit 130 can move as a whole in the first channel 114. The second chuck 145b contracts, the control unit 140 moves downward, and the flow port 146 in the control unit 140 is no longer aligned with the bypass port 116 in the housing 112, and the bypass port 116 is closed. The first chuck 145a reaches the first slot 115a in the first channel 114, and the first chuck 145a elastically expands. Similarly, the second chuck 145b reaches the second slot 115c, and the second chuck 145b elastically expands.

[0071] Wherein, when the bypass port 116 of the running tool 100 is in the closed state, the opening valve seat 134 is not engaged with the opening plug 64, and at this time, fluid is allowed to pass through the opening valve seat 134 along the tool channel 105 to the wellbore; when the opening valve seat 134 is engaged with the opening plug 64, the fluid communication through the opening valve seat 134 and the tool channel 105 is blocked.

[0072] Preferably, refer to Figure 2, the tool body 102 further includes a setting assembly 160, the setting assembly 160 is connected to the lower end of the cementing assembly 110, the setting assembly 160 includes an engaging mechanism 168, the engaging mechanism 168 is engaged and fixed with the inner circumferential surface of the second channel 31 to realize the releasable engagement of the liner hanger assembly 20. A seal packer 170 is provided between the engaging mechanism 168 and the cementing assembly 110. The seal packer 170 is sealed within the liner hanger system 30 and seals the tieback cylinder 35 through a seal actuator 172.

[0073] Preferably, referring to Figure 2 , the lower end of the setting assembly 160 is connected to an isolation assembly 180. The isolation assembly 180 includes a pressure port 185 and a setting seat 186. The pressure port 185 is opened on the outer circumferential surface of the isolation assembly 180 body and is communicated with the first channel 114 and the second channel 31. The pressure port 185 is opened or closed through the setting seat 186. The setting seat 186 is disposed on the inner circumferential surface of the isolation assembly 180 body and can slide along it.

[0074] Sealing packings 188 are provided at both the upper and lower ends of the pressure port 185. The sealing packings 188 are used to seal the second channel 31 and the hydraulic port 36 in the hydraulic mechanism 34. The hydraulic port 36 is opened on the bodies of the hydraulic mechanism 34 and the liner hanger system 30 and is communicated with the second channel 31. Liquid can push the slips of the setting mechanism 32 to actuate to achieve setting through the hydraulic port 36.

[0075] Among them, the setting port 185 is in fluid communication with the hydraulic port 36.

[0076] Among them, the isolation assembly 180 includes a setting seat 186 that can move from a closed position to an open position relative to the setting port 185 in the tool channel 105 in response to the initial position of the setting plug 62 in the bridge plug assembly 60.

[0077] Preferably, referring to Figure 1 , the upper end of the cementing assembly 110 in the running tool 100 is connected to a running string 52. The running tool 100 is at least partially disposed within the liner hanger system 30. The running string 52 is used to run the liner assembly 20 from surface equipment 50.

[0078] Preferably, referring to Figure 2 , a rubber disc is provided on the closing bridge plug 66. The rubber disc is used to wipe the cement on the inner wall of the running string 52.

[0079] Preferably, the structure of the setting mechanism 32 includes slips.

[0080] Generally, referring to Figure 1 Figure 1 , the running tool 100 is used for setting and top-down squeezing cementing of the liner assembly 20 in the wellbore 12.

[0081] The liner hanger system 30 has a setting mechanism 32, such as slips, for setting in the casing 14 of the wellbore 12 using a hydraulic mechanism 36. When the setting mechanism 32 is set, the liner hanger system 30 suspends the liner string 22 and the float shoe assembly 40 on the casing 14, and the packer 38 on the liner hanger system 30 can be used to form an annulus seal in the casing 14.

[0082] To run, set, and cement the liner assembly 20, surface operators use the running tool 100 and the running string 52 to run the liner assembly 20 from the surface equipment 50.

[0083] The liner assembly 20 is assembled with the float shoe assembly 40, the liner string 22, the liner hanger system 30, and the tieback collar 35. The running tool 100 is installed in the liner assembly 20, and the liner assembly 20 is run in the wellbore 12. During running, the fluid flowing downward along the running tool 100 can pass through the float shoe assembly 40 of the liner assembly 20. During the setting process of the running string and the liner hanger system 30, the fluid flows out from the float shoe assembly 40.

[0084] Upon reaching the setting position, using the hydraulic pressure inside the running string 52, the liner hanger system 30 on the liner assembly 20 is installed in the casing 14 of the wellbore 12. The setting plug P1 is dropped from the surface equipment 50 into the running string 52 to the running tool 100. When reaching the tool 100, the setting plug P1 engages with the setting seat 186 of the running tool 100. The hydraulic pressure emitted from the setting port 185 on the tool 100 drives the hydraulic mechanism 34 on the liner hanger system 30 to set the setting mechanism 32. The setting plug P1 passes through the setting seat 186 according to a predetermined hydraulic pressure.

[0085] After the setting mechanism 32 in the casing 14 is set, the liner hanger system 30 is enabled to suspend the liner string 22, and then the cementing operation can be carried out. In a horizontal well, in traditional cementing, cement is pumped into the running string, through the liner string 22, and into the outer annulus of the liner string 22 to cement the liner in place. The current completion system is used for top-down cementing of the outer annulus. In some completion operations, it is not necessary to cement around the liner string 22 in the horizontal section 16 of the wellbore 12, and only the top of the liner string 22 in the vertical section of the wellbore 12 needs to be cemented. To achieve this, cement is pumped into the running string 52 and into the annulus between the liner string 22 and the casing 14 without pumping a large amount of cement through the entire liner string 22 itself. Installing in this way can save a significant amount of time and money for the cementing operation of the liner installation.

[0086] When running the liner string 22 into the well, the bypass port 116 is in the closed position, allowing fluid to circulate through the float shoe assembly 40. The opening plug P2 can free fall / pump from the surface equipment 50 and drop into the opening unit 130, opening the bypass port 116 and closing the passage other than the tool 100 itself (to the lower liner string 22). Then, a top-down squeeze cementing operation is carried out through the opened bypass port 116. During the squeeze operation at the top of the liner, the cement circulates along the running string 52 and flows out from the bypass port 116, while the annulus ram of the surface equipment 50 is closed, so the cement enters the annulus through the bypass port 116. When the cementing is completed, a closing plug P3 is pumped through the running string 52 from the surface equipment 50 to displace the cement outside the running tool 100. Then the closing plug P3 is dropped into the closing unit 150 in the running tool 100. The closing plug P3 located inside the running tool 100 can move the control unit 140 to the closed position relative to the bypass port 116. Among them, the setting plug P1, the opening plug P2 and the closing plug P3 are all prior arts, and their structures are not further defined here.

[0087] The control unit 140 is closed, and at the same time, the closing plug P3, the closing unit 150, the opening plug P2 and the opening unit 130 move to the designated positions, which allow fluid to pass through below the running tool 100 and through the float shoe assembly 40 of the liner.

[0088] Finally, the fluid communication from the running string 52 to the liner string 22 is re-established through the components (closing plug P3, closing unit 150, opening plug P2, opening unit 130) in the running tool 100, and these components are retained in the tool 100, while the fluid passage is closed at the bypass port 116 where the cement is placed. With the bypass port 116 closed, the re-established fluid communication through the running tool 100 allows pressure testing of the liner assembly 20 after the cementing operation is completed.

[0089] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or represent a specific order or sequence.

[0090] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, so that a process, method, article or equipment / device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent in these processes, methods, articles or equipment / device.

[0091] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easily understood by those skilled in the art that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A liner hanger system for upper cementing, characterized in that, the system comprises a running tool (100), a liner assembly (20) and a bridge plug assembly (60); the running tool (100) includes a tool body (102), and the tool body (102) includes a cementing assembly (110); the main body of the cementing assembly (110) is a housing (112), and a first channel (114) is formed in the housing (112) along its axial direction, and the first channel (114) communicates with a bypass port (116), and the bypass port (116) is formed on the outer circumferential surface of the housing (112); a control unit (140) is arranged in the first channel (114), a control port (146) is formed on the outer circumferential surface of the control unit (140), the control port (146) is connected with a control channel (142), the control channel (142) is formed in the axial direction of the control unit (140), an opening unit (130) and a closing unit (150) are arranged in the control channel (142), and the opening unit (130) moves from a closed state to an open state relative to the control port (146) in the control unit (140); the closing unit (150) is used for releasing the control unit (140) to move the control port (146) relative to the bypass port (116) to close; the liner assembly (20) includes a liner hanger system (30) and a liner string (22), the liner hanger system (30) includes a setting mechanism (32) and a hydraulic mechanism (34); the hydraulic mechanism (34) is sleeved on the outer surface of the body of the liner hanger system (30), and the setting mechanism (32) is arranged in the casing (14) of the wellbore (12) through the hydraulic mechanism (34); a second channel (31) is coaxially formed on the body of the liner hanger system (30), and the hydraulic mechanism (34) has a driving port in the second channel (31); the liner string (22) is supported in the wellbore (12) by means of the liner hanger system (30); the bridge plug assembly (60) is arranged on and moves along the opening unit (130) and the closing unit (150), and the bridge plug assembly (60) is used for opening or closing the bypass port (116).

2. The liner hanger system for upper cementing according to claim 1, characterized in that, the liner assembly (20) further includes a float shoe assembly (40), a tieback cylinder (35) and a liner top packer (38); the float shoe assembly (40) is connected to the distal end of the liner string (22); the liner top packer (38) is configured to be set by compression in the casing (14) of the wellbore (12); the tieback cylinder (35) is connected to the upper end of the liner top packer (38), and the liner top packer (38) includes an additional slip (39), and the additional slip (39) engages with the casing (14) to keep the liner top packer (38) in a compressed state.

3. A liner hanger system for upper cementing according to claim 2, wherein, the main body of the control unit (140) is of a cylindrical structure. The control unit (140) is hermetically connected to the first channel (114) through a first seal (141). At both ends of the cylindrical structure of the control unit (140), a first chuck (145a) and a second chuck (145b) are respectively arranged. The first chuck (145a) is used to support the opening unit (130), and the second chuck (145b) is used to support the closing unit; the first chuck (145a) is fixed on the inner circumferential surface of the housing (112), and a plurality of the first chucks (145a) are uniformly arranged along the circumferential direction at one end of the control unit (140); the second chuck (145b) meshes with the groove (115b), and the groove (115b) is circumferentially formed on the inner circumferential surface of the housing (112); the first chuck (145a) can be arranged in the first slot (115a), and the first slot (115a) is formed on the surface of the first channel (114). The second chuck (145b) can be arranged in the second slot (115c), and the second slot (115c) is formed on the surface of the first channel (114).

4. A liner hanger system for upper cementing according to claim 3, wherein, the running tool (100) includes an opening unit (130) at least partially arranged in the control unit (140), which has a movable opening valve seat (134). The opening unit (130) moves from an initial closed position to an open state relative to the bypass port (116) in the control unit (140) in response to the hydraulic pressure applied to the opening plug (64) on the opening valve seat (134), wherein the control unit (140) includes a first chuck (145a) configured to capture the opening unit (130) in a second closed position; the first chuck (145a) is configured to release the opening unit (130) in response to a predetermined pressure.

5. A liner hanger system for upper cementing according to claim 4, wherein, the opening unit (130) is hermetically connected to the control unit (140) through a second seal (131). An opening through hole (132) and an opening valve seat (134) are successively formed on the main body of the opening unit (130); the opening plug (64) in the plug assembly (60) can be installed on the opening valve seat (134) through the opening through hole (132); the main body of the opening unit (130) is fixed to the control unit (140) through a first pin (133), and the main body of the opening unit (130) is used to close the control port (146) and the bypass port (116) in an initial state.

6. A liner hanger system for upper cementing according to claim 5, wherein, The running tool (100) includes a closing unit (150) disposed at least partially in the control unit (140) and having a movable closing valve seat (154) therein. The closing unit (150) is movable from an engaged state to a disengaged state relative to a second chuck (145b) on the control unit (140) in response to hydraulic pressure applied to the closing bridge plug (66), and the disengaged state is achieved by the closing unit (150).

7. A liner hanger system for upper cementing according to claim 6, wherein, the closing unit (150) is sealingly connected to the inner circumferential surface of the housing (112) through a third seal (151); a preset distance is reserved between one end of the closing unit (150) close to the opening unit (130) and the opening unit (130); one end of the closing unit (150) far from the opening unit (130) is fixed to the housing (112) through a second pin (156); a closing through hole (152) and a closing valve seat (154) are sequentially formed in the interior of the main body (153) of the closing unit (150) along its axial direction; the closing bridge plug (66) in the bridge plug assembly (60) can be disposed in the closing valve seat (154) through the closing through hole (152), and the second pin (156) is released by a predetermined force generated by the hydraulic pressure on the closing bridge plug (66), so that the outer circumferential surface of the closing valve seat (154) closes the control port (146) and the bypass port (116); a base (155) is fixed on the main body (153) of the closing unit (150), and the base (155) is supported by the second chuck (145b).

8. A liner hanger system for upper cementing according to claim 1, wherein, the tool body (102) further includes a setting assembly (160), the setting assembly (160) is connected to the lower end of the cementing assembly (110), the setting assembly (160) includes an engaging mechanism (168), the engaging mechanism (168) is engaged and fixed to the inner circumferential surface of the second channel (31) to achieve a releasable engagement of the liner assembly (20), and a sealing packer (170) is provided between the engaging mechanism (168) and the cementing assembly (110). The sealing packer (170) is sealed in the liner hanger system (30) and seals the tie-back cylinder (35) through a sealing actuator (172).

9. A liner hanger system for upper cementing according to claim 1, wherein, The lower end of the setting assembly (160) is connected to the isolation assembly (180), and the isolation assembly (180) includes a pressure port (185) and a setting seat (186); the pressure port (185) is opened on the outer circumferential surface of the isolation assembly (180) body and is communicated with the first channel (114) and the second channel (31), and the pressure port (185) is opened or closed through the setting seat (186), and the setting seat (186) is arranged on the inner circumferential surface of the isolation assembly (180) body and can slide along it; Sealing packings (188) are arranged at both the upper end and the lower end of the pressure port (185), and the sealing packings (188) are used to seal the second channel (31) and the hydraulic port (36) in the hydraulic mechanism (34). The hydraulic port (36) is opened on the bodies of the hydraulic mechanism (34) and the liner hanger system (30) and is communicated with the second channel (31). Liquid can push the slips of the setting mechanism (32) to act through the hydraulic port (36) to realize setting and hanging.

10. A liner hanger system for upper cementing according to claim 1, characterized in that the upper end of the cementing assembly (110) in the running tool (100) is connected to the running string (52), the running tool (100) is at least partially arranged in the liner hanger system (30), and the running string (52) is used to run the liner assembly (20) from the surface equipment (50).

Images