CN114575773A - Tail pipe suspension device with top packer and tail pipe suspension assembly - Google Patents

Abstract

The invention relates to a tail pipe suspension device with a top packer and a tail pipe suspension assembly. The tail pipe linkage includes: a suspension body sleeve extending in an axial direction; the slip hanging mechanism is sleeved outside the hanging main body sleeve; the packer assembly is sleeved outside the suspension main body sleeve and connected to the slip suspension mechanism; the tie-back cylinder is sleeved outside the suspension main body sleeve and connected to the packer assembly; wherein the tieback pipe moves downwards at a first pressure to drive the packer assemblies to move downwards together and drive the slip hanging mechanism to sit and hang; wherein downward movement of the tieback at a second pressure greater than the first pressure drives the packer assembly to set.

Description

Tail pipe suspension device with top packer and tail pipe suspension assembly

Technical Field

The invention relates to the technical field of petroleum well completion, in particular to a tail pipe suspension device with a top packer. The invention also relates to a tail pipe suspension assembly comprising the tail pipe suspension device.

Background

The liner hanger is a common downhole tool in current oil exploration and development, and can be divided into three types, namely a mechanical type, a hydraulic type and a hydraulic mechanical double-acting type according to different sitting and hanging modes, wherein the hydraulic liner hanger is most widely applied.

The hydraulic liner hanger is generally a hydraulic cylinder (driving mechanism) which starts the liner hanger by the pressure build-up in the pipe, and the hydraulic cylinder pushes the hanging mechanism to realize sitting and hanging (ZL 201020678270.5). At present, in order to solve the problem of liner cementing under complex well conditions such as a deep well, a small-clearance well, a large-displacement well and the like, various hydraulic liner hangers of different types are developed in China in succession. However, these liner hangers suffer from two problems, basically.

First, the seating and hanging drive mechanism (hydraulic cylinder) of a conventional hydraulic liner hanger is designed outside the suspension body. After the cementing operation is finished, the driving mechanisms are left in the well for a long time. The hydraulic drive mechanism inevitably requires the use of rubber seals. The presence of the rubber seal limits the overall temperature resistance of the tool. In addition, the rubber sealing element is easy to age in a high-temperature and high-pressure environment in the well for a long time, so that the sealing failure of the hydraulic driving mechanism is caused, and the sealing durability of the whole shaft is influenced.

Second, the seat and hang driving mechanism of the conventional hydraulic liner hanger is generally a double-layer mechanism. Due to the small design space, the pressure resistance is generally smaller than that of the same size of casing. This limits the pressure resistance of the entire liner hanger and is not suitable for high temperature and high pressure wells or high pressure fracturing operations.

In addition, there is a significant risk of gas breakthrough in the annulus for high pressure gas wells. Accordingly, it is desirable to install a corresponding top packer on the liner hanger to avoid the occurrence of a gas breakthrough condition. However, with existing liner hangers having a top packer, it is generally necessary to provide a corresponding setting drive mechanism below the slips and an additional packer setting mechanism above the top packer to avoid interference between the setting and setting processes. This is also an important reason why conventional hydraulic liner hangers necessitate the seating drive mechanism be located outside the body of the hanger.

Disclosure of Invention

In view of the above, the present invention proposes a liner hanger that can be used to eliminate or at least reduce at least one of the above problems. The invention further provides a tail pipe suspension assembly.

According to a first aspect of the present invention, there is provided a tail pipe suspension device including: a suspension body sleeve extending in an axial direction; the slip hanging mechanism is sleeved outside the hanging main body sleeve; the packer assembly is sleeved outside the suspension main body sleeve and connected to the slip suspension mechanism; the tie-back cylinder is sleeved outside the suspension main body sleeve and connected to the packer assembly; wherein the tieback pipe moves downwards at a first pressure to drive the packer assemblies to move downwards together and drive the slip hanging mechanism to sit and hang; wherein downward movement of the tieback at a second pressure greater than the first pressure drives the packer assembly to set.

With the above arrangement, it is made possible to effect setting of the slip suspension mechanism and setting of the packer assembly, respectively, by depressing the tieback cylinder with different degrees of force. In this case, it is not necessary to provide a seat hanging drive mechanism on the tail pipe hanging device. The temperature resistance reduction and the leakage problem in the well caused by the rubber sealing element in the sitting and hanging driving mechanism are avoided. Meanwhile, the tail pipe suspension device can avoid the problem of gas channeling and is very suitable for being applied to high-pressure gas wells.

In one embodiment, the slip suspension mechanism comprises: the slip fixing ring is sleeved and arranged outside the sleeve of the suspension main body; the conical sleeve is sleeved outside the suspension main body sleeve, the conical sleeve is arranged on the slip fixing ring and is spaced from the slip fixing ring, a sitting and hanging inclined joint surface is formed at the lower end of the conical sleeve, and the upper end of the conical sleeve is connected with the packer assembly; and a plurality of slips disposed outside the suspension body sleeve, the plurality of slips being circumferentially spaced apart from one another and axially located between the slip retaining ring and the cone sleeve, a lower end of each slip being hinged to the slip retaining ring, an upper end of each slip being configured as a free end; wherein when the tieback is moved downward at a first pressure and drives the packer assembly downward together, the drogue moves downward such that the landing angled interface is interposed between the slips and the suspension body sleeve to cause the upper ends of the slips to move radially outward to effect landing.

In one embodiment, a first anti-back sleeve is connected between the upper end of the drogue and the packer assembly, the first anti-back sleeve being configured to be movable only downward relative to the suspension body sleeve.

In one embodiment, the packer assembly comprises: the expansion sleeve is sleeved outside the suspension main body sleeve, the lower end of the expansion sleeve is connected with the slip suspension mechanism, the upper end of the expansion sleeve is a free end, a packing rubber cylinder is arranged on the outer side of the upper end of the expansion sleeve, and a gap space is formed between the expansion sleeve and the suspension main body sleeve; the expansion cone is sleeved outside the suspension main body sleeve, the upper end of the expansion cone is connected with the tieback sleeve, the lower end of the expansion cone axially extends into a gap space between the expansion sleeve and the suspension main body sleeve, a section of free space is formed in the gap space below the lower end of the expansion cone, the expansion cone is connected with the expansion sleeve through a first shearing pin, and a setting inclined joint face is formed on the outer side face of the expansion cone; when the tieback cylinder moves downwards under the second pressure, the first shearing pin is sheared, so that the expansion cone can move downwards along the axial direction relative to the expansion sleeve, and the setting inclined joint face is inserted between the upper end of the expansion sleeve and the suspension main body sleeve, so that the packing rubber cylinder moves outwards in the radial direction to realize setting.

In one embodiment, a second anti-back-off is provided between the expansion cone and the suspension body sleeve, the second anti-back-off configured to only allow downward movement of the expansion cone relative to the suspension body sleeve.

According to a second aspect of the present invention there is provided a liner hanger assembly comprising a liner hanger as described above, and a running tool configured to engage the liner hanger and to urge the tieback cylinder downwardly at a first pressure and a second pressure.

In one embodiment, the running tool comprises: a mandrel extending in an axial direction; the sitting and hanging driving assembly is sleeved outside the mandrel and comprises a hydraulic mechanism, and the sitting and hanging driving assembly is constructed to push the tieback cylinder downwards under a first pressure; and the setting driving assembly is sleeved outside the mandrel and arranged below the setting hanging driving assembly, and the setting driving assembly is constructed to push the tieback cylinder downwards under a second pressure.

In one embodiment, the sit-on drive assembly comprises the hydraulic mechanism, the hydraulic mechanism comprising: the hydraulic cylinder sleeve is sleeved outside the mandrel and fixedly connected with the mandrel, and a gap is formed between the upper end of the hydraulic cylinder sleeve and the mandrel; and the hydraulic piston is sleeved outside the mandrel, the lower end of the hydraulic piston axially extends into a gap between the hydraulic cylinder sleeve and the mandrel and is in slidable sealing joint with the hydraulic cylinder sleeve and the mandrel, and the hydraulic piston defines an upper hydraulic cavity and a lower hydraulic cavity in the hydraulic cylinder sleeve. The sitting and hanging driving assembly further comprises a sitting and hanging driving sleeve sleeved outside the upper end of the hydraulic piston, and the sitting and hanging driving sleeve is fixedly connected with the hydraulic piston; the lower end of the tieback cylinder joint sleeve abuts against the upper end of the tieback cylinder; wherein when fluid enters the upper hydraulic chamber of the cylinder sleeve, the hydraulic piston is driven to move downwardly such that the landing drive sleeve pushes the tieback cylinder engagement sleeve downwardly and further pushes the tieback cylinder downwardly.

In one embodiment, the running tool further comprises a pressure holding ball seat disposed in the mandrel, wherein the mandrel is configured with a pressure balancing channel having one end connected to the lower hydraulic chamber of the hydraulic cylinder sleeve and the other end connected to the interior of the mandrel below the pressure holding ball seat.

In one embodiment, the hold pressure tee comprises: a plurality of ball seat pieces arranged annularly in a circumferential direction independently of each other, each ball seat piece having an elastic rib engagement groove formed at an inner side of a lower end thereof; and an elastic sleeve having a lower end configured as a complete ring body and an upper end configured as a plurality of elastic ribs extending upward in an axial direction from the ring body, the plurality of elastic ribs being arranged spaced apart from each other in a circumferential direction, an upper end of each elastic rib being insertable into the elastic rib engagement groove of each ball seating flap in a radially inwardly contracted state; during the running process, the ball seat flaps are arranged in the mandrel, the ball seat flaps are folded relative to each other through the inner wall of the mandrel to form a complete ring shape, and the elastic ribs of the elastic sleeve are in a folded state; upon pressure build-up, the plurality of ball seat lobes move downwardly relative to the mandrel to an inner diameter enlargement of the mandrel, and under the resiliency of the respective resilient ribs, the respective ball seat lobes move radially outwardly such that the inner diameter defined by the respective ball seat lobes increases.

In one embodiment, the outer surface of each ball seat flap is formed with a rubber layer.

In one embodiment, the setting driving assembly comprises a setting driving block sleeved outside the mandrel, the upper end of the setting driving block is hinged relative to the mandrel through a driving block connecting piece, and the lower end of the setting driving block is a free end; in the running-in process, the setting driving assembly is located in the tieback cylinder, so that the setting driving block is in a folded state, when the packer assembly needs to be set, the mandrel is lifted up, the setting driving block moves out of the upper end of the tieback cylinder, the lower end of the setting driving block radially expands outwards to be opposite to the upper end face of the tieback cylinder, and the mandrel is pressed downwards so that the tieback cylinder is pressed downwards through the setting driving block.

Drawings

The invention is described in more detail below with reference to the accompanying drawings. Wherein:

FIG. 1 shows a schematic structural view of a liner hanger assembly according to a first embodiment of the invention, including a liner hanger and a running tool;

FIG. 2 shows a schematic view of a portion of the running tool of FIG. 1;

FIGS. 3 and 4 are schematic diagrams illustrating the operation of the pressure build-up tee of the running tool of FIG. 2;

FIG. 5A shows a schematic side cross-sectional view of a ball seat lobe in a build ball seat of the running tool of FIG. 2;

FIG. 5B shows a schematic top cross-sectional view of the ball seat flap of FIG. 5A;

FIG. 5C shows a schematic perspective view of the ball seat flap of FIG. 5A;

FIG. 6 is a schematic diagram of the configuration of the elastomeric sleeve in the hold down ball seat of the running tool of FIG. 2;

FIG. 7 shows a schematic view of the tailpipe suspension of FIG. 1;

fig. 8 shows an enlarged view of a portion of the tailpipe suspension of fig. 7.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

In this context, unless explicitly stated otherwise or unless contradicted, the term "up" means the side near the wellhead when the equipment is lowered into the well, and the term "down" means the side near the bottom of the well when the equipment is lowered into the well.

As used herein, the terms "connected," "coupled," and the like are intended to encompass both a direct connection or direct connection between the two components, and an indirect connection or indirect connection between the two components, unless expressly specified otherwise or contradicted by context.

FIG. 1 illustrates one embodiment of atailpipe suspension assembly 10 of the present invention. Theliner hanger assembly 10 includes a runningtool 100 and aliner hanger 200.

As shown in FIG. 2, the runningtool 100 includes amandrel 110 that extends in an axial direction. In the embodiment shown in fig. 2, themandrel 110 comprises a plurality of cylinders connected in series from top to bottom. It should be understood that more or fewer barrels may be used to form themandrel 110, as desired.

The runningtool 100 includes a settingdrive assembly 120 that is sleeved over themandrel 110. The hangingdriving assembly 120 further includes ahydraulic mechanism 130 disposed outside themandrel 110. As shown in fig. 2, thehydraulic mechanism 130 includes ahydraulic cylinder sleeve 131 that is sleeved over themandrel 110. The lower end of thecylinder sleeve 131 is fixedly connected (e.g., by threads) to the outer sidewall of themandrel 110, and the upper end is spaced apart from themandrel 110, leaving an opening. Thehydraulic mechanism 130 further comprises ahydraulic piston 132 which is sleeved outside themandrel 110. The upper end of thehydraulic piston 132 is above thecylinder sleeve 131 and the lower end extends through the above-mentioned opening into the gap between thecylinder sleeve 131 and thespindle 110. Thehydraulic piston 132 is slidably and sealingly engaged with thecylinder sleeve 131 and themandrel 110. Thus, an upper hydraulic chamber and a lower hydraulic chamber may be partitioned within thecylinder sleeve 131 by thehydraulic piston 132. The upper hydraulic chamber may communicate with the mandrel interior space through a radially extendingcommunication hole 114 in themandrel 110. In addition, the lower hydraulic chamber communicates into the mandrel interior space through a pressure balancing passage provided on themandrel 110. In the embodiment shown in fig. 2, the pressure equalization channel comprises afirst channel 111 extending in the axial direction, communicating with the lower hydraulic chamber, and asecond channel 112 extending in the radial direction, communicating with thefirst channel 111 and the mandrel inner space. A pressure holdingball seat 140 is provided inside themandrel 110 between a position where the pressure balance passage communicates with the mandrel internal space and a position where thecommunication hole 114 communicates with the mandrel internal space. That is, thecommunication hole 114 communicates into the mandrel inner space above the pressure holdingball seat 140, and the pressure balancing passage communicates into the mandrel inner space below the pressure holdingball seat 140. Hereinafter, thepressure holding tee 140 will be described in detail.

As also shown in fig. 2, the upper end of thehydraulic piston 132 is outside of thecylinder sleeve 131 and is connected to themandrel 110 by athird shear pin 134.

The sitting and hanging drivingassembly 120 further comprises a sitting and hanging drivingsleeve 133 sleeved outside thehydraulic piston 132, a tiebacksleeve engaging sleeve 121 and a connectingsleeve 123. The inner side of the upper end of the tiebackcylinder engaging sleeve 121 is configured with a limitinggroove 121A. The upper end of the connectingsleeve 123 is fixedly connected with themandrel 110, and the lower end of the connecting sleeve is spaced from themandrel 110 to form a limiting gap. In the initial state (i.e., run-in state) shown in fig. 2, the upper end of thehydraulic piston 132 extends into the limit clearance. A limiting hole penetrating in the radial direction is formed at the lower end of theconnection sleeve 123. Astopper 122 is provided in the stopper hole. In the state shown in fig. 2, thestopper 122 is supported on the inner side by the upper end of thehydraulic piston 132 so that it projects radially outward into thestopper groove 121A of the retractioncylinder engagement sleeve 121. Thus, the tiebackbarrel engagement sleeve 121 may be indirectly connected to themandrel 110. An upward stepped surface is formed inside the tiebackcylinder engaging sleeve 121. The seating and hanging drivingsleeve 133 is located above and opposite to the stepped surface.

As shown in fig. 1, the lower end of the tiebackcylinder engagement sleeve 121 abuts the upper end of thetieback cylinder 210 of thetailpipe suspension assembly 200 when the entiretailpipe suspension assembly 10 is assembled.

Thus, the pressure inside themandrel 110 is substantially uniform before the pressure build-upball 300 is run in. Due to the presence of thecommunication hole 114 and the pressure equalizing passage, the pressures in the upper and lower hydraulic chambers are the same. At this time, the pressures at the upper and lower ends of thehydraulic piston 132 are balanced, and thus, the hydraulic piston does not undesirably move and is not seated in advance. In the state that the pressure-building ball seat 140 is in the pressure-building state, the pressures in themandrels 110 on the upper side and the lower side of the pressure-building ball seat 140 are different, and the upper pressure is obviously greater than the lower pressure. This results in the pressure in the upper hydraulic chamber also being significantly greater than the pressure in the lower hydraulic chamber. This causes thethird shear pin 134 to shear and drive thehydraulic piston 132 downward. As thehydraulic piston 132 moves downward, the radially inner side of thestopper 122 is no longer supported, so that thestopper 122 moves radially inward and disengages from thestopper groove 121A. This causes the tiebackbarrel engagement sleeve 121 to separate from themandrel 110. As thehydraulic piston 132 continues to move downwardly, the settingdrive sleeve 133 connected to thehydraulic piston 132 moves downwardly with it and against the step surface on the tiebacksleeve engagement sleeve 121. Thus, the tiebackcylinder engagement sleeve 121 may be driven downward by thehydraulic piston 132 and thereby urge thetieback cylinder 210 downward (e.g., at a first pressure of about 30 kN).

The above-mentioned pressure build-up tee 140 will be described in detail with reference to fig. 2 to 6.

As shown in fig. 2, the holdpressure ball seat 140 includes a plurality ofball seat lobes 141. The respectiveball seat lobes 141 are arranged annularly in the circumferential direction. With reference to fig. 5A to 5C, eachball seat flap 141 includes a tapered pressure holding ball engaging portion, and an extending portion disposed below the pressure holding ball engaging portion. Therubber layer 141B is preferably wrapped outside the ball seat flap 141 (in particular, outside the pressure holding ball joint) by vulcanization. An elasticrib engagement groove 141A extending in the axial direction is formed inside the extension portion. The lower end of the elasticrib engagement groove 141A extends in the axial direction to the lower end of the throughball seat flap 141.

The pressure build-upball seat 140 further comprises anelastic sleeve 142 arranged below theball seat flap 141. As shown in fig. 6, the lower end of theelastic sleeve 142 is configured as acomplete ring body 142A, and the upper end is configured as a plurality ofelastic ribs 142B extending upward in the axial direction from thering body 142A. Theelastic ribs 142B are provided corresponding to the respectiveball seat lobes 141 and are spaced apart from each other in the circumferential direction. Theelastic sleeve 142 is made entirely of an elastic material.

In the initial state shown in fig. 2, theball seat flap 141 is mounted inside themandrel 110. Under the restraining action of themandrel 110, the ball seat flaps 141 are in a collapsed condition, together forming a complete ring. Since therubber layer 141B is provided outside eachball seat flap 141, an effective press seal can be achieved between the adjacent ball seat flaps 141. This is very advantageous to avoid leakage when building pressure. In addition, theelastic sleeve 142 is installed below theball seat flap 141, and is inserted into theball seat flap 141 such that the upper end of eachelastic rib 142B is elastically deformed radially inward. Eachelastic rib 142B is preferably also fixedly connected with the correspondingball seat flap 141 by a connection member such as a screw or bolt.

In the state shown in fig. 3, the pressure-building ball 300 is engaged with the circular ball seat formed by theball seat flap 141. Due to therubber layer 141B on theball seat flap 141, the pressure build-upball 300 can be in sealing engagement with theball seat flap 141, and leakage is avoided. Therefore, effective pressure building can be realized. When the build-up pressure exceeds a certain threshold, theball seat flap 141 is pushed to move downwards to the position shown in fig. 4. At this time, theball seat flap 141 is opposed to the inner diameter-enlargedportion 113 of themandrel 110. Since the outer side of theball seat flap 141 is no longer restricted by themandrel 110, the elastic ribs of theelastic sleeve 142 are expanded radially outward by the elastic force and bring theball seat flap 141 together to move radially outward. Thereby, the ball seat flaps 141 are separated with respect to each other and the inner diameter of the ball seat they form is enlarged, so that the pressure build-upball 300 can continue to fall down downhole, resulting in the end of the pressure build-up.

The above-described structure of the pressure buildingball seat 140 can form a path in themandrel 110 after the pressure building is completed. The hold-down ball seat 140 is advantageous for avoiding unintended hold-down due to downhole pressure surges.

In addition, as also shown in FIG. 2, the runningtool 100 also includes a settingdrive assembly 150. The settingdrive assembly 150 is disposed below the settingdrive assembly 120. The settingdrive assembly 150 includes a settingdrive block 151 that fits over themandrel 110. The upper end of the settingdrive block 151 is hinged relative to themandrel 110 by adrive block connection 152, the lower end being a free end. In the initial state shown in fig. 1, the settingdrive block 151 is inside thetieback barrel 210 of the runningtool 200. Under the restraint of thetieback cylinder 210, the settingdrive block 151 is in a collapsed state. When setting is required, themandrel 110 is lifted upwards so that the settingdrive block 151 moves out of the upper end of thetieback cartridge 210. The lower end of the settingdrive block 151 is expanded radially outward to oppose the upper end face of thetieback cartridge 210 because it is no longer restrained. By pressing down themandrel 110, the settingdrive block 151 can press down the tieback cylinder 210 (e.g., at a second pressure of 200kN or more), thereby performing a setting operation.

Fig. 7 and 8 show a specific structure of thetail pipe hanger 200. Thetailpipe suspension 200 includes asuspension body sleeve 240 extending in an axial direction for coupling with themandrel 110 of the runningtool 100, such as by a reverse threaded connection. The outer side of the suspensionmain body sleeve 240 is sleeved with atieback cylinder 210, apacker assembly 220, a firstanti-back sleeve 250 and aslip suspension mechanism 230 which are sequentially arranged from top to bottom.

The upper end of thetieback barrel 210 abuts the lower end of the tiebackbarrel engagement sleeve 121 of the runningtool 100 and may be directly fixedly attached.

Thepacker assembly 220 includes anexpansion sleeve 223 that is sleeved over asuspension body sleeve 240. The lower end of theexpansion sleeve 223 is connected to the firstanti-backup sleeve 250 and thereby indirectly connected to theslip hanging mechanism 230. The upper end of theexpansion sleeve 223 is a free end, and a packingrubber cylinder 224 is arranged outside the upper end of theexpansion sleeve 223. In the embodiment shown in fig. 7 and 8, theexpansion sleeve 223 is spaced entirely from thesuspension body sleeve 240, forming a clearance space therebetween. Thepacker assembly 220 also includes anexpansion cone 221 that is sleeved outside the hangingbody sleeve 240. Theexpansion cone 221 is connected at its upper end to thetieback 210 and at its lower end extends axially down into the clearance space between theexpansion sleeve 223 and thesuspension body sleeve 240.

In the initial state shown in fig. 7 and 8, a section offree space 223A is formed in the clearance space below the lower end of theexpansion cone 221. Theexpansion cone 221 is connected to the expansion sleeve by afirst shear pin 225. A setting inclinedjoint surface 221A is formed on the outer side surface of theexpansion cone 221. Thus, whentieback cartridge 210 is moved downward by the first, relatively small pressure described above,first shear pin 225 does not shear. Thetieback drum 210,expansion cone 221 andexpansion sleeve 223 may move together downward and act on theslip suspension mechanism 230 below. In this process, theexpansion sleeve 223 is always in the collapsed state. The packingrubber cylinders 224 are spaced from the outer wall or casing of the well. When thetieback cartridge 210 is moved downward by the second, greater pressure described above, thefirst shear pin 225 shears, allowing theexpansion cone 221 to move axially downward relative to theexpansion sleeve 223. At this point, the settingangled interface 221A is wedged between the upper end of theexpansion sleeve 223 and thehanger body sleeve 240 to deform the upper end of theexpansion sleeve 223 radially outwardly to move thepacker rubber cartridge 224 radially outwardly into sealing engagement with the outer well wall for setting. Theexpansion sleeve 223 is preferably made of metal so that a certain force (much greater than that required to set a typical inflation compression packer) is required to force it to deform. In combination with thefirst shear pin 225, this is very effective in preventing thepacker assembly 220 from setting unexpectedly, and in particular, preventing thepacker assembly 220 from setting unexpectedly when theslip suspension mechanism 210 is set by being depressed.

In addition, a second anti-back-off 222 is provided between theexpansion cone 221 and thesuspension body sleeve 240. The second anti-back-out piece 222 is configured to only allow theexpansion cone 221 to move downward relative to the suspension body sleeve. Thus, unintended unsetting can be avoided when thepacker assembly 220 is set.

The first anti-back-offsleeve 250 is connected between theexpansion sleeve 223 of thepacker assembly 220 and thecone sleeve 231 of theslip suspension mechanism 230. A first anti-back-outpiece 251 is provided between the first anti-back-outsleeve 250 and thesuspension body sleeve 240. This allows the firstanti-backup sleeve 250 and the structure connected thereto to move only downwards relative to the suspension body sleeve. This can prevent thepacker assembly 220 from setting unintentionally and can also prevent theslip suspension mechanism 230 from tripping unintentionally.

Theslip suspending mechanism 230 includes aslip fixing ring 233 sleeved and installed outside the suspendingbody sleeve 240, and thetaper sleeve 231 sleeved outside the suspendingbody sleeve 240. Acone sleeve 231 is disposed above theslip retaining ring 233 and is spaced apart from theslip retaining ring 233. The lower end of thedrogue 231 is configured with a sittinginclined engagement surface 231A. The upper end of thecone 231 is connected to a first anti-back-offsleeve 250 and thereby fixedly connected to theexpansion sleeve 223 of thepacker assembly 220. Theslip suspension mechanism 230 also includes a plurality ofslips 232 disposed outside of thesuspension body sleeve 240. A plurality ofslips 232 are circumferentially spaced apart from one another and axially located betweenslip retaining ring 233 andcone sleeve 231. The lower end of eachslip 232 is hinged to aslip retaining ring 233 and the upper end of each slip is configured as a free end. Thus, when the tieback is moved downwardly by the first pressure and thereby drives thepacker assembly 220 and the firstanti-back sleeve 250 downwardly together, thedrogue 231 is forced downwardly such that the setting inclinedengagement surface 231A is wedged between theslips 232 and thesuspension body sleeve 240 to move the upper ends of theslips 232 radially outwardly into engagement with the outer borehole wall to effect setting.

In addition, theslip suspension mechanism 230 includes ashear pin sleeve 234 that fits over thesuspension body sleeve 240 and is disposed below theslip retaining ring 233. Theshear pin sleeve 234 is connected to thesuspension body sleeve 240 by asecond shear pin 235. If the problem of theslip suspension mechanism 230 being set ahead occurs during the liner run in process, the string (running tool) may be lifted up to a certain tonnage to shear thesecond shear pin 235 so that theslips 232 may move down to unlock the suspension mechanism and lift the entire string (including the liner suspension assembly 10) out of the wellhead.

Thus, during downhole operations, the operator first runs the entire string including theliner hanger assembly 10 into the well. The tailpipe is attached to the lower end of thesuspension body sleeve 240 of thetailpipe suspension 200. When run in place, theslip suspension mechanism 230 is set by injecting high pressure fluid into the pipe string, causing thehydraulic piston 132 to move downward, causing thetieback cylinder 210 to be driven downward by a first pressure. Thereafter, conventional cementing operations may be performed. After the cementing operation is complete, the running tool may be lifted up so that the settingdrive assembly 150 is lifted out of thetieback cartridge 210. The running tool is then depressed at a second pressure and thereby drives thetieback 210 downward, effecting setting of thepacker assembly 220. Thereafter, the running tool may continue to be lifted up, completing the entire liner hanging operation.

Thehydraulic mechanism 130, etc., may all be raised uphole by raising the running tool, leaving only thetieback drum 210,packer assembly 220, and slipsuspension mechanism 230 in the well. This enables tightness in the well to be ensured.

The tail pipe suspension device and the tail pipe suspension assembly are suitable for wells such as high-pressure gas wells and the like with high pressure resistance requirements on tail pipe well cementation tools, can greatly improve the pressure resistance and the sealing durability of the tools, and can effectively improve the running reliability of the tools.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (12)

1. A tailpipe suspension, comprising:

a suspension body sleeve extending in an axial direction;

the slip hanging mechanism is sleeved outside the hanging main body sleeve;

the packer assembly is sleeved outside the suspension main body sleeve and connected to the slip suspension mechanism; and

the tie-back cylinder is sleeved outside the suspension main body sleeve and connected to the packer assembly;

wherein the tieback pipe moves downwards at a first pressure to drive the packer assemblies to move downwards together and drive the slip hanging mechanism to sit and hang;

wherein downward movement of the tieback at a second pressure greater than the first pressure drives the packer assembly to set.

2. The liner suspension of claim 1, wherein the slip suspension mechanism comprises:

the slip fixing ring is sleeved and arranged outside the sleeve of the suspension main body;

the conical sleeve is sleeved outside the suspension main body sleeve, the conical sleeve is arranged on the slip fixing ring and is spaced from the slip fixing ring, a sitting and hanging inclined joint surface is formed at the lower end of the conical sleeve, and the upper end of the conical sleeve is connected with the packer assembly; and

a plurality of slips disposed outside the suspension body sleeve, the plurality of slips being circumferentially spaced apart from one another and axially located between the slip retaining ring and the cone sleeve, a lower end of each slip being hinged to the slip retaining ring, an upper end of each slip being configured as a free end;

wherein when the tieback is moved downwardly at a first pressure and drives the packer assembly downwardly together, the taper sleeve moves downwardly such that the landing angled interface is interposed between the slips and the suspension body sleeve to cause the upper ends of the slips to move radially outwardly to effect landing.

3. The liner hanger of claim 2, wherein a first anti-back-off sleeve is connected between the upper end of the cone sleeve and the packer assembly, the first anti-back-off sleeve being configured to move only downward relative to the hanger body sleeve.

4. A liner hanger according to any one of claims 1 to 3, wherein the packer assembly comprises:

the expansion sleeve is sleeved outside the suspension main body sleeve, the lower end of the expansion sleeve is connected with the slip suspension mechanism, the upper end of the expansion sleeve is a free end, a packing rubber cylinder is arranged on the outer side of the upper end of the expansion sleeve, and a gap space is formed between the expansion sleeve and the suspension main body sleeve; and

the expansion cone is sleeved outside the suspension main body sleeve, the upper end of the expansion cone is connected with the tie-back cylinder, the lower end of the expansion cone axially extends into a gap space between the expansion sleeve and the suspension main body sleeve, a section of free space is formed in the gap space below the lower end of the expansion cone, the expansion cone is connected with the expansion sleeve through a first shearing pin, and a setting inclined joint face is formed on the outer side face of the expansion cone;

when the tieback cylinder moves downwards under the second pressure, the first shearing pin is sheared, so that the expansion cone can move downwards along the axial direction relative to the expansion sleeve, and the setting inclined joint face is inserted between the upper end of the expansion sleeve and the suspension main body sleeve, so that the packing rubber cylinder moves outwards in the radial direction to realize setting.

5. The tailpipe suspension apparatus according to claim 4, wherein a second anti-back off member is provided between the expansion cone and the suspension body sleeve, the second anti-back off member being configured to only allow the expansion cone to move downward relative to the suspension body sleeve.

6. A liner hanger assembly comprising a liner hanger according to any of claims 1 to 5, and a running tool configured to engage the liner hanger and to urge the tieback cylinder downwardly at the first and second pressures.

7. The tailpipe suspension assembly according to claim 6, wherein the running tool comprises:

a mandrel extending in an axial direction;

the sitting and hanging driving assembly is sleeved outside the mandrel and comprises a hydraulic mechanism, and the sitting and hanging driving assembly is constructed to push the tieback cylinder downwards under a first pressure; and

the setting driving assembly is sleeved outside the mandrel and arranged below the setting hanging driving assembly, and the setting driving assembly is constructed to push the tieback cylinder downwards under a second pressure.

8. The tailpipe suspension assembly according to claim 7, wherein the seat-hanging drive assembly comprises:

the hydraulic mechanism, the hydraulic mechanism includes:

the hydraulic cylinder sleeve is sleeved outside the mandrel and fixedly connected with the mandrel, and a gap is formed between the upper end of the hydraulic cylinder sleeve and the mandrel; and

a hydraulic piston disposed about said mandrel, said hydraulic piston having a lower end extending axially into a gap between said hydraulic cylinder sleeve and said mandrel and being in slidable sealing engagement with said hydraulic cylinder sleeve and mandrel, said hydraulic piston defining an upper hydraulic chamber and a lower hydraulic chamber within said hydraulic cylinder sleeve;

the sitting and hanging driving sleeve is sleeved outside the upper end of the hydraulic piston and is fixedly connected with the hydraulic piston; and

the lower end of the tieback cylinder joint sleeve is abutted to the upper end of the tieback cylinder;

wherein when fluid enters the upper hydraulic chamber of the cylinder sleeve, the hydraulic piston is driven to move downwardly such that the landing drive sleeve pushes the tieback cylinder engagement sleeve downwardly and further pushes the tieback cylinder downwardly.

9. The liner hanger assembly of claim 8, wherein the running tool further comprises a hold-down ball seat disposed within the mandrel, wherein the mandrel is configured with a pressure balancing passage having one end communicating into the lower hydraulic chamber of the cylinder barrel and another end communicating into the interior of the mandrel below the hold-down ball seat.

10. The tailpipe suspension assembly according to claim 9, wherein the hold pressure ball seat comprises:

a plurality of ball seat pieces arranged annularly in a circumferential direction independently of each other, each ball seat piece having an elastic rib engagement groove formed at an inner side of a lower end thereof; and

an elastic sleeve having a lower end configured as a complete ring body and an upper end configured as a plurality of elastic ribs extending upward in an axial direction from the ring body, the plurality of elastic ribs being arranged spaced apart from each other in a circumferential direction, an upper end of each elastic rib being insertable into an elastic rib engagement groove of each ball seating flap in a radially inwardly contracted state;

during the running process, the ball seat flaps are arranged in the mandrel, the ball seat flaps are folded relative to each other through the inner wall of the mandrel to form a complete ring shape, and the elastic ribs of the elastic sleeve are in a folded state; upon pressure build-up, the plurality of ball seat lobes move downwardly relative to the mandrel to an inner diameter enlargement of the mandrel, and under the resiliency of the respective resilient ribs, the respective ball seat lobes move radially outwardly such that the inner diameter defined by the respective ball seat lobes increases.

11. The tailpipe suspension assembly according to claim 10, wherein an outer surface of each ball seat lobe is formed with a rubber layer.

12. A tailpipe suspension assembly according to any of claims 7 to 11, wherein the setting drive assembly comprises a setting drive block sleeved outside the mandrel, the upper end of the setting drive block being hinged relative to the mandrel by a drive block connection, the lower end of the setting drive block being a free end;

in the running-in process, the setting driving assembly is located in the tieback cylinder, so that the setting driving block is in a folded state, when the packer assembly needs to be set, the mandrel is lifted up, the setting driving block moves out of the upper end of the tieback cylinder, the lower end of the setting driving block radially expands outwards to be opposite to the upper end face of the tieback cylinder, and the mandrel is pressed downwards so that the tieback cylinder is pressed downwards through the setting driving block.

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