WO2021008483A1 - Expansion hanger - Google Patents

Abstract

An expansion hanger and a tail pipe well completion method performed using the expansion hanger. The expansion hanger comprises an expansion hanging cylinder (1) and a slip (2) provided on the outer surface of the expansion hanging cylinder. The slip comprises multiple slip blocks (201) that are peripherally arranged and that have slip teeth (202). Two peripherally neighboring slip blocks are mutually connected by at least two connection ribs (203) arranged at the middle part and the lower part of the slip, respectively; and a mounting ring (204) is provided at the upper part of the slip.

Description

Expansion hanger

Cross references to related applications

This application claims the priority of the Chinese patent application CN 201910633506.9 named "Dual Suspension Double Sealed High Temperature Expansion Hanger" filed on July 15, 2019, the entire content of which is incorporated herein by reference.

Technical field

The invention relates to the field of oil drilling and completion tools, and more specifically to an expansion hanger.

Background technique

Liner suspension cementing technology is the most common completion method in deep wells, sidetracking and deepening well cementing. According to this process, casing can be saved, annulus flow resistance and displacement pressure in cement injection construction can be reduced, the well structure is simplified, and the liner string can be run easily, thereby solving the cementing and completion problems in deep and complex wells.

At present, the liner hanger can be divided into a slip type liner hanger and an expansion liner hanger according to the way of mounting. In general, slip-type tailpipe hangers have problems such as unreliable mounting, small mounting diameter, and unsatisfactory sealing effect. For the expansion liner hanger, it is generally used hydraulic way to realize the expansion seat hanging of the hanger, so that the rubber tube is squeezed between the double-layer casing to realize the seal. This kind of expansion type liner hanger has a single suspension and hanging mode, and relies on a single rubber seal under high temperature conditions in deep wells and thermal recovery wells, so there is still the risk of rubber failure due to high temperature aging and difficulty in undercutting.

In addition, in the normal undercut operation of the expansion hanger, the suspension weight of the drilling tool needs to be adjusted to the weight of the drilling tool above the liner hanger. The suspended weight of the drill here is called the neutral point of the drill. However, for deep wells or inclined wells, the neutral point suspension weight is difficult to adjust accurately, and the error is often large, which makes the on-site undercut operation difficult.

Summary of the invention

In view of the above technical problems, the present invention aims to provide an expansion hanger, which has satisfactory suspension and sealing performance, can easily perform undercut operation, thereby meeting the requirements of oil and gas well liner cementing construction, and is particularly suitable for deep wells, The liner completion operation under the special working conditions of thermal recovery wells reduces the potential safety hazards of the expansion hanger in terms of hydraulic setting, rubber sealing and undercutting.

According to a first aspect of the present invention, an expansion hanger is provided, which includes an expansion suspension cylinder and a slip provided on the outer surface of the expansion suspension cylinder. The slip includes a plurality of circumferentially arranged slip blocks with slip teeth on the surface, and a circulation channel is formed between adjacent slip blocks. Wherein, two adjacent slip blocks in the circumferential direction are connected by at least two elastically deformable connecting ribs, and all slip blocks are fixed to each other by a fixing ring.

In an embodiment, the connecting ribs are respectively arranged in the middle and lower parts of the slips, and the fixing ring is arranged on the upper part of the slips.

In one embodiment, the upper part of each slip block includes a necked part, and the fixing ring is arranged around the necked part of each slip block to fix a plurality of the slip blocks Together.

In an embodiment, the outer diameter of each connecting rib is smaller than the outer diameter of the slip block, and/or the outer diameter of the fixing ring is smaller than the outer diameter of the slip block.

In one embodiment, a sealing cylinder is provided on the outer surface of the expansion suspension cylinder, the sealing cylinder is located downstream of the slips and is composed of a rubber cylinder, a combination of a rubber cylinder and a trapezoidal metal ring, and One or more of the combination of the rubber tube and the sawtooth metal ring is formed.

In one embodiment, a plurality of sealing cylinders are arranged axially spaced apart on the outer surface of the expansion suspension cylinder.

In one embodiment, the trapezoidal metal ring is configured such that the outer dimension is larger than the inner dimension, and both the trapezoidal metal ring and the zigzag metal ring have a smaller outer diameter than the rubber barrel.

In an embodiment, the expansion suspension further includes a safety mechanism, the safety mechanism includes: a bearing mandrel fixedly connected to the expansion mandrel in the expansion suspension cylinder; and the bearing mandrel is mounted on the bearing mandrel through a bearing The spring sleeve; an inverted joint installed on the bearing mandrel, the inverted joint is configured to be able to slide axially along the bearing mandrel and rotate with the bearing mandrel; installed in the inverted The outer side of the buckle joint and the change-over joint threadedly engaged with the undercut joint; and a spring, which is located between the bearing mandrel and the change-over joint in the radial direction, and is located between the spring sleeve and the undercut in the axial direction Between joints. Wherein, the spring sleeve can compress the spring in response to the downward movement of the bearing mandrel until it abuts against the variable buckle joint, and the inverted joint can rotate following the rotation of the bearing mandrel , Thereby disengaging the threaded engagement between the inverted joint and the inverted joint.

In one embodiment, the inverted joint is provided with a left-handed male thread, the changeable joint is provided with a left-handed female thread, and the rotation of the bearing mandrel is clockwise.

In an embodiment, a hollow rubber plug is provided at the downstream end of the bearing mandrel. Alternatively, a rubber plug rod is provided at the downstream end of the bearing mandrel, and a hollow rubber plug is provided at the downstream end of the rubber plug rod.

In one embodiment, a tail pipe is provided at the downstream end of the change buckle joint, and the hollow rubber plug is located in the tail pipe.

In one embodiment, the expansion hanger includes a slip setting mechanism arranged upstream of the slip. The slip setting mechanism includes a central tube arranged in the expansion suspension cylinder, an upper expansion cone that forms an axial sliding seal fit with the central tube, a hydraulic mechanism connected to the upper expansion cone, and To actuate the hydraulic opening assembly of the hydraulic mechanism.

In one embodiment, the hydraulic opening assembly includes a liquid inlet communicating with the inner cavity of the central tube, a rupture disc installed in the liquid inlet, and a fixing block for fixing the rupture disc. Wherein, the rupture piece is configured to be able to rupture under a set pressure, thereby urging the hydraulic mechanism to perform the setting of the slips.

According to a second aspect of the present invention, there is provided a liner completion method using the expansion hanger as described above, which includes the following steps: step one, run in the liner; step two, perform cyclic undercut operation; Step three, perform cementing and slip setting; step four, perform hanger setting; and step five, perform hand-off completion.

In one embodiment, in step two, the drill tool is lifted or pressed down at the load position of the neutral point, so that the bearing mandrel in the safety mechanism slides relative to the inverted joint until the spring sleeve Abuts against the changeable joint, and then rotates the bearing mandrel by rotating the drill rod, thereby driving the reversed joint to rotate, so as to release the threaded connection between the reversed joint and the changeable joint.

In one embodiment, in step 3, the hydraulic pressure generated when the drill rod rubber plug is compounded by the displacement is transmitted to the hydraulic mechanism of the slip setting mechanism, pushing the upper expansion cone to move along the central tube, resulting in The kava is set.

In one embodiment, in step 4, the expansion suspension cylinder is expanded, thereby expanding and squeezing the sealing cylinder of the suspension sealing mechanism between the expansion suspension cylinder and the technical casing.

Description of the drawings

The present invention will be described in more detail below with reference to the accompanying drawings and through illustrative exemplary embodiments. In the picture:

Fig. 1 schematically shows a cross-sectional view of the overall structure of an expansion hanger according to an embodiment of the present invention;

Figure 2 schematically shows the structure of the insurance agency according to the present invention;

Figure 3 schematically shows the structure of the metal slip according to the present invention;

Figure 4 schematically shows the structure of the sealing cylinder in the expansion hanger shown in Figure 1;

Figure 5 is an enlarged view of area A in Figure 1, schematically showing the structure of the hydraulic opening assembly of the slip setting mechanism;

Fig. 6 schematically shows the descending state of the expansion hanger shown in Fig. 1;

Figure 7 schematically shows the inverted state of the expansion hanger shown in Figure 1 before cementing;

Figure 8 schematically shows the cementing and metal slip setting state of the expansion hanger shown in Figure 1;

Fig. 9 schematically shows the sitting state of the expansion hanger shown in Fig. 1;

Fig. 10 schematically shows the state of the pipe string after the construction of the expansion hanger shown in Fig. 1 is completed.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings of the specification. In the following, the directional terms "down", "downstream", "downward", etc. refer to the direction away from the wellhead, and "up", "upstream", "upward", etc. refer to the direction toward the wellhead.

Fig. 1 shows an expansion hanger 100 according to an embodiment of the invention. As shown in the figure, the expansion hanger 100 mainly includes an expansion suspension cylinder 1, a slip suspension mechanism 24, a suspension sealing mechanism 25, an expansion mechanism 26 and a safety mechanism 27.

The expansion suspension cylinder 1 of the expansion hanger 100 according to the present invention is an expandable short section, the top and bottom of which are respectively processed with a pre-expanded, upper bell-shaped expansion outlet 23, and a lower bell-shaped expansion starter 22 . The bottom of the expansion suspension cylinder 1 is fixedly connected to the tail pipe 16 through a changeable joint 15 which will be described in detail below.

The slip setting mechanism 24 of the expansion hanger 100 according to the present invention includes a central tube 7 arranged in the expansion suspension cylinder 1, an upper expansion cone 4 that forms an axial sliding seal fit with the central tube 7, and an upper expansion cone 4 Connected hydraulic mechanism 6. The upper expansion cone 4 is provided with a downwardly facing expansion cone surface and is arranged at the expansion outlet 23 of the expansion suspension cylinder 1. The hydraulic mechanism 6 can be a one-stage or multi-stage hydraulic structure, and is provided with a liquid inlet communicating with the inside of the central pipe 7 (which will be described in detail below). A limit structure is provided on the central tube 7, which can be, for example, a step on the outer surface of the central tube 7 to define the stop point of the lower stroke of the upper expansion cone 4.

The expansion mechanism 26 of the expansion hanger 100 according to the present invention includes an expansion mandrel 9 and a lower expansion cone 5. The expansion mechanism 26 is provided in the expansion starter 22 of the expansion suspension cylinder 1. The expansion mandrel 9 and the lower expansion cone 5 may be an integral hollow structure or a combined hollow structure. The outer surface of the lower expansion cone 5 is provided with an upward expansion cone surface. The upper part of the expansion mandrel 9 can be directly fixedly connected to the central tube 7 or connected to the central tube 7 through a fixed short section 8 as shown in FIG. 1.

In the above structure, the expansion suspension cylinder 1 and the buckle joint 15 are fixedly connected from top to bottom to form an outer pipe string, and the hydraulic mechanism 6, the central pipe 7, the expansion mandrel 9, and the bearing mandrel 10 and The hollow rubber plug 18 is fixedly connected from top to bottom to form an inner pipe string.

The above structure and its functions are all well-known in the field of expansion hangers, so the relevant detailed introduction is omitted here.

The safety mechanism 27 according to the present invention is arranged at the lower part of the expansion mechanism 26. As shown in FIGS. 1 and 2, the safety mechanism 27 includes a bearing mandrel 10 connected to the expansion mandrel 9 of the expansion mechanism 26. In the illustrated embodiment, the front end of the bearing mandrel 10 extends into the inner cavity of the expansion mandrel 9, and is connected to each other by, for example, threads. An inverted joint 14 is installed at the lower part of the bearing mandrel 10. The inverted joint 14 is configured in a sleeve shape, and an inverted thread, such as a left-handed male thread, is provided on its outer surface. The inner surface of the inverted joint 14 is provided with a flat surface part, which cooperates with the corresponding flat part on the outer surface of the bearing mandrel 10, so that the inverted joint 14 can slide axially along the bearing mandrel 10 and can also follow the bearing The rotation of the mandrel 10 rotates.

As mentioned above, the bottom of the expansion suspension cylinder 1 is fixedly connected to the tail pipe 16 through the buckle joint 15. The inner surface of the change-over connector 15 is provided with a left-handed female thread that matches with the undercut thread (ie, a left-handed male thread) of the reversed connector 14. Therefore, the change-over connector 15 is connected to the reversed connector 14 from the outside.

A spring sleeve 12 is provided at one end of the bearing mandrel 10 close to the expansion mandrel 9. The spring sleeve 12 is mounted on the expansion mandrel 9 through the bearing 11 so that the spring sleeve 12 will not follow the rotation of the bearing mandrel 10 when it rotates. In addition, a spring 13 is installed around the bearing core shaft 10 between the spring sleeve 12 and the changeable joint 15. In this way, the spring sleeve 12 can move downward along the bearing mandrel 10 (that is, to the right in FIG. 2) after receiving a force, thereby compressing the spring 13 to a certain extent, until the spring sleeve 12 abuts against the buckle joint 15 .

In this way, the inverted joint 14 and the changeable joint 15 are connected by a left-handed inverted thread. The inverted joint 14 is mounted on the bearing core shaft 10 and can move in the axial direction and rotate with the bearing core shaft 10. The spring sleeve 12 is mounted on the bearing core shaft 10. The expansion mandrel 9 and the bearing mandrel 10 are connected by threads, and the bearing 11 is located between the expansion mandrel 9 and the bearing mandrel 10 so that the spring sleeve 12 will not rotate with the rotation of the bearing mandrel 10.

In the normal undercut operation, the suspension weight of the drill must be adjusted to the neutral point so that the undercut joint does not bear the axial force. This means that the inverted joint does not bear the weight of the lower tail pipe 16 connected to the variable joint. The suspended weight of the drill here is called the neutral point of the drill. However, for deep wells or inclined wells, the neutral point suspension weight is difficult to adjust accurately, and the error is often large, which makes the on-site undercut operation difficult.

According to the present invention, when the drill tool is pressed down, since the undercut joint 14 is fixed in the changeover joint 15, and the bearing mandrel 10 and the flat part of the undercut joint 14 abut each other, the expansion mandrel 9 and the bearing mandrel 10 can The downward movement relative to the inverted joint 14 causes the spring 13 to be compressed by the spring sleeve 12. When the spring sleeve 12 moves down to the upstream end surface of the change-over joint 15 to form abutment, the expansion mandrel 9 and the bearing mandrel 10 stop descending. At this time, when the drill is rotated forward, the bearing mandrel 10 rotates forward, the spring sleeve 12 does not rotate, but the expansion mandrel 9 and the bearing mandrel 10 rotate relative to the spring sleeve 12. The rotation of the bearing mandrel 10 will drive the inverted joint 14 to rotate, disengage the left-hand threaded engagement of the inverted joint 14 and the change-over joint 15, thereby realizing the disengagement of the inverted joint 14 and the change-over joint 15 and complete the undercut operation . As a result, the inner pipe string is separated from the tail pipe.

According to the present invention, since the safety mechanism 27 with a special structure is adopted, there is no need to accurately adjust the suspended weight of the drill to the neutral point. After the drill tool is pressed down, the bearing mandrel 10 moves downward relative to the inverted joint 14, the spring sleeve 12 compresses the spring 13 down to the upper end surface of the buckle joint 15, and the downwardly pressed drill tool is suspended on the buckle joint 15. At this time, the inverted joint 14 is not stressed in the axial direction. Therefore, when the undercut joint 14 is rotated for undercut operation, the undercut joint 14 will not bear weight, so that the rotating torque is easily transmitted to the undercut thread, which facilitates the thread undercut operation. This significantly improves the success rate of the undercut operation.

In the embodiment shown in FIG. 1, the safety mechanism 27 further includes a rubber plug rod 17 connected at the downstream end of the bearing core shaft 10. A hollow rubber plug 18 is fixedly installed at the bottom of the rubber plug rod 17 by, for example, a pin (not shown), which is arranged in a tail pipe 16 connected to the expansion hanger 1 through a changeable joint 15. In an embodiment not shown, the rubber plug rod 17 may be omitted, and the rubber plug 18 is directly connected to the downstream end of the bearing mandrel 10 in this case. The rubber stopper rod 17 and the rubber stopper 18 are both well-known parts in the art, and detailed descriptions thereof are omitted here.

The suspension sealing mechanism 25 of the expansion hanger 100 according to the present invention includes a metal slip 2 and a sealing cylinder 3 fixed on the outer surface of the expansion suspension cylinder 1. In the embodiment shown in FIG. 1, three sealing cylinders 3 are arranged on the outer surface of the expansion suspension cylinder 1 at an axial interval. However, it can be understood that the specific number of the sealing cylinder 3 can be selected according to the specific situation.

As shown in FIG. 3, the metal slip 2 is composed of a plurality of slip blocks 201 arranged in a circle. A circulation channel 205 is formed between adjacent slip blocks 201. Slip teeth 202 are processed on each slip block 201. Two adjacent slip blocks 201 are fixed by at least two elastically deformable connecting ribs 203 and a fixing ring 204. The connecting rib 203 is an open non-closed loop structure, and its outer diameter is smaller than the outer diameter of the slip block 201. In addition, the outer diameter of the fixing ring 204 is slightly smaller than the outer diameter of the slip block 201.

With this arrangement, when the metal slip 2 is expanded and sealed, the slip block 201 itself does not expand, but the connecting rib 203 connecting the slip block 201 is stretched, and the slip teeth 202 on the slip block 201 are squeezed The anchoring on the inner wall of the technical casing 21 is beneficial to reduce the setting pressure of the metal slips.

In the illustrated embodiment, the adjacent slip blocks 201 are fixed by two connecting ribs 203 at the lower part and the middle part, and fixed by a fixing ring 204 at the upper part. In this way, it is avoided that the slip block 201 is embedded in the body of the expansion suspension cylinder 1, thereby ensuring the safe expansion of the expansion suspension cylinder 1, and the slip blocks 201 can be connected organically through the connecting rib 203 and the fixing ring 204 As a whole, it is fixed on the outside of the expansion suspension cylinder 1, and can be seated under a relatively small hydraulic pressure.

In a specific embodiment, a constricted part 208 is formed on the upper part of each slip block 201, and a fixing ring 204 is arranged around the constricted part 208 of each slip block 201.

In an unshown embodiment, the connecting rib and the fixing ring can be combined in other ways. For example, two fixing rings 204 can be used, which are respectively arranged on the upper and lower parts of the slip 2 and a connecting rib 203 is arranged in the middle of the slip 2.

According to the present invention, the slip block 201 of the metal slip 2 is fixed by a connecting rib 203 and a fixing ring 204 with a smaller outer diameter and an elongated shape, so that a larger circulation area is retained at the slip position. At the same time, this structure can also reduce the hydraulic pressure of the metal slip 2 when sitting and hanging, and prevent abnormal pressure when the slip 2 is sitting and hanging. In addition, after the metal slips 2 are seated and hung, there are still circulation channels 205 at the connecting ribs 203 between the slip blocks 201, which can allow liquid to flow.

As shown in Figure 4, the sealing cylinder 3 of the suspension sealing mechanism 25 is a rubber cylinder 301 fixed on the outer surface of the expansion suspension cylinder 1, a combination of the rubber cylinder 301 and a trapezoidal metal ring 302, and a rubber cylinder 301 and a sawtooth metal ring One or more of the combinations of 303. Among them, the rubber cylinder 301 may be, for example, a high-temperature resistant fluorine rubber and is configured in a cylindrical shape. Correspondingly, a metal protrusion (not shown) capable of forming a limit fit with the rubber cylinder 301 is provided on the outer surface of the expansion suspension cylinder 1 at a location corresponding to the rubber cylinder 301. The trapezoidal metal ring 302 has a structure with a wide outside and a narrow inside, that is, its radially outer axial dimension is greater than its radially inner axial dimension, thereby forming an inverted trapezoid. Both the trapezoidal metal ring 302 and the zigzag metal ring 303 can be made of soft metal materials, and the outer diameter is slightly smaller than the outer diameter of the rubber cylinder 301.

The trapezoidal metal ring 302 is embedded in the rubber cylinder 301, which is beneficial to prevent the sealing cylinder 3 from disengaging when it expands. The zigzag metal ring 303 is easy to be squeezed during expansion, so as to avoid excessive compression of the metal ring due to the difference in the inner diameter of the technical sleeve 21, resulting in excessively high expansion pressure of the metal ring, and increasing the risk of field operations. After being seated and hung, the metal slip 2 can increase the tail pipe suspension force, thereby realizing a mechanical-hydraulic double-acting expansion hanger and reducing its expansion hydraulic pressure.

According to the present invention, the suspension sealing mechanism 25 includes a metal slip 2 and a sealing cylinder 3. By using two suspension modes, the metal slip 2 and the sealing cylinder 3, the suspension force of the expansion hanger 100 can be increased. By using two different sealing methods of metal rings 302, 303 and rubber tube 301, the sealing performance and temperature resistance of the expansion hanger 100 can be increased, and it is suitable for liner suspension operations in deep wells and thermal recovery wells. Therefore, the expansion hanger 100 according to the present invention is formed as a double-suspension double-sealed high-temperature resistant expansion hanger.

The slip setting mechanism 24 according to the present invention also includes a hydraulic opening assembly. As shown in FIG. 5, the hydraulic opening assembly includes a liquid inlet 601 communicating with the inner cavity of the central tube 7, a rupture piece 602 installed in the liquid inlet 601, and a fixing block 603 for fixing the rupture piece 602. The fixing block 603 is provided with a hole communicating with the hydraulic mechanism 6. In the initial state, the hydraulic mechanism 6 is in a closed state. When performing cementing displacement, after the drill pipe rubber plug 20 and the hollow rubber plug 18 are compounded, pressure is performed to rupture the rupture piece 602, thereby opening the circulation channel. At this time, the pressure is transmitted to the hydraulic mechanism, so that the metal slips 2 are hydraulically seated.

By providing this hydraulic opening assembly, the hydraulic opening assembly is initially in a closed state, preventing the metal slips 2 from being hung in advance due to the pressure difference when the tool is running, thereby reducing the risk of running the pipe string. After the hydraulic opening assembly is opened, the hydraulic pressure is transmitted to the hydraulic mechanism 6, so that the metal slips 2 are normally seated to ensure the safety of on-site operations.

It is easy to understand that the hydraulic mechanism 6 may be a multi-stage hydraulic cylinder structure. The number of hydraulic cylinder stages of the hydraulic mechanism 6 can be adjusted according to the seating pressure of the metal slip 2.

The following will briefly describe the operation method of using the expansion hanger 100 according to the present invention to perform liner completion.

First, run the tail pipe 16. Referring to Fig. 6, when the tail pipe 16 is run in the field, the assembled expansion hanger is connected to the upper part of the tail pipe string, and then is connected to the stern pipe string through the drill pipe 19 to complete the safe running of the tail pipe string. If obstacles occur during the running of the liner string, the auxiliary running of the string can be carried out by raising and lowering the movable drill pipe 19 (see Figures 1 and 8).

Secondly, the cycle is reversed. Referring to Fig. 7, after the liner 16 is lowered to the designed well depth, a cyclic well washing is carried out, and an undercutting operation is carried out before the cementing operation. During the undercut operation, adjust the suspended weight of the drilling tool, find the neutral point of the drilling tool, and turn the string forward to undercut. Due to the influence of wellbore trajectory and friction factors, even if the neutral point is found by adjusting the suspended weight of the wellhead drilling tool, the safety mechanism 27 of the expansion hanger may be in a state of upward or downward pressure. At the neutral point load position, raise or lower the drill tool to a certain load. Since the inverted joint 14 can slide axially on the bearing core shaft 10, the spring sleeve 12 can compress the spring 13 so as to absorb a certain load. The bearing mandrel 10 has a certain movable stroke, so that the undercut thread bears a small axial force. After the drill pipe 19 is rotated forward, the bearing mandrel 10 drives the inverted joint 14 to rotate, and the spring 13 and the spring sleeve 12 rotate relative to the expansion mandrel 9 through the bearing 11, so that the inverted joint 14 and the changeable joint 15 are connected The undercut thread is disengaged, thus completing the lost hand operation.

Compared with conventional undercut threads, the safety mechanism 27 of the present invention can reduce the axial force of the undercut threads, facilitate finding the neutral point load, and improve the success rate of undercuts.

After that, sit and hang up. 1 and 8, after the undercut operation of the expansion hanger 100 is completed, the lower expansion cone 5 on the expansion mandrel 9 and the expansion starter 22 of the expansion suspension cylinder 1 form a conical surface contact, and the cement is injected according to the normal procedure. Well, the drill pipe rubber plug 20 is thrown for replacement. When the drill rod rubber plug 20 is replaced to the hollow rubber plug 18 at the bottom of the rubber plug rod 17 and blocked, an internal pressure is formed, and the hydraulic pressure is transmitted to the hydraulic mechanism 6 of the slip setting mechanism 24. The hydraulic mechanism 6 pushes the upper expansion cone 4 down the central tube 7 so that the expansion outlet 23 and the metal slip 2 at the upper part of the expansion suspension cylinder 1 form an expansion seal. When the metal slip 2 is expanded and sealed, the slip block 201 does not expand, but the connecting rib 203 connecting the slip block 201 is stretched, and the slip teeth 202 on the slip block 201 are squeezed and anchored to the technical casing On the inner wall of 21, it is helpful to reduce the sitting pressure of metal slips. When the upper expansion cone 4 descends to the limit structure at the lower part of the central pipe 7 and no longer continues to descend, the metal slip 2 is now completely seated. Continue to hold the pressure and cut the hollow rubber plug 18. At this time, the hollow rubber plug 18 separates from the rubber plug rod 17, and continues to be displaced down to the cementing attachment to be impacted.

After that, sit and hang the hanger. Referring to Fig. 9, after the hollow rubber plug 18 is hit, the wellhead continues to hold the pressure to the design pressure. When the suspended weight of the wellhead drilling tool is lowered, the drilling tool is lifted, and the expansion cone 5 is pushed by hydraulic pressure to expand the expansion suspension cylinder 1, thereby expanding and squeezing the sealing cylinder 3 on the suspension sealing mechanism 25 on the expansion suspension cylinder 1 and Between 21 technical casings. Due to the special structure of the sealing cylinder 3 as described above, a powerful mechanical seal of "metal + rubber" dual materials can be formed. When the lower expansion cone 5 expands to the sealing cylinder 3, due to the squeezing of the sealing cylinder 3, its sitting pressure is higher than the internal pressure of the expansion suspension cylinder 1. In order to avoid excessive expansion pressure, the metal slip 2 after sitting can be provided The mechanical support force reduces the expansion pressure of the sealing cylinder 3.

Finally, perform a throwaway completion. Referring to Figure 10, the current expansion cone 5 has all completed the expansion of the expansion suspension cylinder 1, and the lower expansion cone 5 is lifted from the expansion suspension cylinder 1 under the action of hydraulic and mechanical lifting force, and the pressure at the wellhead is relieved to complete the expansion of the expansion suspension cylinder 1. Swell to sit and hang. After circulating the excess cement slurry out of the wellhead, lift up the drilling tool to complete the well.

According to the hanger 100 of the present invention, it can be ensured that the undercut joint will not bear weight during the undercut operation, so that the rotation torque is easily transmitted to the undercut thread, which facilitates the thread undercut operation. After sitting and hanging, the double suspension of the metal slip 2 and the sealing cylinder 3, and the double sealing of metal and rubber can be realized, which effectively improves the suspension force of the expansion hanger and significantly improves the sealing ability of the expansion hanger under high temperature conditions.

In addition, in the cementing completion method according to the present invention, the upper expansion cone 4 and the lower expansion cone 5 are used to set the slips 2 and then the expansion suspension cylinder 1 to increase the mechanical setting force and reduce Hydraulic expansion force, thereby reducing operation risk. Therefore, the hanger 100 according to the present invention can be well suited for liner completion operations in thermal recovery wells, deep wells, and ultra-deep wells under high-temperature well conditions.

The hanger 100 according to the present invention has been described above. However, it is understood that in practice, one or more mechanisms or one or more components may also be omitted. For example, in an embodiment not shown, the hanger 100 according to the present invention may not include the slip setting mechanism 24. In this case, the hanger should be set up directly after the cyclic undercut operation. At this time, slips cannot provide mechanical force for the hanger when sitting, but it can still increase the hanging force of the hanger after being seated.

In this embodiment, although the present invention has been described with reference to preferably, without departing from the scope of the present invention, various improvements can be made to it and the components therein can be replaced with equivalents. In particular, in the absence of structural conflicts, the various technical features mentioned in the various embodiments can be combined in any manner. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims (17)

1. The expansion hanger includes an expansion suspension cylinder (1) and slips (2) arranged on the outer surface of the expansion suspension cylinder (1). The slips (2) include a plurality of circumferentially arranged surfaces provided with slips The slip block (201) of the tooth (202) is formed with a circulation channel (205) between adjacent slip blocks (201), wherein at least two slip blocks (201) pass between two adjacent slip blocks (201) in the circumferential direction. Two elastically deformable connecting ribs (203) are connected, and all the slip blocks (201) are fixed to each other through a fixing ring (204).
2. The expansion hanger according to claim 1, characterized in that the connecting ribs (203) are respectively arranged in the middle and lower parts of the slips (2), and the fixing ring (204) is arranged in the clip The upper part of the tile (2).
3. The expansion hanger according to claim 2, wherein the upper part of each slip block (201) includes a necked portion (208), and the fixing ring (204) surrounds each of the slips. The constricted part of the block (201) is arranged to fix a plurality of the slip blocks (201) together.
4. The expansion hanger according to claim 3, wherein the outer diameter of each connecting rib (203) is smaller than the outer diameter of the slip block (201), and/or the fixing ring (204) The outer diameter of is smaller than the outer diameter of the slip block (201).
5. The expansion hanger according to claim 4, characterized in that a sealing cylinder (3) is provided on the outer surface of the expansion suspension cylinder (1), and the sealing cylinder (3) is located in the slips (2). ) Downstream, and consists of a rubber tube (301), a combination of a rubber tube (301) and a trapezoidal metal ring (302), and a combination of a rubber tube (301) and a zigzag metal ring (303). Several to form.
6. The expansion hanger according to claim 5, characterized in that a plurality of sealing cylinders (3) are arranged axially spaced apart on the outer surface of the expansion suspension cylinder (1).
7. The expansion hanger according to claim 6, wherein the trapezoidal metal ring (302) is configured to have an outer dimension larger than an inner dimension, and the trapezoidal metal ring (302) and the zigzag metal ring (303) have a ratio The rubber tube (301) has a smaller outer diameter.
8. The expansion suspension according to any one of claims 1 to 7, wherein the expansion suspension further comprises a safety mechanism (27), and the safety mechanism (27) comprises:

   A bearing mandrel (10) fixedly connected to the expansion mandrel (9) in the expansion suspension cylinder (1);

   A spring sleeve (12) installed on the bearing mandrel (10) through a bearing (11);

   An inverted joint (14) mounted on the bearing mandrel (10), the inverted joint (14) is configured to be able to slide axially along the bearing mandrel (10) and follow the bearing mandrel (10) Rotate together;

   A changeable joint (15) installed on the outside of the inverted joint (14) and threadedly engaged with the inverted joint (14); and

   The spring (13) is located between the bearing mandrel (10) and the change buckle joint (15) in the radial direction, and between the spring sleeve (12) and the undercut joint (14) in the axial direction,

   Wherein, the spring sleeve (12) can compress the spring (13) in response to the downward movement of the bearing mandrel (10) until it abuts against the variable buckle joint (15), and the undercut The joint (14) can follow the rotation of the bearing mandrel (10) to rotate, thereby disengaging the threaded engagement between the inverted joint (14) and the inverted joint (14).
9. The expansion hanger according to claim 8, wherein the inverted joint (14) is provided with a left-handed male thread, the changeable joint (15) is provided with a left-handed female thread, and the bearing mandrel (10) ) The rotation is clockwise.
10. The expansion hanger according to claim 8, characterized in that a hollow rubber plug (18) is provided at the downstream end of the bearing mandrel (10), or,

    A rubber plug rod (17) is provided at the downstream end of the bearing mandrel (10), and a hollow rubber plug (18) is provided at the downstream end of the rubber plug rod (17).
11. The expansion hanger according to claim 10, characterized in that a tail pipe (16) is provided at the downstream end of the variable buckle joint (15), and the hollow rubber plug (18) is located in the tail pipe (16). )Inside.
12. The expansion hanger according to any one of claims 1 to 7, characterized in that the expansion hanger comprises a slip hanging mechanism (24) arranged upstream of the slip (2), so The slip setting mechanism (24) includes a central tube (7) arranged in the expansion suspension cylinder (1), and an upper expansion cone (4) that forms an axial sliding sealing fit with the central tube (7) , A hydraulic mechanism (6) connected with the upper expansion cone (4), and a hydraulic opening assembly used to activate the hydraulic mechanism (6).
13. The expansion hanger according to claim 12, characterized in that the hydraulic opening assembly comprises a liquid inlet (601) communicating with the inner cavity of the central tube (7), and is installed in the liquid inlet (601). ) In the rupture disc (602), and a fixing block (603) for fixing the rupture disc (602), wherein the rupture disc (602) is configured to be ruptured under a set pressure, thereby activating the The hydraulic mechanism (6) performs the setting and hanging of the slips (2).
14. The liner completion method using the expansion hanger according to any one of claims 1 to 13 includes the following steps:

    Step one, run in the tail pipe;

    Step two, carry out cyclic deduction operation;

    Step three, perform well cementing and slip setting;

    Step four, sit and hang the hanger; and

    Step five is to complete the well.
15. The liner completion method according to claim 14, characterized in that, in step 2, the drilling tool is lifted or pressed down at the load position of the neutral point, so that the bearing mandrel in the safety mechanism (27) (10) Sliding relative to the inverted buckle joint (14) until the spring sleeve (10) abuts the change buckle joint (15), and then rotate the drill rod to make the bearing mandrel (10) The rotation drives the inverted joint (14) to rotate, so as to release the threaded engagement between the inverted joint (14) and the changeable joint (15).
16. The liner completion method according to claim 15, characterized in that, in step 3, the hydraulic pressure generated when the drill pipe rubber plug (20) is compounded is transferred to the slip setting mechanism (24). The hydraulic mechanism (6) pushes the upper expansion cone (4) to move along the central tube (7), causing the slips (2) to set.
17. The liner completion method according to claim 16, characterized in that, in step 4, the expansion suspension cylinder (1) is expanded to expand the sealing cylinder (3) of the suspension sealing mechanism (25) It is squeezed between the expansion suspension cylinder (1) and the technical casing (21).

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