Mud line suspension system suitable for high-temperature and high-pressure environment

Abstract

The utility model relates to the field of offshore oil and gas drilling, and discloses a mud line suspension system suitable for a high-temperature and high-pressure environment, an outer-layer casing hanger body is fixed on a riser through a first seating shoulder, a middle-layer casing hanger body is fixed on the outer-layer casing hanger body through a second seating shoulder, and the middle-layer casing hanger body is fixed on the riser through a second seating shoulder. The inner-layer casing hanger body is fixed on the middle-layer casing hanger body through a ratchet-shaped buckle; the upper portion of the outer-layer casing hanger body, the upper portion of the middle-layer casing hanger body and a lowering tool are sealed through a metal coating and a metal sealing ring, and the upper portion of the inner-layer casing hanger body and a lowering tool are sealed through an arc-shaped conical surface double-V metal sealing structure. Through reasonable structural layout, sealing arrangement, material selection and thread screwing length, the mud line suspension system can be well suitable for a high-temperature and high-pressure harsh environment, and the overall strength and the connection reliability are effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of offshore oil and gas drilling, and in particular to a mud line suspension system suitable for high temperature and high pressure environments. Background Art

[0002] The mudline suspension system can suspend casing near the platform and mudline, provide pressure control, and provide an annular passage to the surface wellhead device. As oil and gas exploration and development gradually develops towards deep and ultra-deep layers, the ambient temperature and pressure of offshore oil and gas drilling wellbore are getting higher and higher. High-temperature and high-pressure wells are usually deeper, and the traditional casing suspension system can no longer meet the stability requirements of the drilling platform. The structure, materials and sealing of some components are not suitable for harsh environments of high temperature and high pressure; and domestic technology is in its infancy, and the underwater tieback system products used on offshore platforms have long relied on imports. Therefore, the development of a high-temperature and high-pressure mudline suspension system is of great significance to my country's implementation of its offshore oil and gas development strategy.

[0003] The utility model patent with announcement number CN206129212U discloses an anti-corrosion cap structure in a casing mud line suspension system, including a circular end plate, the edge of which extends upward to form an annular rib, the circular end plate and the annular rib form an open trough, a fixed plate parallel to the circular end plate is provided in the trough, a connecting joint is also located in the trough, a connecting joint is provided on the fixed plate, and the connecting joint is connected to a conveying tool in the casing mud line suspension system; a plurality of lifting ears are provided along the circumferential direction on the upper edge of the annular rib, and the lifting ears are connected to the conveying tool through a steel wire rope. The utility model can prevent the fishing net from being entangled in the connecting joint, and can also ensure its stability when connected with the conveying tool, and effectively prevent the anti-corrosion cap from falling off. However, the utility model does not involve the issue of how the mud line suspension system copes with high temperature and high pressure environments. Utility Model Content

[0004] In order to overcome the defects of the prior art, the utility model provides a mud line suspension system suitable for high temperature and high pressure environment, and its technical solution is as follows:

[0005] A mudline suspension system suitable for high temperature and high pressure environment, comprising an outer casing hanger body, a middle casing hanger body and an inner casing hanger body, wherein the outer casing hanger body is fixed on a watertight pipe, the middle casing hanger body is fixed on the outer casing hanger body, and the inner casing hanger body is fixed on the middle casing hanger body; a first seating shoulder is installed on the outer periphery of the lower part of the outer casing hanger body, and a first step for receiving the first seating shoulder is provided on the inner wall of the watertight pipe; a second seating shoulder is installed on the outer periphery of the lower part of the middle casing hanger body, and a second step for receiving the second seating shoulder is provided on the inner wall of the lower part of the outer casing hanger body; A thorn-type buckle is installed on the outer periphery of the lower part of the inner casing hanger body, and a thorn-type groove cooperating with the thorn-type buckle is provided on the inner wall of the lower part of the middle casing hanger body; the upper inner wall of the outer casing hanger body, the upper inner wall of the middle casing hanger body, and the upper inner wall of the inner casing hanger body are all provided with trapezoidal threads cooperating with their lowering tools and trapezoidal threads cooperating with their tie-back tools; the upper parts of the outer casing hanger body and the middle casing hanger body and their lowering tools are sealed by metal plating and metal sealing rings, and the upper part of the inner casing hanger body and its lowering tool are sealed by an arc-shaped cone double V metal sealing structure.

[0006] Furthermore, an annular table corresponding to the top surface of the inner casing hanger body is provided on the upper part of the lowering tool of the inner casing hanger body, an annular groove is opened upward on the inner side of the annular table, and an arc-shaped conical double V metal sealing structure is installed on the inner wall of the annular groove; the arc-shaped conical double V metal sealing structure comprises an upper pressure ring, an arc-shaped conical double V metal sealing body and a lower pressure ring, the upper and lower end surfaces of the arc-shaped conical double V metal sealing body are respectively provided with an upper V-shaped groove and a lower V-shaped groove, the top surface of the upper pressure ring is a plane, and the bottom surface is provided with a lower protrusion which is plug-matched with the upper V-shaped groove, the bottom surface of the lower pressure ring is a plane, and the top surface is provided with an upper protrusion which is plug-matched with the lower V-shaped groove, the upper pressure ring is inserted into the upper V-shaped groove with the lower protrusion of its bottom surface, and the lower pressure ring is inserted into the lower V-shaped groove with the upper protrusion of its top surface, and when installed, the bottom surface of the lower pressure ring exposes the annular groove to leave space for downward pressure.

[0007] Furthermore, the first seat shoulder, the second seat shoulder and the outside of the thorn-shaped buckle are each provided with a circumferentially evenly distributed counterflow channel.

[0008] Furthermore, the outer casing hanger body and the first seating shoulder, the middle casing hanger body and the second seating shoulder, and the inner casing hanger body and the thorn-shaped buckle are all configured as separate structures.

[0009] Furthermore, the material of the metal coating is 316 stainless steel.

[0010] Furthermore, the watertight riser is a 30" watertight riser, the outer casing hanger body is a 20" casing hanger body, the middle casing hanger body is a 13-3 / 8" casing hanger body, and the inner casing hanger body is a 9-5 / 8" casing hanger body.

[0011] Furthermore, the material of the 20" casing hanger body, the first stand shoulder, the 13-3 / 8" casing hanger body, and the second stand shoulder are all AISI4130 steel.

[0012] Furthermore, the 9-5 / 8" casing hanger body and the thorn-shaped buckle are made of 718 steel.

[0013] Furthermore, under drilling conditions, the thread engagement length between the 20" casing hanger body and its lowering tool is 90 mm, the thread engagement length between the 13-3 / 8" casing hanger body and its lowering tool is 120 mm, and the thread engagement length between the 9-5 / 8" casing hanger body and its lowering tool is 120 mm.

[0014] Furthermore, under the tieback condition, the thread engagement length between the 20" casing hanger body and its tieback tool is 65 mm, the thread engagement length between the 13-3 / 8" casing hanger body and its tieback tool is 70 mm, and the thread engagement length between the 9-5 / 8" casing hanger body and its tieback tool is 75 mm.

[0015] Compared with the prior art, the utility model mainly has the following beneficial technical effects:

[0016] 1. The utility model makes the mudline suspension system well suited for harsh environments of high temperature and high pressure through reasonable structural layout and sealing settings.

[0017] 2. The utility model effectively improves the overall strength of the mudline suspension system and effectively prolongs its service life by selecting steel materials with excellent performance.

[0018] 3. The utility model effectively enhances the connection reliability of the mudline suspension system through the design of the thread engagement length. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the main assembly view of the mudline suspension system of the utility model;

[0020] Figure 2 It is a cross-sectional diagram of the assembly of the mudline suspension system of the utility model;

[0021] Figure 3 This is a schematic diagram of the main body of the outer casing hanger (i.e., 20" casing hanger) of the utility model;

[0022] Figure 4 This is a schematic cross-sectional view of the outer casing hanger (i.e., 20" casing hanger) of the utility model;

[0023] Figure 5 It is a top view of the first stand shoulder installed on the main body of the outer casing hanger (i.e., 20" casing hanger) of the utility model;

[0024] Figure 6 It is a cross-sectional schematic diagram of the first stand shoulder installed on the body of the outer casing hanger (i.e., 20" casing hanger) of the utility model;

[0025] Figure 7 This is a schematic diagram of the main body of the middle layer casing hanger of the utility model (i.e., a 13-3 / 8" casing hanger);

[0026] Figure 8 This is a schematic cross-sectional view of the middle layer casing hanger of the utility model (i.e., a 13-3 / 8" casing hanger);

[0027] Fig. 9 It is a top view of the second stand shoulder installed on the main body of the middle layer casing hanger (i.e. 13-3 / 8" casing hanger) of the utility model;

[0028] Fig.10 It is a cross-sectional schematic diagram of a second stand shoulder installed on the main body of the middle layer casing hanger (i.e., 13-3 / 8" casing hanger) of the utility model;

[0029] Fig.11 This is a schematic diagram of the main body of the inner casing hanger (i.e., 9-5 / 8" casing hanger) of the utility model;

[0030] Fig.12 This is a schematic cross-sectional view of the body of the inner casing hanger (i.e., 9-5 / 8" casing hanger) of the utility model;

[0031] Fig.13 It is a cross-sectional schematic diagram of the sealing assembly between the inner casing hanger body (i.e., 9-5 / 8" casing hanger) of the utility model and its lowering tool;

[0032] Fig.14 for Fig.13 A three-dimensional schematic diagram of the arc-shaped conical double V metal sealing structure;

[0033] Fig.15 for Fig.13 A schematic diagram of the front view of the arc-shaped conical double V metal seal structure;

[0034] Fig.16 for Fig.13 A schematic cross-sectional view of the arc-shaped conical double V metal seal structure;

[0035] In the figure: 1-outer casing hanger body, 2-middle casing hanger body, 3-inner casing hanger body, 4-first seat shoulder, 5-reverse flow channel, 6-second seat shoulder, 7-thorn buckle, 8-thorn groove, 9-arc cone double V metal sealing structure, 9.1-upper pressure ring, 9.1.1-lower protrusion, 9.2-arc cone double V metal sealing body, 9.2.1-upper V-groove, 9.2.2-lower V-groove, 9.3-lower pressure ring, 9.3.1-upper protrusion, 10-lowering tool, 11-annular table, 12-annular groove. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with specific embodiments and drawings. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict; the described embodiments are only part of the embodiments of the present invention, not all of them. Example 1

[0037] See also Figures 1 to 16 A mudline suspension system suitable for high temperature and high pressure environment, comprising an outer casing hanger body 1, a middle casing hanger body 2 and an inner casing hanger body 3, wherein the outer casing hanger body 1 is fixed on a watertight pipe, the middle casing hanger body 2 is fixed on the outer casing hanger body 1, and the inner casing hanger body 3 is fixed on the middle casing hanger body 2; a first seating shoulder 4 is installed on the outer periphery of the lower part of the outer casing hanger body 1, and a first step for receiving the first seating shoulder 4 is provided on the inner wall of the watertight pipe; a second seating shoulder 6 is installed on the outer periphery of the lower part of the middle casing hanger body 2, and a second step for receiving the second seating shoulder 6 is provided on the lower inner wall of the outer casing hanger body 1; A thorn-type buckle 7 is installed on the lower periphery of the layer casing hanger body 3, and a thorn-type groove 8 cooperating with the thorn-type buckle 7 is provided on the lower inner wall of the middle layer casing hanger body 2; the upper inner wall of the outer layer casing hanger body 1, the upper inner wall of the middle layer casing hanger body 2, and the upper inner wall of the inner layer casing hanger body 3 are all provided with trapezoidal threads cooperating with their lowering tool 10 and trapezoidal threads cooperating with their reconnection tool; the upper parts of the outer layer casing hanger body 1 and the middle layer casing hanger body 2 and their lowering tool 10 are sealed by metal plating and metal sealing rings, and the upper part of the inner layer casing hanger body 3 and its lowering tool 10 are sealed by an arc-shaped conical double V metal sealing structure 9. Example 2

[0038] See also Figures 1 to 16A mudline suspension system suitable for high temperature and high pressure environment, based on the technical solution described in Example 1, an annular table 11 corresponding to the top surface of the inner casing hanger body 3 is provided on the upper part of the lowering tool 10 of the inner casing hanger body 3, an annular groove 12 is upwardly provided on the inner side of the annular table 11, and an arc-shaped conical double V metal sealing structure 9 is installed on the inner wall of the annular groove 12; the arc-shaped conical double V metal sealing structure 9 includes an upper pressure ring 9.1, an arc-shaped conical double V metal sealing body 9.2 and a lower pressure ring 9.3, and the upper and lower end surfaces of the arc-shaped conical double V metal sealing body 9.2 are respectively provided with an upper V-shaped groove 9.2.1, lower V-shaped groove 9.2.2, the top surface of the upper pressure ring 9.1 is flat, and the bottom surface is provided with a lower protrusion 9.1.1 that is plugged into the upper V-shaped groove 9.2.1, the bottom surface of the lower pressure ring 9.3 is flat, and the top surface is provided with an upper protrusion 9.3.1 that is plugged into the lower V-shaped groove 9.2.2, the upper pressure ring 9.1 is inserted into the upper V-shaped groove 9.2.1 with the lower protrusion 9.1.1 on its bottom surface, and the lower pressure ring 9.3 is inserted into the lower V-shaped groove 9.2.2 with the upper protrusion 9.3.1 on its top surface. When installing, the bottom surface of the lower pressure ring 9.3 exposes the annular groove 12 to leave space for downward pressure. When the lowering tool 10 applies pressure to the upper pressure ring 9.1 through threaded cooperation, under the simultaneous action of the upper pressure ring 9.1 and the lower pressure ring 9.3, the double V metal sealing body 9.2 is stretched and deformed, filling the space of the annular groove 12 of the lowering tool 10, forming a large contact pressure to achieve metal sealing. Example 3

[0039] See also Figures 1 to 16 A mudline suspension system suitable for high temperature and high pressure environment, based on the technical solution recorded in Example 1, the first seat shoulder 4, the second seat shoulder 6 and the thorn-shaped buckle 7 are each provided with a circumferentially uniformly distributed reverse flow channel 5 outside to ensure the smooth progress of cementing operation. Example 4

[0040] See also Figures 1 to 16 A mudline suspension system suitable for high temperature and high pressure environment, based on the technical solution recorded in Example 1, the outer casing hanger body 1 and the first seat shoulder 4, the middle casing hanger body 2 and the second seat shoulder 6, the inner casing hanger body 3 and the thorn buckle 7 are all set as separate structures. Such a design has two advantages, one is that it is easy to install; the other is that it is easy to select the first seat shoulder 4, the second seat shoulder 6 and the thorn buckle 7 with materials with higher strength than the hanger body, thereby improving the load-bearing capacity of the hanger. Example 5

[0041] See also Figures 1 to 16. A mudline suspension system suitable for high temperature and high pressure environments. Based on the technical solution described in Example 1, the material of the metal coating is 316 stainless steel. Metal coating sealing refers to covering the metal surface with a thin layer of metal by coating technology to enhance its sealing and protective performance. The contact surface between the upper part of the outer casing hanger body 1 and the middle casing hanger body 2 and its lowering tool 10 is sealed by metal coating, and the quality of the material directly affects the sealing effect. The chemical composition of 316 stainless steel used in the utility model is shown in Table 1.

[0042] Table 1 Chemical composition of 316 stainless steel (%) Example 6

[0043] See also Figures 1 to 16 . A mudline suspension system suitable for high temperature and high pressure environment. Based on the technical solution described in Example 1, the watertight conductor (i.e., the outermost conductor) is set to a 30" watertight conductor; the outer casing hanger body 1 (set to a 20" casing hanger body), the first seat shoulder 4, the middle casing hanger body 2 (set to a 13-3 / 8" casing hanger body), and the second seat shoulder 6 are all made of AISI4130 steel. The inner casing hanger body 3 (set to a 9-5 / 8" casing hanger body) and the thorn-type buckle 7 are all made of 718 steel. AISI4130 steel has high strength and impact resistance; 718 steel not only has excellent mechanical properties, but also has good machinability; the chemical compositions of the two are shown in Table 2 and Table 3, respectively.

[0044] Table 2 Chemical composition of AISI4130 steel (%)

[0045] Table 3 Chemical composition of 718 steel (%) Example 7

[0046] See also Figures 1 to 16A mudline suspension system suitable for high temperature and high pressure environment, based on the technical solution recorded in Example 6, under drilling conditions, the thread engagement length of the outer casing hanger body 1 (i.e., 20" casing hanger body) and its lowering tool 10 is 90㎜, the thread engagement length of the middle casing hanger body 2 (i.e., 13-3 / 8" casing hanger body) and its lowering tool 10 is 120㎜, and the thread engagement length of the inner casing hanger body 3 (i.e., 9-5 / 8" casing hanger body) and its lowering tool 10 is 120㎜. ) and its lowering tool 10 have a thread engagement length of 120 mm; under the tie-back condition, the thread engagement length between the outer casing hanger body 1 (i.e., the 20" casing hanger body) and its tie-back tool is 65 mm, the thread engagement length between the middle casing hanger body 2 (i.e., the 13-3 / 8" casing hanger body) and its tie-back tool is 70 mm, and the thread engagement length between the inner casing hanger body 3 (i.e., the 9-5 / 8" casing hanger body) and its tie-back tool is 75 mm. The thread engagement length refers to the length of the mutually engaged portion of two mating threads along the thread axis direction. It is an important geometric parameter in threaded connection and directly affects the fastening reliability of the thread.

[0047] Table 4 shows the thread matching positions, thread selection models and screw-in lengths of the 20" casing hanger under the three working conditions of drilling, abandonment and tieback.

[0048] Table 4 Thread information of 20" casing hanger under different working conditions

[0049] Table 5 shows the thread matching positions, thread selection models and screw-in lengths of 13-3 / 8" casing hanger under three working conditions: drilling, abandonment and tie-back.

[0050] Table 5 13-3 / 8" casing hanger thread information for different working conditions

[0051] Table 6 shows the corresponding thread matching positions, thread selection models and screw-in lengths of 9-5 / 8" casing hanger under three working conditions: drilling, abandonment and tie-back.

[0052] Table 6 9-5 / 8" casing hanger thread information for different working conditions

[0053] In order to enable those skilled in the art to better understand the present invention, its basic working principle and process are briefly introduced as follows:

[0054] The utility model is reasonably designed to make the rated working pressure of the 20" casing hanger 5000psi (34.5MPa) and the rated working temperature 121℃; the rated working pressure of the 13-3 / 8" casing hanger 10000psi (69MPa) and the rated working temperature 121℃; the rated working pressure of the 9-5 / 8" casing hanger 20000psi (140MPa) and the rated working temperature 180℃. During the drilling installation stage: the mudline hanger is connected to the water-insulating pipe to load the casing in the well. Directly transferred to the seabed, reducing the platform load. After the drilling operation reaches the target depth, the casing hanger is lowered by the lowering tool 10, the outer casing hanger body 1 (i.e., the 20" casing hanger body) is fixed to the water-proof conductor through the first seating shoulder 4, the middle casing hanger body 2 (i.e., the 13-3 / 8" casing hanger body) is fixed to the outer casing hanger body 1 through the second seating shoulder 6, and the inner casing hanger body 3 (i.e., the 9-5 / 8" casing hanger body) is fixed to the middle casing hanger body 2 through the thorn-type buckle 7. Since the 9-5 / 8" casing hanger body is subjected to the highest internal pressure, the highest temperature and the smallest inner diameter, in order to save space for increasing the wall thickness and thus enhancing the structural strength of the 9-5 / 8" casing hanger body, the 9-5 / 8" casing hanger body is suspended with a thorn-shaped clip. During the temporary well abandonment stage: After the drilling operation is completed, the mudline casing suspension system needs to be temporarily abandoned before the drilling platform is evacuated to protect the internal surface, threads and sealing areas of the casing hanger from marine (ocean) organisms, mechanical damage and rock debris. From the inside to the outside, the 9-5 / 8", 13-3 / 8" and 20" casings and lowering tools are recovered in turn, and anti-corrosion caps are installed on each casing hanger body. During the tie-back stage: The casings of each layer are tied back from the hanger to the production platform to establish an oil and gas production channel for the production platform and the mudline casing suspension system. Lower the anti-corrosion cap retrieval tool to connect with the anti-corrosion cap, and lift up and recover the 20", 13-3 / 8" and 9-5 / 8" anti-corrosion caps in turn. After that, install the 20", 13-3 / 8" and 9-5 / 8" casing and tie-back tool in turn to complete the tie-back of the 20", 13-3 / 8" and 9-5 / 8" casing.

Claims

1. A mudline suspension system suitable for high temperature and high pressure environment, comprising an outer casing hanger body, a middle casing hanger body and an inner casing hanger body, characterized in that: The first seating shoulder is installed on the outer periphery of the lower part of the outer casing hanger body, the second seating shoulder is installed on the outer periphery of the lower part of the middle casing hanger body, and the thorn-type buckle is installed on the outer periphery of the lower part of the inner casing hanger body; the upper inner wall of the outer casing hanger body, the upper inner wall of the middle casing hanger body, and the upper inner wall of the inner casing hanger body are all provided with trapezoidal threads matched with the lowering tool and the trapezoidal threads matched with the tie-back tool; the upper part of the outer casing hanger body and the middle casing hanger body are connected with the lowering tool. The inner casing hanger body is sealed by metal plating and metal sealing rings, and the upper part of the inner casing hanger body and its lowering tool are sealed by an arc-shaped conical double-V metal sealing structure; the upper part of the lowering tool of the inner casing hanger body is provided with an annular table corresponding to the top surface of the inner casing hanger body, an annular groove is upwardly opened on the inner side of the annular table, and the arc-shaped conical double-V metal sealing structure is installed on the inner wall of the annular groove, and the arc-shaped conical double-V metal sealing structure includes an upper pressure ring, an arc-shaped conical double-V metal sealing body and a lower pressure ring.

2. A mudline suspension system suitable for high temperature and high pressure environment according to claim 1, characterized in that: The upper and lower end surfaces of the arc-shaped conical double-V metal sealing body are respectively provided with an upper V-shaped groove and a lower V-shaped groove. The top surface of the upper pressure ring is a plane, and the bottom surface is provided with a lower protrusion that is plug-matched with the upper V-shaped groove. The bottom surface of the lower pressure ring is a plane, and the top surface is provided with an upper protrusion that is plug-matched with the lower V-shaped groove. The upper pressure ring is inserted into the upper V-shaped groove with the lower protrusion on its bottom surface, and the lower pressure ring is inserted into the lower V-shaped groove with the upper protrusion on its top surface. When installing, the bottom surface of the lower pressure ring exposes the annular groove to leave space for downward pressure.

3. A mudline suspension system suitable for high temperature and high pressure environment according to claim 1, characterized in that: The first seat shoulder, the second seat shoulder and the outside of the thorn-shaped buckle are each provided with a circumferentially evenly distributed counterflow channel.

4. The mudline suspension system suitable for high temperature and high pressure environment according to claim 1, characterized in that: The outer layer casing hanger body and the first seating shoulder, the middle layer casing hanger body and the second seating shoulder, and the inner layer casing hanger body and the thorn-shaped buckle are all configured as separate structures.

5. The mudline suspension system suitable for high temperature and high pressure environment according to claim 1, characterized in that: The material of the metal coating is 316 stainless steel.

6. The mudline suspension system suitable for high temperature and high pressure environment according to claim 1, characterized in that: The outer layer casing hanger body is a 20" casing hanger body, the middle layer casing hanger body is a 13-3 / 8" casing hanger body, and the inner layer casing hanger body is a 9-5 / 8" casing hanger body.

7. A mudline suspension system suitable for high temperature and high pressure environment according to claim 6, characterized in that: The material of the 20" casing hanger body, the first stand shoulder, the 13-3 / 8" casing hanger body, and the second stand shoulder are all AISI4130 steel.

8. The mudline suspension system suitable for high temperature and high pressure environment according to claim 6, characterized in that: The material of the 9-5 / 8" casing hanger body and the thorn-type buckle are both 718 steel.

9. The mudline suspension system suitable for high temperature and high pressure environment according to claim 6, characterized in that: Under drilling conditions, the thread engagement length between the 20" casing hanger body and its lowering tool is 90mm, the thread engagement length between the 13-3 / 8" casing hanger body and its lowering tool is 120mm, and the thread engagement length between the 9-5 / 8" casing hanger body and its lowering tool is 120mm.

10. A mudline suspension system suitable for high temperature and high pressure environment according to claim 6, characterized in that: Under the tie-back condition, the thread engagement length between the 20" casing hanger body and its tie-back tool is 65mm, the thread engagement length between the 13-3 / 8" casing hanger body and its tie-back tool is 70mm, and the thread engagement length between the 9-5 / 8" casing hanger body and its tie-back tool is 75mm.

Images