An offshore deepwater wellhead abandonment external hang-off

Abstract

The utility model discloses an ocean deepwater well mouth abandonment outer suspension, including outer suspension body, mandril and dog, the dog is installed on outer suspension body and is rotatoryly connected with outer suspension body, the mandril outer wall is provided with lug, the inside of outer suspension body is provided with the positioning slot for accommodating the lug, axial slot and circumferential groove, the lug with positioning slot, axial slot and circumferential groove cooperate to drive dog to realize opening and locking, the utility model discloses through the optimization filtering structure is undulating, under the premise of not changing the flow passage, effectively blocks the iron filings produced when cutting knife operation to enter the clearance between outer suspension body, prevents the situation that internal passage is stuck and tool can not return to unlock, through setting independent emergency hand release function, through underwater robot can easily realize dog release function, and hand action is not affected by tool operation state, and no part is left after hand release submarine.

Description

Technical Field

[0001] This utility model relates to the field of deep-sea operations, specifically to an external suspension for abandonment at deep-sea wellheads. Background Technology

[0002] In deepwater wellhead retrieval, an external suspension system is used for retrieval from outside the wellhead, employing a top drive to power the cutter. However, in deepwater operations, ocean currents and seawater disturbances on the drill string can impact the cutter, making downward-pressure cutting and retrieval operations extremely challenging and risky. An upward-lifting top drive system can mitigate drill string disturbance issues. This involves first retrieving the high-pressure wellhead and then lifting it to cut; however, the rotation of the drill pipe generates vibrations, which can easily cause the external suspension system to slip out of control during the cutting process. Utility Model Content

[0003] To address the problems existing in the prior art, this utility model provides an external suspension for abandonment of deep-sea wellheads.

[0004] To achieve the above objectives, this utility model provides the following technical solution: an external suspension for abandoning deep-sea wellheads, comprising an external suspension body, a spindle, and a chuck, wherein the chuck is mounted on the external suspension body and rotatably connected to the external suspension body; The outer wall of the mandrel is provided with a protrusion, and the inner side of the outer suspension body is provided with a positioning groove, an axial groove and a circumferential groove for accommodating the protrusion. The protrusion cooperates with the positioning groove, axial groove and circumferential groove to drive the pawl to open and lock. The axial groove connects the positioning groove and the circumferential groove; When the protrusion is located in the positioning groove, the chuck is in the open state. When the protrusion is located in the circumferential groove, the chuck is in a locked state.

[0005] Furthermore, the external suspension body is provided with an emergency release assembly, which includes a transmission pin, a pull rod fixed to the top surface of the outer end of the transmission pin, a spring block installed on the bottom surface of the inner end of the transmission pin, and a lateral ridge for axial limiting provided on the side of the transmission pin.

[0006] The outer suspension body has a groove, the transmission pin is installed in the groove, and the pawl is installed on the outer suspension body through the transmission pin.

[0007] Furthermore, the outer suspension body is provided with a support column, and a fixing ring is connected to the side of the claw by screws. The fixing ring is sleeved on the support column, and the outer suspension body restricts the axial movement of the claw through the support column and the fixing ring.

[0008] Furthermore, a filter structure is provided at the bottom of the mandrel. The filter structure includes a wavy filter ring and a fixing pin for positioning the filter ring. The filter ring is fitted onto the bottom of the mandrel and fixed to the mandrel by a base and screws.

[0009] Furthermore, the mandrel is provided with a limiting block and an annular groove, the protrusion is located between the limiting block and the annular groove, and a limiting ring is installed in the annular groove.

[0010] The beneficial effects of this utility model are as follows: This utility model discloses an external suspension for abandonment at deep-sea wellheads. By optimizing the filter structure to a wave shape, it effectively blocks iron filings generated during cutting operations from entering the gaps of the external suspension body without changing the flow channel, preventing the tool from getting stuck in the internal channel and unable to retract or unlock. By setting an independent emergency release function, the claw release function can be easily achieved by an underwater robot. The release action is not affected by the tool's operating state, and no parts are left on the seabed after release. A limit ring is set to prevent the tool string from moving down too much when the tool is lowered or reversed for unlocking, simplifying the on-site operation process. When the tool moves down to the limit position, the tool string can be rotated. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the externally suspended tool string for wellhead retrieval driven by the lifting motor in this utility model; Figure 2 This is a cross-sectional view of the motor external suspension in this utility model; Figure 3 This is a schematic diagram of the mandrel assembly structure in this utility model; Figure 4 This is a schematic diagram of the structure of the external suspension body component in this utility model; Figure 5 This is a schematic diagram of the external suspension body structure of this utility model; Figure 6 This is a schematic diagram of the emergency release component structure in this utility model; In the diagram: 1-Motor, 2-Wellhead nozzle, 3-Expansion joint, 4-Cutter, 5-Center, 6-Rotating seat assembly, 7-External suspension body assembly, 8-Claw, 9-Mandrel assembly, 10-Limit ring; 11-Upper connector assembly, 12-Stator and rotor assembly, 13-Flexible shaft assembly, 14-Bearing assembly; 71-External suspension body, 72-Axial groove, 73-Circumferential groove, 74-Positioning groove, 75-Emergency release assembly, 76-Support column, 77-Fixing ring; 91-Mandrel, 92-Filter ring, 93-Protrusion, 94-Limiting block, 95-Base, 96-Screw, 97-Fixing pin, 98-Annular groove; 751-Drive pin, 752-Spring block, 753-Pull rod, 754-Side rib. Detailed Implementation

[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0013] This utility model discloses an abandoned external suspension for deep-water wellheads, the main purpose of which is to solve the following problems during deep-water cutting and recovery operations: in the case of downward-pressing top drive operation, the drill pipe is greatly disturbed, resulting in unstable cutting; in the case of upward-lifting top drive operation, the vibration of the drill pipe affects the stability of the tool gripping the wellhead, and in severe cases, it can lead to loss of hand; the existing external suspension structure is further optimized by adding a limiting structure and an emergency release structure to ensure the reliability of the tool.

[0014] like Figure 1 As shown, when in use, the tool string is connected from top to bottom as follows: motor 1, wellhead 2, expansion joint 3, cutter 4, and centralizer 5.

[0015] In this utility model, the external suspension structure is directly installed on the motor housing. The spindle assembly 9 of the external suspension structure and the motor bearing housing are integrated into one design, and it is compatible with two tools.

[0016] like Figure 2 As shown, the motor structure includes: upper connector assembly 11, stator and rotor assembly 12, flexible shaft assembly 13, bearing assembly 14, rotating seat assembly 6, external suspension body assembly 7, spindle assembly 9, and limit ring 10.

[0017] like Figures 3-4 As shown, the external suspension body assembly 7 includes an external suspension body 71, a spindle 91, and a pawl 8. The pawl 8 is mounted on the external suspension body 71 and is rotatably connected to the external suspension body 71. The outer wall of the spindle 91 is provided with a protrusion 93, and the inner side of the outer suspension body 71 is provided with a positioning groove 74, an axial groove 72 and a circumferential groove 73 for accommodating the protrusion 93. The protrusion 93 cooperates with the positioning groove 74, the axial groove 72 and the circumferential groove 73 to drive the pawl 8 to open and lock. Axial groove 72 connects positioning groove 74 and circumferential groove 73; When the protrusion 93 is located in the positioning groove 74, the claw 8 is in the open state. When the protrusion 93 is located in the circumferential groove 73, the pawl 8 is in a locked state.

[0018] like Figure 3 As shown, a filter structure is provided at the bottom of the mandrel 91. The filter structure includes a wavy filter ring 92 and a fixing pin 97 for positioning the filter ring 92. The filter ring 92 is fitted onto the bottom of the mandrel 91 and fixed to the mandrel by a base 95 and screws 96. A limiting block 94 and an annular groove 98 are provided on the mandrel 91, and a protrusion 93 is located between the limiting block 94 and the annular groove 98.

[0019] like Figures 5-6 As shown, an emergency release assembly 75 is provided on the external suspension body 71. The emergency release assembly 75 includes a transmission pin 751. A pull rod 753 is fixed on the top surface of the outer end of the transmission pin 751. A spring block 752 is installed on the bottom surface of the inner end of the transmission pin 751. A lateral rib 754 for axial limiting is provided on the side of the transmission pin 751.

[0020] The outer suspension body 71 has a groove, the transmission pin 751 is installed in the groove, and the pawl 8 is installed on the outer suspension body 71 through the transmission pin 751.

[0021] The outer suspension body 71 is provided with a support column 76, and the side of the claw 8 is connected to a fixing ring 77 by screws. The fixing ring 77 is sleeved on the support column 76, and the outer suspension body 71 restricts the axial movement of the claw 8 through the support column 76 and the fixing ring 77.

[0022] In practical use, the abandoned external suspension structure of the deep-sea wellhead is connected according to the tool string. When connecting, ensure that the protrusion 93 on the spindle 91 is located in the positioning groove 74 of the external suspension body 71. At this time, the chuck 8 is in the open state, and the tool string is lowered to the wellhead 2. The limiting ring 10 is installed in the annular groove 98 and fixed with screws. When the tool string is placed on the wellhead 2, the limiting ring 10 can prevent the mandrel 91 from moving down continuously. After the tool string is rotated 60° counterclockwise and the tool string is lifted, the protrusion 93 will rotate to the position of the axial groove 72 and enter the outer suspension body 71. Continue rotating counterclockwise by 30°, and the protrusion 93 enters the circumferential groove 73. At this time, the upper and lower axial directions of the protrusion 93 are limited. The limiting block 94 on the spindle 91 and the protrusion 93 will limit the circumferential counterclockwise rotation. The three evenly distributed pawls 8 are in a locked state, and the wellhead 2 is gripped. Among them, the pawls 8 are connected to the outer suspension body 71 through the transmission pin 751. The arc surface at the top of the transmission pin 751 can ensure the rotation of the pawls 8 to realize the opening and locking functions. Keep the pump in the upward position, start the pump motor to drive the cutter to perform the cutting operation, turn off the pump after the cutting is completed, retract the cutter blade, lift the tool string, and the wellhead 2 is retrieved.

[0023] If the wellhead 2 retrieval operation is unsuccessful and the tool string needs to be retrieved, rotate the tool string 30° clockwise and lower the tool string at the same time. The protrusion 93 on the mandrel 91 will move down from the axial groove 72. At this time, the chuck 8 is in the open state. Then continue rotating the tool string clockwise by 60°. At this time, the protrusion 93 will return to the positioning groove 74. The spindle 91 is limited upward by the outer suspension body 71 and downward by the limiting ring 10 in the axial direction. Therefore, the chuck 8 will always remain open. Simply lift the tool string.

[0024] The function of the external suspension tool is mainly achieved through the relative relationship between the protrusion 93 and the external suspension body 71. During cutting operations, metal debris will enter the internal gap of the tool with the fluid. To prevent the debris from getting stuck on the protrusion 93, this invention designs a filter structure. The bottom of the spindle 91 consists of three wavy filter rings 92, which are positioned by fixing pins 97. A base 95 is installed at the bottom and fixed by screws 96.

[0025] In extreme cases where the jaws 8 cannot be opened by reversing the tool string clockwise, the jaws 8 can be released from the wellhead 2 by using the emergency release component 75.

[0026] The transmission pin 751 positions the pawl 8, the spring block 752 is fixed in the groove of the outer suspension body 71, the spring block 752 and the transmission pin 751 are fixed by screws, the pull rod 753 and the transmission pin 751 are connected together by welding, and the lateral ridge 754 on the transmission pin 751 is installed in the groove of the outer suspension body 71 for axial limiting.

[0027] During operation, the underwater robot grabs the lever 753 and pulls it outward. The elastic block 752 pops out from the groove in the outer suspension body 71 when subjected to force. After the chuck 8 loses the positioning function of the transmission pin 751, it loses its locking function, releasing the wellhead 2 and lifting the tool string. The side of the chuck 8 is connected to the fixing ring 77 by screws. One end of the fixing ring 77 is fitted onto the support column 76 to ensure that the chuck 8 will not fall off after losing the positioning of the transmission pin 751. The support column 76 is connected between the rotating seat assembly 6 and the outer suspension body 71 by screws to ensure axial limit.

[0028] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An abandoned external suspension system for deep-sea wellheads, characterized in that: It includes an external suspension body, a spindle, and a chuck, wherein the chuck is mounted on the external suspension body and rotatably connected to the external suspension body; The outer wall of the mandrel is provided with a protrusion, and the inner side of the outer suspension body is provided with a positioning groove, an axial groove and a circumferential groove for accommodating the protrusion. The protrusion cooperates with the positioning groove, axial groove and circumferential groove to drive the pawl to open and lock. The axial groove connects the positioning groove and the circumferential groove; When the protrusion is located in the positioning groove, the chuck is in the open state. When the protrusion is located in the circumferential groove, the chuck is in a locked state.

2. The method for abandoning external suspension at deep-sea wellheads according to claim 1, characterized in that: The external suspension body is equipped with an emergency release assembly, which includes a transmission pin. A pull rod is fixed to the top surface of the outer end of the transmission pin, a spring block is installed on the bottom surface of the inner end of the transmission pin, and a lateral ridge for axial limiting is provided on the side of the transmission pin.

3. The method for external suspension of abandoned deep-water wellheads according to claim 2, characterized in that: The outer suspension body has a groove, the transmission pin is installed in the groove, and the pawl is installed on the outer suspension body through the transmission pin.

4. The method for external suspension of abandoned deep-water wellheads according to claim 1, characterized in that: The external suspension body is provided with a support column, and a fixing ring is connected to the side of the claw by screws. The fixing ring is sleeved on the support column, and the external suspension body restricts the axial movement of the claw through the support column and the fixing ring.

5. The method for abandoning and externally suspending deep-sea wellheads according to claim 1, characterized in that: The bottom of the mandrel is provided with a filter structure, which includes a wavy filter ring and a fixing pin for positioning the filter ring. The filter ring is fitted onto the bottom of the mandrel and fixed to the mandrel by a base and screws.

6. The method for external suspension of abandoned deep-water wellheads according to claim 1, characterized in that: The mandrel is provided with a limiting block and an annular groove, the protrusion is located between the limiting block and the annular groove, and a limiting ring is installed in the annular groove.

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