Riser emergency disconnect mechanical device

Abstract

The application relates to an emergency release mechanical device for a riser, which comprises a mechanical release connector, a riser stress joint, a bottom hub and a shearing pin. The mechanical release connector comprises a male end, a female end, an outer shell and a shearing pin, the female end is sleeved outside the male end, the outer shell is sleeved outside the female end, corresponding positions of the male end, the female end and the outer shell are respectively provided with a plurality of pin holes, and the shearing pin is inserted into the three-layer corresponding pin holes so that the male end, the female end and the outer shell are connected together. The riser stress joint comprises an inner cylinder and an outer cylinder, the bottom end of the inner cylinder penetrates through the male end and the female end and extends out of the bottom of the female end, the outer cylinder is sleeved outside the inner cylinder, and the lower end of the outer cylinder is connected with the male end. The bottom hub is arranged below the female end and connected with the female end, and the bottom end of the inner cylinder is connected with the bottom hub after extending out of the bottom of the female end so as to block the upward movement of the inner cylinder.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore drilling and production equipment, in particular to a riser emergency release mechanical device. BACKGROUND

[0002] When performing workover operation on underwater wet wellhead, the workover vessel is connected with the underwater wellhead through a workover riser, and the workover riser serves to isolate seawater, lower workover equipment and circulate drilling fluid. The workover vessel will be laterally displaced due to the flow of seawater, and when the displacement is too large, the riser connected to the upper part of the underwater wellhead will be bent, which will result in damage to the wellhead. When encountering severe weather such as typhoon, the workover vessel will be displaced by a large distance in a short time, which will cause the lower corner of the riser and the wellhead to be bent, and if the riser cannot be released in time, the wellhead and the riser will be permanently damaged. Therefore, it is urgent to design a practical and efficient riser emergency release mechanical device. SUMMARY

[0003] In view of the above problems, the present application aims to provide a riser emergency release mechanical device, which can solve the problem of excessive bending of the deep-sea workover riser when encountering severe weather, and damage to the workover riser and the underwater wellhead.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] The riser emergency release mechanical device provided by the present application comprises a mechanical release connector, a riser stress sub, a bottom hub and a flow check valve. The mechanical release connector comprises a male end, a female end, an outer shell and a shear pin, the female end is sleeved outside the male end, the outer shell is sleeved outside the female end, corresponding positions of the male end, the female end and the outer shell are respectively provided with a plurality of pin holes, and the shear pin is inserted into the three corresponding pin holes to connect the male end, the female end and the outer shell together. The riser stress sub comprises an inner cylinder and an outer cylinder, the bottom end of the inner cylinder passes through the male end and the female end and extends out of the bottom of the female end, the outer cylinder is sleeved outside the inner cylinder, and the lower end of the outer cylinder is connected with the male end. The bottom hub is arranged below the female end and connected with the female end. When the bottom end of the inner cylinder extends out of the bottom of the female end, the bottom hub is connected with the inner cylinder to block the upward movement of the inner cylinder.

[0006] Preferably, the riser emergency release mechanical device further comprises a flow check valve, which is arranged between the outer cylinder of the riser stress sub and the male end, the upper end of the flow check valve is connected with the bottom of the outer cylinder, and the lower end of the flow check valve is connected with the male end.

[0007] Preferably, the emergency release mechanism for the riser pipe further includes an umbrella-shaped buffer. The movable end of the umbrella-shaped buffer is sleeved on the outer cylinder of the stress section of the riser pipe and can slide along its length on the outer cylinder. The fixed end of the umbrella-shaped buffer is fixed to the flow-carrying valve.

[0008] Preferably, the umbrella-shaped buffer of the aforementioned emergency release mechanism for the riser includes a sleeve, buffer blades, buffer ribs, and buffer short ribs; the sleeve is fitted over the outer cylinder of the stress-relief section of the riser and can slide along its length on the outer cylinder; a plurality of buffer blades are arranged circumferentially around the upper part of the flow-carrying valve, and one end of each buffer blade is fixed to the upper part of the flow-carrying valve; each buffer blade is provided with a corresponding buffer rib, the buffer rib is fitted and fixedly disposed with the buffer blade; each buffer rib is provided with a corresponding buffer short rib, one end of the buffer short rib is hinged to the buffer rib, and the other end is connected to the sleeve.

[0009] Preferably, in the aforementioned emergency release mechanism for the water-tight pipe, the male end is provided with a first through hole and a first flared opening, the first flared opening being connected to the first through hole; the female end is provided with a second through hole and a second flared opening, the second flared opening being connected to the second through hole.

[0010] Preferably, in the aforementioned emergency release mechanism for the water-tight pipe, an annular groove is provided on the side wall of the first through hole, and a sealing ring is provided inside the annular groove.

[0011] Preferably, the male end of the aforementioned emergency release mechanism for the water-tight pipe includes an upper hub, a connecting plate, and a column structure; the upper hub, the connecting plate, and the column structure are arranged sequentially from top to bottom and integrally formed; a plurality of pin holes are arranged circumferentially around the column structure.

[0012] Preferably, in the aforementioned emergency release mechanism for the water-tight pipe, the female end includes an annular structure and a base, the annular structure and the base being arranged sequentially from top to bottom and integrally formed; when the female end is fitted over the male end, the top of the annular structure abuts against the bottom of the connecting plate; a plurality of pin holes are arranged circumferentially around the base.

[0013] Preferably, the outer shell of the aforementioned emergency release mechanism for the water-tight pipe includes an outer shell body, which has a first radial boss, a second radial boss, and a third radial boss protruding from it. When the outer shell body is fitted over the female end, the top of the first radial boss abuts against the bottom of the connecting disc, and the top of the second radial boss abuts against the bottom of the annular structure. A plurality of pin holes are provided circumferentially around the outer shell body.

[0014] The present invention has the following advantages due to the adoption of the above technical solutions:

[0015] (1) The emergency release mechanism for the riser pipe described in this invention has the function of rapid and reliable release. It does not require remote triggering. In an emergency, by lifting the outer cylinder of the stress short section of the riser pipe and cutting off the shear pin, the riser pipe can be released quickly and reliably to avoid damage to the riser pipe.

[0016] (2) The emergency release mechanism for the water-tight pipe described in this invention has an umbrella-shaped buffer that can reduce backflow. During normal operation, the umbrella-shaped buffer is in a closed state and the buffer blades are retracted, which can reduce water resistance when the water is submerged. During emergency release, the umbrella-shaped buffer is in an open state to reduce backflow.

[0017] (3) The emergency release mechanical device for the riser described in this invention has an outer cylinder and an inner cylinder design for the riser stress short section, which can maintain a sealed state for 60 seconds after the riser is released in an emergency at the bottom of the well repair, ensuring that the fluid inside the pipe will not leak into the seawater.

[0018] (4) The emergency release mechanical device for water-proof pipe described in this invention has a simple structure, does not involve complex hydraulic and electrical components, has high reliability and low cost. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the emergency release mechanism for the water-tight pipe of the present invention;

[0021] Figure 2 This is a cross-sectional structural schematic diagram of the emergency release mechanism for the water-tight pipe of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the umbrella-shaped buffer of the present invention;

[0023] Figure 4 This is a three-dimensional structural schematic diagram of the mechanical release connector of the present invention;

[0024] Figure 5 This is a cross-sectional structural schematic diagram of the mechanical release connector of the present invention;

[0025] Figure 6 This is a schematic diagram of the outer shell of the present invention;

[0026] Figure 7 This is a cross-sectional structural schematic diagram of the outer shell of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of the female end of the present invention;

[0028] Figure 9 This is a cross-sectional view of the female end of the present invention;

[0029] Figure 10 This is a schematic diagram of the structure of the male terminal of the present invention;

[0030] Figure 11 This is a cross-sectional structural diagram of the male end of the present invention;

[0031] Figure 12 This is a schematic diagram of the water-proof pipe stress-relief short section and the mechanical release connector of the present invention in the connected state;

[0032] Figure 13 This is a schematic diagram of the structure in the mechanical release connector of the present invention, showing the separation of the male end from the female end and the outer shell.

[0033] Figure 14 This is a schematic diagram of the structure of the water-proof pipe stress section of the present invention, showing the inner and outer cylinders completely separated.

[0034] The markings in the attached diagram are as follows:

[0035] 1-Mechanical release connector; 101-Male end; 1011-First through hole; 1012-First flared mouth; 1013-Upper hub seat; 1014-Connecting disc; 1015-Columnar structure; 102-Female end; 1021-Second through hole; 1022-Second flared mouth; 1023-Annular structure; 1024-Chassis; 103-Outer shell; 1031-First radial boss; 1032-Second radial boss; 1033-Third radial boss; 104-Shear pin; 2-Waterproof pipe stress stub; 201-Inner cylinder; 202-Outer cylinder; 3-Bottom hub seat; 4-Flow valve; 5-Umbrella-shaped buffer; 501-Sleeve; 502-Buffer blade; 503-Buffer umbrella rib; 504-Buffer short rib; 6-Sealing ring. Detailed Implementation

[0036] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0037] This invention provides an emergency riser release mechanism. By lifting the outer cylinder of the riser stress section, the resulting load shears the pin, accurately, efficiently, and reliably separating the upper riser from the submerged wellhead. The umbrella-shaped buffer changes from a closed to an open state, utilizing seawater resistance to suppress the riser's rebound acceleration. This reduces the risk of rapid riser rebound caused by the instantaneous release of the load generated during emergency riser release or sudden wellhead disconnection. The system is a purely mechanical structure, possessing high reliability and high efficiency in offshore operations. This invention employs a mechanical release method, featuring a simple structure, convenient operation, and high safety and reliability.

[0038] like Figure 1 and Figure 2 As shown, the emergency release mechanism for the water-tight pipe provided by the present invention includes: a mechanical release connector 1 (see...) Figure 4 and Figure 5 The device includes a male end 101, a female end 102, a housing 103, and shear pins 104. The female end 102 is fitted over the male end 101, and the housing 103 is fitted over the female end 102. Corresponding positions on the male end 101, female end 102, and housing 103 are provided with several pin holes. The shear pins 104 are inserted into the corresponding pin holes on the three layers to connect the male end 101, female end 102, and housing 103 together. The water-tight pipe should... The stress-relief section 2 includes an inner cylinder 201 and an outer cylinder 202. The bottom end of the inner cylinder 201 passes through the male end 101 and the female end 102 and extends beyond the bottom of the female end 102. The outer cylinder 202 is fitted over the inner cylinder 201, and its lower end is connected to the male end 101. A bottom hub 3 is located below the female end 102 and is connected to it. The bottom end of the inner cylinder 201 extends beyond the bottom of the female end 102 and connects to the bottom hub 3 to prevent the inner cylinder 201 from moving upward. Thus, in an emergency, by lifting the outer cylinder of the stress-relief section, the upward force shears the shear pin, thereby quickly and reliably releasing the male and female ends to prevent damage to the riser.

[0039] It should be noted that the upper end of the outer cylinder of the riser stress section is connected to the riser pipe, and the lower end of the inner cylinder is connected to the wellhead.

[0040] In the above embodiments, preferably, the present invention further includes a flow-carrying valve 4, which is disposed between the outer cylinder 202 and the male end 101 of the water-proof pipe stress short section 2. The upper end of the flow-carrying valve 4 is connected to the bottom of the outer cylinder 202, and its lower end is connected to the male end 101.

[0041] In the above embodiments, preferably, the present invention further includes an umbrella-shaped buffer 5. The movable end of the umbrella-shaped buffer 5 is sleeved on the outer cylinder 202 of the water-proof pipe stress section 2 and can slide along its length on the outer cylinder 202. The fixed end of the umbrella-shaped buffer 5 is fixed to the flow-carrying valve 4. Thus, during normal operation, the umbrella-shaped buffer is in a closed state, the buffer blades are retracted, and the water resistance can be reduced when water is released; in case of emergency release, the umbrella-shaped buffer is in an open state to reduce backflow.

[0042] In the above embodiments, preferably, as follows: Figure 3 As shown, the umbrella-shaped buffer 5 includes a sleeve 501, buffer blades 502, buffer ribs 503, and buffer short bones 504. The sleeve 501 is fitted around the outer cylinder 202 of the water-tight pipe stress section 2 and can slide along its length on the outer cylinder 202. Several buffer blades 502 are arranged circumferentially around the upper part of the flow-carrying valve 4, and one end of each buffer blade 502 is fixed to the upper part of the flow-carrying valve 4. Each buffer blade 502 is correspondingly provided with a buffer rib 503, which is fitted and fixed to the buffer blade 502. Each buffer rib 503 is correspondingly provided with a buffer short bone 504, one end of which is hinged to the buffer rib 503, and the other end is connected to the sleeve 501. Thus, in an emergency release, lifting the outer cylinder 202 will cause the water pressure to open the buffer blades of the umbrella-shaped buffer, thereby reducing backflow.

[0043] In the above embodiments, preferably, as follows: Figure 5 As shown, the male end 101 has a first through hole 1011 and a first flared opening 1012 inside, and the first flared opening 1012 communicates with the first through hole 1011; wherein the first through hole 1011 and the first flared opening 1012 allow the inner cylinder 201 to pass through, and the first flared opening 1012 serves as a guide during the lowering of the male end; the female end 102 has a second through hole 1021 and a second flared opening 1022 inside, and the second flared opening 1022 communicates with the second through hole 1021; wherein the second through hole 1021 and the second flared opening 1022 allow the inner cylinder 201 to pass through, and the second flared opening 1022 serves as a guide during the lowering of the female end.

[0044] In the above embodiment, preferably, an annular groove is provided on the sidewall of the first through hole 1011, and a sealing ring 6 is provided in the annular groove. Thus, the sealing ring 6 can play a sealing role between the male end 101 and the inner cylinder 201.

[0045] In the above embodiments, preferably, as follows: Figure 10 and Figure 11As shown, the male end 101 includes an upper hub seat 1013, a connecting plate 1014, and a column structure 1015; the upper hub seat 1013, the connecting plate 1014, and the column structure 1015 are arranged sequentially from top to bottom and integrally formed; a number of pin holes are arranged circumferentially around the column structure 1015.

[0046] In the above embodiments, preferably, as follows: Figure 8 and Figure 9 As shown, the female end 102 includes an annular structure 1023 and a base 1024, which are arranged sequentially from top to bottom and integrally formed; when the female end 102 is sleeved on the male end 101, the top of the annular structure 1023 abuts against the bottom of the connecting plate 1014; a number of pin holes are arranged circumferentially around the base 1024.

[0047] In the above embodiments, preferably, as follows: Figure 6 and Figure 7 As shown, the outer shell 103 includes an outer shell body, which has a first radial boss 1031, a second radial boss 1032, and a third radial boss 1033 protruding from it. When the outer shell 103 is fitted over the female end 102, the top of the first radial boss 1031 abuts against the bottom of the connecting plate 1014, and the top of the second radial boss 1032 abuts against the bottom of the annular structure 1023. A plurality of pin holes are provided circumferentially around the outer shell body.

[0048] The process of liberation in this invention:

[0049] The outer cylinder of the riser stress sub is lifted, and the umbrella-shaped buffer changes from a closed state to an open state under water pressure. The load generated by lifting the riser shears the pin, and the inner and outer cylinders of the riser stress sub slowly separate, releasing pressure and triggering the matching well sealing device to start the well sealing action.

[0050] The mechanical release connector is in the connected state. The bottom connector housing, male end, and female end are connected together by shear pins. The umbrella-shaped buffer is in the closed state, preparing for emergency release. The top of the water-resistant pipe begins to experience lifting force, such as... Figure 12 As shown.

[0051] When the upward force exceeds the shearing force of the shear pin, the umbrella-shaped buffer changes from a closed state to an open state, the shear pin is sheared by the upward pulling force, and the male end separates from the female end. Figure 13 As shown.

[0052] Continue lifting the water-tight pipe until the inner and outer cylinders are completely released, as shown. Figure 14 As shown.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mechanical device for emergency release of a water-resistant pipe, characterized in that, The emergency release mechanism for the riser pipe includes: A mechanical release connector includes a male end, a female end, a housing, and shear pins. The female end is sleeved outside the male end, and the housing is sleeved outside the female end. The male end, the female end, and the housing are respectively provided with a plurality of pin holes at corresponding positions. The shear pins are inserted into the three layers of corresponding pin holes to connect the male end, the female end, and the housing together. A water-tightening short section includes an inner cylinder and an outer cylinder. The bottom end of the inner cylinder passes through the male end and the female end and extends out of the bottom of the female end. The outer cylinder is sleeved outside the inner cylinder, and the lower end of the outer cylinder is connected to the male end. A bottom hub is located below the female end and connected to the female end; the bottom end of the inner cylinder extends out of the bottom of the female end and connects to the bottom hub to prevent the inner cylinder from moving upward. A flow-carrying valve is disposed between the outer cylinder of the water-tightening short section and the male end, with its upper end connected to the bottom of the outer cylinder and its lower end connected to the male end. An umbrella-shaped buffer, wherein the movable end of the umbrella-shaped buffer is sleeved on the outer cylinder of the stress short section of the water-proof pipe and can slide along its length on the outer cylinder, and the fixed end of the umbrella-shaped buffer is fixed to the flow-carrying valve; The umbrella-shaped buffer includes a sleeve, buffer blades, buffer umbrella ribs, and buffer short ribs. The sleeve is fitted over the outer cylinder of the stress short section of the water-proof pipe and can slide along its length on the outer cylinder; Several buffer blades are arranged circumferentially around the upper part of the flow-carrying valve, and one end of each buffer blade is fixed to the upper part of the flow-carrying valve; Each of the buffer blades is provided with a corresponding buffer umbrella rib, and the buffer umbrella rib is fitted and fixedly installed to the buffer blade; Each of the buffer umbrella ribs is provided with a corresponding buffer short rib, one end of which is hinged to the buffer umbrella rib and the other end is connected to the sleeve.

2. The emergency release mechanism for the water-tight pipe according to claim 1, characterized in that, The male end is provided with a first through hole and a first flared opening, and the first flared opening is connected to the first through hole; The female end is provided with a second through hole and a second flared opening, and the second flared opening is connected to the second through hole.

3. The emergency release mechanism for the water-tight pipe according to claim 2, characterized in that, The sidewall of the first through hole is provided with an annular groove, and a sealing ring is provided in the annular groove.

4. The emergency release mechanism for the water-tight pipe according to claim 1, characterized in that, The male end includes an upper hub seat, a connecting plate, and a column structure; the upper hub seat, the connecting plate, and the column structure are arranged sequentially from top to bottom and integrally formed; A number of pin holes are provided at intervals around the circumference of the column structure.

5. The emergency release mechanism for the water-tight pipe according to claim 4, characterized in that, The female end includes an annular structure and a base plate, which are arranged sequentially from top to bottom and integrally formed; when the female end is fitted over the male end, the top of the annular structure abuts against the bottom of the connecting plate; A number of pin holes are provided at intervals around the circumference of the chassis.

6. The emergency release mechanism for the water-tight pipe according to claim 5, characterized in that, The outer shell includes an outer shell body, which has a first radial boss, a second radial boss and a third radial boss protruding from it; when the outer shell is fitted over the female end, the top of the first radial boss abuts against the bottom of the connecting plate, and the top of the second radial boss abuts against the bottom of the annular structure. A number of pin holes are provided at intervals around the circumference of the outer shell body.

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