A continuous tube blowout preventer

Abstract

This invention relates to the field of continuous tube blowout preventer (BOP) technology, specifically disclosing a continuous tube BOP comprising a preheating device, an opening piston, a guide assembly, a compression ring, and a rubber core. The opening piston, guide assembly, compression ring, and rubber core are all disposed within the preheating device. The piston end of the opening piston is annular. The guide assembly includes a middle guide sleeve and a lower guide sleeve. A step is provided in the middle of the inner wall of the annular piston end. The middle guide sleeve is slidably connected to the inner wall of the annular piston end, and one end of the middle guide sleeve is driven by the step. The other end of the middle guide sleeve is connected to one end of the compression ring, the other end of the compression ring abuts against one end of the rubber core, and the other end of the rubber core abuts against one end of the lower guide sleeve. The other end of the lower guide sleeve is connected to the end of the preheating device furthest from the opening piston. The preheating device has a hydraulic oil flow channel. This BOP can insulate the internal seals in low-temperature environments, improving their service life and ensuring the stability of the hydraulic system control under low-temperature conditions.

Description

Technical Field

[0001] This invention relates to the field of continuous tube blowout preventer technology, specifically a continuous tube blowout preventer. Background Technology

[0002] Extremely cold climates, with temperatures ranging from -60°C to -30°C, place high demands on the low-temperature adaptability of coiled tubing equipment. The coiled tubing blowout preventer (BOP) is a core component for the successful implementation of coiled tubing operations. It acts as a static or dynamic seal, isolating well pressure from atmospheric pressure and ensuring the safety of coiled tubing operations. In low-temperature and ultra-low-temperature conditions, conventional BOPs suffer from problems such as easy damage and seal failure of rubber seals, accelerated wear of the sealing core due to piston compression and coiled tubing friction, premature aging of the dynamic seal, freezing of hydraulic lines, and hydraulic system malfunction. Particularly under low-temperature and ultra-high-pressure conditions, the BOP seal fails even faster, compromising equipment reliability and potentially leading to major safety accidents during operations.

[0003] Currently, the common practice is to upgrade or replace the internal seals of the blowout preventer with cryogenic seals to adapt to low-temperature operating conditions. However, this cannot completely solve the problem of low-temperature failure of the non-metallic components of the blowout preventer under cryogenic conditions. Furthermore, the hydraulic control system of the blowout preventer only uses cryogenic hydraulic oil and hydraulic tank heating, without heat tracing or insulation of the hydraulic control circuit and the blowout preventer body itself, which cannot guarantee the stability of the hydraulic system control under cryogenic conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a continuous tube blowout preventer that can insulate the internal seals in low-temperature environments, thereby improving their service life and ensuring the stability of hydraulic system control under low-temperature conditions.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A continuous tube blowout preventer includes a preheating device, an opening piston, a guide assembly, a compression ring, and a rubber core. The opening piston, guide assembly, compression ring, and rubber core are all disposed within the preheating device. The piston end of the opening piston is annular. The guide assembly includes an intermediate guide sleeve and a lower guide sleeve. A step is provided in the middle of the inner wall of the annular piston end. The intermediate guide sleeve is slidably connected to the inner wall of the annular piston end, and one end of the intermediate guide sleeve is driven connected via the step. The other end of the intermediate guide sleeve is connected to one end of the compression ring. The other end of the compression ring abuts against one end of the rubber core. The other end of the rubber core abuts against one end of the lower guide sleeve. The other end of the lower guide sleeve is connected to the end of the preheating device furthest from the opening piston. The preheating device has a hydraulic oil passage that communicates with the piston oil inlet of the opening piston.

[0007] In a further embodiment, the preheating device includes an upper preheating sleeve, a lower preheating sleeve, a middle preheating sleeve, a connecting pipe, and a stud. The door-opening piston is enclosed within the upper preheating sleeve, and the piston end of the door-opening piston is slidably connected to the lower preheating sleeve. The upper preheating sleeve is threadedly connected to the lower preheating sleeve via the stud. The middle preheating sleeve is sleeved outside the stud and located between the upper and lower preheating sleeves. Flow channels are provided within the upper, lower, and middle preheating sleeves, and these flow channels are connected to each other via the connecting pipe. The upper preheating sleeve is provided with a hydraulic pipe joint that communicates with the door-opening piston.

[0008] In a further embodiment, both the upper and lower preheating jackets have flange structures, the studs are detachably connected between the flange structures of the two, and the cylinder of the door-opening piston is connected to the flange structure of the upper preheating jacket.

[0009] In a further embodiment, flow channels are provided within the flange structure.

[0010] In a further embodiment, the flow channels are evenly distributed within the upper preheating jacket, the lower preheating jacket, and the middle preheating jacket.

[0011] In a further embodiment, the sealing ring between the piston and the cylinder of the door-opening piston is located within the area enclosed by the upper preheating sleeve and the middle preheating sleeve.

[0012] In a further embodiment, the rubber core is located within the area enclosed by the central preheating sleeve, and the rubber core is directly opposite the central preheating sleeve when the piston extension end of the door opening piston retracts.

[0013] In a further embodiment, the central preheating jacket includes two semi-annular sleeves that are detachably connected to each other. The semi-annular sleeves have interconnected flow channels, and the flow channels within the two semi-annular sleeves are respectively connected to the flow channels within the flange structure through the connecting pipe.

[0014] In a further embodiment, the preheating device also includes a heat circulation pipe, which has a hydraulic oil flow channel inside and a heat circulation medium flow channel outside the hydraulic oil flow channel inside the heat circulation pipe. The hydraulic oil flow channel and the heat circulation medium flow channel inside the heat circulation pipe are connected to the hydraulic pipe joint and connecting pipe on the upper preheating jacket.

[0015] In a further embodiment, the guide assembly also includes an upper guide sleeve, which is fixed to the upper part of the door opening piston and is used to guide the inserted continuous tube.

[0016] The beneficial effects of this invention are:

[0017] The continuous tube blowout preventer of this invention achieves sealing of the continuous tube inserted into the blowout preventer by extending the door piston and driving the guide assembly to drive the compression ring to press the rubber core. The rubber core is reset by retracting the door piston and is preheated and kept warm by a preheating device to prevent freezing, so that it has reliable compression and expansion performance even at low temperatures. The hydraulic oil of the door piston is preheated and kept warm to ensure that its flowability meets the control stability requirements of the hydraulic system. Thus, the blowout preventer achieves dynamic sealing and blowout prevention effect at low temperatures.

[0018] Setting the sealing ring inside the door opening piston within the preheating range of the preheating device can improve its service life and performance under low-temperature conditions.

[0019] A detachable semi-circular sleeve is installed on the outside of the rubber core as a preheating sleeve in the middle to preheat the rubber core. It has a protective function for the rubber core and can be disassembled independently for easy replacement of the rubber core inside the blowout preventer. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the piston connection inside the continuous tube blowout preventer box in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the connection of the preheating device in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the heat circulation medium flow in the preheating device in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the heat circulation pipe in an embodiment of the present invention;

[0025] In the diagram: 1. Preheating device; 11. Upper preheating jacket; 12. Lower preheating jacket; 13. Middle preheating jacket; 131. Semi-annular sleeve; 14. Connecting pipe; 141. Pipe body; 142. Pipe seat; 143. Connecting plug; 15. Stud; 16. Heat circulation pipe; 101. Flange structure; 2. Door piston; 201. Sealing ring; 3. Guide assembly; 31. Upper guide sleeve; 32. Lower guide sleeve; 33. Middle guide sleeve; 4. Extrusion ring; 5. Rubber core. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] A continuous tube blowout preventer, comprising as follows Figure 2 The preheating device 1 shown and as follows Figure 1 The door opening piston 2, guide assembly 3, extrusion ring 4, and rubber core 5 are shown in the attached diagram. Figure 1 and Figure 2 As shown, the door-opening piston 2, guide assembly 3, extrusion ring 4, and rubber core 5 are all arranged inside the preheating device 1. The piston end of the door-opening piston 2 is annular. The guide assembly 3 includes an intermediate guide sleeve 32 and a lower guide sleeve 33. A step is provided in the middle of the inner wall of the annular piston end. The intermediate guide sleeve is slidably connected to the inner wall of the annular piston end. One end of the intermediate guide sleeve 32 is driven connected through the step. The other end of the intermediate guide sleeve 32 is connected to one end of the extrusion ring 4. The other end of the extrusion ring 4 abuts against one end of the rubber core 5. The other end of the rubber core 5 abuts against one end of the lower guide sleeve 33. The other end of the lower guide sleeve 33 is connected to the end of the preheating device 1 away from the door-opening piston 2. The preheating device 1 has a hydraulic oil flow channel, which is connected to the piston oil inlet of the door-opening piston 2.

[0028] Its working principle or implementation method is as follows: First, the sealing ring and rubber core 5 inside the door opening piston 2 are protected by the preheating device 1 to prevent them from freezing at low temperature and to ensure that their working performance is not affected in the low temperature environment. Under low temperature conditions, the piston of the door opening piston 2 can extend the drive guide assembly 3 to drive the extrusion ring 4 to extrude the rubber core 5, thereby sealing the continuous tube inserted in the rubber core 5, thus achieving the purpose of active anti-spray. After the door opening piston 2 retracts, the rubber core 5 can retract, realizing the unsealing between the rubber core 5 and the continuous tube.

[0029] like Figure 2 As shown, the preheating device 1 includes an upper preheating sleeve 11, a lower preheating sleeve 12, a middle preheating sleeve 13, a connecting pipe 14, and a stud 15. The door opening piston 2 is connected inside the upper preheating sleeve 11 and is slidably connected to the lower preheating sleeve 12. The upper preheating sleeve 11 is threadedly connected to the lower preheating sleeve 12 through the stud 15. The middle preheating sleeve 13 is sleeved outside the stud 15 and is located between the upper preheating sleeve 11 and the lower preheating sleeve 12. The upper preheating sleeve 11, the lower preheating sleeve 12, and the middle preheating sleeve 13 are all provided with flow channels, which are connected to each other through the connecting pipe 14. The upper preheating sleeve 11 is provided with a hydraulic pipe joint that communicates with the door opening piston 2.

[0030] By machining flow channels for the flow of thermal circulation medium inside the upper preheating jacket 11, lower preheating jacket 12, and middle preheating jacket 13, the external thermal circulation medium can be introduced to preheat the entire blowout preventer box. In addition to preheating, it should be conceivable that the hydraulic oil can also be preheated by the thermal circulation medium before the hot hydraulic oil is introduced into the door opening piston 2. The preheating temperature can be set according to actual needs.

[0031] Both the upper preheating jacket 11 and the lower preheating jacket 12 have flange structures 101, and studs 15 are detachably connected between the flange structures 101 of the two. The cylinder of the opening piston 2 is connected to the flange structure 101 of the upper preheating jacket 11. The flange structure 101 facilitates the arrangement and installation of the upper preheating jacket 11, the lower preheating jacket 12 and the cylinder of the opening piston 2. The detachable connection via studs 15 facilitates the connection and installation of the entire preheating device 1 after separate processing.

[0032] like Figure 3 As shown, flow channels are provided within the flange structure 101. The arrows in the diagram indicate the circulation direction of the hot circulating medium. The hot circulating medium is introduced through the flow channels to achieve preheating. Generally, a sealing ring is provided inside the flange to prevent freezing.

[0033] The flow channels are evenly distributed within the upper preheating jacket 11, the lower preheating jacket 12, and the middle preheating jacket 13. The flow channels can be rectangular or convex, which increases the preheating area of ​​the preheating device 1, enabling it to provide a uniform preheating and heat preservation effect on the sealing ring, hydraulic oil in the cylinder, and rubber core 5 inside the door piston 2.

[0034] like Figure 1 As shown, the sealing ring 201 between the piston and the cylinder of the door-opening piston 2 is located within the area enclosed by the upper preheating sleeve 11 and the middle preheating sleeve 13. This prevents some parts of the sealing ring from not being preheated, thus reducing its service life.

[0035] The rubber core 5 is located within the area enclosed by the central preheating sleeve 13, and when the piston extension end of the door opening piston 2 retracts, the rubber core 5 is directly facing the central preheating sleeve 13. This prevents some parts of the rubber core 5 from not being preheated, thus reducing its lifespan. It also facilitates preheating of the rubber core 5 even when the door opening piston 2 retracts.

[0036] The central preheating jacket 13 includes two detachably connected semi-annular sleeves 131, with interconnected flow channels between them. The flow channels within the two semi-annular sleeves 131 are respectively connected to the flow channels within the flange structure 101 via connecting pipes 14. It should be understood that the connecting pipe 14 may include a pipe body 142 and a pipe seat 141. The shapes of the pipe body 142 and the pipe seat 141 can be manufactured according to connection requirements. The pipe seat 141 has an inlet and an outlet for the hot circulating medium, and internally machined with hot circulating medium flow channels. It is fixed to the outlet end face of the flange with screws. The inlet of one pipe seat 141 connects to the outlet of the upper flange structure, and the outlet connects to the inlet of an auxiliary heating semi-annular ring; the inlet of the other pipe seat 141 connects to the outlet of another auxiliary heating semi-annular ring, and the outlet connects to the inlet of the lower flange structure. All inlets and outlets are equipped with sealing rings. The connecting plug 143 can connect one auxiliary heating half-ring and another auxiliary heating half-ring, sealing off the communication between the upper and lower flow channels of the two auxiliary heating half-rings; the connecting hose connects one auxiliary heating half-ring and another auxiliary heating half-ring, connecting the flow channels of the two auxiliary heating half-rings in series, ensuring that the heat circulation medium flows through one auxiliary heating half-ring before entering the other auxiliary heating half-ring. The flange structure and the interior of the semi-annular sleeve 131 are equipped with interconnected heat circulation channels for the heat circulation medium, as well as outlets and inlets for the heat circulation medium. The heat circulation medium can circulate in and out of its flow channels through the outlets and inlets of each component to provide heat to the blowout preventer.

[0037] The preheating device 1 also includes, for example, Figure 4 The heat circulation pipe 16 shown has a hydraulic oil flow channel inside and a heat circulation medium flow channel outside the hydraulic oil flow channel inside the heat circulation pipe 16. In this way, when the heat circulation medium flows through, it can preheat the hydraulic oil in the internal hydraulic oil flow channel, thereby increasing the fluidity of the hydraulic oil.

[0038] The guide assembly 3 includes an upper guide sleeve 31, a lower guide sleeve 33, and an intermediate guide sleeve 32. The upper guide sleeve 31 is fixed to the upper part of the door opening piston 2. The intermediate guide sleeve 32 is connected between the upper guide sleeve 31 and the compression ring 4 near the upper guide sleeve 31. The lower guide sleeve 33 is tightly connected to one end of the compression ring 4 away from the upper guide sleeve 31. The upper guide sleeve 31 guides the inserted continuous tube at the top of the BOP box, the lower guide sleeve 33 guides the inserted continuous tube at the bottom of the BOP box, and the middle guide sleeve 32 guides the inserted continuous tube at the middle of the BOP box. Only the middle guide sleeve 32 performs the driving action, which can ensure that the continuous tube is straight when it enters the core 5. When the diameter of the core 5 used to insert the continuous tube is slightly smaller than the diameter of each guide sleeve used to insert the continuous tube, the damage to the core 5 can be reduced. At the same time, the upper guide sleeve 31, lower guide sleeve 33 and middle guide sleeve 32 can also reduce the damage caused by the collision between the upper or lower part of the opening piston 2 and the continuous tube. The piston of the opening piston 2 only drives the middle guide sleeve 32 to slide along the cylinder seat of the opening piston 2 to drive the extrusion ring 4 downward, which can reduce the wear between the entire guide assembly 3 and the continuous tube and the steel seat of the opening piston 2.

[0039] The flange structure of the low-temperature blowout preventer and the semi-annular sleeve 131 for auxiliary heating are coated with a 4-8mm thick high-temperature heat insulation coating. The thermal conductivity of the coating is 0.03W / mK, which effectively reduces the heat loss of the blowout preventer by more than 30% to 70%.

[0040] The heat circulation medium can be liquid or steam, or a high-quality antifreeze with good antifreeze effect. The high-quality antifreeze has a freezing point of -60℃ to -40℃ and a boiling point of over 108℃. It has good antifreeze properties and fluidity in low-temperature environments, preventing the circulation medium from freezing at low temperatures when heating is not started.

[0041] When antifreeze is used as the heat circulation medium, the heating temperature of the circulating antifreeze by the fuel heater is 50°C to 60°C.

[0042] The seal of the blowout preventer in low-temperature environments is made of oil-resistant and low-temperature-resistant nitrile rubber with an acrylonitrile content of 18% to 20%, which can meet the requirements for operation at temperatures as low as -50℃.

[0043] The hydraulic control system of the blowout preventer is equipped with a fuel heater on the hydraulic oil tank. The antifreeze circulation heating system of the fuel heater pumps the hot circulating medium into the hot circulating medium channel pipeline to achieve the same source heating of the hydraulic oil tank, hydraulic oil pipeline and blowout preventer.

[0044] The blowout preventer uses a dual-channel hydraulic pipeline with a hydraulic oil circuit and a hot circulating medium. The inner channel is the hydraulic control oil circuit channel, and the outer channel is the circulating hot circulating medium channel. The hot circulating medium inlet and outlet channels of the pipeline are connected to the hot circulating medium inlet and hot circulating medium outlet on the blowout preventer, respectively, forming a hot circulating medium circulation loop.

[0045] When the blowout preventer operates in low-temperature environments, in some embodiments, a heating furnace first runs to circulate antifreeze in the heating rods to preheat the hydraulic oil in the hydraulic oil tank through heat exchange. An antifreeze tank acts as a replenishment tank to replenish the antifreeze in the circulating heating system. Simultaneously, another heating furnace circulates antifreeze in the hot water circulation pipe, and another antifreeze tank acts as a replenishment tank to preheat the hydraulic lines connected to the blowout preventer and the preheating device 1. Once the hydraulic oil in the hydraulic oil tank and the hydraulic lines are preheated to above 0°C, the blowout preventer's operation can be controlled.

[0046] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A continuous tube blowout preventer, characterized in that, The device includes a preheating device (1), an opening piston (2), a guide assembly (3), a compression ring (4), and a rubber core (5). The opening piston (2), guide assembly (3), compression ring (4), and rubber core (5) are all disposed inside the preheating device (1). The piston end of the opening piston (2) is annular. The guide assembly (3) includes an intermediate guide sleeve (32) and a lower guide sleeve (33). A step is provided in the middle of the inner wall of the annular piston end. The intermediate guide sleeve is slidably connected to the inner wall of the annular piston end, and the intermediate guide sleeve is... One end of the sleeve (32) is driven by the stepped platform, and the other end of the intermediate guide sleeve (32) is connected to one end of the extrusion ring (4). The other end of the extrusion ring (4) abuts against one end of the rubber core (5). The other end of the rubber core (5) abuts against one end of the lower guide sleeve (33). The other end of the lower guide sleeve (33) is connected to one end of the preheating device (1) away from the door piston (2). The preheating device (1) has a hydraulic oil passage, which is connected to the piston oil inlet of the door piston (2).

2. A continuous tube blowout preventer according to claim 1, characterized in that, The preheating device (1) includes an upper preheating sleeve (11), a lower preheating sleeve (12), a middle preheating sleeve (13), a connecting pipe (14), and a stud (15). The door-opening piston (2) is wrapped inside the upper preheating sleeve (11), and the piston end of the door-opening piston (2) is slidably connected to the lower preheating sleeve (12). The upper preheating sleeve (11) is threadedly connected to the lower preheating sleeve (12) through the stud (15). The middle preheating sleeve (13) is sleeved outside the stud (15) and is located between the upper preheating sleeve (11) and the lower preheating sleeve (12). The upper preheating sleeve (11), the lower preheating sleeve (12), and the middle preheating sleeve (13) are all provided with flow channels, and the flow channels are connected to each other through the connecting pipe (14). The upper preheating sleeve (11) is provided with a hydraulic pipe joint that communicates with the door-opening piston (2).

3. A continuous tube blowout preventer according to claim 2, characterized in that, Both the upper preheating sleeve (11) and the lower preheating sleeve (12) have flange structures (101), and the stud (15) is detachably connected between the flange structures (101) of the two. The cylinder of the door opening piston (2) is connected to the flange structure (101) of the upper preheating sleeve (11).

4. A continuous tube blowout preventer according to claim 3, characterized in that, Each flange structure (101) is provided with a flow channel.

5. A continuous tube blowout preventer according to claim 4, characterized in that, The flow channels are evenly distributed in the upper preheating jacket (11), the lower preheating jacket (12), and the middle preheating jacket (13).

6. A continuous tube blowout preventer according to claim 4, characterized in that, The sealing ring (201) between the piston and the cylinder of the door opening piston (2) is within the area enclosed by the upper preheating sleeve (11) and the middle preheating sleeve (13).

7. A continuous tube blowout preventer according to claim 4, characterized in that, The rubber core (5) is located within the area enclosed by the central preheating sleeve (13), and the rubber core (5) is directly opposite the central preheating sleeve (13) when the piston extension end of the door opening piston (2) retracts.

8. A continuous tube blowout preventer according to claim 7, characterized in that, The central preheating sleeve (13) includes two semi-annular sleeves (131) that are detachably connected to each other. The semi-annular sleeves (131) have interconnected flow channels. The flow channels in the two semi-annular sleeves (131) are respectively connected to the flow channels in the flange structure (101) through the connecting pipe (14).

9. A continuous tube blowout preventer according to claim 2, characterized in that, The preheating device (1) further includes a heat circulation pipe (16), which has a hydraulic oil flow channel inside and a heat circulation medium flow channel outside the hydraulic oil flow channel inside the heat circulation pipe (16). The hydraulic oil flow channel and the heat circulation medium flow channel inside the heat circulation pipe (16) are connected to the hydraulic pipe joint and connecting pipe (14) on the upper preheating sleeve (11).

10. A continuous tube blowout preventer according to claim 1, characterized in that, The guide assembly (3) also includes an upper guide sleeve (31), which is fixed to the upper part of the door opening piston (2) and is used to guide the inserted continuous tube.

Images