Double-layer heat insulation oil pipe cutter mechanism

Abstract

The utility model provides a double-layer heat insulation oil pipe cutter mechanism, which belongs to the technical field of oil and gas field well completion and well repair, and comprises an upper joint, a body, a piston rod, a spring, a pin and blades, the left end of the body is in threaded connection with the upper joint, a plurality of uniformly distributed placing notches are milled at the right end of the body, and a blade is respectively arranged in each placing notch. A piston rod and a spring are installed in the body, a cavity is formed between the outer wall of the piston rod and the inner wall of the body, the spring is arranged in the cavity, the piston rod is sleeved with the spring, meanwhile, the spring is pre-compressed between the body and the piston rod, pins are symmetrically installed on the body, and one end of each pin is inserted into a limiting groove of the piston rod. And the other end is mounted in the mounting hole of the body. The cutting device is reasonable in structure, convenient to maintain, high in cutting speed and capable of cutting a double-layer heat insulation oil pipe and a multi-layer non-concentric casing pipe, and the maximum stability performance under various unfavorable cutting conditions can be obtained.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil and gas field completion, workover technical field especially relates to a double -layer heat -insulated oil pipe cutter mechanism. BACKGROUND

[0002] With the continuous development of petroleum exploitation industry and the continuous increase of petroleum consumption, exploitation of heavy oil has become the main source of production of many domestic and foreign oil companies. The use of double-layer heat-insulated oil pipe in large area for heavy oil thermal recovery brings the cutting and fishing of double-layer oil pipe and cutting overhauling for these thermal recovery wells. The current commonly used method is to cut the double-layer oil pipe by using one-time cutting technology. The heat-insulated oil pipe is a double-layer pipe, which is divided into an outer pipe and an inner pipe. Therefore, one-time cutting is equivalent to cutting two pipes at a time, which results in longer cutting time and greater cutting strength than cutting one pipe. In order to achieve one-time cutting, the cutter blade of the heat-insulated oil pipe needs a large pushing force, which results in high pump pressure. In addition, the existing heat-insulated oil pipe cutter usually uses grinding to cut the oil pipe, which requires a large torque. Due to the above problems, the existing heat-insulated oil pipe cutter has low cutting success rate and often has problems such as cutting off the inner pipe but not cutting off the outer pipe, which results in safety problems in subsequent operations. As described above, one-time cutting of double-layer oil pipe has the problems of long cutting time, high strength, high pump pressure, high torque and other characteristics, which makes cutting very difficult. SUMMARY

[0003] In order to solve the many problems of one-time cutting of double-layer heat-insulated oil pipe, the utility model aims to provide a double-layer heat-insulated oil pipe cutter mechanism, which greatly improves the efficiency and safety of cutting operation.

[0004] To achieve the above purpose, the technical scheme of the utility model is as follows: a double-layer heat-insulated oil pipe cutter mechanism, comprising an upper joint, a body, a piston rod, a spring, a pin and a blade, the left end of the body is threadedly connected with the upper joint, the right end of the body is milled with a plurality of uniformly distributed placement notches, one blade is installed in each placement notch, the piston rod and the spring are installed in the interior of the body, a cavity is formed between the outer wall of the piston rod and the inner wall of the body, the spring is arranged in the cavity, the spring is sleeved on the outside of the piston rod, and the spring is pre-compressed between the body and the piston rod, the body is symmetrically provided with the pin, one end of the pin is inserted into the limiting groove of the piston rod, and the other end of the pin is installed in the mounting hole of the body.

[0005] Further, the interior of the upper joint is provided with a first through hole, and the end away from the body is provided with an internal thread connected with the milling pipe column.

[0006] Further, the left end of the piston rod is provided with a sealing check ring, a nut and an O-shaped ring, the O-shaped ring is arranged at the left shaft shoulder position of the piston rod, and the right end of the O-shaped ring is sequentially provided with the sealing check ring and the nut, and the nut is threadedly connected with the piston rod.

[0007] Further, the position, where the sealing check ring contacts the O-shaped ring, is provided with a circular arc concave structure.

[0008] Further, the number of the placing notches of the body is three, each placing notch is communicated with the inner cavity of the body, and each placing notch is provided with a connecting hole, and one pin shaft is arranged in each connecting hole, the cutter is detachably connected with the body through the pin shaft, the body is provided with two mounting holes and two flow discharge holes in a radial symmetry mode, the flow discharge holes are arranged at one end of the body close to the upper joint, and the mounting holes and the flow discharge holes penetrate through the outer wall and the inner cavity of the body.

[0009] Further, the left end surface of the piston rod contacts the right end surface of the upper joint, the position, where the left end of the piston rod contacts the O-shaped ring, is provided with a circular arc structure, the position, where the piston rod is connected with the nut, is provided with a thread structure, the right end of the piston rod is provided with a limiting groove and an annular groove, and the piston rod is internally provided with a second through hole, and the diameter of the second through hole is smaller than that of the first through hole; when the piston rod moves in the axial direction, the pin can slide in the limiting groove, and when the pin contacts the left end surface of the limiting groove, the pin can axially limit the piston rod.

[0010] Further, the left end of the cutter is provided with a hook, the hook is arranged in the annular groove of the piston rod, the position, where the cutter contacts the right end of the piston rod, is provided with an inclined surface structure, the cutting edge portion of the cutter is provided with a wear-resistant area, and the wear-resistant area is brazed with hard alloy.

[0011] Further, when the piston rod moves rightwards under the action of liquid force, the right end of the piston rod can push the inclined surface structure of the cutter, so that the cutters respectively rotate and open outwards along the pin shafts; when the piston rod moves to the axial limiting position, i.e. when the left end of the limiting groove contacts the pin, the cutter reaches the maximum cutting diameter, and at this moment, the flow discharge holes on the body are opened; after the liquid force disappears, the spring pushes the piston rod to move leftwards, and in the process that the piston rod moves leftwards, the right side step position of the annular groove on the piston rod can drive the hook of the cutter, so that the cutter is forced to rotate and retract into the placing notches in the body.

[0012] Compared with the prior art, the double-layer heat-insulated oil pipe cutter mechanism has the following advantages:

[0013] (1) The double-layer heat-insulated oil pipe cutter mechanism can flexibly select the cutter size and the cutter model according to the well condition, select different cutting parameters according to different well conditions, select a reasonable cutting mode according to different well conditions, and quickly and efficiently complete the cutting operation;

[0014] (2) The double-layer thermal oil pipe cutter mechanism can realize one-time cutting of double-layer or multi-layer casings, reduces the operation steps of casing cement ring compared with the traditional single-layer cutting, avoids the potential risks caused by casing (the casing requires higher mud pump equipment, and the risk of sticking is high), saves the construction period, and greatly improves the work efficiency;

[0015] (3) The double-layer thermal oil pipe cutter mechanism can realize one-time cutting of double-layer or multi-layer casings, solves the problems of long cutter working time and large cutting strength, and effectively avoids the construction parameters of high pump pressure and high torque. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which form a part of this description, are included to provide a further understanding of the application. The embodiments of the application and its features are described with reference to the drawings. In the drawings:

[0017] Figure 1 A structure schematic view of the double-layer thermal oil pipe cutter mechanism according to the embodiment of the application;

[0018] Figure 2 An assembly view of the sealing retainer ring, nut, O-ring and piston rod;

[0019] Figure 3 A structure schematic view of the body according to the embodiment of the application;

[0020] Figure 4 A A-A sectional view schematic view in Figure 3 ;

[0021] Figure 5 A B-B sectional view schematic view in Figure 3 ;

[0022] Figure 6 A K direction schematic view in Figure 3 ;

[0023] Figure 7 A structure schematic view of the piston rod according to the embodiment of the application;

[0024] Figure 8 A structure schematic view of the cutter blade according to the embodiment of the application;

[0025] Figure 9 A front view of the cutter blade according to the embodiment of the application;

[0026] Figure 10 A top view of the cutter blade according to the embodiment of the application;

[0027] Figure 11The right view of the blade is described in the embodiment of the utility model.

[0028] Mark explanation:

[0029] 1, upper joint; 2, body; 3, sealing baffle; 4, nut; 5, piston rod; 6, spring; 7, pin; 8, pin shaft; 9, blade; 10, O ring;

[0030] 11, first through hole; 21, placing notch; 22, connecting hole; 23, mounting hole; 24, flow hole; 51, limiting groove; 52, annular groove; 53, screw structure; 54, circular arc structure; 55, second through hole; 91, hook; 92, wear-resistant area; 93, inclined surface structure. Specific implementation

[0031] It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict.

[0032] The utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0033] As Figures 1-11As shown, the utility model of a double -layer heat -insulating oil pipe cutting knife mechanism, it is specially used for cutting double -layer heat -insulating oil pipe cutting class downhole tool. It is a kind of tool that uses water horsepower to push cutter to cut in pipe, the cutter mechanism structure is reasonable, and maintenance is convenient, cutting speed is more fast, simultaneously applicable to cutting multilayer non - concentric casing, when cutting multilayer non - concentric casing, the cutter mechanism can withstand violent vibration. The large extension of robust arm can obtain the maximum stability under various adverse cutting conditions (including hard point, eccentric, discontinuous cutting etc.). Specifically, the cutter mechanism of the utility model includes upper joint 1, body 2, piston rod 5, spring 6, pin 7 and blade 9, the left end of upper joint 1 is provided with internal thread, is connected with mill pipe column, and the right end is threadedly connected with body 2, and the mill pipe column is prior art. The inside of body 2 is provided with sealing baffle 3, nut 4, piston rod 5 and spring 6, and the cavity is formed between the outer wall of piston rod 5 and the inner wall of body 2, the cavity is provided with spring 6, spring 6 is sleeved on the outside of piston rod 5, and spring 6 is pre-compressed between body 2 and piston rod 5, i.e. in initial state, spring 6 is in compression state, so that the left end face of piston rod 5 is attached to the right end face of upper joint 1. The left end (big end) of piston rod 5 is provided with sealing baffle 3, nut 4 and O-ring 10, O-ring 10 is installed at the left side shoulder position of piston rod 5, the right end side of O-ring 10 is sequentially provided with sealing baffle 3 and nut 4, nut 4 is installed on the big end of piston rod 5 by thread, and sealing O-ring 10 is clamped by sealing baffle 3. The right end of body 2 is milled with a plurality of uniformly distributed placing notches 21, one blade 9 is respectively installed in each placing notch 21, preferably, the number of placing notches 21 of body 2 is three, each placing notch 21 is communicated with the inner cavity of body 2, and each placing notch 21 is provided with a connecting hole 22, a pin shaft 8 is installed in one connecting hole 22, and the blade 9 is detachably connected with the body 2 through the pin shaft 8, the body 2 is provided with two installation holes 23 and two drainage holes 24 along the radial symmetry, the drainage hole 24 is arranged at the end of body 2 close to upper joint 1, and the installation hole 23 and the drainage hole 24 respectively penetrate the outer wall and the inner cavity of body 2, the installation hole 23 is used to install pin 7, one end of pin 7 is inserted into the limiting groove 51 of piston rod 5, and the other end is installed in the installation hole 23 of body 2.

[0034] The one end of the upper joint 1 connected with the body 2 is provided with a sealing ring groove, and a sealing ring is installed in the sealing ring groove, which is used for forming a seal when the upper joint 1 is connected with the body 2. The inside of the upper joint 1 is provided with a first through hole 11 as a flow passage. In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the utility model, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0035] Preferably, the sealing baffle 3 is provided with a circular arc concave structure at the position where the sealing baffle 3 is in contact with the O-shaped ring 10, and the circular arc concave structure has the same arc as the O-shaped ring 10. The left end of the piston rod 5 is also provided with a circular arc structure 54 at the position where the left end of the piston rod 5 is in contact with the O-shaped ring 10, and the circular arc structure 54 has the same arc as the O-shaped ring 10. When the nut 4 is extruded to the sealing baffle 3 through the thread on the piston rod 5, the O-shaped ring 10 is pressed tightly by the sealing baffle 3 and the piston rod 5, so as to avoid damage to the O-shaped ring 10 caused by the strong impact of the liquid flow when the leakage hole 24 on the body 2 is opened.

[0036] The left end surface of the piston rod 5 is in contact with the right end surface of the upper joint 1, and the position connected with the nut 4 is provided with a threaded structure 53. The inside of the piston rod 5 is provided with a second through hole 55, and the diameter of the second through hole 55 is smaller than the diameter of the first through hole 11, that is, the inside of the upper joint 1 is provided with a first through hole 11 with a larger diameter, and the inside of the piston rod 5 is provided with a second through hole 55 with a smaller diameter. When the liquid flow passes quickly, the diameter of the through hole through which the liquid flow passes changes suddenly from a large through hole to a small through hole, and a throttling pressure difference is generated, which serves as a power source for the movement of the piston rod 5. A section of reduced diameter, that is, a limiting groove 51, is arranged at the position close to the right end of the middle part of the piston rod 5. The head of the pin 7 can be inserted into the limiting groove 51. When the piston rod 5 moves in the axial direction, the pin 7 can slide in the limiting groove 51. When the pin 7 is in contact with the left end surface of the limiting groove 51, the pin 7 can form axial limiting for the piston rod 5. A section of reduced diameter, that is, an annular groove 52, is arranged at the right end of the piston rod 5, and the hook 91 of the blade 9 head can be placed in the annular groove 52.

[0037] The left end of the blade 9 is provided with a small hole into which the pin shaft 8 can pass, and a hook 91 is arranged below the small hole, and the right side of the hook 91 is provided with a bevel structure 93, and specifically, the bevel structure 93 is arranged at the position of the blade 9 which is in contact with the right end of the piston rod 5, and the cutting edge part of the blade 9 is provided with a wear-resistant area 92 which is brazed with hard alloy, and the blade 9 is designed to be thick and heavy, and can meet the harsh working conditions such as large impact and strong vibration when cutting double-layer oil pipes. In the actual application process, the blade 9 is provided with different models, the structures of the blades 9 of different models are the same, and the sizes are different, and correspondingly, the body 2 matched with the blade 9 is also provided with a plurality of models with different sizes, so as to adapt to the sizes of the blades 9 of different models, and therefore, in order to facilitate the distinction, the blade mechanism with the blade 9 and the body 2 of different models can be understood as a blade mechanism with different models. The workers can flexibly select the size of the blade and the model of the blade 9 according to the well conditions, select a reasonable cutting mode, and quickly and efficiently complete the cutting operation.

[0038] When the blade mechanism is lowered to the predetermined cutting position, the pump is started to circulate, and the working pump (a mud pump is selected here) pumps high-pressure liquid (drilling fluid or seawater) into the body of the blade mechanism, and when the high-pressure liquid passes through the first through hole 11 and then passes through the second through hole 55, a pressure drop is generated, that is, a throttling pressure difference is generated, thereby providing power, that is, hydraulic force, for the movement of the piston rod 5, so as to push the piston rod 5 to compress the spring 6 and make the piston rod 5 move downward (under the action of overcoming the elastic force of the spring 6). When the piston rod 5 moves downward under the action of the hydraulic force, the lower end of the piston rod 5 can push the bevel structure 93 of the blade 9, so as to force each blade 9 to rotate outward along the pin shaft 8 and be in contact with the inner wall of the double-layer heat-insulating oil pipe, and the three blades 9 which are opened outward rotate clockwise along with the cutting drilling tool, and the three blades 9 cut the double-layer heat-insulating oil pipe in the circumferential direction at the same time, until the double-layer heat-insulating oil pipe is completely cut off. When the piston rod 5 moves to the axial limiting position, that is, when the left end of the limiting groove 51 is in contact with the pin 7, the blade 9 reaches the maximum cutting diameter, and at this time, due to the right movement of the piston rod 5, the flow outlet on the body 2 is opened, and the workers on the ground can observe that the pressure of the working pump will obviously decrease, which prompts the workers on the ground that the cutting operation is completed. After the oil pipe is cut off, the pump is stopped, and the pressure difference disappears, and the spring 6 gradually returns to the initial state, and in the process of returning to the initial state, the spring 6 provides an elastic force for the piston rod 5, and under the action of the elastic force of the spring 6, the piston rod 5 moves upward, and the step position of the ring-shaped groove 52 on the piston rod 5 close to the end of the blade 9 can drive the hook 91 of the blade 9, so as to forcibly rotate the blade 9 back to the inside of the body 2. The working pump is prior art. The blade mechanism can not only cut the double-layer heat-insulating oil pipe in one trip, but also can cut the multilayer casing in one trip, and the operation steps for cutting the multilayer casing are consistent with those for cutting the double-layer heat-insulating oil pipe, and it should be noted that the diameter of the multilayer casing is usually larger than that of the double-layer oil pipe, and therefore, when the multilayer casing is cut, the blade 9 of the corresponding specification and model needs to be selected.

[0039] The specific operation method is as follows:

[0040] 1. Before the double-layer thermal-insulated oil pipe cutter mechanism is lowered into the well, hydraulic test is carried out on the drilling platform, the displacement is gradually increased according to the calculated value until the three blades 9 and the pressure relief hole are completely opened, the actual displacement is recorded, then the pressure is released, and the three blades 9 can automatically shrink into the cutter body. The drilling platform is the prior art.

[0041] 2. The cutter mechanism is connected to the lowermost end of the milling pipe column in the cutting drilling tool assembly according to the self-downward order of the cutting drilling tool assembly and the specified fastening torque. The cutting drilling tool assembly is the prior art.

[0042] 3. When the drilling is carried out, the double-layer thermal-insulated oil pipe cutter mechanism is slow when passing through the blowout preventer, casing hanger and other special downhole devices, so as to prevent the cutter from being broken or the blades 9 from being opened too early and causing the cutter to not reach the position. The blowout preventer, casing hanger and other special downhole devices are the prior art.

[0043] 4. The cutting position of the thermal-insulated oil pipe should avoid the coupling of the outer pipe of the thermal-insulated oil pipe. The coupling is the prior art.

[0044] 5. After the double-layer thermal-insulated oil pipe cutter mechanism is lowered to the cutting depth, an empty load test should be carried out. That is, the pump is not started, only the drilling column is rotated, the torque test is carried out at three different rotating speeds of 20 rpm, 30 rpm and 40 rpm, and the records of the hanging weight, drilling pressure, rotating speed and torque are made. The drilling column is a tool in the cutting drilling tool assembly and is the prior art.

[0045] 6. When the double-layer oil pipe is formally cut, the pump is started after the drilling column is rotated, the principle of “low rotating speed first and high rotating speed later and small displacement first and large displacement later” is followed, the rotating speed and the displacement are gradually increased, and the inner and outer pipes of the thermal-insulated oil pipe are uniformly and stably cut, so as to protect the blades from being damaged in the initial stage. At the same time, the drilling fluid displacement is stabilized, and the pump pressure and displacement change are paid attention to.

[0046] 7. After the oil pipe is cut, the pump pressure should suddenly decrease under the condition that the drilling fluid displacement is unchanged, if the condition lasts for one minute, it is indicated that the oil pipe is cut, then the displacement is reduced and the double-layer thermal-insulated oil pipe cutter mechanism is pulled out.

[0047] The above only describes the preferred embodiments of the utility model and does not limit the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A dual barrier tubing cutter mechanism, characterized by: The utility model provides a kind of piston rod, including upper joint (1), body (2), piston rod (5), spring (6), pin (7) and blade (9), the left end of body (2) is threadedly connected with upper joint (1), and right end is milled with multiple uniform placement notch (21), each placement notch (21) is respectively installed with one blade (9), the inside of body (2) is installed with piston rod (5) and spring (6), and the cavity is formed between the outer wall of piston rod (5) and the inner wall of body (2), which is provided with spring (6), spring (6) is sleeved on the outside of piston rod (5), while spring (6) is pre-compressed between body (2) and piston rod (5), body (2) is symmetrically installed with pin (7), one end of pin (7) is inserted into the limiting groove (51) of piston rod (5), and the other end is installed in the mounting hole (23) of body (2).

2. A double barrier tubing cutter mechanism according to claim 1, wherein: The inside of upper joint (1) is provided with first through hole (11), and the end away from body (2) is provided with internal thread connected with milling pipe column.

3. A double barrier tubing cutter mechanism according to claim 2, wherein: The left end of piston rod (5) is installed with sealing baffle ring (3), nut (4) and O ring (10), O ring (10) is installed at the left side shoulder position of piston rod (5), the right end side of O ring (10) is sequentially provided with sealing baffle ring (3) and nut (4), while nut (4) is threadedly connected with piston rod (5).

4. A double barrier tubing cutter mechanism according to claim 3, wherein: The position where sealing baffle ring (3) contacts O ring (10) is provided with circular-arc concave structure.

5. A double barrier tubing cutter mechanism according to claim 1, wherein: The number of placement notch (21) of body (2) is three, each placement notch (21) is communicated with the inner cavity of body (2), while each placement notch (21) is respectively provided with one connecting hole (22), one pin shaft (8) is installed in one connecting hole (22), blade (9) is detachably connected with body (2) through pin shaft (8), two mounting holes (23) and two drainage holes (24) are symmetrically provided on body (2) along radial direction, drainage hole (24) is provided at the end of body (2) close to upper joint (1), while mounting hole (23) and drainage hole (24) respectively penetrate the outer wall and inner cavity of body (2).

6. A double barrier tubing cutter mechanism according to claim 3, wherein: The left end surface of piston rod (5) contacts the right end surface of upper joint (1), the position where the left end of piston rod (5) contacts O ring (10) is provided with circular-arc structure (54), and the position connected with nut (4) is provided with thread structure (53), the right end of piston rod (5) is provided with limiting groove (51) and annular groove (52), the inside of piston rod (5) is provided with second through hole (55), and the diameter of second through hole (55) is smaller than the diameter of first through hole (11); when piston rod (5) moves along axial direction, pin (7) can slide in limiting groove (51), when pin (7) contacts the left end surface of limiting groove (51), pin (7) can form axial location to piston rod (5).

7. A double barrier tubing cutter mechanism according to claim 6, wherein: The left end of the blade (9) is provided with a hook (91) placed in the annular groove (52) of the piston rod (5), and the position of the blade (9) in contact with the right end of the piston rod (5) is provided with a bevel structure (93), and the blade edge part of the blade (9) is provided with a wear-resistant area (92) brazed with hard alloy.

8. A double barrier tubing cutter mechanism according to claim 7, wherein: When the piston rod (5) moves right under the action of liquid force, the right end of the piston rod (5) can push the bevel structure (93) of the blade (9), so that each blade (9) respectively rotates outward along the pin shaft (8); when the piston rod (5) moves to the axial limiting position, that is, the left end of the limiting groove (51) is in contact with the pin (7), the blade (9) reaches the maximum cutting diameter, at this time the drain opening on the body (2) is opened; after the liquid force disappears, the spring (6) pushes the piston rod (5) to move left, and in the process of the left movement of the piston rod (5), the right step position of the annular groove (52) on the piston rod (5) can drive the hook (91) of the blade (9), and forcibly rotate the blade (9) to retract into the placing notch (21) inside the body (2).

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