Multifunctional gas injection tubular column

Abstract

The utility model relates to a multifunctional gas injection tubular column, which comprises a continuous oil pipe, a pipe connector, a weighting rod, an insertion pipe, a baffle valve, a one-way switch valve and a guide shoe, and is characterized in that a feeding tubular column adopts the continuous oil pipe for tripping in without screw thread connection, so that the leakage risk points are few, and the reliability is high; the whole tool string is tripped through the coiled tubing, repeated screwing-on is not needed, the coiled tubing is tripped directly through a coiled tubing operation vehicle, and the operation efficiency is high; the whole tubular column has a one-way injection function, and the risk of gas backflow is avoided; after the inserting pipe and the pipe column above the inserting pipe can be taken out, a pipe column channel below the packer is in a closed state, formation gas cannot flow upwards to the ground, well killing operation is not needed, and the formation can be protected.

Description

Technical Field

[0001] The utility model relates to the technical field of CCUS, in particular to a multifunctional gas injection string. Background Art

[0002] CCUS will capture and purify the carbon dioxide emitted during the production process, and then put it into a new production process for reuse and storage. The most commonly used storage technology currently is to inject the collected carbon dioxide back into the ground through carbon dioxide reinjection wells.

[0003] Carbon dioxide reinjection wells are quite different from conventional natural gas reinjection wells, with the following main features:

[0004] (1) Carbon dioxide reinjection wells are generally abandoned oil and gas wells that are reused. Their casings are not corrosion-resistant, so the airtightness of the entire injection string is required to be high. The fewer leakage risk points, the better.

[0005] (2) Carbon dioxide reinjection only requires injection and does not require production. To ensure the safety of the tubing, the entire tubing must have a one-way injection feature, that is, the underground gas will not flow back to the ground.

[0006] At present, our conventional natural gas production and completion strings are all lowered by oil pipes, which are connected by threads, and there is a risk of leakage at the connection. At the same time, conventional natural gas production strings are all for the purpose of production, so they do not have the function of one-way injection. Utility Model Content

[0007] In order to solve the above problems, the utility model provides a multifunctional gas injection string with fewer leakage risk points, a one-way injection function, and no risk of gas backspitting.

[0008] The technical solution adopted by the utility model is: a multifunctional gas injection pipe string, characterized in that: it comprises a continuous oil pipe, a pipe-to-pipe connector, a weighting rod, a plug, a baffle valve, a one-way switch valve and a guide shoe which are sequentially arranged in a borehole from top to bottom, the plug is provided with a reversing mechanism, and the reversing mechanism is provided with a first reversing groove and a second reversing groove; a sealing mechanism is provided on the outer side of the plug to form a seal with the inner cavity of the packer;

[0009] The packer is provided with a slider, and during the lowering process, the slider is located in the second reversing groove to achieve the hooking of the packer and the cannula, thereby transmitting the axial load; a baffle valve is provided at the lower part of the packer, and in the lowering state, the core shaft of the cannula is located in the baffle valve, and the baffle valve is in an open state;

[0010] After the tubing string is lowered, a soluble ball is dropped from the wellhead. When the soluble ball reaches the constant pressure ball seat, the oil pipe is pressurized from the wellhead until the shear pin is cut off. The packer is sealed after the pump pressure drops instantly. At this time, the one-way switch valve opens the one-way passage function.

[0011] Preferably, the baffle valve includes a baffle valve body, a rotating pin, a closing spring and a baffle, the baffle valve body is a tubular hollow structure, the insert tube can be inserted into the hollow cavity of the baffle valve body, the side wall of the baffle valve body is provided with a baffle mounting port, and the baffle is arranged in the baffle mounting port through a rotating pin and a closing spring.

[0012] Preferably, the core shaft of the insert tube is located in the hollow cavity of the baffle valve body, the baffle is located in the baffle mounting port, the closing spring is in a compressed state, and the baffle valve is opened; the core shaft of the insert tube is pulled out of the hollow cavity of the baffle valve body, and the baffle rotates around the rotating pin under the action of the closing spring, closing the hollow channel of the baffle valve body, and the baffle valve is closed.

[0013] Preferably, the one-way switch valve comprises a switch valve body and a lower joint, in which a constant pressure ball seat, a sealing steel ball, a push rod and a power spring are arranged in sequence from top to bottom, and the constant pressure ball seat is axially fixed to the switch valve body by a shear pin; the sealing steel ball is arranged on the constant pressure ball seat to achieve sealing; the end of the push rod rests on the sealing steel ball, the power spring is sleeved on the push rod, the upper end of the power spring rests on the convex cap at the end of the push rod, and the lower end rests on the boss of the hollow channel of the one-way switch valve.

[0014] Preferably, after the tubing string is lowered, a soluble ball is dropped from the wellhead. When the soluble ball reaches the constant pressure ball seat, the oil pipe is pressurized from the wellhead until the shear pin is sheared off. The pump pressure drops instantly and the sealing of the packer is completed. At this time, the one-way switch valve opens the one-way passage function.

[0015] Preferably, when it is necessary to remove the tubing string, the gravity of the weighted rod is used to press down the upper tubing string of the insert, so that the slider on the packer switches from the second reversing groove to the first reversing groove, and then the continuous oil pipe is directly lifted up to achieve the removal of the upper tubing string; after removal, the baffle of the baffle valve is automatically closed under the action of the closing spring, so that the bottom fluid is sealed at the bottom, forming a double insurance closed reservoir function with the one-way switch valve.

[0016] The beneficial effects achieved by the utility model are:

[0017] (1) The utility model packer is put into the pipe string by continuous tubing, without threaded connection, with few leakage risk points and high reliability;

[0018] (2) The entire tool string is run through the coiled tubing without repeated make-up, and can be run directly through the coiled tubing operation vehicle, which has high operation efficiency;

[0019] (3) The entire string has a one-way injection function, without the risk of gas backflow;

[0020] (4) The insert and the tubing above can be taken out. After the removal, the tubing channel below the packer is in a closed state, and the formation gas cannot flow up to the ground. There is no need for well killing operations, and the formation can be protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the multifunctional gas injection string of the utility model;

[0022] Figure 2 It is a schematic diagram of the packer slider in the second reversing groove of the reversing mechanism;

[0023] Figure 3 It is a schematic diagram of the slider of the packer in the first reversing groove of the reversing mechanism;

[0024] Figure 4 This is a schematic diagram of the flapper valve being opened;

[0025] Figure 5 It is a schematic diagram of the flapper valve when it is closed;

[0026] Figure 6 It is a structural schematic diagram of a one-way switch valve;

[0027] Figure 7 It is a structural schematic diagram of the one-way switch valve when the shear pin is not cut off;

[0028] Figure 8 It is a structural schematic diagram of the one-way switch valve when the shear pin is cut off;

[0029] Fig. 9 This is a schematic diagram of the status of the pipe string entering the well;

[0030] Fig.10 It is a schematic diagram of the state when the packer is set;

[0031] Fig.11 This is a schematic diagram of the state of entering production after the packer is set;

[0032] Fig.12 It is a schematic diagram of the state when the cannula is inserted and the above pipe string is taken out;

[0033] Fig.13 It is a schematic diagram of the state after the intubation and the removal of the above pipe string;

[0034] In the figure: 1-coiled tubing; 2-tube-to-tube connector; 3-weighted rod; 4-insertion tube; 41-sealing mechanism; 42-reversing mechanism; 421-first reversing groove; 422-second reversing groove; 43-core shaft; 5-packer; 6-baffle valve; 7-one-way switch valve; 8-guide shoe; 9-data processing unit; 10-data storage unit; 11-protection control unit; 12-alarm unit; 13-automatic process control module; 14-Internet of Things data module. DETAILED DESCRIPTION

[0035] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] like Figure 1-8 As shown, a multifunctional gas injection string of the utility model comprises a continuous oil pipe 1, a pipe-to-pipe connector 2, a weighting rod 3, a cannula 4, a baffle valve 6, a one-way switch valve 7 and a guide shoe 8 which are sequentially arranged in a borehole from top to bottom. The cannula 4 is provided with a reversing mechanism 42, and the reversing mechanism 42 is provided with a first reversing groove 421 and a second reversing groove 422; a sealing mechanism 41 is provided on the outer side of the cannula to form a seal with the inner cavity of the packer 5; a slider 51 is provided on the packer 5, and during the lowering process, the slider 51 is located at the second The connection between the packer 5 and the insert 4 is realized in the reversing groove 422, so as to transmit the axial load; a baffle valve 6 is provided at the lower part of the packer 5, and when it is lowered, the core shaft 43 of the insert 4 is located in the baffle valve 6, and the baffle valve 6 is in an open state; after the tubing string is lowered, a soluble ball 78 is dropped from the wellhead, and when the soluble ball 78 reaches the constant pressure ball seat 73, the oil pipe is pressurized from the wellhead until the shear pin 72 is cut off, and the pump pressure drops instantly, and the packer 5 is sealed, and at this time, the one-way switch valve 7 opens the one-way passage function.

[0037] Combination Figure 4-5 The baffle valve 6 includes a baffle valve body 61, a rotating pin 62, a closing spring 63 and a baffle 64. The baffle valve body 61 is a tubular hollow structure. The insert 4 can be inserted into the hollow cavity of the baffle valve body 61. A baffle mounting opening is opened on the side wall of the baffle valve body 61. The baffle 64 is arranged in the baffle mounting opening through the rotating pin 62 and the closing spring 63.

[0038] The core shaft 43 of the insert tube 4 is located in the hollow cavity of the baffle valve body 61, the baffle 64 is located in the baffle mounting port, the closing spring 63 is in a compressed state, and the baffle valve 6 is opened; the core shaft 43 of the insert tube 4 is pulled out of the hollow cavity of the baffle valve body 61, and the baffle 64 rotates around the rotating pin 62 under the action of the closing spring 63, closing the hollow channel of the baffle valve body 61, and the baffle valve 6 is closed.

[0039] Combination Figure 6-8The one-way switch valve 7 includes a switch valve body 71 and a lower joint 77, in which a constant pressure ball seat 73, a sealing steel ball 74, a push rod 75 and a power spring 76 are arranged from top to bottom. The constant pressure ball seat 73 is axially fixed to the switch valve body 71 by a shear pin 72; the sealing steel ball 74 is arranged on the constant pressure ball seat 73 to achieve sealing; the end of the push rod 75 rests on the sealing steel ball 74, and the power spring 76 is sleeved on the push rod 75. The upper end of the power spring 76 rests on the convex cap at the end of the push rod 75, and the lower end rests on the boss of the hollow channel of the one-way switch valve 7.

[0040] Combination Fig. 9 In the lowered state, the packer 5 is connected to the cannula 4 through the slider 51 and the reversing mechanism 42, and the one-way switch valve 7 has a constant pressure ball seat 73 that cooperates with the soluble ball 78. Before the shear pin 72 is sheared off, the one-way fluid function of the one-way switch valve 7 is not activated, and the flapper valve 6 is in an open state. Fig.10 When the pipe string is sent to the predetermined position, the soluble ball 78 is put in to form a seal with the constant pressure ball seat 73, the wellhead is pressurized, and the packer 5 is set until the shear pin 72 is sheared, activating the one-way pass function of the one-way switch valve 7. After a certain period of time, the soluble ball 78 automatically dissolves in the liquid environment, and the production stage can be entered.

[0041] Combined with 11-13, when it is necessary to remove the tubing, the gravity of the weighted rod 3 is used to press down the upper tubing of the insert, so that the slider 51 on the packer 5 switches from the reversing groove 422 to the reversing groove 421, and then the continuous oil pipe 1 is directly lifted to achieve the removal of the upper tubing. After removal, the plate valve 6 is automatically closed, so that the bottom fluid is sealed in the formation, forming a double insurance closed reservoir function with the one-way switch valve 7, so that no carbon dioxide gas is injected above the packer, and the corrosion problem of the casing is effectively avoided.

[0042] It should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the utility model thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the utility model is limited only by the scope of the claims.

[0043] Finally, it should be pointed out that the above embodiments are only representative examples of the present utility model. Obviously, the present utility model is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model shall be considered to belong to the protection scope of the present utility model.

Claims

1. A multifunctional gas injection string, characterized in that: The invention comprises a continuous oil pipe (1), a pipe-to-pipe connector (2), a weight rod (3), a plug (4), a baffle valve (6), a one-way switch valve (7) and a guide shoe (8) which are sequentially arranged in a borehole from top to bottom. The plug (4) is provided with a reversing mechanism (42), and the reversing mechanism (42) is provided with a first reversing groove (421) and a second reversing groove (422). The plug (4) is provided with a sealing mechanism (41) on the outside to form a seal with the inner cavity of a packer (5). The packer (5) is provided with a slider (51). During the lowering process, the slider (51) is located in the second reversing groove (422), so as to achieve the connection between the packer (5) and the insert (4), thereby transmitting the axial load. A baffle valve (6) is provided at the lower part of the packer (5). In the lowering state, the core shaft (43) of the insert (4) is located in the baffle valve (6), and the baffle valve (6) is in an open state.

2. The multifunctional gas injection string according to claim 1, characterized in that: The baffle valve (6) comprises a baffle valve body (61), a rotating pin shaft (62), a closing spring (63) and a baffle plate (64); the baffle valve body (61) is a tubular hollow structure; the insert tube (4) can be inserted into the hollow cavity of the baffle valve body (61); a baffle plate installation opening is formed on the side wall of the baffle valve body (61); and the baffle plate (64) is arranged in the baffle plate installation opening via the rotating pin shaft (62) and the closing spring (63).

3. The multifunctional gas injection string according to claim 2, characterized in that: The core shaft (43) of the insert tube (4) is located in the hollow cavity of the baffle valve body (61), the baffle plate (64) is located in the baffle plate mounting opening, the closing spring (63) is in a compressed state, and the baffle valve (6) is opened; the core shaft (43) of the insert tube (4) is withdrawn from the hollow cavity of the baffle valve body (61), and the baffle plate (64) rotates around the rotating pin (62) under the action of the closing spring (63), closing the hollow channel of the baffle valve body (61), and the baffle valve (6) is closed.

4. The multifunctional gas injection string according to claim 1, characterized in that: The one-way switch valve (7) comprises a switch valve body (71) and a lower joint (77), wherein a constant pressure ball seat (73), a sealing steel ball (74), a push rod (75) and a power spring (76) are arranged in sequence from top to bottom. The constant pressure ball seat (73) is axially fixed to the switch valve body (71) by a shear pin (72); the sealing steel ball (74) is arranged on the constant pressure ball seat (73) to achieve sealing; the end of the push rod (75) rests on the sealing steel ball (74), the power spring (76) is sleeved on the push rod (75), the upper end of the power spring (76) rests on the convex cap at the end of the push rod (75), and the lower end rests on the convex platform of the hollow channel of the one-way switch valve (7).

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