CN111927416A - Layered ignition gas injection oil jacket system - Google Patents

Abstract

The application discloses layering ignition gas injection oil jacket system, it includes: the system comprises a wellhead tree, a sleeve, an oil pipe, a linkage type fireflood gas injection device and a plug; an electric igniter can be put into the oil pipe; the gas injection device can divide the oil sleeve annulus into an upper space and a lower space; the linkage type fireflood gas injection device comprises an outer pipe assembly and a central pipe; a gas injection channel is arranged between the outer pipe assembly and the central pipe; the central pipe is provided with a communication hole; the outer pipe assembly is provided with a gas injection hole; the central tube has an upper communication position and a lower communication position; when the central pipe is at the upper communication position, the communication hole is communicated with the upper air injection hole; when the central pipe is positioned at the lower communication position, the communication hole is communicated with the gas injection channel; the central tube can be pushed by the electric igniter to move downwards to the lower communication position when the central tube is at the upper communication position. The system can realize the respective ignition and gas injection of two oil layers in the fireflooding process.

Description

Layered ignition gas injection oil jacket system

Technical Field

The invention relates to the field of oil well production, in particular to a layered ignition gas injection oil jacket system.

Background

Fire flooding is also called in-situ combustion, and refers to an oil extraction method in which the temperature of an oil layer reaches the ignition point of crude oil by using electric and chemical methods, and air or oxygen is injected into the oil layer to continuously combust the crude oil in the oil layer. In the process of fire flooding development, oil reservoirs have great difference in longitudinal exploitation degree, air suction of each layer is uneven, single-layer outburst exists, the difficulty in improving air injection parameters of the gas injection well is high, the production well shows that the high part of the structure takes effect firstly, the low part of the structure takes effect later, and the problems of uneven effect and outburst exist. The results of monitoring the inspiratory profile show that: the overall usage level of the fireflood reaches 75%, but the usage conditions in the longitudinal direction are greatly different. In order to improve the longitudinal utilization condition of the fire flooding oil layer and solve the problem of uneven gas injection, research and field tests of a fire flooding layered gas injection technology are needed to be carried out so as to realize relatively uniform gas injection of a gas injection well and improve the fire flooding development effect. The layered fireflood is characterized in that a development target layer is artificially layered on the basis of a conventional fireflood, layered fireflood development is realized, and the key point of ensuring the layered fireflood development effect is successful ignition and gas injection of each small layer to form a stable combustion front edge and realize smooth displacement of underground crude oil.

The key to the success of in situ combustion is the success of the firing of the reservoir. The ignition of the oil layer mainly comprises chemical ignition and electric ignition, wherein in the electric ignition process, an igniter heats the surrounding oil reservoir, and well mouth auxiliary air is injected to enable the oil layer to be ignited by spontaneous combustion. After ignition is successful, quantitative air needs to be continuously injected according to the combustion characteristics of the oil layer to enable the combustible part of the oil layer to keep combustion, and the high-condensation oil is heated to flow and is extracted. The electric ignition technology can obtain higher ignition temperature through the electric heater, and is suitable for oil wells with higher oil layer combustion threshold temperature.

However, at the present stage, single-well electric ignition is limited by a pipe column structure, and generally only single-layer ignition single-layer quantitative gas injection can be performed, but multilayer ignition multilayer quantitative gas injection cannot be performed respectively.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present application to provide a layered ignition gas injection oil jacket system to enable separate ignition and gas injection of two oil layers during fireflooding.

In order to achieve the purpose, the technical scheme of the application is as follows:

a layered ignition gas injection oil jacket system, the layered ignition gas injection oil jacket system comprising: the device comprises a wellhead tree, a sleeve, an oil pipe sleeved in the sleeve, a linkage type fireflood gas injection device arranged on the oil pipe, and a plug for plugging the tail end of the oil pipe; an electric igniter can be put into the oil pipe;

wherein an oil casing annulus is formed between the oil pipe and the casing pipe; the linkage type fireflood gas injection device can separate the oil sleeve annulus to form an upper space and a lower space; the wellhead tree is communicated with the upper space;

the linkage type fireflood gas injection device comprises an outer tube assembly and a central tube arranged in the outer tube assembly; a gas injection channel is arranged between the outer pipe assembly and the central pipe; the outer tube assembly is also provided with a wire inlet part for a cable to pass through and enter the gas injection channel above the gas injection channel; the lower end of the gas injection channel is provided with a gas outlet communicated with the lower space; the air outlet is also used for the cable to pass out; the central pipe is provided with a communication hole; the outer pipe assembly is provided with an upper air injection hole communicated with the upper space; the central tube moves along the length direction of the central tube and is provided with an upper communication position and a lower communication position; when the central pipe is at the upper communication position, the communication hole is communicated with the upper air injection hole; when the central pipe is positioned at the lower communication position, the communication hole is communicated with the gas injection channel; the central tube can be pushed by the electric igniter to move downwards to the lower communication position when the central tube is at the upper communication position.

As a preferred embodiment, the cable includes a temperature measuring cable provided with a temperature measuring part; the temperature measuring cable extends from the wellhead tree to sequentially penetrate through the upper space and the linkage type fireflood gas injection device to enter the lower space.

In a preferred embodiment, the central tube is pushed by the electric igniter when the central tube is located at the upper communication position; the central tube is passable by the electric igniter when the central tube is in the lower communication position.

As a preferred embodiment, the method further comprises: a push ball for dropping the oil pipe;

the minimum inner diameter of the central tube when the central tube is positioned at the upper communication position is smaller than the outer diameter of the push ball; the central tube is capable of being passed by the pushball when in the lower communication position.

In a preferred embodiment, the central tube is provided with an elastic part; the inner wall of the outer pipe assembly is provided with an accommodating groove; when the central tube is positioned at the upper communication position, the elastic part is positioned above the accommodating groove, and the elastic part is reduced to the outer diameter of the push ball with the inner diameter by the inner wall of the outer tube assembly; when the central tube is positioned at the lower communication position, the elastic part expands and resets and is clamped into the accommodating groove and limited; the inner diameter of the elastic part after reset is larger than the outer diameters of the push ball and the electric igniter.

As a preferred embodiment, the elastic part includes a pawl spring provided at an upper end of the central tube; the outer diameter of the pawl spring is reduced when the central tube is located at the upper communication position, and the outer diameter of the pawl spring is reset when the central tube is located at the lower communication position.

In a preferred embodiment, the outer pipe assembly comprises an upper joint, a pipe inlet pipe, a gas injection pipe, a gas outlet pipe and a lower joint connected to the lower end of the gas outlet pipe which are connected in sequence; the wire inlet part is positioned on the wire inlet pipe; the upper air injection hole is positioned on the upper joint; the gas injection channel is formed between the gas injection pipe and the central pipe; the upper end of the air outlet pipe is provided with an air outlet hole extending obliquely downwards; the air outlet is positioned at the lower end of the air outlet hole.

In a preferred embodiment, the linkage type fireflood gas injection device comprises a driving mechanism arranged on the outer tube assembly and a sealing part; the driving mechanism can press the sealing part along with the temperature rise, so that the sealing part can divide the oil sleeve annulus into an upper space and a lower space.

As a preferred embodiment, the driving mechanism comprises a gland, a piston sleeve; the gland is fixed on the outer wall of the gas injection pipe; the piston sleeve is slidably sleeved outside the gas injection pipe; the upper end of the piston sleeve is in sealing fit with the outer wall of the gland; a medicament capable of expanding under heat is arranged in an annular space between the piston sleeve and the gas injection pipe; the piston sleeve (piston) presses the packing when moving downward; the piston sleeve is also provided with a locking assembly; the locking assembly is capable of restraining the piston sleeve in a position that maintains compression of the packing.

As a preferred embodiment, the locking assembly comprises a locking ring, and a locking sleeve; the locking sleeve is connected to the lower end of the piston sleeve; the locking ring is an open circular ring and is sleeved on the outer wall of the gas injection pipe; the inner wall of the piston sleeve is provided with a backstop step; and an accommodating groove capable of accommodating the locking ring is arranged between the upper end of the locking sleeve and the stopping step.

As a preferred embodiment, the wire inlet part comprises a wire inlet hole arranged on the wire inlet pipe, and a blocking ring is arranged at the upper end of the wire inlet hole; the wire inlet hole is provided with a plurality of graphite sealing rings; the graphite sealing ring can seal the cable and the inner wall of the wire inlet hole; the wire inlet hole extends obliquely inwards.

Has the advantages that:

the layering ignition gas injection oil jacket system that this embodiment provided has coordinated type fire flooding gas injection device, utilize coordinated type fire flooding gas injection device with oil jacket annular space partition form with upper and lower oil reservoir upper and lower space that corresponds respectively, and can switch over the oil pipe inside with upper space intercommunication to with lower part space intercommunication through the removal of center tube, and be linked together through well head tree 50 and upper space, can realize that the gas injection route of oil reservoir about the tubular column is established to a trip, the ignition of oil reservoir about the electric igniter realization again, moreover, the steam generator is simple in structure, need not many sets of gas injection device and packer, only utilize coordinated type fire flooding gas injection device and well head tree 50 can realize the layering ignition gas injection.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a schematic illustration of a stratified ignition gas injection oil jacket system provided in accordance with an embodiment of the present application;

FIG. 2 is a schematic structural view of the linkage type fireflood gas injection device of FIG. 1;

FIG. 3 is a schematic perspective view of FIG. 2;

FIG. 4 is a partial schematic view of the center tube of FIG. 2 in an up-flow position;

FIG. 5 is a partial schematic view of the base pipe of FIG. 2 in a down communication position;

FIG. 6 is a schematic view of a center tube and outer tube assembly provided in accordance with another embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to fig. 1 to 6. The embodiment of the application provides a layering gas injection oil jacket system of igniteing, and this layering gas injection oil jacket system of igniteing can realize respectively igniteing and the ration gas injection of two upper and lower oil reservoirs. This 10 posts of layering ignition gas injection pipe can realize two-layer ignition and temperature monitoring's function through a tubular column, realize two air injection system's the gas injection respectively after the ignition, realize the requirement of layering gas injection, this tubular column relatively is applicable to the more nearer layering of intermediate layer and ignites the tubular column.

Specifically, the stratified ignition gas injection oil jacket system includes: the device comprises a wellhead tree 50, a casing 100, an oil pipe 200 sleeved in the casing 100, a linkage type fireflood gas injection device 300 arranged on the oil pipe 200, and a plug 400 for plugging the tail end of the oil pipe 200. An electric igniter can be put into the oil pipe 200.

Wherein an oil casing annulus is formed between the oil pipe 200 and the casing 100; the linkage type fireflooding gas injection device 300 can separate the oil sleeve annulus to form an upper space 500 and a lower space 600; the wellhead tree 50 communicates with the headspace 500.

The linkage type fireflood gas injection device 300 comprises an outer tube assembly and a central tube 2 arranged in the outer tube assembly; a gas injection channel 9 is arranged between the outer tube assembly and the central tube 2; the outer tube assembly is also provided with a wire inlet part for a cable 700 to pass through into the gas injection channel 9 above the gas injection channel 9; the lower end of the gas injection channel 9 is provided with a gas outlet 20 communicated with the lower space 600; the air outlet 20 is also used for the cable 700 to pass out; the central pipe 2 is provided with a communication hole 6; the outer pipe assembly is provided with an upper air injection hole 8 communicated with the upper space 500; the central tube 2 moves along the length direction thereof and has an upper communication position and a lower communication position; when the central tube 2 is at the upper communication position, the communication hole 6 is communicated with the upper air injection hole 8; when the central tube 2 is positioned at the lower communication position, the communication hole 6 is communicated with the gas injection channel 9; the central tube 2 can be pushed by the electric igniter to move downwards to the lower communication position when in the upper communication position.

When the layered ignition gas injection oil sleeve system provided by the embodiment is used, ignition gas injection is firstly carried out on the upper oil layer 51, and at the moment, the central pipe 2 of the linkage type fireflood gas injection device 300 can be located at an upper communication position. When the pipe column where the oil pipe 200 is located is lowered to the specified position of the casing 100, the linkage type fireflood gas injection device 300 is set to separate the oil casing annulus into an upper space 500 and a lower space 600. The temperature measuring cable 700 is arranged on the linkage type fireflood gas injection device 300 in advance in a penetrating mode and is put into the sleeve 100 together with the oil pipe 200 and the linkage type fireflood gas injection device 300. When the linkage type fire flooding gas injection device 300 is lowered to a preset position, the upper space 500 is correspondingly communicated with the upper oil layer 51, and the lower space 600 is correspondingly communicated with the lower oil layer 52.

When ignition is required, an electric igniter is put into the oil pipe 200 of the layered ignition gas injection oil sleeve system. The upper oil layer 51 is ignited by an electric igniter. When upper oil layer 51 is ignited, gas is injected into oil pipe 200. When the central tube 2 is at the upper communication position, the interior of the linkage type fireflood gas injection device 300 is communicated with the upper space 500, and gas is injected into the upper space 500 through the linkage type fireflood gas injection device 300 through the oil tube 200, so that gas can be injected into the upper oil layer 51. The electric igniter is positioned above the center tube 2 and electrically ignites at a position corresponding to the upper oil layer 51, thereby igniting and driving the upper oil layer 51.

When it is desired to perform gas injection ignition of the lower oil layer 52, an igniter (not shown) is lowered. The pushing tool of the electric igniter can push the central tube 2. The central tube 2 is pushed by the electric igniter to move downward from the upper communication position to the lower communication position. When the central tube 2 is at the lower communication position, the upper air injection hole 8 is blocked and communicated with the air injection channel 9. At this time, the linkage type fireflood gas injection device 300 is communicated with the lower space 600, and gas can be injected into the lower space 600 through the linkage type fireflood gas injection device 300 through the oil pipe 200, so that gas can be injected into the lower oil layer 52. Accordingly, the lower oil layer 52 is fireflooded by heating the air by the electric igniter, thereby igniting the lower oil layer 52. After the ignition is finished, the electric igniter is started.

While injecting gas into lower reservoir 52 through tubing 200, gas may be injected directly into upper space 500 through wellhead tree 50, which is accomplished by injecting gas into upper reservoir 51. Since the upper oil layer 51 and the lower oil layer 52 perform gas injection using different paths, gas injection can be performed at different gas injection pressures, and the gas injection amounts can be controlled separately. In the gas injection ignition process, the thermocouple on the temperature measuring cable can be used for measuring the fireflood temperature in real time so as to judge whether the upper oil layer and the lower oil layer are ignited successfully according to the monitored temperature.

Wellhead tree 50 is a christmas tree disposed at the gas injection wellhead. The tree 50 has different pipe connections that communicate with the tubing 200, or casing 100 (oil casing annulus), respectively. The air injection into the oil pipe 200 or the air injection of the oil sleeve ring can be realized through different pipeline connecting ports.

The layering ignition gas injection oil sleeve system that this embodiment provided has coordinated type fire flooding gas injection device 300, utilize coordinated type fire flooding gas injection device 300 with oil sleeve annular space partition form with upper and lower oil reservoir respectively corresponding upper portion space 500 and lower part space 600, and can switch over oil pipe 200 inside and upper portion space 500 intercommunication to with lower part space 600 intercommunication through the removal of center tube 2, and be linked together through well head tree 50 and upper portion space 500, can realize that the tubular column establishes the gas injection route of upper and lower oil reservoir one time, the ignition of upper and lower oil reservoir is realized to the electrical igniter again, moreover, the steam generator is simple in structure, need not more sets of gas injection device 300 and packer, only utilize coordinated type fire flooding gas injection device 300 and well head tree 50 can realize the layering ignition gas injection.

In the present embodiment, the cable 700 includes a temperature measuring cable provided with a temperature measuring part (e.g., a thermocouple). The temperature measuring cable extends from the wellhead tree 50, sequentially passes through the upper space 500 and the linkage type fireflood gas injection device 300, and enters the lower space 600.

The coordinated type fireflood gas injection device 300 that this embodiment provided carries out wearing to establish of cable 700 through the gas injection passageway 9 that will press from both sides the wall and form to need not to punch on the packing piece 16, can guarantee separating the leakproofness of upper space 500 and lower part space 600, avoid the oil reservoir between the cluster gas, guarantee that different oil reservoirs can adopt different pressure gas injections.

The central tube 2 can be pushed by the electric igniter when it is in the upper communication position. The central tube 2 is able to be passed by the electric igniter when it is in the lower communication position. Electric igniter can be so that need not about through center tube 2 that the oil reservoir is close, even the oil reservoir interval is far away about, through reaching the corresponding position degree of depth of oil reservoir down with electric igniter through center tube 2 to it drives to realize the fire with corresponding oil reservoir ignition.

The diameter of the central pipe 2 can be changed at the lower communication position under the condition that the central pipe 2 is pushed by an electric igniter. The electric igniter may have a pushing tool for pushing the central tube 2. In other embodiments, the electric igniter may also be tapered at the down-flow location to pass through the center tube 2, however, the application contemplates the center tube 2 being tapered as a preferred embodiment.

In a possible embodiment, the electric igniter can be provided with a pushing tool for pushing the central tube 2. In this embodiment, the pushing tool is detachably mounted to the lower end of the electric igniter. In the event of a jam, the electric igniter can be disengaged from the pushing tool, thereby enabling the recovery of the electric igniter (body portion). Specifically, the pushing tool and the electric igniter can be connected through a shearing pin or a safety joint, and when the pulling force outside the well exceeds a preset value, the shearing pin or the safety joint is broken, so that the pushing tool and the igniter are separated. Wherein the pushing tool has a body extending in the axial direction of the oil pipe 200 and a protrusion portion enlarged in the radial direction is provided on the body. The pushing tool may be entirely in the shape of a "wine bottle" or "spindle". The electric igniter pushes the central tube 2 by using a pushing tool and passes through the central tube 2 together after the central tube 2 expands.

In a preferred embodiment of the present application, the electric igniter may also be provided without a pushing tool. As shown in fig. 6, the stratified gas-injection ignition oil casing 100 further includes: a push ball 27 for dropping the oil pipe 200. The minimum inner diameter of the central tube 2 in the upper communication position is smaller than the outer diameter of the push ball 27; the central tube 2 is able to be passed by the pushballs 27 when it is in the lower communication position. Through being equipped with the pushing ball 27, the electric igniter can need not pushing tool and can promote center tube 2 and carry out the switching of position to can realize the reducing of center tube 2, and then through center tube 2.

When it is necessary to inject gas into the lower oil layer 52, a push ball 27 is put into the pipe string through the oil pipe 200 from the outside of the well. The pushballs 27 are seated on the center tube 2 and cannot pass through the center tube 2. The lower discharging igniter pushes the central tube 2 to move downwards to the lower communication position by using the push ball 27, the upper gas injection hole 8 is sealed and closed, and the gas injection channel 9 communicated with the lower space 600 is opened. At this point, the push ball 27 and the electric igniter may pass through the center tube 2. The push ball 27 falls by gravity to the bottom of the string and does not interfere with the gas injection ignition of the lower reservoir 52. In this way, the electric igniter can be ignited in correspondence with the lower oil layer 52, and the electric igniter can be pulled out after the lower oil layer 52 is ignited.

Specifically, the central tube 2 is provided with an elastic part. The inner wall of the outer tube assembly is provided with an accommodating groove 29. When the central tube 2 is in the upper communication position, the elastic part is located above the accommodating groove 29, and the elastic part is reduced to the outer diameter of the push ball 27 with the inner diameter by the inner wall of the outer tube assembly; when the central tube 2 is positioned at the lower communication position, the elastic part expands and resets and is clamped into the accommodating groove 29 and limited; the inner diameter of the elastic part after reset is larger than the outer diameters of the push ball 27 and the electric igniter.

As shown in fig. 6, the outer tube assembly includes an upper joint 1, and a connection tube 26 connected to a lower portion of the upper joint 1. (in this embodiment, the upper air injection hole 8 may be provided on the connection pipe 26). The lower end of the upper joint 1 may be coupled to the internal thread of the upper end of the connection pipe 26 by means of external threads. The inner wall of the outer tube assembly is provided with a receiving recess 29. When the elastic part is reset, the inner diameter of the elastic part is more than the outer diameter of the electric igniter, so that the electric igniter can pass through the elastic part. The elastic part is reduced in diameter by the inner wall of the outer tube assembly above the accommodating part. In the upper communication position, the elastic portion is reduced in diameter, the reduced diameter elastic portion being smaller than the (largest) outer diameter of the electric igniter or pushing tool or pushball 27, so that the electric igniter or pushing tool or pushball 27 cannot pass through. At this time, the electric igniter pushes down the center tube 2 by the elastic portion, so that the center tube 2 is pushed to the lower communication position.

The elastic part comprises a claw spring 28 arranged at the upper end of the central tube 2; the outer diameter of the pawl spring 28 is reduced when the center tube 2 is in the upper communication position, and the outer diameter of the pawl spring 28 is reset when the center tube 2 is in the lower communication position.

In the embodiment with a push ball 27, the resilient portion is reduced in diameter in the upper communication position to an inner diameter smaller than the outer diameter of said push ball 27. In the lower communication position, the elastic portion returns to the inner diameter of the push ball 27. In this embodiment, the requirement for the outer diameter of the electric igniter is small, and the outer diameter of the electric igniter may be smaller than the inner diameter of the elastic portion at the upper communication position. After the pushball 27 is put, the pushball 27 is seated on the upper end of the center tube 2.

As shown in fig. 6. The outer diameter of the elastic portion in the normal state (reset state) is larger than the inner diameter of the outer tube assembly (the portion other than the accommodation groove 29). The central tube 2 is reduced in diameter when it is in the upper communication position, both the outer diameter and the inner diameter being reduced. The resilient portion may be located at the upper end of the central tube 2, but may of course be located elsewhere on the central tube 2. The reduced diameter elastic portion is not passed through by a pushing tool (of an electric igniter) or a push ball 27. As shown in fig. 3, the inner diameter of the elastic portion after the return is enlarged to allow the electric igniter to pass therethrough.

In particular, the central tube 2 is mounted coaxially within the outer tube assembly. The resilient portion comprises a pawl spring 28 arranged at the upper end of the central tube 2. The outer diameter of the pawl spring 28 is reduced when the center tube 2 is in the upper communication position. The outer diameter of the pawl spring 28 is reset when the center tube 2 is in the lower communication position. Wherein the pawl spring 28 comprises a plurality of pawl spring 28 petals distributed at intervals along the circumferential direction. The upper end of the pawl spring 28 flap is provided with a snap-in projection for snapping into the receiving recess 29.

The resilient portion includes a plurality of pawl springs 28 arranged circumferentially about the outer tube assembly. A plurality of pawl springs 28 are evenly distributed in the circumferential direction. And a spacing gap is arranged between two circumferentially adjacent claw springs 28. The upper end of the pawl spring 28 flap has a snap-in projection which can snap into the receiving recess 29 in the reset state of the spring.

When the central tube 2 is at the upper communication position, the communication hole 6 of the central tube 2 is at least partially communicated with the upper air injection hole 8 in a radial direction in an aligned manner, so that the upper air injection hole 8 is not shielded by the central tube 2 and is communicated with the inside of the outer tube assembly to be in an open state. When the snap-in projection is snapped into the receiving recess 29, the outer surface of the part of the pawl spring 28 below the snap-in projection may abut against the inner wall of the outer tube assembly, although some clearance may be left, which is not limited in this application. The outer diameter of the snap-in projection is larger than the inner diameter of the outer tube assembly (the non-receiving recess 29) when the resilient portion is in the normal state or in the reset state.

To avoid unnecessary positional shifting of the central tube 2 during running of the string. The center tube 2 is connected to the outer tube assembly by shear pins to be positioned in the upper communication position. The shear pins position the base pipe 2. (position of the shear pin) when the electric igniter moves downwards to contact with the upper end of the pawl spring 28, the shear pin is sheared by increasing the pushing pressure, so that the central tube 2 moves downwards to the lower communication position, and the upper air injection hole 8 is blocked and blocked. When the center pipe 2 is pushed to the lower communication position, the center pipe 2 shears the shear pin and then slides to the lower communication position. When the central tube 2 is positioned at the lower communication position, the upper gas injection hole 8 is shielded in the outer tube assembly, and the upper gas injection hole 8 is blocked to be communicated with the outer tube assembly and the inner part of the central tube 2.

In this embodiment, hold recess 29 and set up on the inner wall of outer tube assembly, hold recess 29 spacing with center tube 2 when the arch card goes into and holds recess 29, electric igniter can alleviate the application of force in the pit through center tube 2 this moment and can pass through center tube 2, also can remind the outer operating personnel center tube 2 of well to have correctly positioned the intercommunication position under simultaneously.

In the present embodiment, tubing 200 may include plain tubing 200, insulated tubing 200. The length of the heat insulation oil pipe 200 can be matched with that of the ignition oil layer, and the flat oil pipe 200 is adopted as the oil pipe 200 of the other part. When the device is used, the oil pipe 200 is put into the casing 100, the temperature measuring cable is put between the oil casing annuluses, and the linkage type fireflood gas injection device 300 can be penetrated by the temperature measuring cable.

Please continue to refer to fig. 1 to 5. The outer pipe assembly comprises an upper joint 1, a wire inlet pipe 3, a gas injection pipe 10, a gas outlet pipe 21 and a lower joint 23 connected to the lower end of the gas outlet pipe 21 which are connected in sequence. The wire inlet part is positioned on the wire inlet pipe 3. The upper air injection hole 8 is positioned on the upper joint 1. The gas injection channel 9 is formed between the gas injection pipe 10 and the central pipe 2. The upper end of the air outlet pipe 21 is provided with an air outlet hole 19 which extends obliquely downwards. The air outlet 20 is located at the lower end of the air outlet hole 19.

In the present embodiment, the wire inlet portion includes a wire inlet hole 31 provided in the wire inlet tube 3, and a blocking ring 5 is provided at an upper end of the wire inlet hole 31. The wire inlet hole 31 is provided with a plurality of graphite sealing rings. The graphite sealing ring can seal between the cable 700 and the inner wall of the wire inlet hole 31. The wire inlet hole 31 extends obliquely inward and opens into the gas injection channel 9.

Specifically, in order to meet the requirement of high-temperature sealing, a graphite sealing ring 7 for sealing between the inner wall of the wire inlet hole 31 and the cable 700 is arranged in the wire inlet hole. The upper end of the wire inlet hole 31 is connected with a blocking ring 5 in a threaded manner. In order to compress the graphite sealing ring 7, a blocking sleeve can be arranged between the graphite sealing ring 7 and the blocking ring 5. Wherein, a plurality of graphite sealing rings 7 are arranged in the wire inlet hole 31; the plurality of graphite sealing rings 7 are arranged along the extending direction of the wire inlet hole 31. A limiting step is arranged in the wire inlet hole 31, and the graphite sealing rings 7 are clamped between the blocking ring 5 and the limiting step. When a plurality of or different cables 700 need to be threaded, the outer tube can be provided with a plurality of wire inlet holes 31 along the circumferential direction. Wherein each wire entry hole 31 may be, but is not limited to, passing through one target cable 700.

Considering that the cable 700 is required to be bent by a large angle to enter the gas injection channel 9 when the bending angle of the wire inlet hole 31 to the gas injection channel 9 is too large, and the wire inlet hole is not easy to penetrate through. In order to facilitate the cable 700 to pass through and avoid the cable 700 from being bent too much, the wire inlet hole 31 gradually approaches the axis of the outer tube when extending from top to bottom. Specifically, the included angle between the wire inlet hole 31 and the axis is less than 10 degrees. The annular space forms a gas injection channel 9 which is a straight channel and extends in the axial direction of the housing.

In order to realize that the linkage type fireflood gas injection device 300 separates the oil sleeve annulus into an upper space 500 and a lower space 600, the linkage type fireflood gas injection device 300 comprises a driving mechanism arranged on the outer tube assembly and a sealing part 16. The drive mechanism is capable of squeezing the packing 16 as the temperature increases, causing the packing 16 to separate the oil jacket annulus into an upper space 500 and a lower space 600. The sealing member 16 may be made of rubber and have a rubber tube structure.

A first sealing part 4, a second sealing part 22 and a third sealing part 24 are arranged between the central pipe 2 and the outer pipe assembly to ensure that the central pipe 2 is communicated or closed with the upper air injection holes 8 and the air injection channel 9 when located at different positions. Wherein, the upper air injection hole 8 and the first sealing part 4 are positioned on the upper joint 1. The air outlet 20 is located on the air outlet pipe 21. The linkage type fireflood gas injection device 300 can be connected to the oil pipe 200 through the upper joint 1 and the lower joint 23. The end of the string where tubing 200 is located may be plugged with a plug 400.

The outer tube assembly is provided with a first sealing part 4 which is in sealing fit with the central tube 2 between the gas injection channel 9 and the upper gas injection hole 8. When the central tube 2 is located at the upper communication position, the first sealing part 4 is located below the communication hole 6 and is in sealing fit with the outer wall of the central tube 2 below the communication hole 6, so that gas is prevented from leaking to the lower oil layer 52. When the center tube 2 is located at the lower communication position, the first seal portion 4 is located above the communication hole 6 and is in sealing contact with the outer wall of the center tube 2 located above the communication hole 6, thereby preventing gas from leaking to the upper oil layer 51.

Further, the outer tube assembly is provided with a second sealing portion 22 which is in sealing engagement with the central tube 2 below the air outlet 20. When the central tube 2 is located at the lower communication position, the first sealing part 4 and the second sealing part 22 are respectively located at the upper side and the lower side of the communication hole 6 to seal the upper side and the lower side of the communication hole 6, so that the communication hole 6 can only output gas into the gas injection channel 9. In addition, the outer tube assembly is further provided with a third sealing portion 24 above the upper air injection hole 8. When the central pipe 2 is located at the upper communication position, the first sealing part 4 and the third sealing part 24 seal the upper part and the lower part of the communication hole 6, and ensure that the communication hole 6 can only output gas to the upper gas injection hole 8.

In the present embodiment, in order to prevent steam leakage and ensure sealing between the outer tube assembly and the center tube 2, the distance between the first seal portion 4 and the third seal portion 24 in the axial direction (length direction) of the gas injection tube 10 is not less than the distance between the communication hole 6 in the axial direction of the gas injection tube 10. Meanwhile, the distance between the first seal 4 and the second seal 22 in the axial direction of the gas-injection pipe 10 is not smaller than the distance between the communication hole 6 in the axial direction of the gas-injection pipe 10. The first sealing part 4, the second sealing part 22 and the third sealing part 24 are all provided with high-temperature-resistant sealing elements so as to be suitable for high-temperature environments under layered steam injection and testing processes of a heavy oil thermal production well and prolong the service life of sealing measures. Specifically, the high-temperature-resistant sealing element is a graphite sealing ring.

In this embodiment, the first sealing portion 4 includes a first sealing step provided on the inner wall of the upper joint 1, a first pressing ring screwed to the inner wall of the upper joint 1, and a plurality of graphite sealing rings interposed between the first pressing ring and the first sealing step and fitted around the center pipe 2.

The second sealing portion 22 includes a second sealing step arranged on the inner wall of the lower end of the outlet pipe 21, a second pressing ring in threaded connection with the inner wall of the lower end of the outlet pipe 21, and a plurality of graphite sealing rings arranged between the second pressing ring and the second sealing step and sleeved outside the central pipe 2.

The upper end of the outlet pipe 21 is provided with an outlet hole 19. The outlet is located at the lower end of the air outlet hole 19. The inner wall of the air outlet 19 is gradually inclined outwards when extending downwards (conical design). The air outlet pipe 21 adopts a half-moon groove design, so that the cable can conveniently pass through the air outlet hole 19, and the cable is not easily blocked when penetrating out of the air outlet pipe 21. To further facilitate the outward passing of the cable, the portion of the surface of the outlet tube 21 below the outlet hole 19 is gradually inclined outward as it extends downward.

As can be seen from fig. 2, the outlet tube 21 is of a conical design so as to guide the cable 700 exiting from the outlet aperture 19 outwards. The lower end of the air outlet pipe 21 is connected with a lower joint 23 through threads. A covering protrusion is provided on the outer wall of the outlet pipe 21. The covering protrusion is located above the connection part of the air outlet pipe 21 and the lower connector 23, and covers the connection part to prevent the extended cable from extending into the connection part and being clamped. Meanwhile, the outer wall of the covering bulge is designed to be a conical surface, so that the cable is conveniently guided, and smooth passing of the cable is guaranteed.

So, have between gas injection pipe 10 and the central tube 2 and be used for through the cable 700 with the gas injection passageway 9 of gas injection, and venthole 19 and the transition position of gas injection passageway 9 for cable 700 steering department, cable 700 steering department is little and steering angle is less, the cable 700 of being convenient for passes through, and is difficult for producing the breakage, reduces the construction degree of difficulty. The lower end of the inlet pipe 3 is connected to the upper end of the gas injection pipe 10, and the upper end of the gas injection pipe 10 is formed with a gas inlet communicating with the gas injection channel 9, and the central pipe 2 is in at least partial alignment communication with the gas inlet in the radial direction when it is located at the lower communication position.

In order to obtain the position of the central tube 2, the inner wall of the gas injection tube 10 is further provided with a limiting part below the second sealing part 22. The stopper prevents the center pipe 2 from moving downward when the center pipe 2 is in the second position. When pushing the center tube 2 downwards through the electric igniter, the center tube 2 cannot be pushed continuously when being pushed to the limiting part, and the pushing resistance which is suddenly increased is applied to the outside of the well, so that the outside of the well can know that the center tube 2 is located at the second position, and the force application is not required to be continuously applied. Specifically, the limiting portion is located on an inner wall of the lower joint 23. Spacing portion can be stair structure, and the lower terminal surface top of center tube 2 is supported by spacingly when stair structure.

The driving mechanism comprises a gland and a piston sleeve 11. The gland is fixed to the outer wall of the gas injection pipe 10. The piston sleeve 11 is slidably sleeved outside the gas injection pipe 10. The upper end of the piston sleeve 11 is in sealing fit with the outer wall of the gland; an agent capable of expanding under heat is arranged in an annular space between the piston sleeve 11 and the gas injection pipe 10; the piston sleeve 11 (piston) presses the packing 16 when moving downward. The piston sleeve 11 is also provided with a locking assembly; the locking assembly is capable of restraining the piston sleeve 11 in a position that maintains compression of the enclosure 16.

The locking assembly comprises a locking ring 14, and a locking sleeve 15. The locking sleeve 15 is connected to the lower end of the piston sleeve 11. The locking ring 14 is an open circular ring and is sleeved on the outer wall of the gas injection pipe 10. The inner wall of the piston sleeve 11 is provided with a backstop step. And an accommodating groove 13 capable of accommodating the locking ring 14 is arranged between the upper end of the locking sleeve 15 and the retaining step.

Specifically, the lower end of the piston sleeve 11 is provided with a fitting protrusion which is in sealing fit with the outer wall of the gas injection pipe 10. The abutment protrusion, the gland 9, part of the outer wall of the gas-injection pipe 10, and the inner wall of the piston bush 11 enclose a closed space 24 in which an expansion agent is accommodated. The expander may be thermally expanded to move downwardly against the piston sleeve 11. The outer wall of the piston sleeve 11 is provided with an injection hole 12 for injecting an expanding agent, and the injection hole 12 is sealed and sealed after the expanding agent is injected.

In the present embodiment, the retaining mechanism includes a locking ring 14 and a locking sleeve. The locking ring 14 is an open circular ring and is sleeved on the outer wall of the gas injection pipe 10. Wherein, the outer wall of the gas injection pipe 10 is provided with an installation groove, and the locking ring 14 can reduce the diameter along the radial direction. The locking ring 14 has an outer diameter larger than the outer diameter of the gas injection pipe 10 when not reduced in diameter so as to protrude from the outer wall of the gas injection pipe 10, and at the same time, the locking ring 14 has an inner diameter smaller than the outer diameter of the gas injection pipe 10 so as to be retained in the mounting groove. The locking ring 14 may have an outer diameter smaller than the outer diameter of the outer tube when reduced in diameter, and be completely received in the mounting groove.

The inner wall of the piston sleeve 11 is provided with a backstop step. And an accommodating groove 13 capable of accommodating the locking ring 14 is arranged between the upper end of the locking sleeve 15 and the retaining step. The locking sleeve 15 is connected to the lower end of the piston sleeve 11. The locking sleeve 15 moves downward together with the piston sleeve 11. The inner wall of the locking sleeve 15 may be flush with the outer wall of the gas injection pipe 10. When the central tube 2 is in the first position, the locking sleeve 15 covers the mounting groove, and the locking ring 14 is in a reduced diameter state and is completely received in the mounting groove.

The receiving groove 13 is now radially aligned with the mounting groove when the central tube 2 is moved down to the second position. The locking sleeve cannot reduce the diameter of the locking ring 14, and the locking ring 14 resets and expands to a normal state, so that part of the locking ring 14 enters the accommodating groove 13. At this time, the partial locking ring 14 is located in the receiving groove 13 along the radial direction, and the partial locking ring 14 is located in the receiving groove 13, thereby restraining the piston hub 11 such that the piston hub 11 cannot retreat. Of course, the piston sleeve 11 can not move downwards under the action of the locking ring 14, so that the piston sleeve 11 is limited to the current position.

In the present embodiment, a stopper ring 17 is fixedly provided at the lower end of the gas injection pipe 10 below the packing 16. The lower end of the gas injection pipe 10 is connected to the upper end of the gas outlet pipe 21 by a coupling 18. The collar 18 is located below the baffle ring 17. The stop ring 17 prevents the downward movement of the packing 16, so that the packing 16 is pressed together with the locking sleeve (piston sleeve 11) and expanded. The enclosure 16 may be a high temperature resistant glue cartridge to accommodate high temperature downhole environments. The upper end of the coupling 18 is connected to the lower end of the gas injection pipe 10 through an internal thread, and the lower end of the coupling 18 is connected to the upper end of the gas outlet pipe 21 through an internal thread.

Any numerical value recited herein includes all values from the lower value to the upper value that are incremented by one unit, provided that there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of a component or a value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, it is intended that equivalents such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also expressly enumerated in this specification. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. The use of "about" or "approximately" with a range applies to both endpoints of the range. Thus, "about 20 to about 30" is intended to cover "about 20 to about 30", including at least the endpoints specified.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the described attributes that "may" include are optional.

A plurality of elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the inventors be construed as having contemplated such subject matter as being part of the disclosed subject matter.

Claims (11)

1. The layered ignition gas injection oil jacket system is characterized by comprising: the device comprises a wellhead tree, a sleeve, an oil pipe sleeved in the sleeve, a linkage type fireflood gas injection device arranged on the oil pipe, and a plug for plugging the tail end of the oil pipe; an electric igniter can be put into the oil pipe;

wherein an oil casing annulus is formed between the oil pipe and the casing pipe; the linkage type fireflood gas injection device can separate the oil sleeve annulus to form an upper space and a lower space; the wellhead tree is communicated with the upper space;

the linkage type fireflood gas injection device comprises an outer tube assembly and a central tube arranged in the outer tube assembly; a gas injection channel is arranged between the outer pipe assembly and the central pipe; the outer tube assembly is also provided with a wire inlet part for a cable to pass through and enter the gas injection channel above the gas injection channel; the lower end of the gas injection channel is provided with a gas outlet communicated with the lower space; the air outlet is also used for the cable to pass out; the central pipe is provided with a communication hole; the outer pipe assembly is provided with an upper air injection hole communicated with the upper space; the central tube moves along the length direction of the central tube and is provided with an upper communication position and a lower communication position; when the central pipe is at the upper communication position, the communication hole is communicated with the upper air injection hole; when the central pipe is positioned at the lower communication position, the communication hole is communicated with the gas injection channel; the central tube can be pushed by the electric igniter to move downwards to the lower communication position when the central tube is at the upper communication position.

2. The stratified ignition gas injection oil jacket system according to claim 1, wherein the cable comprises a temperature measuring cable provided with a temperature measuring component; the temperature measuring cable extends from the wellhead tree to sequentially penetrate through the upper space and the linkage type fireflood gas injection device to enter the lower space.

3. The stratified ignition gas injection oil jacket system of claim 1 or 2 wherein said central pipe is capable of being pushed by said electric igniter when in said upper communication position; the central tube is passable by the electric igniter when the central tube is in the lower communication position.

4. The stratified ignition gas injection oil jacket system of claim 3, further comprising: a push ball for dropping the oil pipe;

the minimum inner diameter of the central tube when the central tube is positioned at the upper communication position is smaller than the outer diameter of the push ball; the central tube is capable of being passed by the pushball when in the lower communication position.

5. The stratified ignition gas injection oil jacket system of claim 4 wherein said central tube is provided with an elastic portion; the inner wall of the outer pipe assembly is provided with an accommodating groove; when the central tube is positioned at the upper communication position, the elastic part is positioned above the accommodating groove, and the elastic part is reduced to the outer diameter of the push ball with the inner diameter by the inner wall of the outer tube assembly; when the central tube is positioned at the lower communication position, the elastic part expands and resets and is clamped into the accommodating groove and limited; the inner diameter of the elastic part after reset is larger than the outer diameters of the push ball and the electric igniter.

6. The layered ignition gas-injection oil jacket system according to claim 5, wherein the elastic portion comprises a pawl spring disposed at an upper end of the central tube; the outer diameter of the pawl spring is reduced when the central tube is located at the upper communication position, and the outer diameter of the pawl spring is reset when the central tube is located at the lower communication position.

7. The stratified ignition gas-injection oil-jacket system according to claim 3, wherein the outer tube assembly comprises an upper joint, a gas inlet tube, a gas injection tube, a gas outlet tube, and a lower joint connected to the lower end of the gas outlet tube, which are connected in sequence; the wire inlet part is positioned on the wire inlet pipe; the upper air injection hole is positioned on the upper joint; the gas injection channel is formed between the gas injection pipe and the central pipe; the upper end of the air outlet pipe is provided with an air outlet hole extending obliquely downwards; the air outlet is positioned at the lower end of the air outlet hole.

8. The stratified ignition gas-injection oil-jacket system according to claim 7, wherein the coupled fireflooding gas-injection device comprises a driving mechanism disposed on the outer tube assembly, and a packing; the driving mechanism can press the sealing part along with the temperature rise, so that the sealing part can divide the oil sleeve annulus into an upper space and a lower space.

9. The stratified ignition gas-injection oil-jacket system of claim 8, wherein the drive mechanism comprises a gland, a piston sleeve; the gland is fixed on the outer wall of the gas injection pipe; the piston sleeve is slidably sleeved outside the gas injection pipe; the upper end of the piston sleeve is in sealing fit with the outer wall of the gland; a medicament capable of expanding under heat is arranged in an annular space between the piston sleeve and the gas injection pipe; the piston sleeve (piston) presses the packing when moving downward; the piston sleeve is also provided with a locking assembly; the locking assembly is capable of restraining the piston sleeve in a position that maintains compression of the packing.

10. The stratified ignition gas-injection oil-jacket system of claim 9, wherein the locking assembly comprises a locking ring, and a locking sleeve; the locking sleeve is connected to the lower end of the piston sleeve; the locking ring is an open circular ring and is sleeved on the outer wall of the gas injection pipe; the inner wall of the piston sleeve is provided with a backstop step; and an accommodating groove capable of accommodating the locking ring is arranged between the upper end of the locking sleeve and the stopping step.

11. The layered ignition gas-injection oil jacket system according to claim 10, wherein the wire inlet portion comprises a wire inlet hole arranged on the wire inlet pipe, and a blocking ring is arranged at the upper end of the wire inlet hole; the wire inlet hole is provided with a plurality of graphite sealing rings; the graphite sealing ring can seal the cable and the inner wall of the wire inlet hole; the wire inlet hole extends obliquely inwards.

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