A layered ignition process column and ignition method

Abstract

The present invention provides a layered ignition process string and an ignition method. The layered ignition process string includes an outer string, an inner string and an ignition assembly. The outer string is provided with a first packer and a second packer. The inner string is arranged inside the outer string. The inner string is provided with a third packer. The outer string is provided with a gas injection hole between the first packer and the third packer. The outer string is provided with a first connecting assembly between the third packer and the second packer. The lower end of the outer string is provided with a second connecting assembly. The ignition assembly penetrates the inner string from top to bottom and extends to the inside of the outer string. The ignition end of the ignition assembly can move between the first connecting assembly and the second connecting assembly. The present invention can form channels for gas injection for the upper oil layer and the lower oil layer respectively inside the casing through the arrangement of the first packer, the second packer, the third packer and the gas injection hole, the first connecting assembly and the second connecting assembly, so as to realize the process requirements of layered ignition and gas injection for the upper oil layer and the lower oil layer.

Description

Technical Field

[0001] The invention relates to the technical field of oil production, in particular to a layered ignition process pipe column and an ignition method. Background Art

[0002] Fire drive technology is an important conversion method in the later stage of heavy oil development in oil fields. Electric ignition is the main ignition method currently used, and it has changed from general ignition of oil layers to layered ignition. At present, the main process method used for layered electric ignition is: lower the outer pipe string to the lower ignition oil layer, lower the inner pipe string to the upper ignition oil layer, and use the packer to isolate the casing and the outer pipe string, and the outer pipe string and the inner pipe string annulus near the ignition oil layer to achieve layered ignition. The problems of this process method are: the igniter is all in the inner pipe string, and the annulus space is small, which increases the risk of the igniter encountering obstruction, getting stuck, and sticking to the inner pipe string; the packer between the annulus of the inner and outer pipe strings is directly in a high temperature environment, the packer is easily damaged, and the seat seal fails; the inner pipe string is lowered to the upper ignition oil layer, which increases the production and manufacturing cost. Summary of the invention

[0003] The purpose of the present invention is to provide a layered ignition process pipe string and an ignition method, which can effectively ensure the smooth progress of ignition, increase the service life of the packer and reduce the production cost of the inner pipe string.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a layered ignition process string, wherein the layered ignition process string comprises an outer string, an inner string and an ignition assembly, the outer wall of the outer string is provided with a first packer near its upper end and a second packer near its lower end, the inner string is coaxially arranged inside the outer string, the outer wall of the inner string is provided with a third packer that can be set on the inner wall of the outer string, the third packer is located below the first packer and above the second packer, and the outer string is provided with a third packer between the first packer and the third packer There is at least one gas injection hole, a first connecting component is provided on the outer tubing string between the third packer and the second packer, the lower end of the inner tubing string is located above the first connecting component, and the lower end of the outer tubing string is provided with a second connecting component below the second packer, the first connecting component and the second connecting component can respectively open and connect the inner side of the outer tubing string with the outer side of the outer tubing string, the ignition component passes through the inner tubing string from top to bottom and extends to the inside of the outer tubing string, and the ignition end of the ignition component can move between the first connecting component and the second connecting component.

[0005] The layered ignition process column as described above, wherein the outer column has a structure with an open top, a closed bottom and a hollow interior, and the outer column includes an external gas injection pipe, a first section of thermal insulation pipe, a first sliding sleeve switch, a second section of thermal insulation pipe and a second sliding sleeve switch which are sequentially connected from top to bottom, the lower end of the second sliding sleeve switch is closed by a wire plug, the first packer is arranged on the outer wall of the external gas injection pipe, the second packer is arranged on the outer wall of the second section of thermal insulation pipe, the third packer is located inside the external gas injection pipe, the first sliding sleeve switch is the first connecting component, and the second sliding sleeve switch is the second connecting component.

[0006] The layered ignition process column as described above, wherein the lower end of the inner column is higher than the upper end of the first section of the thermal insulation tube, or the lower end of the inner column is flush with the upper end of the first section of the thermal insulation tube.

[0007] The layered ignition process column as described above, wherein the ignition assembly includes a cable and an electric igniter, the cable passes through the inner column from top to bottom, the lower end of the cable extends from the lower end of the inner column to the interior of the first section of the thermal insulation tube, the upper end of the electric igniter is connected to the cable, the lower end of the electric igniter extends between the first sliding switch and the second sliding switch, and the lower end of the electric igniter is the ignition end.

[0008] The stratified ignition process column as described above, wherein the first sleeve switch and the second sleeve switch each include an outer tube and an inner tube, the outer tube is provided with a connecting hole, the inner tube can be reciprocatingly slidably arranged inside the outer tube along the axial direction of the outer tube, and the inner tube can shield and close each of the connecting holes or be misaligned with each of the connecting holes and connect the connecting holes.

[0009] In the layered ignition process column as described above, there are a plurality of gas injection holes, and the plurality of gas injection holes are evenly spaced and distributed along the axial direction of the outer gas injection pipe.

[0010] In the above-mentioned layered ignition process column, a one-way valve capable of allowing gas to flow from the inside of the outer column to the outside of the outer column is installed at the gas injection hole.

[0011] The layered ignition process string as described above, wherein the first packer is a mechanically set packer, and the second packer and the third packer are both thermally set packers.

[0012] In the above-mentioned layered ignition process column, the upper end of the inner column and the upper end of the outer column are both provided with a gas injection flow control component.

[0013] The present invention also provides a stratified ignition method, wherein the stratified ignition method is implemented using the stratified ignition process column as described above, and the stratified ignition method comprises:

[0014] Step 1: lowering the outer pipe string of the layered ignition process pipe string into the oil well casing, so that the first connecting component corresponds to the upper oil layer, and the second connecting component corresponds to the lower oil layer, so that the first packer is set on the inner wall of the oil well casing above the upper oil layer, and the second packer is set on the inner wall of the oil well casing between the upper oil layer and the lower oil layer;

[0015] Step 2: lowering the inner tubular column of the layered ignition process tubular column into the inner part of the outer tubular column, so that the third packer is set on the inner wall of the inner tubular column;

[0016] Step 3: lowering the ignition assembly of the layered ignition process column into the interior of the inner column so that the ignition end of the ignition assembly is located at the first connecting assembly;

[0017] Step 4: Open the first connecting component to connect the inner side of the outer tube string with the outer side of the outer tube string;

[0018] Step 5: injecting gas into the inner pipe string, controlling the ignition assembly to ignite, and causing the upper oil layer to burn;

[0019] Step 6: injecting gas into the interior of the outer pipe string, closing the first connecting component, and moving the ignition component downward so that the lower end of the ignition component is located at the second connecting component;

[0020] Step 7: Open the second connecting component to connect the inner side of the outer tube string with the outer side of the outer tube string;

[0021] Step 8: Inject gas into the inner pipe string, control the ignition assembly to ignite, and cause the lower oil layer to burn.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The layered ignition process pipe string and ignition method provided by the present invention can form gas injection channels for the upper oil layer and the lower oil layer respectively inside the casing through the arrangement of the first packer, the second packer, the third packer and the gas injection hole, the first connecting component and the second connecting component, so as to realize the gas injection and ignition of the upper oil layer and the lower oil layer respectively, and meet the process requirements of layered ignition and gas injection; at the same time, the present invention shortens the length of the inner pipe string extending into the inner part of the outer pipe string, so that the ignition end of the ignition component penetrates the inner pipe string and extends into the inner part of the outer pipe string for ignition operation. Since the inner diameter of the outer pipe string is much larger than the inner diameter of the inner pipe string, the ignition space can be effectively increased to ensure the smooth progress of the ignition operation. At the same time, since the length of the inner pipe string is shortened, the purpose of reducing the production cost of the inner pipe string can be effectively achieved; in addition, in the present invention, the first packer and the second packer are both arranged outside the ignition space, and the third packer is far away from the ignition position, so that each packer can be effectively placed at a position with a lower temperature, thereby improving the service life of each packer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings are only intended to illustrate and explain the present invention, and do not limit the scope of the present invention.

[0025] Figure 1 It is a structural schematic diagram of the layered ignition process column provided by the present invention;

[0026] Figure 2 It is a schematic diagram of the use state of the layered ignition process pipe string provided by the present invention when injecting gas into the upper oil layer;

[0027] Figure 3 It is a schematic diagram of the state in which the layered ignition process pipe string provided by the present invention is used to inject gas into the lower oil layer;

[0028] Figure 4 It is a flow chart of the steps of the stratified ignition method provided by the present invention.

[0029] Description of Figure Numbers:

[0030] 1. Outer pipe string;

[0031] 11. External injection tube;

[0032] 111, air injection hole;

[0033] 1111, one-way valve;

[0034] 12. The first section of thermal insulation pipe;

[0035] 13. First sliding switch;

[0036] 14. The second section of thermal insulation pipe;

[0037] 15. Second sliding switch;

[0038] 16. Wire plug;

[0039] 2. Inner pipe string;

[0040] 3. The first packer;

[0041] 4. Second packer;

[0042] 5. The third packer;

[0043] 6. Ignition assembly;

[0044] 61. Cable;

[0045] 62. Electric igniter;

[0046] 7. Upper oil layer;

[0047] 71. Perforation;

[0048] 8. Lower oil layer;

[0049] 81. Perforation;

[0050] 9. Oil well casing;

[0051] A. Gas injection path;

[0052] B. Gas injection path;

[0053] C. Gas injection path. DETAILED DESCRIPTION

[0054] In order to have a clearer understanding of the technical solution, purpose and effect of the present invention, the specific implementation mode of the present invention is now described in conjunction with the accompanying drawings.

[0055] like Figure 1 to Figure 3As shown, the present invention provides a layered ignition process pipe string, wherein the layered ignition process pipe string comprises an outer pipe string 1, an inner pipe string 2 and an ignition assembly 6, a first packer 3 near its upper end and a second packer 4 near its lower end are arranged on the outer wall of the outer pipe string 1, the inner pipe string 2 is coaxially arranged inside the outer pipe string 1, a third packer 5 which can be set and sealed on the inner wall of the outer pipe string 1 is arranged on the outer wall of the inner pipe string 2, the third packer 5 is located below the first packer 3 and above the second packer 4, at least one gas injection hole 111 is opened between the first packer 3 and the third packer 5 on the outer pipe string 1, a first connecting assembly which can be opened and closed is arranged between the third packer 5 and the second packer 4 on the outer pipe string 1, the lower end of the inner pipe string 2 is located above the first connecting assembly, that is, the lower end surface of the inner pipe string 2 is not lower than the position of the first connecting assembly, so that the length of the inner pipe string 2 extending into the inner part of the outer pipe string 1 can be shortened degree, thereby reducing the production and manufacturing cost of the inner tubular column 2. The lower end of the outer tubular column 1 is provided with a second connecting component that can be opened and closed below the second packer 4. The first connecting component and the second connecting component can respectively open and connect the inner side of the outer tubular column 1 and the outer side of the outer tubular column 1. The ignition component 6 penetrates the inner tubular column 2 from top to bottom and extends to the interior of the outer tubular column 1, that is, the ignition component 6 extends into the interior of the inner tubular column 2 from top to bottom, and the lower end of the ignition component 6 extends from the lower end of the inner tubular column 2 and reaches the interior of the outer tubular column 1, so that the ignition component 6 ignites inside the outer tubular column 1. Since the inner diameter of the outer tubular column 1 is much larger than the inner diameter of the inner tubular column 2, such a setting can effectively expand the ignition space compared with the structure of igniting inside the inner tubular column 2 in the prior art, and ensure the smooth progress of the ignition operation. The ignition end of the ignition component 6 can move between the first connecting component and the second connecting component to ignite at different positions. When in use, the position of the first connecting component is made to correspond to the perforation 71 of the upper oil layer 7, and the position of the second connecting component is made to correspond to the perforation 81 of the lower oil layer 8. Ignition near the first connecting component in the outer tubular column 1 can achieve the ignition operation of the upper oil layer 7, and ignition near the second connecting component in the outer tubular column 1 can achieve the ignition operation of the lower oil layer 8.

[0056] When performing the ignition operation, the installation operation of the present invention is first performed. First, the outer pipe string 1 is lowered into the oil well casing 9, so that the first connecting component corresponds to the upper oil layer 7, and the second connecting component corresponds to the lower oil layer 8, so that the first packer 3 is set on the inner wall of the oil well casing 9 above the upper oil layer 7, and the second packer 4 is set on the inner wall of the oil well casing 9 between the upper oil layer 7 and the lower oil layer 8; then the inner pipe string 2 is lowered into the inner part of the outer pipe string 1, so that the third packer 5 is set on the inner wall of the inner pipe string 2; then the ignition component 6 is lowered into the inner part of the inner pipe string 2, so that the ignition end of the ignition component 6 is located at the first connecting component; and then the ignition operation of the upper oil layer 7 is performed (see Figure 2), open the first connecting component, so that the first connecting component connects the inner side of the outer tubular column 1 with the outer side of the outer tubular column 1, at this time, the annulus between the inner tubular column 2 and the ignition component 6, the annulus between the outer tubular column 1 and the ignition component 6 and the first connecting component are connected to form a gas injection path A, and the annulus between the inner tubular column 2 and the outer tubular column 1, the gas injection hole 111 and the annulus between the outer tubular column 1 and the oil well casing 9 are connected to form a gas injection path B, inject gas into the inner tubular column 2, and control the operation of the ignition component 6 at the same time, the injected air is preheated inside the outer tubular column 1 along the gas injection path A and reaches the upper oil layer 7, ignites, and starts the upper oil layer 7 to burn, then injects gas into the inner side of the outer tubular column 1, after a period of gas injection, closes the first connecting component, at this time, the upper oil layer 7 is kept burning by the air injected in the gas injection path B; then the ignition operation of the lower oil layer 8 is performed (please refer to Figure 3 ), move the ignition component 6 downward so that the lower end of the ignition component 6 is located at the second connecting component, open the second connecting component, and connect the inner side of the outer tubing string 1 with the outer side of the outer tubing string 1. At this time, the annulus between the inner tubing string 2 and the ignition component 6, the annulus between the outer tubing string 1 and the ignition component 6, and the second connecting component are connected to form a gas injection path C, and gas is injected into the interior of the inner tubing string 2. At the same time, the ignition component 6 is controlled to operate, and the injected air is preheated inside the outer tubing string 1 along the gas injection path C and then reaches the lower oil layer 8, where it is ignited and the lower oil layer 8 starts to burn. In this way, the stratified gas injection and stratified ignition operations of the upper oil layer 7 and the lower oil layer 8 are completed.

[0057] Furthermore, if Figure 1 to Figure 3As shown, the layered ignition process pipe string provided by the present invention, wherein the outer pipe string 1 has a structure with an open top, a closed bottom and a hollow interior, the outer pipe string 1 comprises an outer gas injection pipe 11, a first section of thermal insulation pipe 12, a first sleeve switch 13, a second section of thermal insulation pipe 14 and a second sleeve switch 15 which are connected in sequence from top to bottom, the lower end of the second sleeve switch 15 is closed by a screw plug 16, the first packer 3 is arranged on the outer wall of the outer gas injection pipe 11, the second packer 4 is arranged on the outer wall of the second section of thermal insulation pipe 14, the gas injection hole 111 is opened on the outer gas injection pipe 11, the third packer 5 is located inside the outer gas injection pipe 11, the first sleeve switch 13 is a first connecting component, the second sleeve switch 15 is a second connecting component, and since the distance between the upper oil layer 7 and the lower oil layer 8 in each oil well is not the same, the distance between the first sleeve switch 13 and the second sleeve switch 15 can be changed by replacing the second section of thermal insulation pipe 14 with different lengths. The distance between the switches 15 is determined to ensure that the first sleeve switch 13 and the second sleeve switch 15 can correspond to the upper oil layer 7 and the lower oil layer 8 respectively; wherein, since the first packer 3 and the third packer 5 are both located at the external gas injection pipe 11, and the ignition point is respectively located at the first sleeve switch 13 and the second sleeve switch 15, the distance between the first packer 3 and the third packer 5 and the ignition point is relatively far, so the temperature at the position where the first packer 3 and the third packer 5 are located is relatively low, thereby effectively ensuring the service life of the first packer 3 and the third packer 5. At the same time, since the second packer 4 is arranged on the outer wall of the second section of the thermal insulation pipe 14, and the second section of the thermal insulation pipe 14 has a good thermal insulation effect, the position of the second packer 4 is also greatly reduced, thereby ensuring the service life of the second packer 4 and avoiding the first packer 3, the second packer 4 and the third packer 5 from failing to set in a high temperature environment.

[0058] As a preference, Figure 1 to Figure 3 As shown, the layered ignition process column provided by the present invention, wherein the lower end of the inner column 2 is higher than the upper end of the first section of the insulation tube 12, or the lower end of the inner column 2 is flush with the upper end of the first section of the insulation tube 12, thereby effectively shortening the length of the inner column 2 and reducing the production cost of the inner column 2.

[0059] As a preference, Figure 1 to Figure 3 As shown, the layered ignition process column provided by the present invention, wherein the ignition assembly 6 includes a cable 61 and an electric igniter 62, the cable 61 passes through the inner column 2 from top to bottom, the lower end of the cable 61 extends from the lower end of the inner column 2 and extends to the interior of the first section of the thermal insulation tube 12, the upper end of the electric igniter 62 is connected to the cable 61, and the lower end of the electric igniter 62 extends between the first sliding switch 13 and the second sliding switch 15, the lower end of the electric igniter 62 is the ignition end, the ignition end ignites at the first sliding switch 13 to realize the ignition operation of the upper oil layer 7, and ignites at the second sliding switch 15 to realize the ignition operation of the lower oil layer 8.

[0060] Preferably, the layered ignition process string provided by the present invention, wherein the first sleeve switch 13 and the second sleeve switch 15 both include an outer tube and an inner tube, the outer tube is provided with a connecting hole, the inner tube can be reciprocatingly slidably arranged inside the outer tube along the axial direction of the outer tube, and by inserting a downhole tool, the inner tube can be controlled to block and close each connecting hole or be misaligned with each connecting hole and connect each connecting hole.

[0061] As a preference, Figure 1 to Figure 3 As shown, the layered ignition process string provided by the present invention has a plurality of gas injection holes 111, and the plurality of gas injection holes 111 are evenly spaced and distributed along the axial direction of the outer gas injection pipe 11, so that air can be evenly injected into the annulus between the outer pipe string 1 and the oil well casing 9.

[0062] As a preference, Figure 1 to Figure 3 As shown, the layered ignition process string provided by the present invention has a one-way valve 1111 installed at the gas injection hole 111, which can allow gas to flow from the inside of the outer pipe string 1 to the outside of the outer pipe string 1, so as to prevent the air injected into the annulus between the outer pipe string 1 and the oil well casing 9 from flowing back along the gas injection hole 111, thereby ensuring that there is enough air in the annulus between the outer pipe string 1 and the oil well casing 9 to support the upper oil layer 7 to maintain combustion.

[0063] Preferably, the layered ignition process string provided by the present invention comprises the first packer 3 being a mechanically set packer, and the second packer 4 and the third packer 5 being thermally set packers. However, it should be noted that the above-mentioned setting methods of the first packer 3, the second packer 4 and the third packer 5 are only preferred embodiments of the present invention, and the present invention is not limited thereto.

[0064] Preferably, in the layered ignition process string provided by the present invention, both the upper end of the inner string 2 and the upper end of the outer string 1 are provided with a gas injection flow control assembly to control and observe the gas injection amount of the inner string 2 and the outer string 1.

[0065] like Figure 4 As shown, the present invention also provides a stratified ignition method, wherein the stratified ignition method is implemented using the stratified ignition process column as described above, and the stratified ignition method includes:

[0066] Step 1: lower the outer pipe string 1 of the layered ignition process pipe string into the oil well casing 9, so that the first connecting component corresponds to the upper oil layer 7, and the second connecting component corresponds to the lower oil layer 8, so that the first packer 3 is set on the inner wall of the oil well casing 9 above the upper oil layer 7, and the second packer 4 is set on the inner wall of the oil well casing 9 between the upper oil layer 7 and the lower oil layer 8;

[0067] Step 2: lower the inner pipe string 2 of the layered ignition process pipe string into the outer pipe string 1, so that the third packer 5 is seated on the inner wall of the inner pipe string 2;

[0068] Step 3: lower the ignition assembly 6 of the layered ignition process column into the inner column 2, so that the ignition end of the ignition assembly 6 is located at the first connecting assembly;

[0069] Step 4: Open the first connecting component to connect the inner side of the outer pipe string 1 with the outer side of the outer pipe string 1;

[0070] Step 5: inject gas into the inner pipe string 2, control the ignition assembly 6 to ignite, and make the upper oil layer 7 burn;

[0071] Step 6: inject gas into the interior of the outer pipe column 1, close the first connecting component, and move the ignition component 6 downward so that the lower end (ignition end) of the ignition component 6 is located at the second connecting component;

[0072] Step 7: Open the second connecting component to connect the inner side of the outer pipe string 1 with the outer side of the outer pipe string 1;

[0073] Step 8: Inject gas into the inner pipe string 2 and control the ignition assembly 6 to ignite, so that the lower oil layer 8 burns.

[0074] In this way, the layered gas injection and layered ignition of the upper oil layer 7 and the lower oil layer 8 can be achieved.

[0075] Compared with the prior art, the advantages of the present invention are as follows:

[0076] The layered ignition process pipe string and ignition method provided by the present invention can form gas injection channels for the upper oil layer and the lower oil layer respectively inside the casing through the arrangement of the first packer, the second packer, the third packer and the gas injection hole, the first connecting component and the second connecting component, so as to realize the gas injection and ignition of the upper oil layer and the lower oil layer respectively, and meet the process requirements of layered ignition and gas injection; at the same time, the present invention shortens the length of the inner pipe string extending into the inner part of the outer pipe string, so that the ignition end of the ignition component penetrates the inner pipe string and extends into the inner part of the outer pipe string for ignition operation. Since the inner diameter of the outer pipe string is much larger than the inner diameter of the inner pipe string, the ignition space can be effectively increased to ensure the smooth progress of the ignition operation. At the same time, since the length of the inner pipe string is shortened, the purpose of reducing the production cost of the inner pipe string can be effectively achieved; in addition, in the present invention, the first packer and the second packer are both arranged outside the ignition space, and the third packer is far away from the ignition position, so that each packer can be effectively placed at a position with a lower temperature, thereby improving the service life of each packer.

[0077] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by a person of ordinary skill in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A layered ignition process column, characterized in that: The layered ignition process string comprises an outer string, an inner string and an ignition assembly, the outer wall of the outer string is provided with a first packer near its upper end and a second packer near its lower end, the inner string is coaxially arranged inside the outer string, the outer wall of the inner string is provided with a third packer which can be set and sealed on the inner wall of the outer string, the third packer is located below the first packer and above the second packer, at least one gas injection hole is opened on the outer string between the first packer and the third packer, and a gas injection hole is installed at the gas injection hole for gas to flow from the inside of the outer string to the The one-way valve on the outside of the outer tubular column, the first connecting component is provided on the outer tubular column between the third packer and the second packer, the lower end of the inner tubular column is located above the first connecting component, and the lower end of the outer tubular column is located below the second packer and is provided with a second connecting component, the first connecting component and the second connecting component can respectively open and connect the inner side of the outer tubular column with the outer side of the outer tubular column, the ignition component passes through the inner tubular column from top to bottom and extends to the inside of the outer tubular column, and the ignition end of the ignition component can move between the first connecting component and the second connecting component; The outer pipe column has a structure with an open top, a closed bottom and a hollow interior. The outer pipe column includes an external gas injection pipe, a first section of thermal insulation pipe, a first sliding sleeve switch, a second section of thermal insulation pipe and a second sliding sleeve switch which are connected in sequence from top to bottom. The lower end of the second sliding sleeve switch is closed by a wire plug. The first seal is arranged on the outer wall of the external gas injection pipe, the second seal is arranged on the outer wall of the second section of thermal insulation pipe, the third seal is located inside the external gas injection pipe, the first sliding sleeve switch is the first connecting component, and the second sliding sleeve switch is the second connecting component.

2. The layered ignition process column according to claim 1, characterized in that: The lower end of the inner pipe column is higher than the upper end of the first section of the thermal insulation pipe, or the lower end of the inner pipe column is flush with the upper end of the first section of the thermal insulation pipe.

3. The layered ignition process column according to claim 2, characterized in that: The ignition assembly includes a cable and an electric igniter. The cable passes through the inner tube column from top to bottom. The lower end of the cable extends from the lower end of the inner tube column to the interior of the first section of the thermal insulation tube. The upper end of the electric igniter is connected to the cable. The lower end of the electric igniter extends between the first sliding switch and the second sliding switch. The lower end of the electric igniter is the ignition end.

4. The layered ignition process column according to claim 2, characterized in that: The first sliding sleeve switch and the second sliding sleeve switch both include an outer cylinder and an inner cylinder, the outer cylinder is provided with a connecting hole, the inner cylinder can be reciprocatingly slidably arranged inside the outer cylinder along the axial direction of the outer cylinder, and the inner cylinder can block and close each connecting hole or be misaligned with each connecting hole and connect the connecting holes.

5. The layered ignition process column according to claim 2, characterized in that: There are a plurality of gas injection holes, and the plurality of gas injection holes are evenly spaced and distributed along the axial direction of the outer gas injection pipe.

6. The layered ignition process column according to claim 1, characterized in that: The first packer is a mechanically set packer, and the second packer and the third packer are both thermally set packers.

7. The layered ignition process column according to claim 1, characterized in that: The upper end of the inner pipe string and the upper end of the outer pipe string are both provided with a gas injection flow control component.

8. A stratified ignition method, characterized in that: The stratified ignition method is implemented by using the stratified ignition process column according to any one of claims 1 to 7, and the stratified ignition method comprises: Step 1: lowering the outer pipe string of the layered ignition process pipe string into the oil well casing, so that the first connecting component corresponds to the upper oil layer, and the second connecting component corresponds to the lower oil layer, so that the first packer is set on the inner wall of the oil well casing above the upper oil layer, and the second packer is set on the inner wall of the oil well casing between the upper oil layer and the lower oil layer; Step 2: lowering the inner tubular column of the layered ignition process tubular column into the inner part of the outer tubular column, so that the third packer is set on the inner wall of the inner tubular column; Step 3: lowering the ignition assembly of the layered ignition process column into the interior of the inner column so that the ignition end of the ignition assembly is located at the first connecting assembly; Step 4: Open the first connecting component to connect the inner side of the outer tube string with the outer side of the outer tube string. Step 5: injecting gas into the inner pipe string, controlling the ignition assembly to ignite, and causing the upper oil layer to burn; Step 6: injecting gas into the interior of the outer pipe string, closing the first connecting component, and moving the ignition component downward so that the lower end of the ignition component is located at the second connecting component; Step 7: Open the second connecting component to connect the inner side of the outer tube string with the outer side of the outer tube string; Step 8: Inject gas into the inner pipe string, control the ignition assembly to ignite, and cause the lower oil layer to burn.

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