Layered ignition process column and ignition heat drive method

Abstract

The present invention is a layered ignition process pipe string and an ignition heat drive method, the layered ignition process pipe string comprises a casing, an igniter pipe string is inserted in the casing, the layered ignition process pipe string also comprises a gas injection inlet structure, the gas injection inlet structure can be connected with the inner cavity of the igniter pipe string and the casing annulus respectively; a first packer is sleeved between the upper oil layer and the lower oil layer on the side wall of the igniter pipe string; a second packer is sleeved below the lower oil layer on the side wall of the igniter pipe string; a first sieve hole portion is arranged on the side wall of the casing at a position opposite to the upper oil layer, a second sieve hole portion is arranged on the side wall of the igniter pipe string at a position opposite to the lower oil layer, and a third sieve hole portion is arranged on the side wall of the casing at a position opposite to the lower oil layer. The layered ignition process pipe string and the ignition heat drive method can realize layered ignition without moving the igniter up and down after the igniter is lowered into the well once, without the need to lower the gas injection pipe string, and the structure is simple and the construction is convenient.

Description

Technical Field

[0001] The invention relates to the field of oil production technology and testing, and in particular to a layered ignition process pipe column and an ignition heat drive method for oil field fire drive wells. Background Art

[0002] Fire flooding technology is an important conversion method in the late stage of heavy oil development in oil fields. In layered ignition, due to the limitations of the mobile electric igniter and the structure and process of the gas injection string, the construction is difficult and the structure of the gas injection string is complex.

[0003] Therefore, the inventors, relying on their many years of experience and practice in related industries, propose a layered ignition process column and an ignition heat drive method to overcome the defects of the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a layered ignition process string and an ignition heat drive method, which overcome the problems of limited process, great construction difficulty and complex structure in the prior art. The layered ignition process string and the ignition heat drive method do not need to be lowered into the gas injection string, and can realize layered ignition after the igniter is lowered into the well once, without moving the igniter up and down. The structure is simple and the construction is convenient.

[0005] The object of the present invention is achieved in this way. A layered ignition process string comprises a casing connected to a gas injection wellhead, an igniter string with a bottom seal and a top seal passing through the gas injection wellhead is radially spaced in the casing, the bottom end of the igniter string extends to below the lower oil layer, a temperature measuring line is passed through the igniter string, the bottom end of the temperature measuring line extends to the lower oil layer, and a heating cable capable of igniting and heating the igniter string is arranged in the igniter string;

[0006] A casing annulus is formed between the outer wall of the igniter pipe string and the inner wall of the casing; the layered ignition process pipe string also includes a gas injection inlet structure arranged on the ground, and the gas injection inlet structure can be communicated with the inner cavity of the igniter pipe string and the casing annulus respectively;

[0007] A first packer is sleeved on the side wall of the igniter tube string, located between the upper oil layer and the lower oil layer; a second packer is sleeved on the side wall of the igniter tube string, located below the lower oil layer; a first sieve hole portion is provided on the side wall of the casing, at a position opposite to the upper oil layer; a second sieve hole portion is provided on the side wall of the igniter tube string, at a position opposite to the lower oil layer; and a third sieve hole portion is provided on the side wall of the casing, at a position opposite to the lower oil layer.

[0008] In a preferred embodiment of the present invention, a wellhead annulus is formed between the outer wall of the igniter tubular string and the inner wall of the gas injection wellhead, and the wellhead annulus is connected to the casing annulus; a gas injection distributor is arranged at the outlet of the gas injection inlet structure, one outlet of the gas injection distributor is connected to the wellhead annulus, and the other outlet of the gas injection distributor is connected to the inner cavity of the igniter tubular string.

[0009] In a preferred embodiment of the present invention, a first flow meter is arranged at the inlet of the gas injection distributor, a second flow meter is arranged between an outlet of the gas injection distributor and the wellhead annulus, and a third flow meter is arranged between another outlet of the gas injection distributor and the inner cavity of the igniter pipe string.

[0010] In a preferred embodiment of the present invention, the top end seal of the igniter tube column is connected to a temperature measuring line sealer, the top end seal of the temperature measuring line passes through the temperature measuring line sealer, the heating cable is connected to the temperature measuring line sealer, and the other outlet of the gas injection distributor is connected to the temperature measuring line sealer.

[0011] In a preferred embodiment of the present invention, an igniter sealer is provided at the top of the gas injection wellhead, and the igniter pipe string seal passes through the igniter sealer.

[0012] In a preferred embodiment of the present invention, a heat insulating sleeve is sleeved on the outer wall of the sleeve, a first heat insulating sleeve ring groove is set at a position corresponding to the first sieve hole portion, and a second heat insulating sleeve ring groove is set at a position corresponding to the third sieve hole portion.

[0013] In a preferred embodiment of the present invention, a sealing plug is provided at the bottom end of the igniter tube column.

[0014] In a preferred embodiment of the present invention, the igniter pipe string includes a short pipe portion with a sealed bottom, the second packer is sleeved on the short pipe portion, the top of the short pipe portion is connected to a screen pipe, the second screen hole portion is arranged on the screen pipe, and the top of the screen pipe is connected to a tubular igniter.

[0015] The object of the present invention can also be achieved in this way. An ignition heat drive method using the aforementioned layered ignition process string includes: fixing the casing in the well, lowering the igniter string into the casing, and completing the setting of the first packer and the second packer; energizing the heating cable to complete the ignition of the upper oil layer and the lower oil layer; and injecting gas into the inner cavity of the igniter string and the casing annulus respectively to heat drive the upper oil layer and the lower oil layer.

[0016] In a preferred embodiment of the present invention, the ignition thermal drive method comprises the following steps:

[0017] Step a, lowering the casing into the well, and connecting the top of the casing with the gas injection wellhead; inserting the temperature measuring line into the igniter string, and connecting the heating cable to the top of the igniter string; connecting the gas injection inlet structure with the inner cavity of the igniter string and the casing annulus respectively;

[0018] Step b, placing the first packer and the second packer in sequence at the gas injection wellhead, and the igniter string passes through the first packer and the second packer in sequence; fixing the second packer to the bottom end of the igniter string, lowering the igniter string for a distance, and then fixing the first packer on the igniter string;

[0019] Step c, continue to lower the igniter string until the second packer reaches below the lower oil layer and the first packer reaches between the upper oil layer and the lower oil layer, and the first packer and the second packer are set;

[0020] Step d, energizing the heating cable to complete ignition of the upper oil layer and the lower oil layer;

[0021] Step e: The gas injection inlet structure injects gas into the inner cavity of the igniter pipe string and the casing annulus respectively to heat drive the upper oil layer and the lower oil layer.

[0022] As described above, the layered ignition process column and ignition heat drive method provided by the present invention have the following beneficial effects:

[0023] In the layered ignition process string provided by the present invention, the gas injection inlet structure is respectively connected with the inner cavity of the igniter string and the casing annulus, the casing annulus and the inner cavity of the igniter string constitute the gas injection channels of the upper oil layer and the lower oil layer respectively, the igniter string has both the function of the igniter and the function of the gas injection channel, the igniter string is lowered into the well once, and there is no need to lower the gas injection string again, and there is no need to move the igniter up and down to realize layered ignition, which can be the first oil layer or the second oil layer first, or the two oil layers can be ignited at the same time; the layered ignition process string provided by the present invention has a simple structure and is convenient to construct, and can be widely used in the field of oilfield fire drive wells; the ignition heat drive method provided by the present invention is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 1 : is a schematic diagram of the layered ignition process column of the present invention.

[0026] In the figure:

[0027] 100. Layered ignition process column;

[0028] 101, casing annulus;

[0029] 1. Casing;

[0030] 11. first sieve hole portion; 12. third sieve hole portion; 14. first sleeve; 15. first heat-insulating sleeve; 16. second sleeve; 17. second heat-insulating sleeve; 18. third sleeve; 19. third heat-insulating sleeve;

[0031] 2. Ignition tube column;

[0032] 20. Sealing plug; 21. Second sieve hole portion; 22. Short tube portion; 23. Sieve tube; 24. Tubular igniter;

[0033] 3. Temperature measuring line; 31. Temperature measuring line sealer; 32. Ignition device sealer;

[0034] 4. Heating cable;

[0035] 5. Gas injection inlet structure; 51. Gas injection distributor;

[0036] 61. first packer; 62. second packer;

[0037] 71. a first flow meter; 72. a second flow meter; 73. a third flow meter;

[0038] 90. Gas injection wellhead; 91. Upper oil layer; 92. Lower oil layer. DETAILED DESCRIPTION

[0039] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0040] like Figure 1As shown, the present invention provides a layered ignition process string 100, including a casing 1 connected to a gas injection wellhead 90, an igniter string 2 with a bottom seal and a top seal passing through the gas injection wellhead 90 is radially sleeved in the casing 1, and the igniter string 2 has both the function of an igniter and the function of a gas injection channel. In this embodiment, a sealing plug 20 is provided at the bottom end of the igniter string 2. The bottom end of the igniter tube string 2 extends to below the lower oil layer 92 (the oil layer at the bottom in the stratified ignition), a temperature measuring line 3 is passed through the igniter tube string 2, the bottom end of the temperature measuring line 3 extends to the lower oil layer 92, the other end of the temperature measuring line 3 is connected to the temperature controller (existing technology), a heating cable 4 that can ignite and heat the igniter tube string 2 is set in the igniter tube string 2, and the top of the heating cable 4 is connected to the power control cabinet (existing technology); the heating cable 4 is used for ignition, and the heating cable 4 consists of two parts. The part located in the lower part of the well is a heating part, which is used to heat the gas injected into the well (the gas injected into the well is heated to about 450 degrees, and the air heated to 450 degrees enters the oil layer, so that the crude oil in the oil layer is oxidized and burned, and the oil layer is ignited), and the part located in the upper part of the well and on the ground is a conductive part, which is electrically connected to the power control cabinet. The temperature measuring line 3 can transmit the temperature signal of the heated gas to the ground and monitor the temperature of the heated gas in real time. In order to facilitate monitoring of the outlet temperature of the igniter tube column 2, a temperature measuring sensor is set at the outlet of the igniter tube column 2 (existing technology).

[0041] The outer wall of the igniter string 2 and the inner wall of the casing 1 form a casing annulus 101; the layered ignition process string 100 also includes a gas injection inlet structure 5 arranged on the ground, and the gas injection inlet structure 5 can be connected to the inner cavity of the igniter string 2 and the casing annulus 101 respectively;

[0042] A first packer 61 is sleeved on the side wall of the igniter tube string 2, between the upper oil layer 91 (the upper oil layer in stratified ignition) and the lower oil layer 92; a second packer 62 is sleeved on the side wall of the igniter tube string 2, below the lower oil layer 92; a first sieve hole portion 11 is provided on the side wall of the casing 1, at a position opposite to the upper oil layer 91; a second sieve hole portion 21 is provided on the side wall of the igniter tube string 2, at a position opposite to the lower oil layer 92; and a third sieve hole portion 12 is provided on the side wall of the casing 1, at a position opposite to the lower oil layer 92.

[0043] In the layered ignition process string provided by the present invention, the gas injection inlet structure is respectively connected with the inner cavity of the igniter string and the casing annulus, the casing annulus and the inner cavity of the igniter string constitute the gas injection channels of the upper oil layer and the lower oil layer respectively, the igniter string has both the function of the igniter and the function of the gas injection channel, the igniter string is lowered into the well once, and there is no need to lower the gas injection string again, and there is no need to move the igniter up and down to realize layered ignition, which can be the first oil layer or the second oil layer first, or the two oil layers can be ignited at the same time; the layered ignition process string provided by the present invention has a simple structure and is convenient to construct, and can be widely used in the field of oilfield fire drive wells.

[0044] Further, if Figure 1 As shown, a wellhead annulus is formed between the outer wall of the igniter tubular column 2 and the inner wall of the gas injection wellhead 90, and the wellhead annulus is connected to the casing annulus 101; a gas injection distributor 51 is arranged at the outlet of the gas injection inlet structure 5, one outlet of the gas injection distributor 51 is connected to the wellhead annulus, and the other outlet of the gas injection distributor 51 is connected to the inner cavity of the igniter tubular column 2. The gas injection distributor 51 realizes the diversion of the gas injection, and gas can be injected into the casing annulus 101 first, the inner cavity of the igniter tubular column first, or the casing annulus 101 and the inner cavity of the igniter tubular column are injected at the same time.

[0045] Further, if Figure 1 As shown, a first flow meter 71 is provided at the inlet of the gas injection distributor 51, a second flow meter 72 is provided between one outlet of the gas injection distributor 51 and the wellhead annulus, and a third flow meter 73 is provided between the other outlet of the gas injection distributor 51 and the inner cavity of the igniter string 2. The first flow meter 71, the second flow meter 72 and the third flow meter 73 can monitor the gas injection flow rate of each gas injection channel in real time, which is conducive to accurately controlling the flow rate of each gas injection channel.

[0046] Further, if Figure 1 As shown, the top seal of the igniter tube column 2 is connected to the temperature measuring line sealer 31, the top seal of the temperature measuring line 3 passes through the temperature measuring line sealer 31, the heating cable 4 is connected to the temperature measuring line sealer 31, and the other outlet of the gas injection distributor 51 is connected to the temperature measuring line sealer 31.

[0047] Further, if Figure 1 As shown, an igniter sealer 32 is disposed at the top of the gas injection wellhead 90 , and the igniter pipe string 2 passes through the igniter sealer 32 in a sealed manner.

[0048] In this embodiment, if Figure 1 As shown, the igniter string 2 can be composed of a multi-section structure, and the igniter string 2 includes a short tube portion 22 with a bottom seal, a second packer 62 is sleeved on the short tube portion 22, a screen tube 23 is connected above the short tube portion 22, a second screen hole portion 21 is arranged on the screen tube 23, and a tubular igniter 24 is connected above the screen tube 23.

[0049] Further, if Figure 1 As shown, a heat-insulating sleeve is sleeved on the outer wall of the casing 1, a first heat-insulating sleeve annular groove is arranged at a position of the heat-insulating sleeve corresponding to the first sieve hole portion 11, and a second heat-insulating sleeve annular groove is arranged at a position of the heat-insulating sleeve corresponding to the third sieve hole portion 12. The casing 1 can be composed of a multi-section structure, and the casing 1 includes a first casing 14 connected to the gas injection wellhead 90 at the top, a first heat-insulating sleeve 15 connected below the first casing 14, a second casing 16 connected below the first heat-insulating sleeve 15, a first sieve hole portion 11 is arranged on the second casing 16, a second heat-insulating sleeve 17 is connected below the second casing 16, a third casing 18 is connected below the second heat-insulating sleeve 17, a third sieve hole portion 12 is arranged on the third casing 18, and a third heat-insulating sleeve 19 is connected below the third casing 18.

[0050] The present invention also provides an ignition heat drive method using the aforementioned layered ignition process string, firstly, a casing 1 is fixed in the well, an igniter string 2 is lowered into the casing 1, and the first packer 61 and the second packer 62 are set; the heating cable 4 is energized to complete the ignition of the upper oil layer 91 and the lower oil layer 92 (the upper oil layer can be ignited first, or the lower oil layer can be ignited first, or both oil layers can be ignited at the same time); gas is injected into the inner cavity of the igniter string 2 and the casing annulus 101 respectively, to heat drive the upper oil layer 91 and the lower oil layer 92.

[0051] Specifically, the ignition heat drive method comprises the following steps:

[0052] Step a, lowering the casing 1 into the well, and connecting the top of the casing 1 to the gas injection wellhead 90; inserting the temperature measuring line 3 into the igniter string 2, and connecting the heating cable 4 to the top of the igniter string 2; connecting the gas injection inlet structure 5 to the inner cavity of the igniter string 2 and the casing annulus 101 respectively;

[0053] Step b, placing the first packer 61 and the second packer 62 in sequence at the gas injection wellhead 90, and the igniter string 2 passes through the first packer 61 and the second packer 62 in sequence; fixing the second packer 62 to the bottom end of the igniter string 2, lowering the igniter string 2 for a distance, and then fixing the first packer 61 on the igniter string 2;

[0054] Step c, continue to lower the igniter string 2 until the second packer 62 reaches below the lower oil layer 92, and the first packer 61 reaches between the upper oil layer 91 and the lower oil layer 92 (the positions of the first packer 61 and the second packer 62 in the well are determined by calculating the depth of the well), and the first packer 61 and the second packer 62 are set;

[0055] Step d, the heating cable 4 is energized to complete the ignition of the upper oil layer 91 and the lower oil layer 92;

[0056] The ignition sequence can be carried out according to actual needs. The upper oil layer can be ignited first, the lower oil layer can be ignited first, or both oil layers can be ignited at the same time.

[0057] Step e: The gas injection inlet structure 5 injects gas into the inner cavity of the igniter pipe string 2 and the casing annulus 101 respectively to heat drive the upper oil layer 91 and the lower oil layer 92.

[0058] The gas injection channel of the upper oil layer 91 is: gas injection inlet structure 5 → gas injection distributor 51 → first flow meter 71 → second flow meter 72 → wellhead annulus → casing annulus 101 → first sieve hole portion 11 → upper oil layer 91 .

[0059] The gas injection channel of the lower oil layer 92 is: gas injection inlet structure 5 → gas injection distributor 51 → first flow meter 71 → third flow meter 73 → temperature measuring line sealer 31 → inner cavity of igniter tube column 2 → second sieve hole part 21 → third sieve hole part 12 → lower oil layer 92.

[0060] As described above, the layered ignition process column and ignition heat drive method provided by the present invention have the following beneficial effects:

[0061] In the layered ignition process string provided by the present invention, the gas injection inlet structure is respectively connected with the inner cavity of the igniter string and the casing annulus, the casing annulus and the inner cavity of the igniter string constitute the gas injection channels of the upper oil layer and the lower oil layer respectively, the igniter string has both the function of the igniter and the function of the gas injection channel, the igniter string is lowered into the well once, and there is no need to lower the gas injection string again, and there is no need to move the igniter up and down to realize layered ignition, which can be the first oil layer or the second oil layer first, or the two oil layers can be ignited at the same time; the layered ignition process string provided by the present invention has a simple structure and is convenient to construct, and can be widely used in the field of oilfield fire drive wells; the ignition heat drive method provided by the present invention is simple and easy to implement.

[0062] 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 any person skilled 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 string, comprising a casing connected to a gas injection wellhead, characterized in that: The casing is radially spaced with an igniter string having a bottom seal and a top seal passing through the gas injection wellhead, the bottom end of the igniter string extends to below the lower oil layer, a temperature measuring line is passed through the igniter string, the bottom end of the temperature measuring line extends to the lower oil layer, and a heating cable capable of igniting and heating the igniter string is arranged in the igniter string; A casing annulus is formed between the outer wall of the igniter pipe string and the inner wall of the casing; the layered ignition process pipe string also includes a gas injection inlet structure arranged on the ground, and the gas injection inlet structure can be communicated with the inner cavity of the igniter pipe string and the casing annulus respectively; A first packer is sleeved on the side wall of the igniter string between the upper oil layer and the lower oil layer; a second packer is sleeved on the side wall of the igniter string below the lower oil layer; a first sieve hole portion is arranged on the side wall of the casing at a position opposite to the upper oil layer, a second sieve hole portion is arranged on the side wall of the igniter string at a position opposite to the lower oil layer, and a third sieve hole portion is arranged on the side wall of the casing at a position opposite to the lower oil layer; A wellhead annulus is formed between the outer wall of the igniter pipe string and the inner wall of the gas injection wellhead, and the wellhead annulus is connected with the casing annulus; a gas injection distributor is arranged at the outlet of the gas injection inlet structure, one outlet of the gas injection distributor is connected with the wellhead annulus, and the other outlet of the gas injection distributor is connected with the inner cavity of the igniter pipe string; A sealing plug is arranged at the bottom end of the igniter tube column.

2. The layered ignition process column according to claim 1, characterized in that: A first flow meter is arranged at the inlet of the gas injection distributor, a second flow meter is arranged between an outlet of the gas injection distributor and the wellhead annulus, and a third flow meter is arranged between another outlet of the gas injection distributor and the inner cavity of the igniter pipe string.

3. The layered ignition process column according to claim 1, characterized in that: The top seal of the igniter column is connected to a temperature measuring line sealer, the top seal of the temperature measuring line passes through the temperature measuring line sealer, the heating cable is connected to the temperature measuring line sealer, and the other outlet of the gas injection distributor is connected to the temperature measuring line sealer.

4. The layered ignition process column according to claim 1, characterized in that: An igniter sealer is arranged at the top of the gas injection wellhead, and the igniter pipe string seal passes through the igniter sealer.

5. The layered ignition process column according to claim 1, characterized in that: A heat-insulating sleeve is sleeved on the outer wall of the sleeve, a first heat-insulating sleeve ring groove is arranged at a position of the heat-insulating sleeve corresponding to the first sieve hole portion, and a second heat-insulating sleeve ring groove is arranged at a position of the heat-insulating sleeve corresponding to the third sieve hole portion.

6. The layered ignition process column according to claim 1, characterized in that: The igniter pipe string comprises a short pipe portion with a sealed bottom, the second packer is sleeved on the short pipe portion, a screen pipe is connected above the short pipe portion, the second screen hole portion is arranged on the screen pipe, and a tubular igniter is connected above the screen pipe.

7. An ignition heat drive method using the layered ignition process column according to any one of claims 1 to 6, characterized in that: The casing is fixed in the well, and the igniter string is lowered into the casing to complete the setting of the first and second packers; the heating cable is energized to complete the ignition of the upper and lower oil layers; gas is injected into the inner cavity of the igniter string and the annulus of the casing respectively to heat drive the upper and lower oil layers.

8. The ignition heat drive method according to claim 7, characterized in that: The following steps are included: Step a, lowering the casing into the well, and connecting the top of the casing with the gas injection wellhead; inserting the temperature measuring line into the igniter string, and connecting the heating cable to the top of the igniter string; connecting the gas injection inlet structure with the inner cavity of the igniter string and the casing annulus respectively; Step b, placing the first packer and the second packer in sequence at the gas injection wellhead, and the igniter string passes through the first packer and the second packer in sequence; fixing the second packer to the bottom end of the igniter string, lowering the igniter string for a distance, and then fixing the first packer on the igniter string; Step c, continue to lower the igniter string until the second packer reaches below the lower oil layer and the first packer reaches between the upper oil layer and the lower oil layer, and the first packer and the second packer are set; Step d, energizing the heating cable to complete ignition of the upper oil layer and the lower oil layer; Step e: The gas injection inlet structure injects gas into the inner cavity of the igniter pipe string and the casing annulus respectively to heat drive the upper oil layer and the lower oil layer.

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