Automatic gas generation acidification plug removal method for gas well

Abstract

The invention discloses an automatic gas generation acidification plug removal method for a gas well. The method is specifically implemented according to the following steps that 1, 10 m < 3 >-15 m < 3 > of an agent A is injected into a near wellbore zone in a stratum through an oil pipe; 2, after injection of the agent A is completed, 2.5 m < 3 >-7.5 m < 3 > of the agent B is injected; 3, after injection of the agent B is completed, well shut-in reaction is carried out for 12-24 hours, and then blowout is carried out; and 4, after the residual liquid and the blockages are subjected to blowout, 0.5 m < 3 >-1 m < 3 > of the C agent is injected into the stratum. According to the automatic gas generation acidification blockage removal method for the gas well, the gas generation amount is large, the problems that in the prior art, the gas generation amount is insufficient, and gas needs to be injected to achieve sufficient flowback are solved, the automatic gas generation acidification blockage removal agent is adopted, deep blockage of the gas well can be effectively removed, and the method has the advantages that gas injection is not needed, flowback is easy, and the process is simple.

Description

Technical Field

[0001] The invention belongs to the technical field of gas well plugging removal, and relates to a self-generating acidizing plugging removal method for a gas well. Background Art

[0002] With the continuous deepening of oil and gas field development, the properties of underground fluids change with the entry of working fluids during drilling, completion, production increase and production, which makes it easy for oil and gas reservoirs to be blocked, resulting in varying degrees of damage. Due to the increase in injection pressure, the injection rate is forced to be reduced, which seriously affects the production increase effect of oil and gas reservoirs. At present, there are four main methods for dealing with reservoir blockage at home and abroad, namely chemical method, physical method, physical and chemical method and microbial method. Among them, chemical acid unblocking technology is relatively mature, with the advantages of fast effect, simple construction process, low cost and strong adaptability, and is widely used in major oil and gas fields. However, with the production of oil and gas in the formation, the energy of the oil and gas well formation decreases. Most old wells have low formation pressure and insufficient gas generation of unblocking agents, which makes it difficult to return residual acid and causes secondary damage to the reservoir.

[0003] According to the investigation, the existing technology has the problem of insufficient gas production, and the need to inject gas to achieve sufficient backflow after adding the self-generating agent, and the construction process is complicated. Summary of the invention

[0004] The purpose of the present invention is to provide a method for removing plugging by self-generated gas acidification for gas wells, which solves the problem of insufficient gas volume in the prior art and the need to inject gas to achieve sufficient backflow.

[0005] The technical solution adopted by the present invention is a method for removing plugging by autogenous gas acidification for gas wells, which is specifically implemented according to the following steps:

[0006] Step 1: Use the oil pipe to transfer 10m 3 -15m 3 Agent A is injected into the formation near the wellbore area;

[0007] Step 2: After the injection of agent A is completed, inject 2.5m 3 -7.5m 3 of B agent;

[0008] Step 3: After the injection of agent B is completed, the well is shut down for 12-24 hours and then the well is blown;

[0009] Step 4: After the residual liquid and blockage are released, 0.5m 3 -1m 3 Agent C is injected into the formation.

[0010] The invention is also characterized in that: Agent A is composed of 8%-15% hydrochloric acid, 6%-12% organic acid, 1%-1.5% corrosion inhibitor, and 71.5%-85% water in mass percentage, and the total mass of the above raw materials is 100%.

[0011] The concentration of hydrochloric acid in Agent A is 36%-38%; the organic acid in Agent A is any one of formic acid, acetic acid and citric acid; the corrosion inhibitor in Agent A is one of Mannich base corrosion inhibitor and benzyl chloroquinoline corrosion inhibitor.

[0012] The preparation method of agent A is as follows:

[0013] Step 1: Weigh the following raw materials by mass percentage:

[0014] Hydrochloric acid 8%-15%, organic acid 6%-12%, corrosion inhibitor 1%-1.5%, water 71.5%-85%, the total mass of the above raw materials is 100%;

[0015] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0016] Agent B is composed of 30%-40% of self-gasifying agent, 10%-20% of oxidant, 0.5-2% of foaming agent, 0.6-1% of foam stabilizer and 37%-58.9% of water by mass percentage, and the total mass of the above raw materials is 100%.

[0017] The self-gassing agent in Agent B is 5-aminotetrazole; the oxidizing agent in Agent B is ammonium nitrate; the foaming agent in Agent B is any one of alkyl sulfonate betaine, lauramide propylamine oxide, and sodium ether sulfate; and the foam stabilizing agent in Agent B is polyacrylamide.

[0018] The preparation method of Agent B is as follows:

[0019] Step 1: Weigh the following raw materials by mass percentage:

[0020] Self-gasifying agent 30%-40%, oxidant 10%-20%, foaming agent 0.5-2%, foam stabilizer 0.6-1%, water 37%-58.9%, the total mass of the above raw materials is 100%;

[0021] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0022] Agent C is composed of 10%-25% of surfactant, 15%-30% of scale inhibitor and 45%-75% of water in terms of mass percentage, and the total mass of the above raw materials is 100%.

[0023] The surfactant in Agent C is any one of sodium dodecyl sulfate, alkylphenol polyoxyethylene ether phosphate, and polyoxyethylene polyoxypropylene alkylphenol ether; the scale inhibitor in Agent C is any one of diethylenetriaminepentamethylenephosphonic acid, aminotrimethylenephosphonic acid, and tetrasodium aminotrimethylenephosphonic acid.

[0024] The preparation method of Agent C is:

[0025] Step 1: Weigh the following raw materials by mass percentage:

[0026] Surfactant 10%-25%, scale inhibitor 15%-30%, water 45%-75%, the total mass of the above raw materials is 100%;

[0027] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0028] The beneficial effects of the present invention are as follows: a self-generated acidizing plugging removal method for gas wells with a large amount of gas is proposed, which solves the problem of insufficient gas volume in the prior art and the need to inject gas to achieve sufficient backflow. The present invention adopts a self-generated acidizing plugging removal agent, which can effectively remove deep blockages in gas wells and has the advantages of no need to inject gas, easy backflow and simple process. DETAILED DESCRIPTION

[0029] The present invention is described in detail below in conjunction with specific implementation modes.

[0030] The present invention provides a method for removing plugging by autogenous gas acidification for a gas well, which is specifically implemented according to the following steps:

[0031] Step 1: Use the oil pipe to transfer 10m 3 -15m 3 Agent A is injected into the formation near the wellbore area, and Agent A dissolves inorganic scale and organic plugging in the formation near the wellbore area;

[0032] Step 2: After adding agent A, inject 2.5m 3 -7.5m 3 The self-generating agent in the B agent is oxidized by the oxidant at the formation temperature to generate nitrogen, and forms foam under the action of the foaming agent and the foam stabilizer;

[0033] Step 3: After shutting in the well for 12-24 hours, the well is blown out, and the foam carries the residual acid and the blockage in Agent A back out of the wellbore;

[0034] Step 4: After the discharge is completed, 0.5m 3 -1m 3The C agent is injected into the formation, and the surfactant in the C agent is adsorbed on the rock surface to form a certain protective film, which increases the contact angle of water on the rock surface, thereby reducing capillary resistance and increasing gas phase permeability. At the same time, the scale inhibitor is dispersed into the reservoir formation water to inhibit the precipitation of scale-forming ions.

[0035] Agent A is composed of the following substances by mass fraction:

[0036] Agent A is composed of 8%-15% hydrochloric acid, 6%-12% organic acid, 1%-1.5% corrosion inhibitor, and 71.5%-85% water;

[0037] The concentration of hydrochloric acid is 36%-38%, the organic acid is one of formic acid, acetic acid and citric acid; the corrosion inhibitor is one of Mannich base corrosion inhibitor or benzyl chloroquinoline corrosion inhibitor;

[0038] The preparation method of agent A is as follows:

[0039] Step 1: Weigh the following raw materials by mass percentage:

[0040] Hydrochloric acid 8%-15%, organic acid 6%-12%, corrosion inhibitor 1%-1.5%, water 71.5%-85%, the total mass of the above raw materials is 100%;

[0041] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0042] The B agent is composed of the following substances by mass fraction:

[0043] Agent B is composed of 30%-40% of self-gasifying agent, 10%-20% of oxidant, 0.5-2% of foaming agent, 0.6-1% of foam stabilizer, and 37%-58.9% of water;

[0044] The self-generating agent is 5-aminotetrazolyl; the oxidant is ammonium nitrate; the foaming agent is one of alkyl sulfonate betaine, lauramide propylamine oxide, and sodium ether sulfate; and the foam stabilizer is polyacrylamide;

[0045] The preparation method of Agent B is as follows:

[0046] Step 1: Weigh the following raw materials by mass percentage:

[0047] Self-gasifying agent 30%-40%, oxidant 10%-20%, foaming agent 0.5-2%, foam stabilizer 0.6-1%, water 37%-58.9%, the total mass of the above raw materials is 100%;

[0048] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0049] The C agent is composed of the following substances by mass fraction:

[0050] Agent C is composed of 10%-25% surfactant, 15%-30% antiscalant, and 45%-75% water;

[0051] The surfactant is one of sodium dodecyl sulfate, alkylphenol polyoxyethylene ether phosphate, and polyoxyethylene polyoxypropylene alkylphenol ether; the scale inhibitor is one of diethylenetriamine pentamethylene phosphoric acid, aminotrimethylene phosphonic acid, and tetrasodium aminotrimethylenephosphonic acid.

[0052] The preparation method of Agent C is:

[0053] Step 1: Weigh the following raw materials by mass percentage:

[0054] Surfactant 10%-25%, scale inhibitor 15%-30%, water 45%-75%, the total mass of the above raw materials is 100%;

[0055] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0056] The self-generating acidizing and plugging removal method for gas wells is different from the prior art in that agent A dissolves inorganic scale and organic plugging materials in the near-well area, agent B generates a large amount of gas during the plugging removal process of the gas well, and discharges the residual acid and plugging materials in agent A back into the wellbore, and agent C forms a protective film in the reservoir to inhibit the precipitation of scale ions, thereby avoiding the difficulty in returning residual acid and causing secondary damage to the reservoir, thereby solving the problem of insufficient gas generation in the prior art and the need to inject gas to achieve sufficient return.

[0057] Example 1

[0058] The autogenous gas acidizing plugging removal method for gas wells is specifically implemented according to the following steps:

[0059] Step 1: Use the oil pipe to transfer 10m 3 Agent A is injected into the formation near the wellbore area;

[0060] Step 2: After the injection of agent A is completed, inject 2.5m 3 of B agent;

[0061] Step 3: After the injection of agent B is completed, the well is shut down for 12-24 hours and then the well is blown;

[0062] Step 4: After the residual liquid and blockage are released, 0.5m 3 Agent C is injected into the formation.

[0063] Agent A is composed of 8% hydrochloric acid, 12% organic acid, 1% corrosion inhibitor, and 77% water, and the total mass of the above raw materials is 100%.

[0064] The concentration of hydrochloric acid in Agent A is 36%; the organic acid in Agent A is acetic acid; and the corrosion inhibitor in Agent A is a Mannich base corrosion inhibitor.

[0065] The preparation method of agent A is as follows:

[0066] Step 1: Weigh the following raw materials by mass percentage:

[0067] 8% hydrochloric acid, 12% organic acid, 1% corrosion inhibitor, 77% water, the total mass of the above raw materials is 100%;

[0068] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0069] Agent B is composed of 36% of self-gasifying agent, 18% of oxidant, 1.5% of foaming agent, 0.6% of foam stabilizer and 43.9% of water, and the total mass of the above raw materials is 100%.

[0070] The self-gassing agent in Agent B is 5-aminotetrazolyl; the oxidizing agent in Agent B is ammonium nitrate; the foaming agent in Agent B is alkyl sulfonate betaine; and the foam stabilizing agent in Agent B is polyacrylamide.

[0071] The preparation method of Agent B is as follows:

[0072] Step 1: Weigh the following raw materials by mass percentage:

[0073] 36% of self-gasifying agent, 18% of oxidant, 1.5% of foaming agent, 0.6% of foam stabilizer, 43.9% of water, the total mass of the above raw materials is 100%;

[0074] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0075] Agent C is composed of 15% surfactant, 20% scale inhibitor and 65% water, and the total mass of the above raw materials is 100%.

[0076] The surfactant in Agent C is sodium dodecyl sulfate; the scale inhibitor in Agent C is diethylenetriaminepentamethylenephosphonic acid.

[0077] The preparation method of Agent C is:

[0078] Step 1: Weigh the following raw materials by mass percentage:

[0079] 15% surfactant, 20% scale inhibitor, 65% water, the total mass of the above raw materials is 100%;

[0080] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0081] Example 2

[0082] The autogenous gas acidizing plugging removal method for gas wells is specifically implemented according to the following steps:

[0083] Step 1: Use the oil pipe to transfer 15m 3 Agent A is injected into the formation near the wellbore area;

[0084] Step 2: After the injection of agent A is completed, inject 7.5m 3 of B agent;

[0085] Step 3: After the injection of agent B is completed, the well is shut down for 12-24 hours and then blown out;

[0086] Step 4: After the residual liquid and blockage are released, 1m 3 Agent C is injected into the formation.

[0087] Agent A is composed of 15% hydrochloric acid, 6% organic acid, 1.5% corrosion inhibitor, and 77.5% water, and the total mass of the above raw materials is 100%.

[0088] The concentration of hydrochloric acid in Agent A is 37%; the organic acid in Agent A is citric acid; and the corrosion inhibitor in Agent A is benzylquinoline chloride corrosion inhibitor.

[0089] The preparation method of agent A is as follows:

[0090] Step 1: Weigh the following raw materials by mass percentage:

[0091] 15% hydrochloric acid, 6% organic acid, 1.5% corrosion inhibitor, 77.5% water, the total mass of the above raw materials is 100%;

[0092] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0093] Agent B is composed of 32% of self-gasifying agent, 12% of oxidant, 1% of foaming agent, 0.8% of foam stabilizer and 54.2% of water, and the total mass of the above raw materials is 100%.

[0094] The self-gassing agent in Agent B is 5-aminotetrazolyl; the oxidizing agent in Agent B is ammonium nitrate; the foaming agent in Agent B is lauramide propylamine oxide; and the foam stabilizing agent in Agent B is polyacrylamide.

[0095] The preparation method of Agent B is as follows:

[0096] Step 1: Weigh the following raw materials by mass percentage:

[0097] 32% of self-gasifying agent, 12% of oxidant, 1% of foaming agent, 0.8% of foam stabilizer, 54.2% of water, the total mass of the above raw materials is 100%;

[0098] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0099] Agent C is composed of 25% surfactant, 30% scale inhibitor and 45% water, and the total mass of the above raw materials is 100%.

[0100] The surfactant in Agent C is alkylphenol polyoxyethylene ether phosphate; the scale inhibitor in Agent C is aminotrimethylene phosphonic acid.

[0101] The preparation method of Agent C is:

[0102] Step 1: Weigh the following raw materials by mass percentage:

[0103] 25% surfactant, 30% scale inhibitor, 45% water, the total mass of the above raw materials is 100%;

[0104] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0105] Example 3

[0106] The autogenous gas acidizing plugging removal method for gas wells is specifically implemented according to the following steps:

[0107] Step 1: Use the oil pipe to connect 12.5m 3 Agent A is injected into the formation near the wellbore area;

[0108] Step 2: After the injection of agent A is completed, inject 5m 3 of B agent;

[0109] Step 3: After the injection of agent B is completed, the well is shut down for 12-24 hours and then the well is blown;

[0110] Step 4: After the residual liquid and blockage are released, 0.75m 3 Agent C is injected into the formation.

[0111] Agent A is composed of 12% hydrochloric acid, 10% organic acid, 1% corrosion inhibitor, and 77% water, and the total mass of the above raw materials is 100%.

[0112] The concentration of hydrochloric acid in Agent A is 38%; the organic acid in Agent A is formic acid; and the corrosion inhibitor in Agent A is benzylquinoline chloride corrosion inhibitor.

[0113] The preparation method of agent A is as follows:

[0114] Step 1: Weigh the following raw materials by mass percentage:

[0115] 12% hydrochloric acid, 10% organic acid, 1% corrosion inhibitor, 77% water, the total mass of the above raw materials is 100%;

[0116] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0117] Agent B is composed of 40% of self-gasifying agent, 20% of oxidant, 2% of foaming agent, 1% of foam stabilizer and 43% of water, and the total mass of the above raw materials is 100%.

[0118] The self-gassing agent in Agent B is 5-aminotetrazole; the oxidizing agent in Agent B is ammonium nitrate; the foaming agent in Agent B is sodium ether sulfate; and the foam stabilizing agent in Agent B is polyacrylamide.

[0119] The preparation method of Agent B is as follows:

[0120] Step 1: Weigh the following raw materials by mass percentage:

[0121] Agent B consists of 40% of self-gasifying agent, 20% of oxidant, 2% of foaming agent, 1% of foam stabilizer, and 43% of water, and the total mass of the above raw materials is 100%;

[0122] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0123] Agent C is composed of 20% surfactant, 15% scale inhibitor and 65% water, and the total mass of the above raw materials is 100%.

[0124] The surfactant in Agent C is polyoxyethylene polyoxypropylene alkylphenol ether; the scale inhibitor in Agent C is tetrasodium aminotri(methylenephosphonic acid).

[0125] The preparation method of Agent C is:

[0126] Step 1: Weigh the following raw materials by mass percentage:

[0127] 20% surfactant, 15% scale inhibitor, 65% water, the total mass of the above raw materials is 100%;

[0128] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0129] Example 4

[0130] The autogenous gas acidizing plugging removal method for gas wells is specifically implemented according to the following steps:

[0131] Step 1: Use the oil pipe to transfer 15m 3Agent A is injected into the formation near the wellbore area;

[0132] Step 2: After the injection of agent A is completed, inject 5m 3 of B agent;

[0133] Step 3: After the injection of agent B is completed, the well is shut down for reaction for 24 hours and then the well is blown;

[0134] Step 4: After the residual liquid and blockage are released, 1m 3 Agent C is injected into the formation.

[0135] Agent A is composed of 15% hydrochloric acid, 6% organic acid, 1.5% corrosion inhibitor, and 77.5% water, and the total mass of the above raw materials is 100%.

[0136] The concentration of hydrochloric acid in Agent A is 37%; the organic acid in Agent A is citric acid; and the corrosion inhibitor in Agent A is benzylquinoline chloride corrosion inhibitor.

[0137] The preparation method of agent A is as follows:

[0138] Step 1: Weigh the following raw materials by mass percentage:

[0139] 15% hydrochloric acid, 6% organic acid, 1.5% corrosion inhibitor, 77.5% water, the total mass of the above raw materials is 100%;

[0140] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

[0141] Agent B is composed of 32% of self-gasifying agent, 12% of oxidant, 1% of foaming agent, 0.8% of foam stabilizer and 54.2% of water, and the total mass of the above raw materials is 100%.

[0142] The self-gassing agent in Agent B is 5-aminotetrazolyl; the oxidizing agent in Agent B is ammonium nitrate; the foaming agent in Agent B is lauramide propylamine oxide; and the foam stabilizing agent in Agent B is polyacrylamide.

[0143] The preparation method of Agent B is as follows:

[0144] Step 1: Weigh the following raw materials by mass percentage:

[0145] 32% of self-gasifying agent, 12% of oxidant, 1% of foaming agent, 0.8% of foam stabilizer, 54.2% of water, the total mass of the above raw materials is 100%;

[0146] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

[0147] Agent C is composed of 20% surfactant, 15% scale inhibitor and 65% water, and the total mass of the above raw materials is 100%.

[0148] The surfactant in Agent C is polyoxyethylene polyoxypropylene alkylphenol ether; the scale inhibitor in Agent C is tetrasodium aminotri(methylenephosphonic acid).

[0149] The preparation method of Agent C is:

[0150] Step 1: Weigh the following raw materials by mass percentage:

[0151] 20% surfactant, 15% scale inhibitor, 65% water, the total mass of the above raw materials is 100%;

[0152] Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.

[0153] The autogenous acidizing agent for gas wells is applied to gas wells with reservoir blockage. Agent A dissolves inorganic scale and organic blockages in the near-wellbore area in the formation; the autogenous gasifier in agent B is oxidized by the oxidant at the formation temperature to generate nitrogen, and forms foam under the action of the foaming agent and the foam stabilizer, carrying the residual acid in agent A and the blockage back out of the wellbore; the surfactant in agent C is adsorbed on the rock surface to form a certain protective film, increasing the contact angle of water on the rock surface, thereby reducing capillary resistance and increasing gas phase permeability. At the same time, the scale inhibitor is dispersed into the reservoir formation water to inhibit the precipitation of scale ions.

Claims

1. A method for removing plugging by autaptic gas acidification for a gas well, characterized by: Follow the steps below to implement it: Step 1: Use the oil pipe to transfer 10m 3 -15m 3 Agent A is injected into the formation near the wellbore area; Step 2: After the injection of agent A is completed, inject 2.5m 3 -7.5m 3 of B agent; Step 3: After the injection of agent B is completed, the well is shut down for 12-24 hours and then blown out; Step 4: After the residual liquid and blockage are released, 0.5m 3 -1m 3 Agent C is injected into the formation.

2. The method for removing plugging by autaptic acid for gas wells according to claim 1, characterized in that: The agent A is composed of 8%-15% hydrochloric acid, 6%-12% organic acid, 1%-1.5% corrosion inhibitor and 71.5%-85% water in terms of mass percentage, and the total mass of the above raw materials is 100%.

3. The method for removing plugging by autaptic acid for gas wells according to claim 2, characterized in that: The concentration of hydrochloric acid in the agent A is 36%-38%; the organic acid in the agent A is any one of formic acid, acetic acid and citric acid; the corrosion inhibitor in the agent A is one of a Mannich base corrosion inhibitor and a benzyl chloroquinoline corrosion inhibitor.

4. The method for removing blockage by autaptic acidification for gas wells according to claim 3, characterized in that: The preparation method of the A agent is: Step 1: Weigh the following raw materials by mass percentage: Hydrochloric acid 8%-15%, organic acid 6%-12%, corrosion inhibitor 1%-1.5%, water 71.5%-85%, the total mass of the above raw materials is 100%; Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent A.

5. The method for removing plugging by autogenous acidification for gas wells according to claim 1, characterized in that: The agent B is composed of 30%-40% of self-gasifying agent, 10%-20% of oxidant, 0.5-2% of foaming agent, 0.6-1% of foam stabilizer and 37%-58.9% of water in terms of mass percentage, and the total mass of the above raw materials is 100%.

6. The method for removing plugging by autogenous acidification for gas wells according to claim 5, characterized in that: The self-gassing agent in the agent B is 5-aminotetrazole; the oxidant in the agent B is ammonium nitrate; the foaming agent in the agent B is any one of alkyl sulfonate betaine, lauramide propylamine oxide, and sodium ether sulfate; and the foam stabilizing agent in the agent B is polyacrylamide.

7. The method for removing plugging by autaptic acid for gas wells according to claim 6, characterized in that: The preparation method of the B agent is: Step 1: Weigh the following raw materials by mass percentage: Self-gasifying agent 30%-40%, oxidant 10%-20%, foaming agent 0.5-2%, foam stabilizer 0.6-1%, water 37%-58.9%, the total mass of the above raw materials is 100%; Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent B.

8. The method for removing plugging by autogenous acidification for gas wells according to claim 1, characterized in that: The agent C is composed of 10%-25% of a surfactant, 15%-30% of a scale inhibitor, and 45%-75% of water in terms of mass percentage, and the total mass of the above raw materials is 100%.

9. The method for removing plugging by autaptic acid for gas wells according to claim 8, characterized in that: The surfactant in the agent C is any one of sodium dodecyl sulfate, alkylphenol polyoxyethylene ether phosphate, and polyoxyethylene polyoxypropylene alkylphenol ether; the scale inhibitor in the agent C is any one of diethylenetriamine pentamethylene phosphoric acid, aminotrimethylene phosphonic acid, and tetrasodium aminotrimethylenephosphonic acid.

10. The method for removing plugging by autogenous gas acidification for gas wells according to claim 9, characterized in that: The preparation method of the C agent is: Step 1: Weigh the following raw materials by mass percentage: Surfactant 10%-25%, scale inhibitor 15%-30%, water 45%-75%, the total mass of the above raw materials is 100%; Step 2: Add the weighed raw materials into a reactor and stir evenly to obtain Agent C.