CN-122012060-A - Alcohol-based chelating acid liquid system and preparation method, use method and application thereof

Abstract

The invention belongs to the technical field of oil and gas field development and exploitation, and particularly relates to an alcohol-based chelating acid liquid system, and a preparation method, a use method and application thereof. The alcohol-based chelating acid solution system provided by the invention comprises, by weight, 20% -80% of alcohol, 0.1% -20% of acid solution, 5% -60% of chelating agent, 0.1% -10% of corrosion inhibitor, 0.1% -10% of cleanup additive and 14.7% -74.7% of water. The alcohol-based chelating acid solution system can effectively chelate various ions generated by acid etching reaction, prevent precipitation and generation of natural gas hydrate, ensure that the holes dredged by acid etching are not blocked by pollution, and prevent production pipelines from being blocked by ice. After acidification, the pH of the flowback fluid is kept at 6-8, residual liquid does not need to be neutralized, which indicates that the flowback fluid of the system can directly enter a tank or enter a production flow, special treatment is not needed, and the flowback fluid has great significance for oil and gas field development and exploitation.

Inventors

• RONG XINMING
• WANG MING
• CHEN KAI
• NI DANWEI
• TONG ZHINENG
• QI HAOYANG
• WANG SHUN
• CUI BO
• FENG PUYONG
• ZHANG BO
• FU DIANKUI
• ZHANG HONGJING
• LI XIANG
• WU GUANG

Assignees

• 中海油田服务股份有限公司

Dates

Publication Date

20260512

Application Date

20260126

Claims (11)

1. 1. An alcohol-based chelating acid solution system is characterized by comprising, by weight, 20% -80% of alcohol, 0.1% -20% of acid solution, 5% -60% of chelating agent, 0.1% -10% of corrosion inhibitor, 0.1% -10% of cleanup additive and 14.7% -74.7% of water.
2. 2. The alcohol-based chelating acid system according to claim 1, wherein the alcohol-based chelating acid system comprises, by weight, 25% -40% of alcohol, 1% -10% of acid, 40% -50% of chelating agent, 0.1% -1% of corrosion inhibitor, 0.1% -1% of cleanup additive and 18.8% -33.8% of water.
3. 3. The alcohol-based chelating acid system of claim 1, wherein the alcohol comprises one or more of isopropanol, n-butanol, n-pentanol, n-hexanol, ethylene glycol, propylene glycol.
4. 4. The alcohol-based chelating acid system of claim 1, wherein the acid comprises one or more of industrial hydrochloric acid, formic acid, acetic acid, lactic acid, sulfamic acid.
5. 5. The alcohol-based chelating acid system of claim 1, wherein the chelating agent comprises one or more of sodium citrate, trisodium nitrilotriacetate, trisodium hydroxyethyl ethylenediamine triacetate, disodium ethylenediamine tetraacetate, tetrasodium aminotrimethylene phosphate, tetrasodium hydroxyethylidene diphosphate, pentasodium diethylenetriamine pentamethylene acid, pentasodium diethylenetriamine pentaacetate, and tetrasodium glutamate diacetate.
6. 6. The alcohol-based chelating acid system of claim 1, wherein the corrosion inhibitor comprises one or more of chromates, nitrites, silicates, molybdates, tungstates, polyphosphates, zinc salts, thiolamines, imidazolines, urotropins, phosphonic acids, phosphates, phosphinocarboxylic acids, boratabenzthiazoles, benzotriazoles, sulfonated lignans, polyethylenes, polyaspartic acids.
7. 7. The alcohol-based chelating acid system of claim 1, wherein the cleanup additive comprises one or more of an anionic fluorocarbon surfactant, a cationic fluorocarbon surfactant, a nonionic fluorocarbon surfactant, an amphoteric fluorocarbon surfactant, a silicon-containing fluorocarbon surfactant, a hybrid fluorocarbon surfactant, a long chain fluorocarbon surfactant, a non-hydrophilic fluorocarbon surfactant.
8. 8. The method for preparing the alcohol-based chelating acid system according to any one of claims 1 to 7, which is characterized by comprising the steps of mixing alcohol, acid, chelating agent, corrosion inhibitor, cleanup additive and water according to a proportion, and stirring for 0.5 to 2 hours at a temperature of between 0 and 50 ℃ to obtain the alcohol-based chelating acid system.
9. 9. A method of using the alcohol-based chelating acid system as claimed in any one of claims 1 to 7, comprising: (1) Injecting a test fluid into the well; (2) Injecting an alcohol-based chelating acid liquid system into the well; (3) Injecting a displacement fluid into the well; (4) Closing the well and reacting for 4-48 hours; (5) And (5) flowback.
10. 10. The method for using the alcohol-based chelating acid system according to claim 9, wherein the displacement of the test liquid is 0.1-1.5 m 3 /min, the displacement of the alcohol-based chelating acid system is 0.1-1.5 m 3 /min, and the displacement of the displacing liquid is 0.1-1.5 m 3 /min.
11. 11. Use of the alcohol-based chelating acid system according to any one of claims 1-7 in carbonate hydrocarbon reservoir development and exploitation.

Description

Alcohol-based chelating acid liquid system and preparation method, use method and application thereof Technical Field The invention belongs to the technical field of oil and gas field development and exploitation, and particularly relates to an alcohol-based chelating acid liquid system, and a preparation method, a use method and application thereof. Background Deep water hypotonic, extremely low carburization acid salt rock reservoir is poor in reservoir physical property, and seepage channels are filled with muddy and other hetero-base, so that a conventional acid liquor system reacts with carbonate minerals in the process of acidizing acid pressure to generate a large amount of divalent calcium and magnesium ions, secondary precipitation is easy to generate, and the holes after corrosion and dredging are blocked again, so that acid liquor injection is difficult, the seepage channels cannot be effectively expanded, and the acidizing acid pressure yield increasing effect of the reservoir is seriously influenced. In addition, the deep water reservoir is characterized by low temperature and high pressure, and is often accompanied by the generation of natural gas hydrate, and an acid liquor system used for acidizing and acid pressing of the conventional carbonate reservoir can not effectively reduce the freezing point of the natural gas hydrate to inhibit the generation of the natural gas hydrate, so that the generated natural gas hydrate is extremely easy to cause ice blockage to a production pipeline, and great challenges are presented to the conventional acidizing process. The present patent is Chinese patent No. 106590616A discloses an organic chelating acid system for acidifying oil-water well, which can effectively remove stratum obstruction and also can remove wax, asphaltene and inorganic scale. The metal ion chelating ability is strong, the formation damage caused by secondary precipitation formed in the acidification process is effectively prevented, and the system does not have the performance of inhibiting the generation of hydrate. The invention discloses an offshore oil field acidification yield increasing system and a preparation method thereof, wherein the invention adopts chelating acid to provide H +, forms a chelating earth acid system with NH 4 F in the system, continuously provides H + by the chelating acid when encountering clay minerals and mud after entering a well, and simultaneously consumes F in the systemBecause the chelating acid has stronger chelating ability to metals, the chelating ability to heavy metals such as iron can be ensured in the measure process, secondary sedimentation is avoided, and the system does not have the performance of inhibiting the generation of hydrate. The invention patent CN117683524A discloses an oilfield blocking remover and a blocking removing method, and the invention patent shows that an oilfield blocking remover system integrating oil washing, oil displacement and acidification is prepared by mixing benzene, polybasic organic acid, nonionic surfactant, chelating agent, alcohols and the like, has the advantage of strong oil-based core corrosion capacity, and does not have the performances of dissolving clay minerals and inhibiting the generation of hydrates. The method aims at solving the problems that the best method for inhibiting secondary precipitation in the acidulation process of the hypotonic and ultra-hypotonic reservoir is to introduce a chelating agent into an acid liquor system, and the chelating agent is used for capturing metal cations generated by acid rock reaction, so that the generation of secondary precipitation is obviously inhibited. However, the low-temperature and high-pressure environment peculiar to the deepwater environment provides ideal conditions for the generation of natural gas hydrate, and the production pipeline is extremely easy to be blocked by ice in the process of acidizing acid fracturing of the deepwater hypotonic and ultra hypotonic reservoir. Unfortunately, the acid liquor system widely used at present has limited effect in inhibiting the generation of natural gas hydrate, and seriously influences the effect of deep water hypotonic and ultra-hypotonic reservoir acidification acid fracturing. Therefore, there is a need to develop an acid liquor system that can inhibit both secondary precipitation and natural gas hydrate formation, so as to break through in the production increase of deep water hypotonic and ultra-hypotonic complex lithologic oil and gas reservoir acidizing acid pressure. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an alcohol-based chelating acid liquid system, and a preparation method, a use method and application thereof. Specifically, the alcohol-based chelating acid liquid system provided by the invention comprises, by weight, 20% -80% of alcohol, 0.1% -20% of acid liquid, 5% -60% of chelating agent, 0.1% -10% of corrosion inhibitor, 0.1% -10% of c