CN-117625162-B - Micro lactic acid and application thereof

Abstract

The invention relates to a micro lactic acid and application thereof. Wherein the micro lactic acid is a microemulsion which is formed by the components including oleic acid, a main surface active agent and a cosurfactant and contains acid-in-oil liquid drops.

Inventors

• ZHANG LUFENG
• HE JIAYUAN
• LI FENGXIA
• WANG HAIBO

Assignees

• 中国石油化工股份有限公司
• 中国石油化工股份有限公司石油勘探开发研究院

Dates

Publication Date

20260508

Application Date

20220825

Claims (10)

1. 1. A micro lactic acid which is a microemulsion formed from components including oil, acid, a primary surfactant and a cosurfactant, the microemulsion containing acid-in-oil droplets; the oil is light oil, and aromatic hydrocarbon solvent and/or dearomatization solvent; the mass ratio of the light oil to the aromatic hydrocarbon solvent and/or the dearomatization solvent is (10 to 37): (24 to 37); The main surface active agent is a mixture of OP-10 and NP-4 or a mixture of span85 and span 80; In the mixture of OP-10 and NP-4, the mass ratio of the OP-10 to the NP-4 is 1:1 to 2:1; In a mixture of span85 and span80, the mass ratio of span80 to span85 is 4:7 to 1:1; The mass ratio of the main surface active agent to the cosurfactant is 1:1 to 11:8.
2. 2. The polylactic acid according to claim 1, wherein the droplets have a particle size of 15 to 35 nm.
3. 3. The polylactic acid according to claim 1, wherein the light oil is at least one of kerosene, cyclohexane, toluene, and limonene; the aromatic hydrocarbon solvent is Solvesso 150; The dearomatization solvent is D40.
4. 4. The polylactic acid according to claim 1, wherein the acid is hydrochloric acid.
5. 5. The polylactic acid according to claim 1, wherein the cosurfactant is an alcohol.
6. 6. The polylactic acid according to claim 1, wherein the cosurfactant is at least one of propanol to octanol.
7. 7. The polylactic acid of claim 1, wherein the cosurfactant is at least one of isopropanol, octanol, n-hexanol, n-pentanol, and n-butanol.
8. 8. The polylactic acid according to claim 1, wherein the oil content is 34% to 67%, the acid content is 30% or less, and the total content of the main surface active agent and the cosurfactant is 18% to 36%, based on 100% of the total amount of the polylactic acid.
9. 9. Use of the polylactic acid according to any one of claims 1 to 8 for unblocking organic and/or inorganic precipitated scale.
10. 10. Use of the polylactic acid according to any one of claims 1 to 8 for unblocking a carbonate well.

Description

Micro lactic acid and application thereof Technical Field The invention relates to the technical field of oil and gas field development and acidification. Background In the processes of drilling and completion, water injection pressurization, reservoir transformation and the like of a carbonate oil-gas field, a near-wellbore zone is often polluted, so that the permeability of the reservoir is reduced, and the injection and production amount cannot meet the design requirements. Because of the particularity of carbonate minerals, acid liquor is used to erode the minerals to form acid etched wormholes which penetrate the near-well damage zone, and oil gas can flow into the shaft through the acid etched wormholes. However, the conventional hydrochloric acid acidification can only temporarily erode the organic deposited scale, and has the problems of high reaction speed, short acid-etched earthworm holes, uneven acid liquor distribution and the like. Disclosure of Invention One aspect of the present invention provides a microemulsion comprising acid-in-oil droplets formed from components including an oil, an acid, a primary surfactant, and a cosurfactant. In a specific embodiment, the droplets have a particle size of 15 to 35nm. In a specific embodiment, the droplets have a particle size of 19 to 35nm. In a specific embodiment, the oil is a light oil, and the aromatic hydrocarbon solvent and/or the dearomatization solvent. In a specific embodiment, the light oil is at least one of kerosene, cyclohexane, toluene, and limonene. In a specific embodiment, the aromatic hydrocarbon solvent is Solvesso 150. In one embodiment, the dearomatization solvent is D40. In one embodiment, the mass ratio of the light oil to the aromatic hydrocarbon solvent and/or dearomatization solvent is (10 to 37): (24 to 37). It is specifically noted that when the aromatic hydrocarbon solvent and/or the dearomatization solvent are contained at the same time, the mass ratio is the ratio of the mass of the light oil to the total mass of the aromatic hydrocarbon solvent and the dearomatization solvent. In a specific embodiment, the mass ratio of the light oil to the aromatic hydrocarbon solvent and/or dearomatization solvent is from 5:16 to 37:30. In one embodiment, the acid is hydrochloric acid. In one embodiment, the primary surfactant is a nonionic surfactant. In one embodiment, the primary surfactant is at least two of a sorbitol fatty acid ester, a sorbitan trioleate, a nonylphenol polyoxyethylene ether (NP) and an alkylphenol polyoxyethylene ether (OP). In a specific embodiment, when the number of primary surfactants is two, the mass ratio of the two surfactants is 3:5 to 1:1. In a specific embodiment, the primary surfactant is at least two of OP-10, NP-4, span85, and span 80. In a specific embodiment, the primary surfactant is a mixture of OP-10 and NP-4 or a mixture of span85 and span 80. In a specific embodiment, the mass ratio of OP-10 to NP-4 in the mixture of OP-10 and NP-4 is from 1:1 to 2:1. In a specific embodiment, the mass ratio of span85 to span80 in the span85 to span80 mixture is from 4:7 to 1:1. In one embodiment, the cosurfactant is an alcohol. In a specific embodiment, the cosurfactant is at least one of propanol to octanol. In one embodiment, the cosurfactant is at least one of isopropanol, octanol, n-hexanol, n-pentanol and n-butanol. In one embodiment, when the cosurfactants are two, the mass ratio of the two cosurfactants is 4:7 to 2:1. In a specific embodiment, the mass ratio of the primary surfactant to the cosurfactant is 1:1 to 11:8. In one embodiment, the oil is present in an amount of 34% to 67%, the acid is present in an amount of 30% or less, and the total amount of the primary surfactant and the cosurfactant is 18% to 36%, based on 100% of the total amount of the polylactic acid. In a specific embodiment, the acid is present in an amount of 15% to 30%. The second invention provides the application of the polylactic acid in the plugging removal of organic precipitated scale and/or inorganic precipitated scale, in particular to the application in the plugging removal of carbonate wells. The invention has the beneficial effects that: The polylactic acid provided by the invention can remove organic deposited scale, inorganic deposited scale and mixed scale of the stratum, and the dissolution rate of the polylactic acid on various scales is 100%. Meanwhile, the high-temperature-resistant and high-speed-resistant composite fiber-reinforced composite fiber has the characteristics of high temperature resistance, high speed retardation (the speed retardation is more than 99 percent) and capability of suspending temporary plugging fibers by viscosity, so that deep plugging removal of a reservoir can be realized. In addition, the micro lactic acid provided by the invention simplifies the construction flow, saves the construction time, realizes cost reduction and synergy, has great significance for oil-gas field developm