Nano oil displacement agent for thermodynamic oil extraction process

Abstract

A nano-type oil displacement agent for thermal recovery process consists of the following raw materials, by weight percentage, (1) biphenyl, polycyclic aromatic hydrocarbons or polycyclic aromatic hydrocarbon derivatives free of chlorine and sulfur elements; (2) liquid petroleum products containing arene larger than 5%, petroleum resin in liquid state at normal temperature or natural hydrocarbon aggregates in particle state at normal temperature; (3) surfactant; (4) fusel oil; (5) alcohol ethers with a closed cup flash point larger than 20 DEG C; (6) one of oil-soluble or water-soluble polymers respectively having a nonpolar section eutectic with paraffin molecule and a polar section for twisting crystal form of wax crystal on a main chain and / or a branch chain, or mixture of two or more oil-soluble or water-soluble polymers mixed together at arbitrary ratios; and (7) peroxides. The product of the invention can efficiently assist the prior various thermal recovery processes in exploring high pour-point oil and heavy oil reservoirs, with the advantages of greatly reduced exploitation cost, prolonged production cycle of the oil well, increased output of the oil well, and increased ultimate recovery of the oil reservoir.

Description

technical field [0001] The invention relates to an auxiliary agent for oil recovery, in particular to a nano-type oil displacement agent for thermal recovery of heavy oil and high pour point oil. Background technique [0002] At present, the thermal oil recovery process is mainly used in the recovery of heavy oil and high pour point oil, and oil recovery additives are generally used as auxiliary additives. Existing oil recovery additives of this type are generally divided into two types: water-based oil recovery additives and oil-based oil recovery additives, and water-based oil recovery additives are further divided into water-soluble oil recovery additives, oil-in-water emulsion oil recovery additives, and oil-based oil recovery additives. The base oil recovery additives are further divided into oil-soluble oil recovery additives and organic solvent-based oil recovery additives, all of which have different defects. [0003] Water-soluble oil recovery additives are mainly ...

AI Technical Summary

Problems solved by technology

[0003] Water-soluble oil recovery additives are mainly composed of surfactants and water, and they have the following defects when used in thermal oil recovery processes: First, they mainly use the principle of emulsification to reduce viscosity, and cannot directly dissolve asphaltene, colloid, and wax crystals. The coagulation effect is limited; the second is that it is difficult to automatically diffuse into the crude oil after being injected into the oil layer from the oil well; the third is that there is no effect or the opposite effect when the crude oil in the oil layer has a low water content

[0004] Oil-in-water emulsion oil recovery additives are mainly composed of surfactants, water, and organic solvents. They have the following defects when used in thermal oil recovery processes: First, they mainly use the principle of emulsification to reduce viscosity, directly dissolve and break asphaltenes, gums, etc. The oil quality and wax crystal structure ability are limited, and the effect of pour point reduction is limited; the second is that it is difficult to automatically diffuse into the crude oil after being injected into the oil layer from the oil well; the third is that the effect is extremely poor or the effect is opposite when the water content of the oil layer is low; The oil emulsion immediately delaminates under the heating of high-temperature fluid, and the synergistic injection construction process cannot be realized

[0005] Oil-soluble oil recovery additives are mainly composed of oil-soluble pour point depressants, organic solvents, etc., and have the following defects: First, although oil-soluble oil recovery additives can inhibit or disperse wax crystals, colloids, and asphaltenes, they cannot achieve true The particle size of the sol has a limited ability to reduce viscosity and pour point; second, the flash point of oil-soluble oil recovery additives is low, and there are construction safety problems when injected with high-temperature fluid; third, oil-soluble oil recovery additives are highly targeted, and the workload of screening tests is large; Fourth, oil-soluble oil recovery additives cannot solve the problem of emulsified particle clogging in the oil reservoir; fifth, there is a problem of timeliness, that is, its ability to reduce viscosity and pour point decreases with time; sixth, it is expensive and difficult to use in thermal oil recovery processes high dose application

[0006] Organic solvent-based oil recovery additives are mainly composed of hydrocarbon organic solvents, and have the following defects: First, organic solvent-based oil recovery additives have limited solubility in wax crystals and colloids, and extremely poor solubility in layered asphaltenes. Second, organic solvent-based oil recovery additives have a low flash point, and there are construction safety problems associated with high-temperature fluid injection; third, it is difficult for organic solvent-based oil recovery additives to inhibit the geometric dimensions of asphaltene and wax crystal structures; fourth, Organic solvent-based oil recovery additives cannot solve the problem of clogging of emulsified particles in the oil reservoir; fifth, there is a problem of timeliness, that is, its ability to reduce viscosity and pour point decreases with time; sixth, the amount added is too large, resulting in a significant increase in production costs , it is difficult to be practical in the thermal oil recovery process

[0007] In short, the existing oil recovery additives have poor practicability in the thermal oil recovery process and are difficult to apply on a large scale