Efficient pour inhibitor for thermal oil recovery process

Abstract

The invention relates to an efficient pour inhibitor for a thermal oil recovery process. The efficient pour inhibitor comprises the following ingredients including (1) biphenyl, condensed aromatics or polycyclic aromatic hydrocarbon derivatives not containing an oxygen element and a sulfur element, (2) liquid petroleum type products with the aromatic content exceeding 5 percent, petroleum resin being in a liquid state at normal temperature, or hydrocarbon natural aggregates being in a particle state at the normal temperature. (3) surfactants; (4) fusel oil. (5) alcohol anhydride with a closed-cup flash point greater than 20 DEG C. and (6) oil-soluble or water-soluble polymers, each of which is provided with a nonpolar part co-crystallized with paraffin moleculars and a polar part capable of warping a wax crystal form, on a main chain and / or a branched chain. The efficient pour inhibitor has the advantages that all functions of water-based pour inhibitors and oil-based pour inhibitors are integrated, the existing various thermal exploitation processes can be effectively assisted for exploiting high condensation oil and heavy oil reservoirs, the exploitation cost is greatly reduced, the production period of an oil well is prolonged, the oil well yield is increased, the final recovery ratio of the oil reservoirs is improved, and the economic benefit is obvious.

Description

technical field [0001] The invention relates to a pour point depressant for oil exploitation, in particular to a high-efficiency pour point depressant for thermal exploitation of high pour point oil and heavy oil. Background technique [0002] At present, the thermal oil recovery process is mainly used in the recovery of high pour point oil and heavy oil, and the pour point depressant is generally used as an auxiliary method. The existing pour point depressants are generally divided into two types: water-based pour point depressants and oil-based pour point depressants, wherein water-based pour point depressants are further divided into water-soluble pour point depressants, oil-in-water emulsion pour point depressants: oil The base pour point depressants are further divided into oil, soluble pour point depressants, and organic solvent-based pour point depressants. [0003] Water-soluble pour point depressants are mainly composed of surfactants and water, and have the follow...

AI Technical Summary

Problems solved by technology

[0003] Water-soluble pour point depressants are mainly composed of surfactants and water, and have the following defects when used in thermal oil recovery technology: one is that they mainly use the principle of emulsification to depress pour point, and cannot directly dissolve asphaltenes, colloids, and wax crystals, and the pour point depressant ability 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] The oil-in-water emulsion pour point depressant is mainly composed of surfactant, water and organic solvent, etc., and there are following defects in the thermal oil recovery process: one is that it mainly utilizes the principle of emulsification to depress the pour point, and directly dissolves and breaks asphaltenes and colloids. 1. The wax crystal structure ability is limited, and the pour point depressing ability 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 low water content; Immediate delamination under fluid heating, unable to achieve synergistic injection

[0005] Oil-soluble pour point depressants are mainly composed of oil-soluble polymers, organic solvents, etc., and have the following defects: one, although oil-soluble pour point depressants can suppress or disperse wax crystals, colloid sheets, and asphaltene layers, they cannot achieve The particle size of true sol has limited ability to reduce pour point and viscosity; second, the oil-soluble pour point depressant has a low flash point, and there are safety problems when it is injected with high-temperature fluid; third, the oil-soluble pour point depressant is highly targeted, and the screening test workload is heavy; Fourth, it cannot solve the problem of emulsified particle clogging in the oil layer; fifth, there is a timeliness problem, that is, its ability to reduce pour point and viscosity decreases with time; sixth, the cost is high, and it is difficult to apply large doses in thermal oil recovery technology

[0006] Organic solvent-type pour point depressants are mainly composed of hydrocarbons, and have the following defects: First, the organic solvent-type pour point depressants have limited solubility to wax crystals and colloids, and extremely poor solubility to layered asphaltene, so the ability to reduce the level of impermeability is limited. Second, organic solvent-based pour point depressants have a low flash point, and there are safety problems associated with injection with high-temperature fluids; third, organic solvent-based pour point depressants are difficult to suppress the geometric dimensions of asphaltene and wax crystal structures, and cannot solve the problem of emulsification in oil reservoirs. Particle clogging; Fourth, there is a problem of timeliness, that is, its pour point depressing ability will continue to decrease with time; Fifth, the amount of addition is too large, resulting in a significant increase in production costs, making it difficult to be practical in thermal oil recovery processes

[0007] In short, most of the current pour point depressants have certain defects, and the comprehensive effect is not very good in the thermal oil recovery process.