Biological enzyme oil displacement agent

Abstract

The invention belongs to the technical field of chemical products of petrochemical industry, and in particular to a biological enzyme oil displacement agent to improve recovery efficiency of crude oil. The oil displacement agent is prepared by dissolving the following raw materials in water: biological enzyme, polyoxyethylene ether, polyacrylamide, formaldehyde, alkyl glucoside and biquaternary ammonium salt. The oil displacement agent provided by the invention can attach on the surface of metal and rock to form a layer of active molecular film to prevent deposition of wax and catalytic action of acetone wax crystal, change the wax crystal morphology and prevent further growth of wax crystal, so as to effectively prevent the precipitate scaling and effect of water damage, effectively improve the water injection capacity, and reduce sand carrying ability of reduce oil and the friction of fluid and sandstone; therefore, the purposes of stabilizing reservoir structure and improving oil recovery are achieved. The oil displacement agent is non-corrosive and non-toxic, has high oil displacement efficiency on complex water with the conditions of high degree of mineralization and high calcium, low tension and stability at oil-water interface, and increases oil displacement efficiency by more than 15%.

Description

technical field [0001] The invention belongs to the technical field of chemicals used in petrochemical industry, and in particular relates to a bio-enzyme oil displacement agent for enhancing crude oil recovery. Background technique [0002] In the current oilfield development process, primary oil recovery is a process in which crude oil is sprayed out of the ground through oil wells relying on underground pressure. With the decrease of underground pressure, the self-spraying ends, and primary oil recovery can recover about 10-15% of the underground. Secondary oil recovery is to replenish underground energy by continuously injecting water into the ground, so as to achieve the purpose of water flooding. However, with continuous water injection, the water content in the produced fluid continues to rise. At present, the water content in the produced fluid of my country's onshore oilfields is as high as 92-95%. According to international standards, when the water content in the...

AI Technical Summary

Problems solved by technology

However, the existing oil displacement agents usually only pursue ultra-low interfacial tension, and do not pay attention to the geological characteristics of the reservoir and the physical properties of crude oil.

[0003] At present, the oil displacement agents used in oil field enhanced oil recovery technology mainly include polymer oil displacement agents, surfactant oil displacement agents, microbial oil displacement agents, etc., polymer oil displacement agents and microbial oil displacement agents are not suitable for special oil displacement agents due to their large molecular weight. In low permeability oil fields, most commonly used surfactant oil displacement agents have poor salt and temperature resistance, and the field application is limited by the salinity of formation water

The reservoirs in the Ordos Basin are dense in lithology, poor in physical properties and high in salinity of formation water. Most of them are low-porosity, low-permeability, and ultra-low-permeability oil fields.

After water injection is used to maintain energy, the secondary recovery rate can be increased to 25-30%, but there is still a large amount of crude oil left underground that cannot be recovered, and the development effect is poor