Biological modifying and flooding agent capable of resisting against high temperature and high salt for oil field exploitation

Abstract

The invention discloses a biological modifying and flooding agent capable of resisting against high temperature and high salt for oil field exploitation. The biological modifying and flooding agent is prepared from the following raw materials by weight percent: 0.01-5% of microbial polysaccharide, 0.05-10% of surfactant, 0.01-10% of binding force accelerator and the balance of water. The biological modifying and flooding agent disclosed by the invention is capable of forming lower interfacial tension with the crude oil, has relative stable viscosity and can keep higher involving rate under alkali-free, high-temperature and high-salt conditions; the application scope is wide; the operability is simple and convenient; the use cost of the user is lowered; and the environmental pressure is reduced.

Description

technical field [0001] The invention relates to a medium-high-temperature-resistant, high-salt biological control and displacement agent for oilfield exploitation, which belongs to the technical field of oil exploitation. Background technique [0002] After decades of exploitation, my country's oil fields have entered a stage of high water cut, and the production is facing a decline. The development of tertiary oil recovery is an important way to improve oil recovery. Tertiary oil recovery is compared with primary and secondary oil recovery. In layman's terms, in the initial stage of oil exploitation, only the natural energy of the formation is used to extract oil, which is called primary oil recovery, and its recovery rate is only about 10%. The method of extracting oil by adding energy to the formation, such as water injection, gas injection, etc., is called secondary oil recovery. At present, a large number of oil fields in the world have adopted the secondary oil recov...

AI Technical Summary

Problems solved by technology

However, this kind of surfactant liquid has a series of problems such as unstable performance, poor resistance to salt, especially divalent cations, etc., and is not suitable for oilfield blocks with high temperature and high salt

At present, surfactants have been successfully applied in ordinary oil reservoirs (first and second types of oil reservoirs), but for high-temperature and high-salt oil reservoirs, the surface active agents that are more effective for first and second types of oil reservoirs The active agent cannot reduce the interfacial tension, and shows that the chemical structure is variable, severe chromatographic separation, etc., and cannot be competent

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