A method for reducing oxygen by air foam flooding microorganisms

Abstract

The invention relates to an air-foam displacement microbial oxygen reduction method. The air-foam displacement microbial oxygen reduction method includes dissolving foam stabilizers, foaming agents and clear water in a liquid dispensing pond to prepare oil displacement foam liquid; adding aerobic microbial bacteria into the oil displacement foam liquid; adding nutritional agents such as phosphate, ammonium salt and carbohydrate into the foam liquid, stirring the nutritional agents to dissolve the nutritional agents and uniformly mixing the nutritional agents and the foam liquid with one another to obtain mixed air-foam liquid; injecting the mixed air-foam liquid into strata at injection speeds designed according to oil displacement schemes. The aerobic microbial bacteria are fermented and cultivated in indoor environments. The air-foam displacement microbial oxygen reduction method has the advantages that certain oil displacement effects can be realized by biogas, biological surfactants and the like along oil displacement procedures of the air-foam liquid, the biogas, the biological surfactants and the like are generated by microorganisms in growth procedures, oxygen in air-foam is gradually reduced without affecting low-temperature oxidation effects of the air-foam on crude oil in near borehole zones of injection wells, the microorganisms continue growing in the strata, accordingly, the content of oxygen in the air-foam can be reduced, the content of oxygen in output gas of the oil producing wells is lower than required safe lower limit of 11%, and safe production can be guaranteed.

Description

technical field [0001] The invention belongs to the technical field of oil recovery, and relates to an oxygen reduction method used in the air foam flooding process, in particular to an air foam flooding microbial oxygen reduction method. Background technique [0002] In the petroleum industry, the method of exploiting oil by utilizing the energy of the oil layer is usually called primary oil recovery; the oil recovery method of increasing the pressure of the oil layer through water injection is called secondary oil recovery; the method of injecting other fluids or heat and using them to change the viscosity of crude oil or change the crude oil The method of displacing the discontinuous and difficult-to-recover crude oil in the oil layer by interfacial tension with other media in the formation is called tertiary oil recovery. Judging from the methods of enhancing oil recovery at home and abroad, the tertiary oil recovery technology is basically based on chemical flooding, ga...

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Problems solved by technology

[0005] In the process of realizing the above-mentioned enhanced oil recovery, most of the existing oxygen reduction technologies use ground oxygen reduction devices, which have certain defects: first, the investment is relatively large, and second, there are very strict requirements for equipment operation, and energy consumption Higher, and its oxygen reduction effect is limited to the ground system, after the air foam enters the system and formation, it no longer has oxygen reduction and other effects