A method for microbial oil recovery in medium and high permeability reservoirs

Abstract

The invention discloses a microbial enhanced oil recovering method of a moderate-high permeability reservoir. The method particularly comprises the following steps of carrying out field sampling on a tested oil reservoir; analyzing function microorganisms in the oil reservoir and screening an endogenesis activator; screening exogenous function microorganisms; optimizing field injection process parameters; carrying out field implementation and effect tracking and evaluating. The microbial enhanced oil recovering method has the advantages of being wide in oil reservoir range and high in pertinence and operability. The endogenesis activator or the exogenous function microorganisms are selected according to the specific oil reservoir, field injection process parameters are optimized by utilizing physical simulation experiments, the field test effect is obvious, and the accuracy and practically of the process parameter optimizing result are improved by combination physical simulation and field tests, so that the field implementation effect of displacement of reservoir oil through the microorganisms is improved. Therefore, the microbial enhanced oil recovering method of the medium-high permeability oil reservoir can be widely applied to the field tests for enhancing the oil recovery of the medium-high permeability oil reservoir.

Description

technical field [0001] The invention belongs to the technical field of tertiary oil recovery, and in particular relates to a method for microbial oil recovery of medium and high permeability oil reservoirs. Background technique [0002] With the rapid development of my country's economy, the demand for oil is increasing day by day, and the shortage of oil is becoming more and more serious. At present, the recovery of crude oil in my country is less than 40%, and the remaining recoverable oil reserves are huge, especially in medium and high permeability oil reservoirs. According to statistics, medium and high permeability reservoir resources account for more than 60% of the total resources. After long-term water flooding development, medium and high permeability reservoirs have reached the middle and late stages of the high water cut period, and the production decline is serious, and it is difficult to stabilize production. Therefore, new improvements are urgently needed. Techn...

AI Technical Summary

Problems solved by technology

However, the disadvantages of this method are: (1) Due to the low permeability and porosity of the low-permeability reservoir itself, the use of microorganisms that produce larger particle sizes and are not easy to degrade biopolymers will easily cause the pores to be completely blocked and the reservoir permeability to be significantly reduced. (2) The fermented liquid of two types of functional bacteria is injected into the oil reservoir at a certain volume ratio at the same time. Since it takes a certain time for microbial metabolism to produce biopolymers, the metabolite biopolymers have not had time to In the case of effective plugging and adjustment of the reservoir, the microorganisms producing biosurfactant have already migrated to the deep part of the reservoir or have been produced together with the injected water, and the two types of functional bacteria have not achieved effective synergy, so in a certain (3) Since microbial growth and metabolism are limited by reservoir conditions such as reservoir temperature, pressure, and salinity, the application range of exogenous functional microbial flooding reservoirs adopted by this method is small; (4 ) does not inject different amounts or proportions of functional microorganisms according to the characteristics of the reservoir, so this method is not targeted, general and operable

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