Oilfield produced water microorganism water quality modification treatment method

Abstract

The invention discloses an oilfield produced water microorganism water quality modification treatment method. The method comprises the following steps that wellhead crude oil, oily sludge in an oil field and oily sludge in an oil gathering station are collected, a microbial strain is bred indoor for culture expanding and production, and a microbial fermentation broth meeting the index requirementsis produced; the produced microbial fermentation broth is put into an oilfield produced water treatment station microorganism water quality modification treatment device, and a predominance strain isbred; the microbial fermentation broth is stopped putting, and normal production is conducted; for produced water microorganism water quality modification treatment, finally by means of filtration, when the water injection requirements are met, produced water can enter a water injection tank and then return to an oil injection layer. Accordingly, an enzyme produced in the microorganism growth andmetabolism process plays a role of a viscosity reducer for crude oil, the flowability of the crude oil is enhanced, and the crude oil recovery can be effectively improved; due to the fact that polysaccharides produced in the microorganism growth and metabolism process play a role of a surfactant, the water injection effect is improved.

Description

technical field [0001] The invention relates to the technical field of oilfield produced water treatment, in particular to a microbial water quality modification treatment method for oilfield produced water. Background technique [0002] The quality of reinjection water after oilfield produced water treatment must meet the three requirements of "corrosion, scale prevention, and clogging prevention". The main control indicators of reinjection water quality are: oil content, suspended solid content, median particle size of suspended solids, and sulfate reducing bacteria. (SBR), iron bacteria (IB), saprophytic bacteria (TGB) content and average corrosion rate. In oilfields, the "oil removal + coagulation sedimentation (or air flotation) + filtration" water treatment process is generally used to remove oil and suspended solids. This process is based on adding various water treatment chemicals. The station, the operation effect is not bad. However, for small-scale water treatme...

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Problems solved by technology

However, since this process only aims to control the content of petroleum and suspended solids, the content of sulfate reducing bacteria (SBR), iron bacteria (IB) and saprophytic bacteria (TGB) is not controlled during the biochemical treatment process, and the effluent needs to be sterilized At the same time, the oxygen content in the effluent of this process is high, which intensifies the corrosiveness of the high-salinity produced water treatment and reinjection system, and it is necessary to add corrosion inhibitors to control the corrosion rate; moreover, this process only reduces The content of oil and suspended solids in the produced water is the target, and no attention is paid to the changes in the viscosity and surface tension of the produced water, nor the amount of microbial metabolite enzymes and polysaccharides (surfactants) in the produced water, and even the added fungicides (oxidizers) property or reductivity) will also destroy the characteristics of these substances that are beneficial to improving the fluidity of crude oil in the reservoir

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