Oil field ultra-high water cut stage fly ash reinforced multiphase composite profile control and flooding method

Abstract

The invention discloses an oil field ultra-high water cut stage fly ash reinforced multiphase composite profile control and flooding method. The method comprises the following step: sequentially adopting fly ash reinforced foam, surfactant foam, microemulsion and water for profile control and flooding, wherein the fly ash reinforced foam is prepared from a gas phase and a liquid phase I; the liquid phase I is an aqueous solution of a foaming agent I, fly ash and a gas-liquid interface regulator; the surfactant foam is prepared from a gas phase and a liquid phase II; the liquid phase II is an aqueous solution of a foaming agent II; the microemulsion consists of a compound surfactant, a cosurfactant, an oil phase, an inorganic salt and water; and the compound surfactant is a compound of SDSand Tween 80. According to the method, through the action among the fly ash reinforced foam slug, the surfactant foam slug and the microemulsion slug, the opening and closing of a large pore channel can be regulated and controlled, the flow resistance is reduced, the regulation and flooding effect of blocking without blocking off is realized, the flow and production of crude oil are facilitated, and the purpose of economic and efficient development of an oil reservoir is achieved.

Description

technical field [0001] The invention relates to an enhanced multi-phase composite control and flooding method of fly ash in an oil field with extra high water content, which belongs to the utilization technology of fly ash solid waste and CO 2 Storage and flooding technology field. Background technique [0002] After decades of development, some major oil regions in eastern China have entered the stage of ultra-high water-cut development. After the oilfield development enters the stage of ultra-high water cut, the interlayer, intralayer and plane heterogeneity of the reservoir is serious, and the injected water in the strongly swept area is easy to point along the water channel, causing the reservoir cement to be continuously washed by water, resulting in some The unconsolidated sandstone with low cementation strength is washed away, and the micro-particles migrate in the rock pores, which leads to the strengthening of the micro-heterogeneity of the reservoir, which not onl...

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Problems solved by technology

[0005] The purpose of the present invention is to provide an enhanced multi-phase composite flood control method with fly ash in the extra-high water-cut period of the oil field, so as to solve the serious heterogeneity of the reservoir and the channeling of the injected fluid along the water in the process of remaining oil production in the extra-high water-cut period. For problems such as channel fingering and low sweep coefficient, the method of the present invention can intelligently block high-permeability zones, improve microscopic heterogeneity of reservoirs, suppress channeling fingering, expand swept volume, improve oil washing efficiency, and control macropores The opening and closing of the channel reduces the flow resistance, realizes the effect of "blocking but not dead", which is beneficial to the flow and recovery of crude oil, so as to achieve the purpose of economical and efficient development of oil reservoirs

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