Double tracer method for identifying heterogeneity of water-drive reservoir

Abstract

The invention discloses a double tracer method for identifying the heterogeneity of a water-drive reservoir. According to the method, the heterogeneity of the water-drive reservoir is identified by using a tracer A and a tracer B of which diffusion coefficients have obvious difference. The double tracer method is characterized in that the tracer A and the tracer B of which the diffusion coefficients have obvious difference respectively reflect the total pore size volume of heterogeneous porous media and the pore size volumes of mobile areas in the heterogeneous porous media, thus quantitatively identifying existing conditions of high permeability layers in the heterogeneous porous media and evaluating sweep conditions of injected water. The double tracer method disclosed by the invention can be used for quantitatively identifying the existing conditions of the high permeability layers in the heterogeneous porous media and evaluating the sweep conditions of the injected water, and can be used for actual production of a mine field, and indoor evaluation of the heterogeneity of a physical simulation model and profile control and displacement properties of various profile control and displacement agents of an injection well; the double tracer method has the advantages of low workload of the mine field, low cost, convenience and quickness in data interpretation and high maneuverability.

Description

technical field [0001] The invention relates to a double tracer method for identifying the heterogeneity of a water flooding oil reservoir, and belongs to the technical field of identifying the heterogeneity of an oil reservoir. Background technique [0002] The reservoir heterogeneity of the reservoir seriously affects the water injection development effect of the oilfield; the heterogeneous reservoir is affected by the water-oil mobility ratio, the difference between injection and production, and the long-term erosion and denudation of the injected water, and the phenomenon of differential seepage occurs gradually. Predominant seepage channels, and then form large pores, which are characterized by rapid breakthrough of injected water, high injection rate, strong water flooding, high recovery degree, high water-oil ratio, etc. The sweep efficiency of injected water is low, and the oilfield development effect is poor; therefore , in order to take measures to improve the swee...

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Problems solved by technology

[0007] The main disadvantages of the existing water drive reservoir heterogeneity identification technology: ①The well test monitoring and discrimination technology cannot quantitatively identify the reservoir heterogeneity, and the basic data used requires special instruments for field measurement. The workload is heavy and the cost is high; ②The wellhead pressure drop curve monitoring technology can quantitatively determine the existence of large pores in the water flooding reservoir, but this method has few data sources, which is not conducive to accurate judgment and has strong ambiguity; ③Interwell tracer The actual mine field of tracer monitoring technology is highly operable, which is conducive to the promotion and use at the grassroots level, but the interpretation process of the single tracer method is relatively complicated

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