Method for judging mixed phase mechanism of gas with high content of hydrogen sulfide and carbon dioxide

Abstract

The invention discloses a method for judging a mixed phase mechanism of gas with high content of hydrogen sulfide and carbon dioxide. The method comprises the following steps of: S1, collecting oil reservoir and injected gas related basic data; S2, simulating a multi-stage contact process of gas with high content of H2S and CO2 and crude oil by utilizing a phase balance calculation model, and drawing a multi-stage contact experiment quasi-ternary phase diagram of the gas with high content of H2S and CO2 under the oil reservoir temperature condition; S3, drawing a thin tube characteristic curveof the gas with high content of H2S and CO2 under the oil reservoir temperature condition by utilizing a thin tube experiment; and S4, judging the mixed phase mechanism of the gas with high content of H2S and CO2 through the quasi-ternary phase diagram in the S2 and the thin tube characteristic curve in the S3. According to the method disclosed by the invention, the mixed phase mechanism of the gas with high content of H2S and CO2 can be rapidly judged by drawing the quasi-ternary phase diagram and the thin tube characteristic curve.

Description

Technical field[0001]The invention belongs to the field of enhanced oil recovery by gas injection, and specifically relates to a method for judging the mixed theory of high-content hydrogen sulfide and carbon dioxide gas.Background technique[0002]As one of the three major enhanced oil recovery technologies, gas flooding has expanded its application range year by year, especially in the development of low-permeability reservoirs. Relative to Note N2And CO2, Hydrocarbon gas injection is not only easy to obtain gas source, but also does not cause damage to the reservoir. In addition, the minimum miscible pressure of hydrocarbon gas injection is often less than N injection2Therefore, hydrocarbon gas flooding has significant advantages and broad application prospects.[0003]For gas injection production technology, it can be divided into miscible flooding and immiscible flooding in mechanism. Miscible flooding means that when one fluid is displacing another fluid in a porous medium, the tw...

AI Technical Summary

Problems solved by technology

However, there are few studies on the dominance of a single miscibility mechanism (condensation or evaporation) on the miscibility of hydrocarbon injection gas; when the crude oil contains high H 2 S and CO 2 The mixed-phase mechanism of re-injection of dissolved gas during composition is rarely reported, and H 2 S and CO 2 The influence mechanism of components on miscibility mode, miscibility pressure and miscibility process is also unclear

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