Study on the Change Rules of Reservoir Parameters in Water Flooding Reservoirs

摘要

During the conventional flow theory analysis, the porosity and permeability are usually considered as the constant.However, the production practice in water flooding oil fields has proved that, reservoir parameters will change due to the influence of long time water flooding.The present study on time-variant characteristic of reservoir parameters is limited in the qualitative analysis of time-variant mechanisms and statistical description of reservoir parameters change, only several authors introduce the time-variant characteristic into numerical simulation.In this paper, with deep analysis on time-variant mechanism of water flooding, reservoir parameters and the continuum damage mechanics, the mathematical modeling of porosity and permeability with time-variant mechanism is built, and the quantitative relationships among porosity, permeability and time-variant parameters are described.Then, mechanical model is proposed to describe the basic reason and mechanic basis of time-variant parameters for the first time, mathematical derivation is processed in detail and the final results are verified by experiments results.Results show that, the reservoir permeability increases with flooding times increasing, the permeability change times have a linear relationship with 3/4 power of flooding times.