The Foundational Theory Of Nonlinear Flow In Porous Media And Numerical Simulation In Low Permeability Reservoirs

There are extensive distribution and abundant storage in low permeability reservoirs. For a considerably long period of time, it will be the main fossil resources to be discovered and developped, therefore, it has profound significance for the sustainable development of petroleum industry to study on low permeability reservoirs development.Compared with moderate and high permeability reservoirs, low permeability reservoirs differ in terms of flow characteristics, microscopic flow mechanism and theory of fluid flow in porous medium. The main difference is that there exists nonlinear flow. Researchers both home and abroad have deeply studied on this problem and demonstrate their views, but an agreement can not be reached in microscopic flow mechanism and theory of fluid flow in porous media up to now. Based on the fundamental theory of low permeability reservoirs, a new explanation of microscopic flow mechanism is made, which lays the foundation of theory of fluid flowing in low permeability reservoirs. Nonlinear seepage model is established based on the comprehensively understanding of microscopic flow mechanism. Nonlinear theory of fluid flowing in low permeability porous media is systemically discussed and production characteristics considering the nonlinear flow are described, which provide the theoretical instruction for the effective development of low permeability reservoirs.At present, the reservoir numerical simulation technology at home and abroad is based on Darcy's law, numerical simulation software based on pseudo start pressure gradient model has been developed, but it does not consider the influence of bending section of nonlinear seepage curve, therefore, the predicted results are different from the reality. Considering the mentioned problems, the key technologies of nonlinear numerical simulation are described and numerical simulation technologies for single and dual porous media are established, which provide an accurate and powerful tool for the design of well pattern and plan assessments.