Study On Porous Flow Characteristic In Micro-fractured Ultra-low Permeability Reservoirs

In this dissertation, both reservoir physical characteristics and microcosmic porous flow characteristics together with the stable percolation theory of vertical well, vertically fractured well, and horizontal well are principally researched for micro-fractured ultra-low permeability reservoirs.Based on the research of the experiments with scanning electron microscope, nuclear magnetic resonance and constant rate mercury penetration , the difference between micro-fractured ultra-low permeability reservoirs and normal ultra-low permeability reservoirs are presented, with regard to microcosmic pore configuration, percentage of movable fluid, poroperm characteristics, heterogeneous, anisotropic, pressure-sensitive effecct and so on, and lastly the reservoir physical characteristics of this typical reservoirs are also generalized.Based on the research of the experiments of microcosmic porous flow, the characteristics of the overflow pressure, single-phase flow curve and two-phase flow curve are summarized. And accordingly generalized Darcy's law is established, which integrate the pressure-sensitive effecct of fluid and porous media and the threshold pressure gradient. Finally according to the characteristics of relative permeability curve and the principle of material balance, production decline equation is derived, and these factors affecting production decline are illuminated.A scale transformation expression of nisotropy is presented, and a vital conclusion is put forward: that is, the unsymmetry of scale transformation of nisotropy. Lastly the factors which affect nisotropic parameter are discussed.In this part, firstly, two integrate mathematical modals about stable percolation of linearity and radial are established, and the analytical formulas of pressure distribution and production are also obtained. Secondly, the characteristics of pressure distribution...