Leading Injection Percolation Mechanism Of The The Xifeng Special Low Permeability Reservoirs And Development Of Technology Policy Research

With the development of exploration technique and the reforming of engineering in petroleum reservoir and our country's energy resources development strategy, the exploitation of reserve volume in low and extremely low permeable reservoir has become an important potence in the development of our country's ashore petroleum industrial and also the technical direction of petroleum industry's sustainable development of our country in the future. The reserve volume in low and extremely low permeable reservoir is abundant, so it will be the main resource basic in the increasing reserve volume for a long time in the future. As a result, the exploration of low permeable reservoir can not be neglected and the research on the mechanism of fluid flow through porous medium, development plan and development technique in low permeable reservoir has an important significance.Considering that when the fluid flow through the extremely low permeable reservoir, it always has some special features, such as no-Darcy flow which has the kickoff pressure gradient and the elastic-plastic deformation in oil clay, so in the long period of exploratory run for the proper development, the Xi Feng oil filed has proposed an effective water injection mode in order to improve the effect of oil reservoir development, and that is advanced water injection. While the research on the mechanism about advanced water injection for improving the development effect and the policy for this development plan has been few. So this paper will take Bai Ma and Dong Zhi district of Xi Feng oil filed for example to research the mechanism about advanced water injection and the policy for this development plan, which has the important theoretical meaning and practical application value.The research on the flow mechanism and development technique in low permeable reservoirs in this paper is based on the solving of practical problems during the development of the low and extremely low permeable reservoir by our predecessors. The essay has analyzed the geologic conditions and development performance in Xi Feng extremely low permeable reservoir and some main research results has been achieved in the following:1)Research on the geologic characteristic of Bai Ma and Dong Zhi district in Xi Feng oil field by using the geological information of Xi Feng oil field, analyzing the general geology including the low-porosity, low pressure and low permeability, fluid property, flow characteristic and pressure temperature system.2)Resarch on flow mechanism of low permeable reservoirs, and put the focus on the kick off pressure gradient, water drive production decline curves, production decline method, interlayer employ degree and well network adaptability. Derive the diverging/converging deliverability equations,percolation rate equations and limited producer-injector spacing equations considering the kick off pressure gradient and establish the displacement pressure gradient equations of low permeable reservoirs.3) Establish the flow mechanism of advanced water injection by associating the unique feature and analyzing the sesitivity of low permeable reservoirs in Xi Feng oil field. Do research on the enhancing low-permeability reservoir single well's deliverability by advanced water injection and establish the advanced water injection diverging/converging deliverability equations. And this becomes a theoretical proof that advanced water injection can enhance single well's deliverability and improve the flow condition in low permeable reservoirs.4) Establish the development technical policy of advanced water injection in Xi Feng oil field. Do research on the development technical policy of advanced water injection (advanced water injection time, water injection response, water injection pressure, water intake per unit thickness, development index of well constant rate of production), and guide the rational development of oil field.5) Evaluating the development effect of advanced water injection by tracing and analyzing Xi Feng oil field developed by advanced water injection to find out the main problems and propose the next step technical direction of constant rate of production.The research on the flow mechanism and development technical policy of Xi Feng extremely low permeable reservoirs developed by advanced water injection can apply theoretical foundation and technical supports to enhance oil recovery efficiency in extremely low permeable reservoirs developed by water injection and establish the rational development policy of advanced water injection. And it has the directive meaning to enhance well production and assure the production will be the maximal in Xi Feng extremely low permeable reservoir, and its theoretical foundation can be used for reference in our country's congeneric reservoirs' development.