Using The Fluid-Solid Coupling Theory Of Elastic-Plastic Behavior Carrying On The Research Of Geo-Stress And Flow-Pressure That Affect The Casing

Failure process of casing well is a difficult problem to be solved urgently on the range of the world. It has been found in various degrees in every world oil field. There are Daqing oil field , Jilin oil field , Zhongyuan Oil Field and Shengli Oil Field in the serious areas of casing well damages in our country. In recent year the number of oil casing well damages is still in high level, the problem is fairly serious. The emergence of casing well damages has close contact with interaction of rock body and fluid. So the research of fluid-solid coupling theory model seems very important. This article chooses using the fluid-solid coupling model of elastic and elastic-plastic behavior carrying on the research of flow pressure and geo-stress that affect the casing as research content, which is the ready work for casing mechanical analysis. On the basis of analyzing the materials already obtained further, the article builds a kind of fluid-solid mathematics-mechanics model, combining the understanding of fluid-solid problem in oil field development. Under certain condition wo can simplify the model. After deriving the FEM weak integral form of elastic and elastic-plastic fluid-solid coupling via FEM, we work out FEM program to calculate flow pressure and geo-stress ,through analyzing pointing out casing damages factors have close relation with fluid-solid coupling from stratum while working; drawing the effect of injection-production craft and geological state on geo-stress and flow pressure; offering reference for adjusting injection-production craft, monitoring oil casing condition, preventing oil casing damages, guaranteeing oil field safety in production.