Research On The Fluid Stress And Crustal Stress Of Stratum In Affecting Sleeve

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, This article deeply calculates and analyses the fluid-solid coupling problem about from two dimensions to three dimensions and from linearity to no linearity gradually. Fluid stress and solid (especially casing and cement annulus) deformation and stress are acquired through calculation and analysis in the process of the oil field injection -production. This provides the experience and support of software in the corresponding theory study. This article synthesizes underground fluid-solid coupling theory, mathematics-mechanical model and software realizing, linearity and no linearity model.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 we 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 fluid stress and crustal stress, analyzing pointing out casing damages factors have close relation with fluid-solid coupling from stratum while working; fluid stress and crustal stress affect casing through cement annulus, therefore, it is very important studying fluid stress and crustal stress in the process of the oil field injection-production; and forming fluid-solid coupling model to simulate fluid stress and crustal stress from stratum in the process of the oil field injection-production,offering reference for adjusting injection-production craft, monitoring oil casing condition, preventing oil casing damages, guaranteeing oil field safety in production.