Research On Casing Damage Caused By Injecting Water And Finite Element Emulation

The present oilfield development has entered the stage, while using a variety of ways to enhance oil recovery, and this lead to a result that the working environment of casing has become worse, and exacerbate its damage trend. The speed of casing damage has become faster in recent years and it affected the normal production of oilfield seriously, and most of them can not be repaired, it will bring huge economic losses, so the study of mechanism of casing damage is very meaningful.The paper consult a lot of documents about casing damage, found out the situation of the study of casing damage. After analysis, decided to solve it by the idea of control theory, which take the mechanism of casing damage as a control system, and reduce the casing damage by the way of control the pressure of injection water.In this paper, the following aspects of work have been done:First, consult a lot of documents about casing damage, summarize the type of casing damage, influencing factors of casing damage and standard of computation of casing strength; Second, by the idea of control theory, determine the train of thought that control the pressure of injection water, and deduce the solving methods of stress, formation fracture stress, formation slip stress, formation creep and fluid-solid coupling; Third, according to the derivation of the mechanical properties of solution, using the known oil field production data, solved the security value of the injection pressure, and compared with the actual injection pressure value, prove its usefulness and meaningful; Fourth, establish casing model by the way of finite element analysis, analyze the affect of injection water to stress and casing deformation.