A study on casing damage based on effect of water injection pressure

Abstract

The water flooding extraction of the oilfield, the quantity and increasing speed of oilfield casing damage are rising obviously. Casing damage creates the loss of economy and also affect the development of the oilfield. The problem of casing damage has become an urgent problem an the oilfield. This paper gives a study of casing damage based on effect of water injection pressure in a particular oil field and the datas are analysed and the results are tabulated. Mechanism of casing damage is discontinuous deformation in the overloading strata and the discontinuous deformation includes interlayer sliding and fault movement induced by subsidence, which results in casing shear damage. The oil pressure goes down axial compression and bending of casing are caused by large vertical displacement. The casing damage in the middle of production floor is because of the largest axial strain and casing bent because of excessive axial load and its surroundings without sufficient lateral support. Channeling is easily caused when water injection pressure fracture pressure in the case of poor cementing quality. In the case of water channel, immersion area forms and strata stress is out of balance, which results in that the casing damage area from in large immersion area. However, there is no effective way to prevent and slow the damage of casing well. Example as pubei oilfield in china “Casing damage on effect of water injection pressure” The distribution of casing damage is raised and the effect rule and mechanism that water injection pressure acts on casing damage of injection wells and oil wells are studied.