COUPLING MECHANICS MODEL OF CASING DEFORMATION

Acoording to the research results of casing deformation at west region of Sazhong in No.1 Oil Production Department of Daqing Oilfield,we firstly present the stress pressure coupling mechanics model.This model perfectly explains the causes of casing deformation in this region.The critical pressure difference is 0 767MPa when the high and low pressure zones distribute along the direction of maximum principal stress.However,when the high and low pressure zones distribute along the other directions,the critical pressure difference is 1.08MPa.The preferred orientation of casing compression is NWW.The casing deformation is generally located at the region which has the greatest pressure gradient.The analysis is in good concordance with the observed measurements for many years.Therefore,the stress pressure coupling mechanics model is proper for the research of casing deformation.