关键词: 套管变形, 地层压力, 应力方向, 应力测试, 岩石力学, 复合力学模型, 微型压裂

Abstract: 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.

Key words: casing deformation, reservoir pressure, stress orientation, stress measurement, rock mechanics, coupling mechanics model, microfracturing