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

摘要： 根据大庆油田采油一厂萨中西区套管变形的研究结果,提出了应力—压力复合力学模型.该模型很好的解释了该区的套管变形发生原因.高、低压力区沿最大水平主应力方向分布时,发生套管变形的临界压差为0.767MPa.高、低压力区沿其它方向分布时,发生套管变形的临界压差为1.08MPa.优势套管压缩方向为北西西向.套变区分布在压力梯度较大的位置.上述分析与多年的实际观测结果有较好的一致性.应力—压力复合力学模型是一个可以适用于油田套管变形研究的模型.

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