【摘要】 目前确定石油工程中地应力的方法均存在各自的局限性,为了得到直接反应地应力大小和方向的信息,提出一种基于实钻资料确定地应力的新方法,不将井眼看作理想的圆筒,而是通过力学分析建立井壁围岩的变形程度与岩石物理力学性质、地应力、孔隙压力及钻井液密度的关系,在此基础上由钻井液录井和常规测井,反演出地应力及孔隙压力,并进一步计算井壁坍塌和破裂压力。研究发现,破裂压力计算值与实测值符合较好,而反演得到的孔隙压力与实用钻井液密度符合,说明该方法合理可行。若结合随钻测量,该方法可实现地应力及井壁稳定的实时预测,应用前景广阔。更多还原

【Abstract】 A new method based on actual data to determine geostress is introduced.Without the traditional assumption that wellbore is cylindrical,the relationship among wellbore deformation,rock mechanical properties,geostress,pore pressure and mud density is established by using dual media elastic mechanics.Using this relationship,geostress and pore pressure are inverted from mud log and conventional log.Then collapse pressure and fracture pressure are calculated.The results show that the calculated fracture pressure is in good agreement with the actually measured value,and the inverted pore pressure is in agreement with the practical mud density.The agreement verifies the rationality of this new method.It is a breakthrough to determine earth pressure and pore pressure from actual mud log and conventional log.Due to the basis of rigorous mechanical model and actual data,this new method has high degree of accuracy.With measurements while drilling,this method can predict pore pressure,geostress and wellbore stability at real time.So the method may be wildly used.更多还原