井中应力场的计算及其应用研究

Calculation of borehole stress with full-wave acoustic logging data and its application

1. University of Petroleum, Beijing 102200, China;2. Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Production, Nanjing 210014, China;3. East China Petroleum Bureau, SINOPEC Star Petroleum Exploration and Production Company, Nanjing 210011, China

介绍了井孔周围地应力的分布状态及在井壁上地层应力的表述方程式, 分析了地层应力变化对井壁的破坏作用, 讨论了井壁在受到拉张及压缩应力作用下的破坏机理, 给出了井孔的拉张及压缩破坏准则, 进一步分析了安全钻井的最大最小泥浆密度。

This paper discusses the stress distribution around a borehole and expression of stress at borehole wall, and analyzes the damaging effect of earth stress on borehole wall and damaging mechanism of borehole wall under extensional and compressional stresses. The criterion of damage for borehole wall under extension and compression is presented, and the lower and upper limits of mud density for drilling safety are derived. The method has been applied in the data processing and interpretation of full-wave acoustic logging data from a well in north China. Satisfactory results have been achieved.