摘要
声波在岩石中的传播速度与岩石的性质、孔隙度以及孔隙中所充填的流体性质密切相关,因此可以利用声波在断层岩中传播的时差异常来分辨断层的力学性质。通过对东营凹陷的砂泥岩和其间断层岩的声波时差随深度变化特征及其相互间关系研究,进一步揭示张性断层声波时差异常的变化幅度和异常范围与断层埋藏深度有关。在1600m左右以上区段,断层带的声波时差比围岩要大,断层为开启性质,断层对油气不具有封闭作用;在1600m以下区段,断层带的声波时差比围岩要小,为压性断层性质,断层处于封闭性状态,断层对油气具有封闭作用。
As propagation velocity of acoustic wave in rocks is closely related with rock properties, porosity and properties of fluids in pores, acoustic travel time anomaly in fault rock can be used to determine the dynamic properties of faults. Studying on variations of the acoustic travel times of sandstone and mudstone and the fault rocks with depth in Dongying depression indicates that variation amplitude and scope of acoustic travel time anomaly of exten-sional faults are related with burial depth of the faults. When the burial depth is less than about 1600m, the a-coustic travel time in fault zone is larger than that in surrounding rocks and the faults are open faults without sealing ability. While when the burial depth is larger than 1600m, the acoustic travel time in fault zone is less than that in the surrounding rocks and the faults are closed faults of compressional nature that can act as seals.
出处
《河南石油》
2005年第5期13-15,18,共4页
Henan Petroleum
关键词
断层
声波时差
断层岩
东营凹陷
Fault, acoustic travel time, fault rock, Dongying depression
