摘要
随着页岩气勘探开发工作的不断深入，地震相关勘探技术在页岩气钻井部署和页岩气富集带或“甜点”区评价中发挥重要作用。不同应力环境下岩石的弹性波速及其各向异性实验数据是地震资料叠前反演的重要约束性基础资料，对深部页岩气地球物理探测、储层评价及甜点预测具有重要意义。本文以湘西桑页1井龙马溪组页岩、五峰组页岩及底板泥灰岩钻孔岩芯为研究对象，实验测量了不同应力条件下岩芯的弹性波速特征，计算了应力环境下的波速差异，并对比了页岩与泥灰岩的波速各向异性。结果表明，在5-100MPa应力环境下，粉砂质、硅质和含粉砂页岩的纵波速度分别为4．8～5．1km／s、5．1～5．3km／s和5．2～5．5km／s，泥灰岩的纵波速度在5．9～6．4km／s之间；原位应力环境下，页岩与泥灰岩的纵波速度差异介于14．9％～21．7％之间；受微裂缝和层理面的影响，页岩垂直层理方向纵波速度明显低于平行层理方向，而泥灰岩的纵波速度为平行层理方向明显高于垂直层理方向。
With the development of exploration and production of the shale gas, the elastic properties of shale play an important role in the ＂sweet spot＂ discrimination. Seismic velocities and anisotropies with different confining pressures are important for geophysical exploration and reservoir assessment of the shale. Taking the core from SangYe 1 well of western Hunan as the study object, the authors measured the seismic velocity with different confining pressures. The result shows that the seismic velocities of siltstone, siliceous shale, silty shale and marlstone are 4.8-5.1 km/s, 5.1-5.3 km/s, 5.2-5.5 km/s and 5.9-6.4 kin/s, respectively, with the confining pressures being 5-100 MPa. Under the condition of in situ stress state, the difference of compressional wave velocity between shale and marlstone is between 14.9% and 21.7%. For the microfracture and bedding, the perpendicular velocity of shale is lower than the horizontal velocity of shale, while the horizontal velocity of marlstone is lower than the perpendicular velocity of marlstone.
出处
《地球学报》
EI
CAS
CSCD
北大核心
2016年第3期333-339,共7页
Acta Geoscientica Sinica
基金
中国地质调查局地质调查项目(编号:12120115007401)
国家自然科学基金项目(编号:41404080)联合资助
关键词
龙马溪组页岩
弹性波速
各向异性
实验
Longmaxi Formation shale
elastic velocity
anisotropy
experiment
