【摘要】 近几年的页岩油气开发实践表明,页岩非均质性及水平井段的方位对页岩气单井产量、采收率及页岩气开采的经济性影响较大,而页岩非均质性主要受到天然微裂缝的影响。因此,开展页岩内天然微裂缝研究,寻找页岩储层"甜点"等是成功部署高产气井、提高页岩气开采经济效益的必然选择。基于美国阿巴拉契亚盆地Marcellus页岩区的3C/3D高分辨率地震资料,利用快/慢速转换横波(PSV-1/PSV-2)反射时间厚度差法,对Marcellus地层的天然微裂缝发育带进行了探测。应用纵-转换横波(PP-PS)联合反演技术,结合联合反演密度、纵横波速度比(vP/vS)等组合属性参数,对天然微裂缝的开闭性及张性天然微裂缝孔隙空间的含气性分别进行了识别和检测,并利用实钻井资料对地球物理方法预测的页岩储层"甜点"(含气张性微裂缝)进行验证,取得较好效果。实际应用表明,纵-横波联合反演技术对于张性天然微裂缝的识别及含气性检测具有突出优势,能有效降低钻探风险。更多还原

【Abstract】 In recent years,the development of shale oil and gas shows that shale heterogeneity and lateral orientation have relatively great impacts on single well shale gas production,recovery factor and the economy of shale gas exploitation,and natural micro-fracture is the main factor resulting in shale heterogeneity. Accordingly,to carry out research on the natural micro-fractures and prediction of sweet spots within shale has become an inevitable choice for successful emplacement of high-yielding wells and improving economic benefits of shale gas exploitation. Based on the high resolution 3C /3D seismic data in Marcellus shale play within Appalachian Basin,North America,natural micro-fracture zone of Marcellus shale was predicted by means of fast and slow converted shear wave( PSV-1 / PSV-2) integrated interpretation,then the open / closed fractures and gas-bearing property of extensional micro-fractures were separately identified and detected by utilizing combined attribute parameters like joint inversion density,velocity ratio of compressional and converted wave( vP/ vS) extracted from joint inversion of compressional wave and converted shear wave( PP-PS). In addition,drilling data were used to verify the sweet spots predicted by geophysical method in Marcellus shale. Joint inversion technique( PP-PS) has outstanding advantages in natural extensional micro-fractures identification and gas-bearing detection,which can effectively reduce the drilling risk.更多还原