成像测井新技术在川西须二段储层评价中的应用

APPLICATION OF IMAGE LOGGING TECHNOLOGY TO EVALUATION OF RESERVOIRS IN THE 2ND MEMBER OF XUJIAHE FM IN THE WESTERN SICHUAN BASIN

川西地区须家河组二段埋深近5000m,储层为特低孔渗的裂缝性致密碎屑岩储层,测井评价的难点主要是流体性质识别和裂缝及有效性评价。文章通过实例展示了声波含气性检测技术在气层识别中的应用,利用斯通利波能量衰减和流体移动指数可以进行储层的渗透性分析,成像测井与常规测井结合可进行裂缝识别和裂缝有效性评价;总结了将测井新技术与常规测井结合进行致密碎屑岩储层评价的过程,认为应在准确划分储层类型的基础上进行流体性质识别和裂缝及有效性分析;客观分析了现代测井技术在致密碎屑岩储层评价中的适用性,认为成像测井基本解决了裂缝识别及裂缝有效性评价问题,流体性质的识别技术仍是测井在裂缝性致密碎屑岩储层评价领域的难点。

The 2nd member of Xujiahe Formation in the western Sichuan Basin with a burial depth of near 5000 m is fractured tight clastic rock reservoir with ultra low permeability and porosity. Identification of fluid property and evaluation of fractures and their effectiveness are the main challenges facing logging evaluation of this kind of reservoir. The application of acoustic gas detection technology to identification of gas layers is introduced through case study. The energy decay of Stoneley wave and fluid flow indexes can be used to analyze reservoir permeability. Image logging in combination with conventional loggings can be used to recognize fractures and evaluate their effectiveness. The process of tight clastic rock reservoir evaluation with the combination of image logging and conventional loggings is summarized and it is believed that identification of fluid properties and analysis of fractures and their effectiveness should be based on accurate classification of reservoir types. The applicability of modern logging technologies to evaluation of tight clastic rock reservoirs is objectively analyzed and it is believed that image logging can basically solve the problem of fracture identification and their effectiveness evaluation. Identification of fluid property is still a big challenge facing the application of logging technologies in evaluation of fractured tight clastic rock reservoirs.