多极子阵列声波测井技术在煤层气储层评价中的应用

Application of Multipole Acoustic Logging to the Evaluation of Coalbed Methane Reservoirs

介绍多极子阵列声波测井仪器(MPAL)的声系结构和测量数据。MPAL仪器提供了丰富的煤层气地层声学参数。通过处理MPAL在煤层气储层的声波测量数据得到了滑行纵波、偶极横波和斯通利波的速度,衰减以及横波速度各向异性,地层渗透率等信息。在分析上述信息与煤层气储层特性关系的基础上,研究了煤层气储层的多极子阵列声波测井评价的步骤和方法。MPAL测得的纵、横波速度及衰减能够用于煤层识别和煤层厚度计算;从斯通利波数据中提取的渗透率信息可以评价煤层气储层的渗透性能;结合地层密度数据可得到地层弹性信息,能够为钻井、水力压裂等工程提供重要的参考数据。

The acoustic system and measured data of the multipole acoustic logging tool（MPAL）are described.The velocity and attenuation of compressional,shear and Stoneley waves,as well as the anisotropy and permeability of the formation are obtained by processing the MPAL data in coalbed methane reservoirs.The evaluation method of coalbed utilizing MPAL is studied by comparing the relationship between processing results and characteristics of coalbed.The results show that the slowness and attenuation of compressional and shear waves are available for coalbed recognition and thickness calculation,and the coalbed peameability could be evaluated by the inversion results of Stoneley data.MPAL provides enough acoustic parameters that can be used to compute elastic parameters of formations combined with density data,and elastic parameters are important references for petroleum engineering problems.