测井评价煤层气藏面临的挑战与发展方向

The Challenges and Research Direction of Logging Technologies in Coalbed Methane Reservoir

煤层具有低孔隙度、非均质强、有机质骨架以及气体赋存状态多样等特点,煤层易碎造成井眼垮塌、夹矸发育、气体响应不明显等问题,现有的煤心实验装备在测量方法和测量精度上都难以满足煤层气储层评价的需要。从井眼环境、测井响应入手,系统分析了常规测井评价煤层气储层的局限性。从理论基础、实验装备、测井仪器以及测井新技术与新方法等方面提出了测井评价煤层气储层的发展方向与新思路。测井新技术如元素俘获谱测井、电成像测井、核磁共振测井以及阵列声波测井与常规测井相比具有独特的技术优势,在煤层气储层评价和工程应用方面都能发挥明显的作用。

The coalbed is characterized by low porosity, strong heterogeneity, various organic matrix and gas storages. The coalbed is breakable to cause borehole collapes, developed dirtband, unclear gas response, etc. The existed coal core test devices can＇t meet the requirement of combed methane evaluation in measuring methods and precision. Based on the borehole environment and logging response, the disadvantage of logging technologies in coalbed methane reservoirs are reviewed in this paper. And the new ideas of well logging for combed methane reservoir are discussed from basic theory, experimental equipment, logging tools and new technologies. Compared with conventional log, the new log technologies such as the element captured spectrum log, electric imaging log, NMR log and array sonic log have great advantages in coalbed methane evaluation.