关键词： 沁水盆地 南部 潘河煤层气田 区域地质 储集层 特征 水文地质条件 产能
Regional geological and reservoir characteristics of the Panhe CBM Gas Field in the southern Qinshui Basin and their influences on CBM gas production capacity
Ye Jianping, Wu Jianguang, Fang Chao, Wu Jian, Xiong Dehua
China United Coalbed Methane Co., Ltd., Beijing 100011, China
The Panhe field in the southern Qinshui Basin is the first largescale commercial CBM gas field with good economic benefits. Analysis of its regional geological and reservoir features as well as the evaluation of its recoverability and production potential can provide basic information for the selection of well pattern, drilling & completion and stimulation technologies as well as the determination of water drainage and gas production policies. Production data of over 200 CBM wells in the study area, previous geological exploration data of the coal fields, and data from CBM parameter wells are fully utilized to describe in detail the regional geological and reservoir features of this CBM field, and analyze the geological and reservoir factors influencing the CBM production capacity. The following conclusions are obtained. 1) The geological conditions and structures are relatively simple in the study area with welldeveloped secondary folding. 2) The coal seams are stable in distribution and large in thickness and the coal bed 3# is 6.5 m in thickness. 3) The coal is anthracite with high metamorphic grade and its gas content is relatively high, but show large lateral variation. 4) Gas quality is good with the methane content over 98% and gas saturation is high in the range of 95 ~ 100%. 5) Both reservoir permeability and pressure are relatively high. As a whole, the geological and reservoir parameters reveal that this study area has favorable conditions for CBM enrichment and recovery. A geologic model is built based on the test data of parameter wells including PH1-09, TL-006 and TL-007 and the exploration data of the Panzhuang1 coal field, providing valuable reference for the well pattern design, the selection of engineering technologies, and highly efficient development of similar CBM gas fields.