煤田地质与勘探2024，Vol.52Issue(2)：113-121,9.DOI:10.12363/issn.1001-1986.23.08.0517
松辽盆地南部王府断陷深部煤层气地质特征及有利区评价
Geological characteristics and favorable area evaluation of deep coalbed methane in Wangfu fault depression,southern Songliao Basin
摘要
Abstract
The Wangfu fault depression in the southern Songliao Basin is rich in coalbed methane(CBM)resources.However,CBM exploration in this area has been restricted by the low-level exploration of deep CBM and a lack of sys-tematic studies on the geological characteristics of CBM,primary factors controlling CBM enrichment and accumula-tion,and the selection of favorable targets.Therefore,based on the systematical analysis of the geological characteristics of coal-bearing strata,this study identified the major factors controlling deep CBM accumulation,established the index system for favorable area selection,and predicted the favorable areas of CBM enrichment.The results show that:(1)Macroscopically,coals in the Huoshiling Formation in the Wangfu fault depression can be primarily categorized into bright and semi-bright coals,possessing the characteristics of low moisture,low volatile constituents,and low ash con-tent.They exhibit vitrinite reflectance＞1.8%,average porosity of 5.01%,and average gas content of 21.80 m3/t(calcu-lated based on well CS38).(2)The sedimentary environment,filled and leveled through volcanic eruption,of the Hu-oshiling Formation in the Wangfu fault depression is conducive to the formation of coal seams.Specifically,coal seams primarily occur between the double steep slope zones and in the shallow water areas of the central and eastern Wangfu fault depression,which were formed by the filling and leveling effects of volcanic eruption.In this manner,the coal formation mode featuring filling and leveling is formed.Additionally,the presence of large-area thick mudstone roofs and closed faults allow for CBM enrichment and preservation in the fault depression.(3)Class Ⅰ favorable areas in the Wangfu fault depression predominantly occur in the northern and central parts of the fault depression,with coal seam thicknesses＞5m,fault throw＜50 m,cover thicknesses＞80 m,and gas logging-derived total hydrocarbon values＞15%.These suggest great potential for exploration and exploitation.Classes Ⅱ and Ⅲ favorable areas are mainly found in the northern and southern parts of the fault depression,with coal seam thicknesses＜5m,cover thicknesses＜80 m,and gas logging-derived total hydrocarbon values＜15%.Weak-sealing or open faults and greatly different cover thick-nesses pose risks to CBM exploration and exploration in these areas.关键词
松辽盆地/王府断陷/深部煤层气/地质特征/有利区评价Key words
Songliao Basin/Wangfu fault depression/deep coalbed methane/geological characteristic/favorable area evaluation分类
天文与地球科学引用本文复制引用
沈霞,公海涛,邵明礼,杨敏芳,霍万国..松辽盆地南部王府断陷深部煤层气地质特征及有利区评价[J].煤田地质与勘探,2024,52(2):113-121,9.基金项目
中国石油天然气股份有限公司攻关性应用性科技专项项目(2023ZZ18) （2023ZZ18）
