摘要
中国煤层气资源丰富,煤层气中的游离态烃和溶解态烃气体可通过地层中的断裂、裂隙、微裂缝和孔隙等通道垂直运移到地表,进而在近地表形成化探指标异常。延川南区块煤层气油气化探技术应用研究表明:顶空气甲烷、酸解烃甲烷等烃类化探指标主体异常区呈环形模式分布于延1井煤层气富集区上方,异常成因主控因素包括深部烃源(煤层气)、烃源(煤层气)上覆盖层、深部断层(中垛断层和白鹤断层)等地质要素;热释汞指标主体异常区呈顶端形式分布于延1井煤层气富集区上方,主要受控因素包括深部煤层、深部断层(中垛断层和白鹤断层)等地质要素;研究区煤层气有效化探指标综合熵值圈定了3个环状异常区:程河原—延1井熵值异常区、掷沙熵值异常区和井西岭南熵值异常区,其中程河原—延1井熵值环状异常区有效地指示了延1井煤层气富集区,中垛断层和白鹤断层之间的掷沙熵值异常区、井西岭南熵值异常区可能部分受断层的影响,亦是煤层气有利富集区。
China is rich in coalbed methane resources. The free coalbed hydrocarbon gas and the water-dissolved hydrocarbon gas can migrate to the surface of the earth through the channels such as faults,fractures,cracks and micro pores,and form the near-surface geochemical anomalies. The application of the coalbed methane geochemical exploration technique to Yanchuan south block shows that the geochemical indicators of the headspace methane and the acid-extracted methane have the halo anomaly features over Well Yan 1coalbed enrichment area,and the main factors controlling the anomalies include deep hydrocarbon source（ CBM）,cap rocks over the hydrocarbon source,deep faults such as Zhongduo fault and he Baihe fault and other geological elements. The heat-released mercury indicators have the top anomaly features over Well Yan 1 coalbed enrichment area,and the main factors controlling the anomalies include deep coal seams,deep faults such as Zhongduo fault and Baihe fault and other geological elements. Three halo anomalous areas were delineated in the study area according to the coalbed methane effective geochemical indicator of the comprehensive entropy,which are Chengheyuan-Well Yan 1 anomaly area,Zhengshan anomaly area and Jingxiling anomaly area. Chenheyuan-Well Yan 1 halo anomaly effectively indicates the CBM enrichment area of Well Yan 1; Zhengshan anomaly,which is located between the Zhongduo and Baihe faults,and Jingxiling anomaly can also reflect the coalbed favorable areas although they may be partially influenced by the faults.
出处
《物探与化探》
CAS
CSCD
2016年第2期318-326,共9页
Geophysical and Geochemical Exploration
基金
国家自然科学基金项目(41072099)
关键词
煤层气勘探
油气化探
有效指标
异常模式
鄂尔多斯盆地
coalbed gas exploration
oil and gas geochemical exploration
effective indicator
anomaly model
Ordos Bain
