徐家围子断陷深层天然气地球化学特征及成因  

GEOCHEMICAL CHARACTERISTICS AND GENESES OF THE DEEP NATURAL GAS IN XUJIAWEIZI FAULT DEPRESSION

作　　者：尚尧[1] 施尚明[1] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318

出　　处：《大庆石油地质与开发》2015年第2期19-25,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家重点基础研究发展计划课题"火山岩油气藏分布规律与资源预测"(2009CB219308)资助

摘　　要：以试气井段为单位对徐家围子断陷深层天然气进行分析,探索各气藏天然气组成及碳同位素的分布规律。研究表明:乙烷碳同位素在平面上存在明显差异,断陷边部乙烷碳同位素较重,具有煤型气特征,断陷中部乙烷碳同位素较轻,达到油型气标准;天然气C_5以上的重烃碳同位素异常轻,可能来源于原油裂解;碳同位素反序的天然气不一定是无机成因,复杂的碳同位素序列可能是油型气和煤型气混合造成;无机成因烃气数量甚微,不可能单独成藏。Taking the tested gas-well intervals as the unit, the deep natural gas from Xujiaweizi Fault Depression is analyzed to explore the gas compositions and carbon isotope distribution laws of each natural gas reservoir. The stud- ies show that there are obvious differences for the ethane carbon isotopes distributed on the plane, and the ethane car- bon isotopes at the edge of the fault depression are heavier and with the characteristics of coal-type gas, meanwhile, the ethane carbon isotopes are lighter in the central faulted depression and reach the standards of oil-type gas; theheavy hydrocarbon carbon isotopes above C5 of the natural gas are anomaly lighter, which are possible derived from the crack of the crude oil ; the natural gas with reverse order carbon isotopes is not necessarily inorganic origin and the complex sequence of the carbon isotopes may be the mixture of both oil-type gas and coal-type gas; the gas reservoir couldn＇t be separately accumulated due to the minor quantity of the hydrocarbon gas of inorganic origin.

关 键 词：徐家围子断陷 深层天然气 地球化学特征 碳同位素 无机成因 重烃 

分 类 号：TE122.1[石油与天然气工程—油气勘探]