【作者】 赵兴齐； 陈践发； 张晨； 李清春； 唐友军； 张俊华；

【Author】 ZHAO Xing-qi~1,CHEN Jian-fa~1,ZHANG Chen~1,LI Qing-chun~2,TANG You-jun~3, ZHANG Jun-hua~1 (1.State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum,Beijing, 102249 China;2.Research Institute of Exploration and Development,Liaohe Oilfield Company,CNPC, Panjing 124010,China;3.Key Laboratory of Exploration Technologies for oil and Gas Resources,Ministry of Education,Yangtze University,Jingzhou,Hubei 434023,China)

【机构】 中国石油大学(北京)油气资源与探测国家重点实验室； 辽河油田公司勘探开发研究院； 长江大学油气资源与勘探技术教育部重点实验室；

【摘要】 奈曼凹陷已经历了20多年的勘探历程,近年来获得工业油流,但关于该区天然气的地球化学特征及成因的研究未见报道,通过对奈1区块的38个天然气样品的组分及碳同位素组成进行分析,并结合地质背景详细剖析了该区烃类气体的地球化学特征及成因。指出该区天然气为有机成因气,天然气热演化程度低,属于低熟—成熟的油型气;烃类气中以甲烷为主,重烃气含量较高,天然气干燥系数低,呈现出明显的湿气特征。结合该区烃类气碳同位素特征及成熟度,认为该区天然气为原油伴生气;利用(δ¹³C₂-δ¹³C₃)与ln（C₂/C₃）以及ln（C₁/C₂）与ln（C₂/C₃）关系综合分析认为奈1区块天然气为干酪根热解气。更多还原

【Abstract】 After 20 years exploration,although we got commercial oil flow,researches related to natural gas,such as geochemical characteristic and origin have not been reported.Based on the analysis of natural gas composition and carbon isotope from 38 gas samples in Naiman 1 Block,coupled with geological background,this paper supplies the gap and figure out geochemical characteristic of hydrocarbon gas and possible origin in study area.Furthermore,it raises up that the natural gas from study area at low evolutionary phase whose origin is organic belongs to oil-type gas with low-middle maturity.CH₄ accounts for a big fraction of hydrocarbon gas with higher content of heavy hydrocarbon gas and lower dry coefficient that shows the typical characteristic of wet gas.Combined with carbon isotopic characteristic and maturity of hydrocarbon gas,data shows that natural gas in this area is accompanying gas.Meanwhile,δ¹³C₁, C₁/C_1-5,iC₄/nC₄and iC₅/nC₅ of natural gas from upper jiufotang Formation are obviously higher than counterpart from the lower section.And this phenomenon is mainly associated with maturity.更多还原