川西北地区九龙山构造须家河组二段天然气气源分析  

Natural Gas Sources Ananlysis of the Second Member of Upper Triassic Xujiahe Formationin at the Jiulong Mountains Structure in the Northwest of Sichuan Province

作　　者：邓涛[1] 李勇[1] DENG Tao;LI Yong(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,Sichuan)

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059

出　　处：《四川师范大学学报（自然科学版）》2019年第2期246-252,共7页Journal of Sichuan Normal University（Natural Science）

基　　金：国家自然科学基金(41372114);四川省科技厅项目(2017JY0140)

摘　　要：通过对九龙山气藏须二段天然气组分和碳同位素组成的详细分析,结合烃源岩和储层沥青生物标志化合物开展气源对比,明确该气藏须二段产气层的天然气来源.研究结果表明:1)九龙山气藏具有典型干气特征,除个别井之外,绝大多数井位天然气的CH_4质量分数都超过了95%,重烃含量低,且非烃类气体(CO_2和N_2)质量分数均未达到1%; 2)九龙山气藏天然气整体上呈现CH_4碳同位素组成重,而C_2H_6碳同位素组成相对较轻的特征,九龙山气藏T_3x^(2中)烃源岩自身属于腐泥型,故判定其为典型的腐泥型成因气; 3)九龙山气藏T_3x^2气层的沥青生标物与T_3x^(2中)烃源岩生标物在甾、萜类化合物特征上存在极大的相似性.综上认为九龙山气藏须二段气层天然气主要来自于须二中亚段烃源岩,并有少量下伏海相地层的混源气特征.Based on the detailed analysis of T3x^2 in Jiulong Mountains gas reservoir with gas component and carbon isotopic com-position,combined with the hydrocarbon source rock and reservoir bitumen biomarker compound gas-source correlation,this study in-vestigates the sources of T3x^2 gas reservoir production.The results show that:1)the Jiulong Mountains gas reservoir’s gas is dry,ex-cept for several wells,the CH4 content of natural gas in the vast majority of the wells is more than 95%,heavy hydrocarbon content is low,and non-hydrocarbon gas content is not high,CO2 and N2 content has not reached 1%;2)on the Jiulong Mountains gas reservoir gas all have heavy-carbon with CH4 and relatively light-carbon of C2 H6,considering that the hydrocarbon source rocks in the Jiulong Mountains T3x^2中gas reservoir itself belongs to sapropelic type,so we judge it as a typical sapropelic type gas;3)the Jiulong Mountains T3x^2 gas reservoir bitumen biomarker compounds of the asphalt feature and terpenoids feature have great similarities with the feature of hydrocarbon source rock in T3x^2中.In view of the above three aspects,it can be concluded that the Jiulong Mountains gas reservoir of T3x^2 natural gas mainly comes from the middle of the second member of Xujiahe Formation hydrocarbon source rocks,in addition,a small amount of the mixed gas comes from underlying stratum.

关 键 词：须二段 烃源岩 地球化学 气源分析 九龙山构造 

分 类 号：TE121.32[石油与天然气工程—油气勘探]