川西拗陷天然气丁烷地球化学特征

发布时间：2018-06-02 16:30

本文选题：丁烷 + 天然气成因　；参考：《成都理工大学学报(自然科学版)》2017年04期

【摘要】：丁烷与甲烷、乙烷、丙烷同为天然气的烷烃气组分,但是对其研究及应用明显不如甲烷、乙烷及丙烷。本文在川西拗陷天然气地球化学分析测试的基础上,重点对天然气中丁烷的地球化学特征进行分析,探讨丁烷与天然气成因、天然气运移的关系。测试结果显示,研究区天然气以烷烃气为主,其中甲烷含量最高,其体积分数85%,平均值93%;重烃含量相对较低。研究区天然气中丁烷含量较低,其体积分数1%;其中异丁烷与正丁烷含量相当,体积分数均不超过0.5%。iC_4/nC_4值能示踪未受到明显次生变化天然气的成因类型,煤型气iC_4/nC_40.8,油型气iC_4/nC_40.8;受到次生作用影响的天然气,iC_4/nC_4值可能失去判别天然气成因类型的功能。目前,对iC_4/nC_4值能否示踪天然气运移及其示踪机理存在较多争议,在研究区iC_4/nC_4值就未能有效示踪天然气的垂向运移过程,因此在选择该指标示踪天然气运移时应慎重。
[Abstract]:Butane, methane, ethane and propane are the components of natural gas alkanes, but their research and application are obviously inferior to methane, ethane and propane. Based on the geochemical analysis and test of natural gas in western Sichuan depression, the geochemical characteristics of butane in natural gas are analyzed, and the relationship between butane and natural gas genesis and gas migration is discussed. The test results show that the natural gas in the study area is mainly alkane gas, in which methane content is the highest, its volume fraction is 85, the average value is 933.The heavy hydrocarbon content is relatively low. The content of butane in natural gas in the study area is relatively low, and its volume fraction is 1. The content of isobutane is equal to that of n-butane, and the volume fraction does not exceed the 0.5%.iC_4/nC_4 value to trace the genetic types of natural gas without obvious secondary changes. Coal type gas iC4 / nCstack 40.8, oil gas IC 4 / nC40.8; natural gas affected by secondary effects, natural gas C 4 / n C 4 may lose the function of judging the origin type of natural gas. At present, there are many controversies about whether iC_4/nC_4 value can trace natural gas migration and its tracing mechanism. In the study area, iC_4/nC_4 value cannot effectively trace the vertical migration process of natural gas, so we should be careful in choosing this index to trace natural gas migration.
【作者单位】：中国石化西南石油工程有限公司临盘钻井分公司;油气藏地质及开发工程国家重点实验室(成都理工大学);宜宾学院资源与环境工程学院;中国石化西南石油工程有限公司湖南钻井分公司;
【基金】：国家自然科学基金项目(41172119)
【分类号】：P618.13

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