新疆石油地质

新疆石油地质 ›› 2007, Vol. 28 ›› Issue (4): 413-415.

• 油气勘探 • 上一篇    下一篇

准噶尔盆地乌夏地区天然气地球化学特征

李秀鹏, 查明, 吴孔友   

  1. 中国石油大学 地球资源与信息学院, 山东 东营 257062
  • 收稿日期:2006-12-29 出版日期:2007-08-01 发布日期:2020-07-31
  • 作者简介:李秀鹏(1983-), 男, 山东济南人, 在读博士研究生, 油气藏形成与分布,(Tel) 13854646369(E-mail) lixp0526@163.com.

Geochemical Feature of Natural Gas in Wu-Xia Area, Junggar Basin

LI Xiu-peng, ZHA Ming, WU Kong-you   

  1. Faculty of Geo-Resources and Information, China University of Petroleum, Dongying, Shandong 257061, China
  • Received:2006-12-29 Online:2007-08-01 Published:2020-07-31

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摘要： 准噶尔盆地乌夏地区天然气主要含烃类气体,以甲烷为主,干燥系数平均为0.8801,多为湿气,V(iC4)/V(nC4)平均为0.88,V(iC5)/V(nC5)平均为0.99,热演化程度较高。非烃气体中氮气含量较高,其次为二氧化碳,氧气含量最少,不含硫化氢。随着深度增加,天然气相对密度、干燥系数、甲烷含量、重烃气含量和非烃气体含量可按规律分为7个变化带。天然气具有δ13C1<δ13C2<δ13C3<δ13C4的正碳同位素系列特征,烷烃气是原生型有机成因气。天然气源岩Ro为0.21%～1.66%,烃源岩主要在低成熟和成熟阶段生气,根据δ13C1与δ13C2-δ13C1关系以及有机成因气δ13C1与V(C1)/V(C2+3)关系,判断天然气的成因类型主要为石油伴生气,乌32井区可能存在凝析油伴生气。

关键词: 准噶尔盆地, 乌尔禾-夏子街地区, 天然气, 地球化学, 成因类型

Abstract: The natural gas in Wu-Xia area is dominated by methane wet gas of high maturity with dry coefficient of 0.8801, V(iC4)/V(nC4) of 0.88, V(iC5)/V(nC5) of 0.99 in average. Its non-hydrocarbon gas contains high content of N2, less CO2, micro-O2 and free H2S. With increase of the depth, the relative density, dry coefficient, methane content, heavy hydrocarbon gas content and non-hydrocarbon gas content have 7 changing trends by regularity. The natural gas is characterized by δ13C1<δ13C2<δ13C3<δ13C4 and the alkane gas is original organic genetic gas. The source rocks produce gases in low-matured and matured stages with Ro from 0.21% to 1.66%. According to the relationship between δ13C1 and δ13C2-δ13C1 as well as δ13C1 vs. V(C1)/V(C2+3), it is judged that the origin of natural gas belongs to associated gas of crude oil, and a small amount of associated gas of condensate oil may occur in Wu-32 Wellblock.

Key words: Junggar basin, Wuerhe-Xiazijie area, natural gas, geochemistry, genetic type

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