Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

按检索

Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China

Authors:	WANG XianBin GUO ZhanQian TUO JinCai GUO HongYan LI ZhenXi ZHUO ShengGuang JIANG HongLiang ZENG LongWei ZHANG MingJie WANG LianSheng LIU ChunXue YAN Hong LI LiWu ZHOU XiaoFeng WANG YongLi YANG Hui & WANG Guang Key Laboratory of Gas Geochemistry Chinese Academy of Sciences Lanzhou China Daqing Oilfield Company Ltd Daqing

Institution:	(1) Key Laboratory of Gas Geochemistry, Chinese Academy of Sciences, Lanzhou, 730000, China;(2) Daqing Oilfield Company Ltd., Daqing, 163712, China;(3) Institute of Earth Sciences and Information Technology, Northeast University at Qinhuangdao, Qinhuangdao, 066000, China;(4) School of Earth and Environment Sciences, Lanzhou University, Lanzhou, 730000, China

Abstract:	This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mechanisms and from different sources in nature. It is demonstrated that the biodegradation or thermodegradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ¹³C₁ value ranges from −110% to −50% for microbial gases but from −50% to −35% (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ¹³C and δ D values characterized by normal distribution, i.e. δ¹³C₁< δ ¹³C₂< δ ¹³C₃< δ ¹³C₄ and $\delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} }$ , and by a positive correlation between the δ ¹³C and δ D values. Simple carbon-bearing molecules (CH₄, CO and CO₂) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ¹³C₁ heavier than −30‰ Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ ¹³C values and a normal trend of δ D values, namely δ¹³C₁> δ ¹³C₂> δ ¹³C₃> δ ¹³C₄ and $\delta D_{CH_4 } < \delta D_{C_2 H_6 } < \delta D_{C_3 H_8 } < \delta D_{C_4 H_{10} }$ . The δ ¹³C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ¹³C₁ values ranging from −30.5% to −16.7% with a very narrow δ D range between −203‰−196‰ These gases are characterized by a reverse distribution of δ ¹³C values but a normal distribution of δ C values, and a negative correlation between their δ ¹³C and δ C values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m³. The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide. Supported by National Natural Science Foundation of China (Grant Nos. 49233060, 40572087), Key Technologies R & D Programme (Grant Nos.96110010602, 2008ZX05008) and the Foundation of Chinese Academy of Sciences (Grant No. K2000315)

Keywords:	generation mechanism of natural gases kinetic isotope fractionation the Songliao Basin of China commercial abiogenic hydrocarbon gaspool
本文献已被 CNKI SpringerLink 等数据库收录！

设为首页 | 免责声明 | 关于勤云 | 加入收藏