Petroleum Science >2015, Issue 1: 81-95 DOI: https://doi.org/10.1007/s12182-014-0003-8
Genetic types and geochemical characteristics of natural gasesin the Jiyang Depression, China Open Access
文章信息
作者：Wen-Tao Li,Yang Gao and Chun-Yan Geng
作者单位：
School of Energy Resources, China University of Geosciences, Beijing 100083, China Geoscience Research Institute, Shengli Oilfield Company SINOPEC, Dongying 257015, Shandong, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Geoscience Research Institute, Shengli Oilfield Company SINOPEC, Dongying 257015, Shandong, China e-mail: swap124@163.com;Geoscience Research Institute, Shengli Oilfield Company SINOPEC, Dongying 257015, Shandong, China
投稿时间：2015-01-22
引用方式：Li, WT., Gao, Y. & Geng, CY. Pet. Sci. (2015) 12: 81. https://doi.org/10.1007/s12182-014-0003-8
文章摘要
Natural gases were widely distributed in the
Jiyang Depression with complicated component composition,
and it is difficult to identify their genesis. Based on
investigation of gas composition, carbon isotope ratios,
light hydrocarbon properties, as well as geological analysis,
natural gases in the Jiyang Depression are classified
into two types, one is organic gas and the other is abiogenic
gas. Abiogenic gas is mainly magmatogenic or mantlederived
CO2. Organic gases are further divided into coaltype
gas, oil-type gas, and biogas according to their kerogen
types and formation mechanisms. The oil-type gases
are divided into mature oil-type gas (oil-associated gas)
and highly mature oil-type gas. The highly mature oil-type
gases can be subdivided into oil-cracking gas and kerogen
thermal degradation gas. Identification factors for each
kind of hydrocarbon gas were summarized. Based on
genesis analysis results, the genetic types of gases buried in
different depths were discussed. Results showed that
shallow gases (\1,500 m) are mainly mature oil-type
gases, biogas, or secondary gases. Secondary gases are rich
in methane because of chromatographic separation during
migration and secondary biodegradation. Secondary biodegradation
leads to richness of heavy carbon isotope ratios
in methane and propane. Genesis of middle depth gases
(1,500–3,500 m) is dominated by mature oil-type gases.
Deep gases (3,500–5,500 m) are mainly kerogen thermal
degradation gas, oil-cracking gas, and coal-type gas.
Jiyang Depression with complicated component composition,
and it is difficult to identify their genesis. Based on
investigation of gas composition, carbon isotope ratios,
light hydrocarbon properties, as well as geological analysis,
natural gases in the Jiyang Depression are classified
into two types, one is organic gas and the other is abiogenic
gas. Abiogenic gas is mainly magmatogenic or mantlederived
CO2. Organic gases are further divided into coaltype
gas, oil-type gas, and biogas according to their kerogen
types and formation mechanisms. The oil-type gases
are divided into mature oil-type gas (oil-associated gas)
and highly mature oil-type gas. The highly mature oil-type
gases can be subdivided into oil-cracking gas and kerogen
thermal degradation gas. Identification factors for each
kind of hydrocarbon gas were summarized. Based on
genesis analysis results, the genetic types of gases buried in
different depths were discussed. Results showed that
shallow gases (\1,500 m) are mainly mature oil-type
gases, biogas, or secondary gases. Secondary gases are rich
in methane because of chromatographic separation during
migration and secondary biodegradation. Secondary biodegradation
leads to richness of heavy carbon isotope ratios
in methane and propane. Genesis of middle depth gases
(1,500–3,500 m) is dominated by mature oil-type gases.
Deep gases (3,500–5,500 m) are mainly kerogen thermal
degradation gas, oil-cracking gas, and coal-type gas.
关键词
-
Genetic types Natural gases JiyangDepression Light hydrocarbon properties Carbon isotoperatios Identification factors