Laboratory Studies of Differences Between Oil-Derived and Kerogen Maturation Gases
详细信息
- 责任者：Guo Liguo (Department of Geosciences ; Geosciences and Engineering Institute ; Nanjing University ; Nanjing 210093 ; China) ; Xiao Xianming
- 刊名：Petroleum Geology & Experiment
- 出版年：2011
- 卷期：33(4)
- 关键词：原油 ; crude oil ; 裂解气 ; cracked gas ; 干酪根 ; kerogen
- 页码：p.428-436
- 图表：illus., 1 table, 41 refs.
- 分类号：1003
- issnNo：ISSN1001-6112
- isbnNo：CN32-1151/TE
摘要
An immature type-I mudstone collected from the third section of the Tertiary Shahejie Formation(Es33) in the Dongying Sag of the Bohai Bay Basin was studied with laboratory experiments.Products were extracted,fractionated into chemical groups,and re-mixed to obtain synthetic oil(s-oil) with a group composition similar to reservoir oil and a pseudo-kerogen(p-kerogen) composed of 83% kerogen and 17% residual soluble organic matter.The two samples were pyrolyzed in sealed gold tubes under constant pressure and non-isothermal heating conditions and the generated gases were analyzed.The two gases are quite different in their chemical and isotopic composition.Compared with the gas derived from p-kerogen,the s-oil-derived gas is rich in C2-C5 hydrocarbons during the early cracking stages and C1-C3 hydrocarbons are depleted in δ13C throughout the cracking stages.The carbon isotopic ratio differences between the two gases can reach 10‰(δ13 C1),14‰(δ13 C2),and 9‰(δ13 C3).The δ13C2-δ13C3 value of the s-oil gas is much more sensitive to thermal stress than that of the p-kerogen gas and the plots of(δ13C2-δ13C3) versus δ13 C1 and(δ13C2-δ13C3) versus ln(C2/C3) are effective in identifying the two gas types.These results provide a guide to differentiate gases derived from oil cracking from those derived from kerogen maturation.