Configurational Transformation of Sterane and Terpane and Significance to Petroleum Exploration

Songnian Lu, Li Weimin, Gao Jianjun

According to the relative internal energy difference of various sterane and terpane stereoisomers, the order of thermodynamic stability is as follows: 13ß, 17^agr > 14ß, 17ß > 13^agr, 17ß > 14^agr, 17^agr; 5^agr > 5ß; 20S >= 20R; 17^agr, 21ß > 17ß, 21^agr > 17ß, 21ß; 18^agr-C27 > 17^agr > 17ß; 22S < 22R. The relative stability of various sterane and terpane stereoisomers can provide a sound basis for studying oil and rock maturity using biological markers. The configurational transformation of sterane and terpane in several oils has been studied in cores from the Liaohe, China area. The results show that the threshold depth of oil generation in lower Tertiary source rocks is 2,350 m.

AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.