Hydrocarbon Occurrence Models Controlled by Graded Multi-Factors in Marine Reservoirs, Southern China

Sihuang Xu¹, Yongsheng Ma², Lianfu Mei³, Caiping Yuan³, and Tongluo Guo^2
1 China University of Geosciences, Lawrence, KS
² South China Filiale of SINOPEC, Kunming, China
³ China University of Geosciences, Wuhan, China

Pool-controlling factors are defined as the main geological factors that control the formation, reconstruction, preservation and distribution of hydrocarbon pools. In southern China, the marine petroleum, reconstructed several times by later structural movements during geohistory, was controlled by varied and graded geological factors. The main pool-controlling factors include various sources of pool fluids, multi-period of formation and reconstruction, and preservation condition at different scales. Five sources of pool fluids are gas cracked by oil, gas dissolved in water, inorganic gas, hydrocarbon primarily and secondarily generated from source rocks. The pool-controlling factors are divided into different grades by controlling range. Primary grade of pool-controlling factor, controlling the largest region, is the source of fluid; the secondary factor is the period of formation and reconstruction; the third, controlling more local range, is pool-forming manner including preservation condition. Ten types of dynamic occurrence models are set up based on primary and secondary grades of pool-controlling factors, which are primary source - primary or secondary accumulation, secondary source - primary or secondary accumulation, dissolved gas source - primary or secondary accumulation, inorganic gas source - primary or secondary accumulation, cracked gas source - secondary accumulation and mixed source - secondary accumulation, of which four have been found as typical cases. The principle that pools are controlled by graded multi-factors and the dynamic classification of hydrocarbon occurrence models have a significant impact on studying the formation and distribution of marine reservoirs in southern China as a whole, and comparing that in different parts.