Petroleum potential of Oligocene lacustrine mudstones and coals at Dong Ho, Vietnam — an outcrop analogue to terrestrial source rocks in the greater Song Hong Basin

摘要: The outcrop of Oligocene age at Dong Ho, northern Vietnam, may constitute an immature analogue to offshore terrestrial source rocks in the greater Song Hong Basin. includes interval with two rocks: (1) highly oil-prone carbonaceous mudstones containing kerogen types IIA and IIA/I, TOC contents from 6.48 16.89 wt%, HI values 472 690; (2) oilprone humic coals (kerogen type III) 200 242. were deposited oxygen-deficient lakes, which on occasion subject marine influence, accumulated freshwater peat-forming mires. have broad activation energy (Ea) distributions, while Ea distributions characterised by a pronounced principal Ea. During artificial maturation about 16‐17% organic carbon 45‐50% participated petroleum formation. primary generate oil secondary gas, however, realised majority their potential over more narrow temperature range than coals. excellent generative Ho is encouraging for exploration reservoirs charged Cenozoic rift-lake successions. q 2001 Elsevier Science Ltd. All rights reserved.