SOURCE ROCK THERMAL AND MATURITY HISTORY MODELING IN THE BAIYUN SAG OF THE PEARL RIVER MOUTH BASIN

It is significant to study the source rock maturity history of the Baiyun Sag for the deep water exploration in the Baiyun Sag of the Pearl River Mouth Basin.Based on geohistory and thermal history of the Baiyun Sag,using EASY% R_o model reconstruction of the source rock maturity history in the western sag,the middle sag and the eastern sag of the Baiyun Sag.Comparing to the character of the Wenchang and Enping Formation source rocks maturity evolution in the western sag,the middle sag and the eastern sag.The studies indicate: 1)The studies of the Well B1 indicate that the character of the heat flow evolution is divided into two phase which is continuate rise in the forepart and gradually decline in the latter part in the Baiyun Sag.The heat flow reaches the maximum(76.7 mW/m²) at 44.4 Ma,the heat flow is about 60 mW/m² at present.2)The Wenchang Formation source rock in the western sag,the middle sag and the eastern sag begins to generate hydrocarbon(R_o=0.5%)about at 43,44,35 Ma,reaches the hydrocarbon generation peak(R_o=1.0%) about at 30,35,17 Ma,reaches the high maturity(R_o=1.3%) about at 25,33,13 Ma.The Enping Formation source rock begins to generate hydrocarbon about at 20,30,22 Ma,reaches the hydrocarbon generation peak about at 10,22,8 Ma,reaches the high maturity about at 8,17,0 Ma.3)The thermal evolution of the Wenchang and Enping Formation source rocks in the middle sag of the Baiyun Sag is the highest,the time of the hydrocarbon generation is earliest and the main hydrocarbon generation phase is the shortest;the thermal evolution of the Wenchang and Enping Formation source rocks in the western sag is the lowest,the time of the hydrocarbon generation is latest and the main hydrocarbon generation phase is the longest.