Wangjiang - Buried Hill Basin Formation And Evolution Of Petroleum Systems

Wangjiang-Qianshan basin, which is one of area developed marine strata in South China has superior original conditions of marine source rocks, great hydrocarbon potential and better oil-gas preserving condition than other basins in lower Yangtze area. It is a region with good prospect for exploration.Based on the wholly, dynamics and integrated principle, the guide of petroleum geology and computer technology, the research has been done as follows by the factors of geology, gravity, magnetism and electricity: (1)Building Chronostratic framework of Wangjiang-Qianshan and its neighbor, divide and compare Carbonic and Permain sequence .(2)Studying distribution of sediment series in different period. (3)Studying the basic tectonic transform style, preliminarily dividing main tectonic units. (4) Describing the formation and evolution of basin. (5)Dividing conjectural petroleum system basing on the former research. Conclusion are obtained as follows:1. Basin accepted sedimentation since sinian, and strata were well developed. It was marine sedimentary series from sinian to middle-Triassic and become continental sedimentary series since late-Triassic.2. Different tectonic style exists in the upper and lower layers of the Yanshanian boundary. The lower layers takes on the tectonic style of thrust fault and nappel. The upper layers hi step positive fault. It takes on "double layers" structure on the whole.3. Basin formation and reformation are divided into two stages. The first is the stage of formation and evolution of the marine basin, including passive margin basin (Z-O2), Southern forland basin (O2-O3), great interior cratonic basin (D3-T2). The second is the stage of formation of the continetal basin and the reformation of the marine basin, including ramp forland basin (T2-3-J1-2), strike slip-pull apart basin (J3-K1), faulting-depression basin (K2-E) and consume of continetal basin (N-Q).4. The source-reservior-caprock conditions were very good and have been provided with necessary condition to the formation of petroleum system. Four suit of conjectural petroleum systems are divided.