The Study Of Dynamic System Of Petroleum Accumulation In The South Step-fault Zone Of Gao Yang Sag

This paper studies mainly on dynamics of Petroleum accumulation in the south step-fault zone in Gaoyou sag by analyzing pressure filed, temperature filed, water chemical filed and hydrodynamic field of this area. Through the study, 4 achievements as follows major will be reached.1. Zhen-1 fault inherits the foundation of substratum thrust having the characteristics of contemporaneous fault namely early formation, long period of movement, far extention and long break of fault. Zhen-2 fault which covers the distance from Hung Yu to Zhou Zhuang comes down to Zhen-1and goes up to Yan-2. Wu-1 and Wu-2 are strike-slip faults with en-echelon surface. Wu-2 fault is straight and plain disappearing from Wu-1 which has shovel shape.2. In the south step-fault are there two types of dynamic system: ordinary pressure else-sourced closed dynamic system (Fu Ning group--Tai Zhou group)and ordinary pressure else-sourced semi-closed dynamic system(San Duo group--Dai Nan group).3. Oil and gas of south step-fault horizontally gathers mainly on a series of three-normal-unit distribute closing to Zhen-2 fault and its secondary fault, and vertical ly on Ny,E2s,E2d,E1f3,E1f2+1,K2t,K2c distribute, and E1f1 is the richest one.4. By the fine interpretation of south step-fault, seven favorable targets will be predicted, among which four are in Xu Zhuang area, two in Zhu Dun area and one in Chen Bao area.