渤海湾盆地南堡凹陷地层压力演化及其成藏意义
Pressure Evolution and Its Effect on Petroleum Accumulation in Nanpu Sag , Bohai Bay Basin

渤海湾盆地南堡凹陷2900m以下超压现象较普遍，然而超压成因演化研究较为薄弱.基于数值模拟技术对南堡凹陷古超压的形成与演化进行了恢复，结合沉积速率演化、生烃演化及孔隙度演化研究了超压的成因演化特征，并进一步探讨了地层压力演化的成藏意义.研究表明，南堡凹陷地层压力演化经历了原始积累(东营组剥蚀期以前)、超压释放(东营组抬升剥蚀期)及超压重新积累(东营组末期至今)3个阶段；东营组剥蚀期以前超压成因以欠压实为主，超压幕式排放利于油气幕式排出，东营组剥蚀期发生超压卸载，超压卸载使得早期形成的油气藏进行一定程度的调整，东营组末期至今以生烃增压为主，生烃增压期与2次重要成藏期及油源断层活动增强期相耦合，一方面大量油气沿断裂及岩性通道运移形成源内成藏组合，另一方面在源储剩余压力差作用下，油气沿活化的油源断层运移形成源上成藏组合；油气有利聚集区与压力分布密切相关，在相应层段油层压力系数分布区间内，总体油层厚度与压力系数具有正相关关系，因此建议将勘探重点放在相应层段压力系数分布区间内的压力系数高值区.
Resources of the zone or the 3rd (or the 4th) tectonic trap are often evaluated by directly and simply cumulating the resources size of its segments weighted by discovery probability in China. Obviously, not all segments certainly have been discovered due to constraints of special geological conditions. In addition, prediction value generally doesnt honestly reflect the practical geological model if quantifying the direct effect of geological model constraints on volumetric parameters and Monte Carlo simulation process is ignored. For the development of PetroV, an improved nondeterministic volumetric method with quantifying kinds of geological constraints is devised in the paper: to sample and composite the undivided segments which should stay in the same combination, then quantify impact caused by the key geological factors in order to objectively delineate volumetric uncertainty. It is confirmed by applications and detailed analysis that “combination probability cumulating” method proposed in this paper could explain each quantile value of resource distribution with clear geological scenarios, which leads to more reasonable exploration strategies