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渤海湾盆地南堡凹陷2 900m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.
The overpressure below 2 900 m in the Nanpu Sag, Bohai Bay Basin is relatively common, but the evolution of overpressure evolution is relatively weak.Based on the numerical simulation technique, the formation and evolution of the paleo-overpressure in the Nanpu Sag have been restored. Combined with the evolution of sedimentation rate and hydrocarbon generation Evolution and Porosity Evolution The origin and evolution of overpressure were studied and the significance of reservoir pressure evolution for formation pressure evolution was discussed. The study shows that the evolution of formation pressure in Nanpu sag has undergone primitive accumulation (before Dongning denudation period), overpressure release (Dongying Formation uplifted and eroded) and re-accumulation of overpressure (from the end of Dongying Formation up to now). Dongying formation was dominated by over-compaction during the denudation period. During overpressure unloading in the denudation period, over-pressure unloading makes the early formation of oil and gas reservoirs to be adjusted to some extent. Since the end of the Dongying Formation, hydrocarbon generation and pressurization have been dominated. Hydrocarbon generation and pressurization period and two important hydrocarbon accumulation and oil source faults During the enhancement phase, a large amount of oil and gas flow along the fault and lithologic channel to form a source-reservoir assemblage. On the other hand, with the residual pressure difference in the source reservoir, oil and gas flow along the activated oil source fault And the favorable accumulation area of oil and gas is closely related to the pressure distribution. In the distribution interval of the pressure coefficient of the reservoir in the corresponding interval, the total reservoir thickness has a positive correlation with the pressure coefficient, so it is suggested that the exploration be focused on the corresponding interval Pressure coefficient distribution range of high pressure coefficient zone.