东濮凹陷文东地区深层超压与成藏模式探讨

Discussion on the overpressure and reservoir-forming model of deep formation in Wendong area in Dongpu depression

文东地区紧邻东濮凹陷最大的前梨园生油气洼陷,深层储量丰富。地层压力在纵向上具有典型双层结构,其沙三中下亚段超压普遍发育,且为强超压中心。采用流体包裹体热动力学模拟技术结合盆地数值模拟成果恢复了本区古流体压力。研究表明,深部沙三中亚段压力演化具有波动性。明化镇组沉积期至现今,生烃作用引起的超压强度逐渐增加,超压的存在对油气运聚产生重要的影响。提出文东油气成藏具有超压系统源外断压联控和源内超压充注两类成藏模式。加强超压相关研究对于本区下一步深层致密砂岩等非常规气藏的勘探开发具有重大意义。

Wendong area is close to the Qianliyuan sag which is the biggest rich source kitchen in Dongpu depression, it has rich reserves in the deep. The very high abnormal pressure mainly occured in the middle and low of Es3 with the binary structure in vertical. The pressure of Paleo-liquid was recovered by the fluid inclusion PVTX modeling on the basis of previous numerical modeling of the basin. The result show that the middle of the Es3 has the characteristics of fluctuation. From the stage of sedimentation of Nm to now, the hydrocarbon generation result in the intensity of the overpressure is increasing gradually and the overpressure played an important role in the hydrocarbon accumulation. There are two kinds of reservoir-forming mode of overpressure system, the resources outside pressure offjoint control and resources inside overpressure filling. Strengthening the study of overpressure is significant for future exploration of tight sand reservoir in this area.