通过恢复库车坳陷克拉苏构造带深层和鄂尔多斯盆地伊陕斜坡延长组主要成藏期的过剩压力,结合对研究区低渗透储层的物性演化历史分析,对低渗透致密砂岩储层运移过程中油气可能的动力条件进行评价.结果表明:低渗透致密砂岩储层中油气运移的主要动力具有多样性；库车坳陷克拉苏构造带深层在天然气的成藏时期储层已经致密,天然气运移的主要动力为快速沉积、生烃、构造挤压等多因素作用形成的异常高压；鄂尔多斯盆地伊陕斜坡延长组在早、中期油充注时储层尚未致密,在浮力作用下发生侧向运移,晚期油充注时储层已经致密,油利用先前与油长期接触而具亲油性的残留路径沿优势输导通道侧向运移,毛细管力为主要动力,储层间的过剩压力差也起一定作用,是多期次多动力联合作用的结果.%By restoring the overpressure of main accumulation period in the deep of Kelasu structural belt of Kuqa depression and Yanchang formation of Yishan slope of Ordos Basin, the possible dynamic conditions during the process of hydrocarbon migration in the low permeability -tight sandstone reservoir were estimated combined with the analysis on reservoir physical properties evolution. The results show that the main dynamics of hydrocarbon migration in the low permeability-tight sandstone reservoir is characterized by diversity. The reservoir becomes tight in the natural gas accumulation period in the deep of Kelasu structural belt. The main dynamic of natural gas migration is the overpressure formed by the multiple factors of high-rate deposition, hydrocarbon generation, and tectonic compression and so on. The reservoir does not become tight in the oil infill injection early and middle stage in Yanchang formation of Yishan slope of Ordos Basin. The oil migrates laterally due to buoyancy. The reservoir becomes tight in the oil infill injection late stage. It mainly migrates laterally along the residual pathways that are oil-wet due to long-term contact with oil. The main dynamic of oil migration is capillary force and the difference of excess pressure among the reservoirs also plays a role in the oil migration. So the oil migration of main accumulation periods in Yanchang formation of Yishan slope of Ordos Basin is the joint action of the multi-stage and multi-dynamic.
展开▼
