“动态物源”控砂模式

油气勘探的进程对物源的供给和分配研究提出了更精细的要求。动态物源是指物源的供给与分配是随时空的变化而变化的,不同层序位置、湖平面变化不同阶段,物源区的大小均是变化的,影响沉积作用的发生;不同古地貌位置,物源供给与分配是有差异的,影响沉积砂体的非均质分布。物源区的变化是个动态的过程,后期被覆盖的低凸起区在沉积的早期都有可能是物源区,这样就重新认识了凹陷中许多远离大物源区的继承性凹中隆,认为它们在沉积早期都可能成为物源区并在周边形成一定规模的沉积砂体,而不是传统观点的"找砂禁区"。忽视物源的动态变化性,导致埕北低凸起中部的储集层预测失利;重视动态物源的分析,使JZ25-1井区储集层预测取得成功,突破了传统的勘探"禁区"。图8参15

Model of dynamic source controlling sand

Exploratory course and researching development require an intensive research on source supply and distribution. Dynamic source means that source supply and distribution changes with temporal and spatial variation. Source supply area is variable in different sequences and lake level transformation stages, which affect sedimentation in turn. Source supply and distribution is discrepant in different palaeogeomorphic positions, affecting sand sediment nonhomogeneous distribution. Change of source area is a dynamic course. Lower uplifts covered by later sediment may be source area in early stage. Under this understanding, many successive uplifts-in-depression far away from large source areas are effective source area, many sand-bodies could be found around there, and they are not forbidden zones for finding sand. Ignorance for dynamic source caused the failure of reservoir prediction in the Chenbei area, and recognition of it maked a success in the JZ25-1 area.