深部调驱后续水驱渗流特征--以蒙古林砂岩油藏为例

Seepage characteristics of water-flooding operations after deep profile control and oil displacement: A case study of Menggulin sandstone reservoir

深部调驱是改善砂岩油藏开发效果的重要技术之一,但是调驱后地层孔隙结构发生变化,后续水驱渗流规律与常用的化学驱技术又有所不同,剩余油分布认识更为困难。利用已大规模实施深部调驱技术的华北油田蒙古林砂岩油藏调驱井后续注水压降试井资料,采用双对数导数曲线和压力半对数曲线进行解释,并结合油井生产动态深入认识不同类型试井曲线对应的地层渗流特征。建立了砂岩油藏深部调驱后续水驱的渗流模式共5种类型,分别为无限导流型、有限导流型、双重介质型、凝胶段塞边界型及均质地层型。对于无限导流型和有限导流型渗流特征,需要进行注采井网调整和继续深部调剖;双重介质型压力导数曲线出现"凹"型特征,调驱后适当进行分注措施;凝胶段塞边界型和均质地层型,可以通过解除油井凝胶的堵塞来改善现有低压油井的地层能量状况。

Deep profile control and oil displacement are key techniques deployed to enhance development performances of sandstone reservoirs. With changes in formation pore structures upon completion of profile control, together with consequential water-flooding seepage patterns and different chemical flooding techniques, it may become even harder to clearly understand distribution of residual oil. Under such circumstances, test data in deep profile control and oil displacement in Menggulin sandstone reservoir of Huabei Oilfield after deep profile control and oil displacement operations were used in combination with log-log derivative curve and pressure semi-log curve for data interpretation. In addition, production performances were analyzed to highlight seepage characteristics corresponding with relevant plots. Sandstone reservoir deep profile control and oil displacement. Seepage patterns in consequential water-flooding operations can be categorized into 5 types, i.e. infinite flow, finite flow, double media, gel plug boundary and homogeneous formation. With regard to seepage characteristics of infinite flow and finite flow types, well patterns can be modified to proceed with deep profile control operations. As for the concave features in pressure derivative curves of double media type, suitable flooding operations in different layers can be performed upon completion of profile-control operations. As for gel plug boundary and homogeneous formation types, formation energy conditions in low-pressure oil producers can be enhanced through removal of gel plugs in these wells.