注水开发中粘土矿物及其岩石敏感性的演化模式

Evolutionary pattern of clay mineral and rock sensitivity in water-flooding reservoir

以华北油田主力砂岩油藏中4种典型沉积相类型的储集砂体为例,探讨了油藏在注水开发过程中储集层岩石属性的微观变化。通过大量岩心样品的室内驱替模拟注水试验,探讨了储集层岩石粘土矿物成分、含量及组合特征的定量演化模式,分析了这种演化所引起储层岩石孔隙结构、敏感性、润湿性、渗流机理变化的特点及对原油采收率的影响。研究结果表明,水驱过程的一系列演化,特别是岩石润湿性的亲水性加强,在一定程度上进一步提高油藏水驱油效率。

The microscopic change of rock attributes in four water-flooding sandstone reservoirs with typical sedimentary facies of Huabei Oilfield was investigated. The quantitative evolutionary patterns of the component, content and the Combination features of clay minerals in rock of reservoir were simulated in laboratory using core samples. The effects of these evolutionary patterns on oil recovery of reservoir and the variations of pore configuration, sensitivity, wettability and percolation mechanism of rock in the reser- voir were analyzed. The result shows that the oilisplacement efficiency of water-flooding reservoir was enhanced by serious evolvement of parameters in the process of water drive, especially by the improvement of rock wettabiltity.