厚层碳酸盐岩油藏宏观物理模拟实验研究

以中东Missan油田的厚层碳酸盐岩油藏BU为原型,根据相似理论,利用人造碳酸盐岩岩心模拟目标油藏储层,设计与目标油藏典型单元相似、尺寸为80 cm×80 cm×10.7 cm的宏观物理模型,用于研究厚层碳酸盐岩油藏的水驱规律和水淹模式,对比不同井网井型的开发效果.水驱实验结果表明:厚层碳酸盐岩油藏水驱规律主要受纵向非均质性和重力的影响,呈现双峰状和单峰状特征.水淹模式为:注入水在近注水井区域沿纵向运移到高渗透层并沿高渗透层向前突进;远离注水井区域后上部突进的注入水在重力作用下向下运移,然后沿下部高渗透层突进并率先突破到生产井井底,形成次生底水;最后次生底水向上托进,导致油井水淹.遵循上述水淹模式,剩余油主要分布在远离注水井的上部层位;水平井加密井网较其他井网对上部层位储量控制程度更高,因此拥有更高的采收率和开发效率.

Large-scale physical simulation experimental study on thick carbonate reservoirs

Aiming at a thick carbonate reservoir(BU)in the Middle East Missan Oilfield,based on similarity theory,the arti?ficial carbonate sample is used to simulate target reservoir,an large-scale physical model with size of 80 cm×80 cm×10.7 cm that is similar to the typical unit of target reservoir is built to study the water flooding performance,water flooding modes,and the development effect of different well patterns.Results show that the water flooding performance of thick car?bonate reservoirs are mainly affected by the longitudinal heterogeneity and gravity,and are characterized by double peaks or single peaks.The water flooding mode is summarized as follows:the injected water moves longitudinally to the high-per?meability layer near the water injection well and flow forward along the high-permeability layer.Away from the injection well,the top injected water moves downward under the effect of gravity,then moves along the lower high-permeability layer and breakthroughs to the bottom of the production well to form a secondary bottom water.Finally,the secondary bottom wa?ter moves upward,causing the production well to be completely watered.Based on above mode,the remaining oil mainly distributes in the upper layers far from the water injection well;correspondingly,the horizontal well infill well pattern shows a higher control over the reserves of the upper layer than other well patterns,hence it can lead to the higher recovery and development efficiency.