洪积扇砂砾岩储层岩石相渗流特征及剩余油分布规律

Flow Mechanism and Waterflooding Characteristic of Conglomerate Lithofacies

洪积扇砂砾岩储层岩石类型复杂多样,不同岩石相的含油性、渗流性能及油水运动存在差异,以此可以寻找砂砾岩油藏开发后期的剩余油。研究表明:通过野外考察和岩心观察及FMI测井分析,砂砾岩储层可以划分出7种类型的岩石相,其中片流成因的交错层理-细砾岩相和平行层理砂岩相大孔粗喉,饱含油,渗流性能最佳,注水开发快速水进;杂基颗粒支撑—中粗砾岩相和含砾块状粗砂岩相属于中孔中喉,油浸、渗流性能次之,开发效果好;杂基支撑无序—泥质砾岩相和波状层理粉细砂岩相储层的含油性和流动性最差。结合生产动态信息,杂基颗粒支撑-中粗砾岩相和含砾块状粗砂岩相是后期开发调整的目标岩石相。

The remaining oil in the conglomerate reservoir can be prospected and recovered based on the diversity of alluvial fan rock types of the reservoir and oiliness and fluidity and oil-water movement of different lithofacies.The field observation,core analysis and FMI logging of the conglomerate reservoir show that this reservoir consists of 7 types of lithofacies.The study result shows that the cross bedding-fine conglomerate and parallel-bedding sandstone is the best in porosity,oil saturation and fluidity,grain-supported middle-coarse conglomerate and massive pebbled sandstone are the next,while argillaceous conglomerate and wavy-bedding siltstone are the worst.It is then concluded that middle-coarse conglomerate and massive pebbled sandstone should be the main object of later development or adjustment.