储集层构型研究在油田精细开发中的应用

胜利油区的孤岛油田属于强非均质河流相砂岩油藏,特高含水期应用储集层构型理论进行油藏精细描述,将储集层结构层次进行细分,由原来的单砂层、单砂体进一步细分到单一成因单砂体,研究砂体内部构型及各种微地质界面对剩余油的控制作用,在老油田开发调整和挖潜中取得了良好的应用效果。实践证明,主河道厚油层边滩和心滩内部结构复杂,发育的侧积夹层和落淤层夹层具有层内分隔特性,有利于水平井开发挖掘顶部剩余油潜力;河流相二元结构的上部溢岸沉积和边部废弃河道薄砂体物性差、动用程度低,是后期开发的重要潜力区;复合曲流带砂体局部存在废弃河道,形成半连通和不连通,通过识别分析,进一步完善平面注采对应关系,可提高注采效果;单一成因砂体内部可以细分为若干个不同的流动单元,分析其流动特性差异,有助于治理油藏水侵。图8表1参10

Application of reservoir structure research in the fine exploitation of oilfields

Gudao Oilfield in the Shengli oil area, as a typical strong heterogeneous sandstone reservoir of fluvial facies, has successfully applied the reservoir configuration theory to describe reservoirs finely in the extra-high water cut stage. It finely divided the structural levels of reservoir: the original single layer sandstone and mono-sand body are further divided into single-origin monosandstone bodies. The effect of internal configurations and micro-geologic interfaces in sandstones on the remaining oil distribution was studied, achieving favorable effects on exploiting adjustment and tapping potential. Practices proved: (1) the internal structure is complicated in marginal banks and channel bars in thick layers of the main stream channel, and the interlayers in lateral depositions and dropping silts have some separation characteristics, favorable for horizontal wells to tap remaining oil in the top of thick layers; (2) the upper overbank deposits in the double structure of fluvial facies and the thin sandstone layers in marginal abandoned stream channels, which have relative poor physical properties and low exploiting degree, are all important potential areas at the later period of development; (3) abandoned stream channels existing inside the complex curving-flow zones of the reservoir form semi-connection or no connection, affecting the effect of development, and analyzing and identifying them are helpful to improve the corresponding relationship between the injection and production; (4) a single-origin sandbody can be divided into several flow units, and analyzing their difference in the flow characteristics can help to treat the water invasion of reservoir.