低渗透油田高注采比机理研究

Study on the Mechanism of High Injection-Production Ratio(IPR) for Low-permeability Oil Reservoirs

低渗透油田注水开发过程中,普遍具有注采比偏高的现象,这与物质平衡原理相悖。综合研究了新立油田地质特征和开发特点,认为高注采比主要受无效注水、垂直裂缝、弹性存水量、储层沉积特点和固井质量等因素影响,通过校正计算,合理地解释了低渗透油田高注采比现象,并对开发后期注采比变化趋势进行了预测,引入油层盈余率概念作为评价低渗透油藏注采平衡的1种新方法。

There exists a high injection-production ratio(IPR) in water floodded low permeability reservoirs,which contradicts the principle of material balance.The author believes that the reasons causing high IPR are ineffective water injection,vertical fractures,elastic remaining water volume,sedimentary characteristics of reservoirs,well cementation quality and so on based on the study on geology feature and development feature of Xinli Oilfield.The phenomena of high IPR of low permeability reservoirs are rationally interpreted by calibration and calculation.The variation trend of IPR in late development is predicted and a new method that is used for evaluating the balance of injection and production by introducing a new concept,namely,formation surplus ratio.