Method Of Evaluating And Predicting Remaining Oil In Late Water Cut Stage

The generating reason,response characteristic and distributing rule of remaining oil was deeply studied aiming at water-flooded continental reservoir with characteristic of intense heterogeneity,high water-cut,low recovery efficiency,complex distributing rule of mobile remaining oil,intergrowth of major and untabulated formation . At the same time,a systemic method of evaluation and predicating remaining oil and pressure was put forward basing on the theory of development geology,seepage flow mechanics,fluid mechanics which resolved the hard technologic problem of predicting remaining oil and pressure.On base of development geology,seepage flow mechanics,fluid mechanics and geology statistics the method was built through core test,theory analysis and numeric simulation. After much work was done such as analysis of remaining oil generating reason,study of formation and fluid changing characteristic,identification of well log response to water-flooded layer ,the evaluating and predicting model of single well was built by core scale and flow write restriction. As to production and injection well in different condition,a new method was built for flow connection and production matching , determination of threshold value of permeability dispersion,calculating of starting pressure,handle of untabulated layer and boundary,determination of relative permeability type and dynamic model parameters adjustment. It can be used to evaluate remaining oil saturation and predict distributaries rule of remaining oil with well logging information and other data.Eventually,the method was used to evaluate and predict distribution of remaining oil in pilot area of oilfield. It has been proved that the method of predicting remaining oil was feasible and the results of evaluation and prediction were in accordance with geology and development,which has good applied prospect in water-flooded oil reservoir.