Research On Method For Remaining Oil Prediction In High Water Cut Reservoir

Tracing the advanced research of remaining oil prediction and correlative subjects, comprehensively applying the geology, coring, oil testing and reservoir dynamic data, the dissertation studied the methods of remaining oil prediction in high water cut period, with the theory guidance of sedimentology, well log geology, development geology, reservoir engineering, with the methods of the mathematical geology and geological statistics and with the computer. Aiming at high water reservoir remaining oil prediction, this dissertation studied flow unit, sedimentary microfacies, reservoir engineering, numerical simulation, reservoir fine characterization and development dynamic, and provide evidences to remaining oil prediction. From the views of sedimentary microfacies—lithfacies, flow unit, microstructure, reservoir heterogeneity, reservoir engineering, and numerical simulation, the remaining oil distribution was predicted comprehensively. Taking the Mesozoic reservoir in G142 fault block of WangGuanTun oilfield as an example, basing on the formation division and correlation, this dissertation studied flow unit, established interlayer identification criterion, studied flow unit parameters selection, analyzed fine scale, and provided flow unit classification method of high water cut reservoir. The G142 fault block was classified 13 minilayers and 4 kinds of flow unit based on the flow unit classification. Combining the sedimentary microfacies with lithfacies, this dissertation showed that the reservoir developed mid-coarse sand channel bar, carbonate sand channel bar, glutenite braided channel, carbonate glutenite braided channel and flood plain, and quantificational identification modes were built. This dissertation built the reservoir 3D geological model and the flow unit 3D model with the method of high density parameters note, studied reservoir heterogeneity, and also provided reservoir dynamic analysis, reservoir waterflood performance evaluation, well pattern rationality evaluation and fluid characters changing law analysis. This dissertation discussed the problems in reservoir numerical simulation, put forward simulation grid division based on the flow unit classification, established simulation geological model with the method which combined high density parameters notes with perpendicular bisector(PEBI) grid. The complicated geological conditions of high water cut reservoir could be finely characterized with this method. This dissertation showed that staged simulation could characterized dynamic change law of the reservoir parameters in the process of the reservoir development. Thus, the history match accorded with the practical reservoir development so well that the simulation become more reasonable. The remaining oil distribution of G142 fault block was predicted and analyzed by comprehensively using microstructure, flow unit, sedimentary microfacies—lithfacies, and reservoir heterogeneity, reservoir engineering, and numerical simulation. This dissertation put forward the reservoir geology and engineering method for remaining oil prediction in the high water cut reservoir. Combining the "static"which represents reservoir formation characters with the "dynamic"which represents reservoir performance, this dissertation summarized a set of method for remaining oil prediction in the high water cut reservoir.