Modeling Method of Point Bar Internal Lateral Accretion Interlayers of Meandering River Reservoir Based on Reservoir Numerical Simulation Dynamic Response

Abstract

In the process of point bar internal architecture modeling, it is common to use local grid refinement method to model lateral accretion interlayers, which are often less than 1 meter thick but have a considerable impact on fluid flow. Due to huge grid amount and grid size difference, it often causes non-converging or converging too slowly of reservoir dynamic numerical simulation algorithm, which is not beneficial to practical application. In this study, we proposed a new method to model lateral accretion interlayers based on reservoir numerical simulation dynamic response. Firstly, modeling target area of lateral accretion interlayers is defined by history matching results analysis based on the point bar level geological model. Then, the lateral accretion interlayers of the selected target area are modeled and equivalently characterized through transmissibility multiplier data instead of geometric parameters in numerical simulation model. Lastly, the multiplier value of transmissibility multiplier data is determined based on reservoir numerical simulation dynamic response. The method of this paper only models the lateral accretion interlayers which have influence on fluid flow, which greatly reduced research workload than modeling the lateral accretion interlayers of the entire oilfield. The fluid seepage effect impacted by lateral accretion interlayers is characterized through transmissibility multiplier data; it has overcome the shortcomings of traditional local grid refinement method, and operation efficiency is greatly improved. The method has been successfully applied to model the lateral accretion interlayers for fine remaining oil distribution prediction in Q oilfield. Compared with traditional local grid refinement method, the computation time of numerical simulation is greatly reduced. The historical fitting rate of water content of a single well is grastly improved. Based on the new method, the water flooding degree coincidence rate between model prediction results and post-drilling logging interpretation is above 90%. In this study, we proposed a new lateral accretion interlayers modeling method to improve the numerical simulation accuracy and efficiency. It can also be used in other sedimentary facies types such as deltas for internal architecture modeling.