A modified method of multiple point geostatistics for spatial simulation of sedimentary facies for carbonate reservoirs

Abstract

Sedimentary facies information plays an important role in elastic parameter modeling, seismic inversion, and other aspects of marine oil and gas exploration. Multiple-point geostatistics is an important method used to obtain accurate and reliable simulation sedimentary facies data; the filtersim algorithm. However, it is difficult to use the filtersim algorithm to extract the features in a training image by scanning indirect data, such as multiple seismic attributes, as several filters are required. Therefore, we constructed a new method by applying filters to directly scan the training image for a target, such as sedimentary facies, from which two types of prototypes of sedimentary facies and seismic attributes could be obtained. In addition, we modified the method of dividing the filter score and added the score range for the sedimentary facies boundary, which increased the accuracy of the pattern classification. We reduced the number of prototypes with multiple filters by dividing each sedimentary facies prototype by its boundary prototype. Subsequently, we eliminated some empty bins, and improved the efficiency of the simulation. We verified the accuracy of this simulation by comparing the distribution of sedimentary facies in well logs. The results showed that this simulation algorithm can effectively construct 2D or 3D spatial distributions of sedimentary facies in carbonate reservoir by adding the constraints of sedimentary facies and seismic attributes to the filtersim algorithm. The simulation results have valuable implications for situations in which marine oil and gas exploration is being conducted with limited information.