Optimization analysis of the high-precision variogram function fitting with multiple data: a case study of TZ4 Donghe sandstone reservoir

In 3D geological modeling of low well density oilfield, it is always difficult to match variogram flawlessly.This paper comprehensively uses data from vertical wells, horizontal wells and 3D seismic survey to create a new variogram matching method for Donghe sandstone in Tazhong area.By comparing variogram results of different orientation and different model, two conclusions are made.Horizontal wells have ample lateral information and could be used to match horizontal variogram which has high correlation rate and little nugget; seismic data can be used to analyze variograms of different orientations for oilfield which has few wells and the ideal variogram could be found.Based on horizontal well data and 3D seismic data, variogram of high matching degree could be calculated and reliable geological data for geological modeling is provided.