Application of stratigraphic-sedimentological forward modeling of sedimentary processes to predict high-quality reservoirs within tight sandstone.

Abstract The prediction of high-quality reservoirs within tight sandstone is presently a popular and challenging research topic. Many geophysical characteristics of tight sandstone reservoirs are similar to those of the surrounding rock, making it difficult to predict the distribution of these reservoirs. In this paper, a stratigraphic-sedimentological forward modeling is proposed to predict the distribution of high-quality tight sandstone reservoirs in the Xihu Depression, East China Sea. Stratigraphic-sedimentological forward modeling can evaluate the influences of different geological parameters on sedimentary processes and the results. To reproduce the spatial distribution of sedimentary strata in a progradational delta and the overall stratigraphic stacking pattern, different parameters were tested by numerical simulation. According to the influence of the parameters on the sedimentary process, the parameters can be divided into two types: high-sensitivity parameters (transport capacity of the river and sand ratio) and low-sensitivity parameters (maximum initial water depth, lake level change, and tectonic subsidence). The analysis results are suitable for continental sedimentary basins with relatively high deposition rates. In the process of optimizing the simulation parameters, 236 simulations were carried out by adjusting the high-sensitivity parameters and then the low-sensitivity parameters. An optimal model that can reflect the development characteristics of high-quality tight sandstone reservoirs was obtained. According to the characteristics of high-quality reservoirs, the product of the sand ratio and reservoir thickness from the sedimentary simulation results is used as the parameter for evaluating high-quality reservoirs. The ratio can effectively overcome the difficulties of insufficient amounts of data and seismic prediction and effectively predict the locations of high-quality reservoirs in low-exploration areas of tight sandstone reservoirs. This method also provides a new idea for the prediction of high-quality reservoirs in this kind of area in the future. Highlights • Parametric sensitivity analysis shows that river transport capacity and sand ratio are the main factors affecting the model. • Parameter optimization is carried out according to the parameter sensitivity classification. • High-quality reservoirs are predicted by stratigraphic-sedimentological forward modeling. [ABSTRACT FROM AUTHOR]