Three-dimensional geological modeling of thin ore body and complex strata based on multi-point geostatistics

The geological environment of coal mines often includes thin coal seams, in which the geological structures have great randomness and uncertainty. Three-dimensional (3D) geological modeling and stratigraphy uncertainty quantification reflect the complexity of geological conditions, as well as contribute to safe and efficient underground mining. In this paper, a 3D geological modeling method of thin ore bodies and complex strata based on Multi-point Geostatistics (MPS) is proposed using borehole data and stratigraphic occurrence constraints. Firstly, we adopt principal component analysis and autocorrelation function to obtain the approximate distribution of each stratum (coal/rock) and the prior model. Secondly, the Simulated Path Optimization (SPO) strategy and the Occurrence-based Local Scan (OLS) strategy are proposed, which emphasize the importance of stratigraphic occurrences in modeling thin coal seams and reduce simulation time-consuming. Here, we use four hypothetical cases with different stratigraphic dips to analyze the sensitivity of the parameters, as well as the effectiveness of the proposed method in this paper. Additionally, taking the boreholes from Western Australia as an example, we compare the results of different modeling methods. Finally, the Shuangyang Coal Mine in Heilongjiang, China, is used to verify the validity of our method, by which the stratigraphic model reveals the structural morphology and coverage relationship of coal and rock seams. Therefore, our method can conveniently obtain the complexity and model reliability at any location, which may provide decision support for intelligent mining of thin coal seams.