3-D tight sandstone gas outcrop simulation based on unmanned aerial vehicle oblique photography data— A case study from the Pingtouxiang outcrop in North Shanxi, China

Abstract

Current methods of acquiring data from outcrops with tight gas rocks yield insufficient data. To resolve this, unmanned aerial vehicle (UAV) oblique photogrammetry was used to quantitatively assess the Pingtouxiang outcrop in the North Shanxi province, China. Rapid and flexible data acquisition, processing, and interpretation helped, develop a three-dimensional (3-D) geological model for a typical outcrop; here, the model of the delta deposit outcrop has 3-D coordinates that correspond to oblique image data, allowing for both the accurate location of field points and for measurements of the rock body. This provides the foundation for studying the stratigraphic architecture of the outcrop. Assessments of experimental sand plot contours and deposition patterns were carried out, in addition to the physical distribution of different sand bodies including superimposed distributary channels, superimposed distributary channels with sheet sand and bars or with continuous or isolated sheet sand. Different sand body types have varied scales and architecture patterns. Virtual well data, lithological calibration, and a geological model and database were used to establish 3-D stratigraphic and lithological models of a typical outcrop via sequential indicator simulation (SIS). Multi-point geostatistical simulations (MPS) were then used to establish a 3-D geological model of the sand bodies that is more in line with our current understanding of the geology of the outcrop area.