Abstract: The bedrock gas reservoir in the Dongping Gas Field is a rare and unconventional fractured gas reservoir, and it is challenging to model the development and distribution of the naturally occurring fractures in the area. We aimed to solve this problem by establishing a Discrete Fracture Network (DFN) model of the bedrock reservoir based on the spatial characteristics of the reservoir in the Dongping gas field. We first divided these natural fractures in the Dongping Gas Field into two roughly perpendicular groups based on fracture characteristics measured in image logs, such as the inclination angle and azimuth, and we modelled the density distribution of each group. A DFN model was then built using a fracture density curve as the target curve and seismic attributes as constraints. By extracting attribute parameters such as fracture density, porosity, and permeability, we studied the distribution characteristics of the fractures in the Dongping bedrock reservoir. The results showed that these fractures are generally controlled by faults, and there is strong non-uniform development along both horizontal and vertical axes. Finally, this paper validates that the DFN model is suitable for bedrock reservoirs by demonstrating fitting between the dynamic characteristics of production in the Dongping bedrock reservoir and the modelled production of the gas reservoir.

Key words: Dongping Gas Field, bedrock reservoir, fracture modelling, DFN model, seismic attributes