Numerical investigating the effect of nonuniform proppant distribution and unpropped fractures on well performance in a tight reservoir

Distribution of the propped and unpropped fracture is an important factor affecting well performance that is necessary to study. This paper presents new numerical proppant and rock fracture conductivity models. The models are based on the results of physical experiments conducted for this study and the models consider proppant deformation, embedding, and loading paths. The models were implemented in a 3D hydromechanical coupled numerical simulator to model well production. A 3D hydraulic fracturing simulator was used to generate an artificial fracture with nonuniform proppant distribution using reservoir and operational parameters from a tight oil reservoir in northwestern China. The fracture generated by the model was further used to investigate the influence of the nonuniform propped fracture on well performance. According to the study, proppant distribution can significantly affect well performance, a decreased aperture distribution from the well to the fracture front is preferred when using certain amounts of proppant. A parameter sensitivity study was carried out during which the influence of proppant deformation, proppant embedment, proppant permeability, proppant volume, reservoir damage, in-situ stress, and the loading path effect were investigated. Based on the results, suggestions were given to improve the well performance.