Investigating the Effect of Improved Fracture Conductivity on Production Performance of Hydraulic Fractured Wells through Field Case Studies and Numerical Simulations

Abstract

Abstract Various analytical and numerical models have been proposed to predict production performance of hydraulic fractured wells and to investigate the effect of fracture geometry and fracture conductivity on well performance. These completion design parameters greatly impact E&P operators' return on investment (ROI). In this study, we conducted numerous field case studies in the Bakken formation to compare production performance of hydraulic fractured wells with different completion designs. Since all wells are located in the same field, the geological difference was considerably minimized. The wells were grouped and analyzed by different completion and stimulation design parameters. Specific grouped categories included percentage of upgraded proppant in the total proppant amount, lateral length, number of stages, etc. We then simulated post-fracturing production performance of these fractured wells. An advanced meshing technique was developed to honor complex fracture networks with unstructured Voronoi grids. We applied this technique to investigate the characteristics of hydraulic fractures such as fracture conductivity, aperture and permeability distribution on the long-term production of the wells. Core data and well logs were analyzed for reservoir characterization. Several assumptions were made to estimate pumped fracture width, stress-dependent fracture permeability and stimulated reservoir volume. Finally, sensitivity studies were performed to investigate the effect of fracture conductivity on production performance due to superior vs. low-quality proppants. The objective of this study was to determine if upgrading completion designs to high quality proppant materials would achieve better fracture conductivities and long-term production performance. After all well data was analyzed and the production related parameters were summarized, it was determined that upgrading the completion designs with higher quality proppants provided dramatically improved production rates. The following unstructured mesh generation algorithms successfully implemented the local grid refinement feature around fractures, which can handle non-orthogonal fractures and more complex fracture geometries. The final simulation runs and sensitivity studies further demonstrated the importance of both stimulated reservoir volume and fracture conductivities. The same long-term production performance was also predicted by using reduced amounts of upgraded proppant with improved fracture conductivities.