The work in this project concentrates on comparing the results of hydraulic fracture mapping and modeling using two microseismic monitoring techniques: downhole and surface arrays. There were three objectives achieved in this project in order to obtain the resulting comparisons. The first objective was to develop detailed posttreatment models of the hydraulic fracturing treatments in the subject well, Well D1, which was monitored with downhole microseismic data. The second objective was to develop detailed post-treatment models of the hydraulic fracturing treatments in the subject well, Well S1, which was monitored with surface microseismic data. The final objective of this project was to determine the match characteristics of the downhole and surface microseismic data to hydraulic fracture models developed for both Wells D1 and S1. Comparisons of the match characteristics of the multiple inputs were then developed.In this study, GOHFER™, a fully three-dimensional fracture simulator was used to build hydraulic fracture stimulation models that were integrated with microseismic events detected during actual hydraulic fracture treatments on Wells D1 and S1.GOHFER™ uses data from actual hydraulic fracturing treatments (pressure, slurry rate, and proppant concentration) and log-derived data to supplement reservoir and mechanical iv Input data for this project were obtained from five wells in the Greater Natural Buttes, Uinta basin, Utah. Two wells, Wells D1 and S1, were stimulated with hydraulic fracturing treatments where each well was monitored by geophone arrays that were placed at different locations. Downhole geophone receivers were employed in an observation well, Well D2, to monitor microseismic activities in the treatment well, Well D1. For the other treated well, Well S1, geophone receivers were placed on the ground surface surrounding the treatment well to monitor microseismic events in the subsurface.Multiple log data were provided for the treated wells including the sonic log from which rock mechanical properties were calculated.Ten fracture models were built using GOHFER™ for five stages each from Wells D1 and S1. Pressure matching procedures were performed to achieve the final simulated fracture geometries. The integration process took place by utilizing data from two sources: microseismic mapping during actual hydraulic fracturing treatment; and fracture profiles from simulated fracture models. Results from the integration process show good agreement for most stages in the downhole-monitored well, whereas comparisons of surface microseismic mapping measurements with the simulated fracture geometries yield questionable results especially regarding microseismic event locations with respect to depth.