| dc.description.abstract | Since the turn of the century, North American E&P companies have sought to increase production from unconventional reservoirs. This is due to the value added by horizontal drilling and hydraulic fracturing. Infilling wells, or the process of drilling and completing new wells between existing producing wells, has also resulted in increased hydrocarbon recovery. However, infill drilling can result in well-to-well interference, sometimes detectable through deviations in forecasted production. Heterogeneity, variable stress fields, pressure depleted zones, and unknown fracture geometries from completion techniques introduce significant uncertainties in determining an optimal well spacing design for these types of reservoirs. The goal of this study was to quantify well-to-well interference impacts on production so future work might use the results to optimize well spacing for select areas in one of the most popular plays in North America, the Eagle Ford Shale play.
Data gathered from 1,996 horizontal hydraulically fractured wells in South Texas’ Eagle Ford Shale play was used in this research. This involved gathering public well data, including monthly production volumes, completion information, and directional surveys from Western Karnes County and Northern La Salle County, Texas. These areas surround acreage held by Matador Resources, the primary source of support for this research.
Through the use of decline curve analysis and regression techniques, the effects on production of existing producing wells due to new offset completions revealed statistically significant differences in production forecasts performed before and after an offset completion. Results indicated tighter well spacings in both study areas generally increased the magnitude of impacts from well-to-well interference. However, existing producers are impacted both positively and negatively, and it is difficult to predict the direction of impact and how this impact varies with well spacing. New infill wells showed positive interference impacts on their production in the Western Karnes County area, but were inconclusive in Northern La Salle County. The methodologies employed in this work to assess interference effects yielded considerable uncertainty in results and conclusions, which limit their application. | en |
