Investigating a Pilot Area in the Williston Basin Three Forks Formation to Determine the Optimal Inter-Well Spacing and Hydraulic Fracture Length to Maximize Economic Recovery

摘要

The objective of this work is to determine optimal inter-well spacing and hydraulic fracture length of the Three Forks assets in the Williston Basin operated by SM Energy. SM Energy is an independent exploration and production company with operations across North America, mainly in Texas and North Dakota. SM Energy recently switched to infill drilling development in their North Dakota assets and is interested in knowing the economically optimal number of wells that can be drilled per two-section drilling unit.A simulation approach was taken in this research to address SM Energy’s issue. For research purposes a small pilot area was chosen from the Williston Basin with twelve operating wells. The pilot area is located at Colgan Field, Williston Basin North Dakota USA. The geological and reservoir model of the pilot area was simulated in Petrel and hydraulic fracture properties were obtained from SM Energy and incorporated into the Petrel model.After building a sound geological model the next focus was to match observed production data from the wells in the study area. After validating the model by successful history matching, the simulated model was used to answer the study question. The study question was answered by evaluating different case scenarios with symmetrical well spacing and varying well densities. Economic analysis was performed using current drilling costs, operating costs and a range of oil prices. Results from economic analysis were used to determine the most profitable situation for SM Energy.Another focus of this thesis was on high water cuts in the operating wells. The study wells are operating around 50% water cut. In this work water influx was modelled using different aquifer models and flow geometries to match the water production data from the field. This work determined the number of wells that can be drilled economically in the Three Forks asset. In addition, SM Energy also benefits by understanding the predominant source of water influx in the study area.