The Marcellus Shale is a prolific source of natural gas and is located in much of the Appalachian Basin, The combination of horizontal drilling and multistage hydraulic fracturing have proven extremely successful in achieving commercial production from this ultra-low permeability formation. Even though advances in technology have unlocked considerable gas reserves, the emergence of unconventional shale formations as targets for exploration and development have created new challenges for resource development. These challenges arise because the impact many reservoir and fracture parameters have on the effectiveness of the stimulation treatments to increase reserves and improve production efficiency is not well established.
The focus of this study is to identify what effect fracture half-length and well spacing have on the maximization of gas production and gas recovery efficiency from Marcellus Shale horizontal wells. A commercial reservoir simulator was used to develop a base model for the Marcellus Shale formation. These simulations models were constructed using information from the Marcellus Shale Energy and Environment Laboratory (MSEEL). MSEEL is a research collaboration between West Virginia University, Ohio State University, The National Energy Technology Laboratory, and Northeast Natural Energy. MSEEL is a long-term laboratory and field study that will assess the hydrocarbon production potential and the environmental and economic impacts of drilling and producing wells in the Marcellus Shale. The base model incorporated many of the complex reservoir characteristics that are associated with the Marcellus Shale. They include a horizontal wellbore, multi-stage fracture treatment, adsorbed gas, and in situ rock properties. Reservoir properties, such as porosity, permeability, natural fracture spacing, etc., were determine using history matching. The available data from two original horizontal Marcellus Shale gas wells at MSEEL were utilized for history matching the daily and cumulative gas production. The impact of completion parameters on gas recovery was investigated using history-matched models to evaluate the impact that fracture half-length and well spacing have on production. The predicted optimized production will be presented and compared to the baseline production results, and be presented in the paper.