Geologic controls and reservoir characterization of the Bradley Brook Field; Madison County, New York

Bradley Brook Field in Madison County, New York State produces natural gas from the Oneida Sandstone where the Oswego Sandstone subcrops immediately below the Oneida Sandstone. The Middle Oswego Sandstone subcrop is not evenly eroded and forms a paleo-cuesta in places within the subcrop. The best producing wells in the Bradley Brook Field are found in a cluster and located within the fault bound Oswego Sandstone subcrop.;Two faults, a north-south and a west-northwest, were proposed independent of seismic data by using geophysical well logs only and later confirmed by proprietary 2-D seismic data in the study area. The fault bounded Middle Oswego Sandstone subcrop makes the trapping mechanism both stratigraphic and structural for the best Oneida Sandstone gas producing wells in the Bradley Brook Field. The Middle Oswego Sandstone subcrop in combination with the two established faults in the Bradley Brook Field explains the cluster of the best producing wells in the study area. Anomalous thinning observed in the Oneida Sandstone is also controlled by the two established faults.;Water saturation and porosity in the Oneida Sandstone in the best producing wells are controlled by the two established faults; whereas, water saturation and porosity in the Oswego Sandstone is not effected by the two established faults as the Oswego Sandstone is stratigraphically lower and is water saturated. Communication between the Oswego and the Oneida sandstones is observed and therefore it is proposed that the Oswego Sandstone acts as a carrier bed for gas migration into the Oneida Sandstone.