A systematic evaluation of the Medina Group in Chautauqua County, New York was performed in 1998 to identify production and reserve improvement opportunities in this large, continuous, low permeability gas accumulation. Petrophysical analysis, geological mapping and advanced production type curve analysis was performed over a 200 well study area covering 38,000 acres. Net pay, net sand and hydrocarbon pore-feet was determined from the log analysis. Structure, isopach, pay thickness, gas in place, permeability and well drainage areas were mapped.

Several infill/stepout locations were identified based on geologic parameter mapping and four new wells were drilled in the fall of 1998. Medina pay was encountered in agreement with the geologic prognosis for the wells. However, pore pressure was below original conditions indicating partial depletion at the new locations. Weekly production data was collected from the new wells for a six month period and decline curve analysis performed to estimate recovery.

Keywords:
fluid dynamics, medina group, upstream oil & gas, top curve, grimsby formation, tight sand evaluation, flow in porous media, permeability, spe 57440, drainage area
Subjects:
Well & Reservoir Surveillance and Monitoring, Reservoir Characterization, Reservoir Fluid Dynamics, Formation Evaluation & Management, Reserves Evaluation, Flow in porous media, Open hole/cased hole log analysis
Copyright 1999, Society of Petroleum Engineers
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