An integrated study of the North Riley Unit has been made in order to quantify engineering parameters needed to justify improvements in a secondary recovery system. Data available included well logs from more than 200 wells, approximately one third with open-hole logs; cores along with special core analysis, depositional facies descriptions, diagenesis evaluation, and standard core measurements; as well as production history and wellbore completions. These data were used to calibrate well logs, first to predict geologic parameters, and then to calculate physical properties for individual reservoir facies. Separate porosity equations were developed for each facies. These were followed by saturation and permeability assessments which were calibrated with field-wide data.

Well logs were used to extrapolate the core and production data to the entire field with resulting geological and engineering parameters mapped on a zone-by-zone basis. Results included oil in place, Rw (which varies systematically across the field), water cut, permeability and an estimate of producibility. Using these maps and summary tables, engineering efforts are now underway to increase sweep efficiency and productivity in a cost effective manner. Specifically, recovery from this very heterogeneous reservoir can be improved by increasing well-to-well continuity with additional wells and by greater selectivity in choosing production or injection intervals within each well.

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