Abstract: New Oil from an Old Reservoir: The Petrolia East Pool

TREVAIL, ROBERT A.
Orion Resources Consulting Ltd.,JAMES O. RAYNOR
Geophysical Consultant, and S. M. BRUCE BAILEY
Bailey Geological Services, Ltd., London, ON

Ideal reservoir management begins the day a commitment is made to explore for and develop new oil and gas resources. However, sometimes an opportunity arises to introduce reservoir management techniques to an older, still producing pool in hopes of locating bypassed pay, increasing current production rates, and maximizing profitability.

The Petrolia East Pool, discovered in 1972 in Lambton County, Ontario, produced 342,330 bbls of oil to the end of 1996 from a Silurian Niagaran pinnacle reef. CanEnerco Limited, the current operator, purchased the pool in 1996 with the intent of further developing the remaining reserves. Initial work included workovers of a number of the wells, plugging wells with mechanical problems, and acquisition of a 3D seismic survey over the entire structure. Preliminary inversion analysis of the seismic data indicated an undrilled anomaly in the extreme northeast part of the reef. Subsequent drilling encountered two producing zones, totaling 112 ft of dolomite reservoir with average porosity and permeability of 10.8% and 240 mD respectively. The initial production rate was approximately 120 bopd.

Utilizing all available data (drill cuttings samples, core, well logs, bottom hole pressures, GOR measurements, seismic, etc.) an attempt was made to better understand the heterogeneity of the reef in order to apply proper reservoir management techniques. Results to date indicate a complex blend of depositional facies, diagenetic fabrics, and halite plugging contribute to compartmentalization of the reservoir. Work continues on integrating well data with 3D seismic to optimize future drilling and production operations.

AAPG Search and Discovery Article #90930©1998 AAPG Eastern Section, Columbus, Ohio