The Liard Basin straddles the British Columbia, Yukon, and Northwest Territories borders, and has an areal extent of over 9600 square kilometers. The basin is fault-bounded on the eastern margin by the Bovie fault, which has been active since the Early Paleozoic. To the southwest, the basin is bounded by the Rocky Mountain Foothills, and to the north and northwest by the Liard Plateau. Much of the subsurface within the Liard Basin remains unexplored, however, previous work has noted that the Lower Cretaceous strata do contain reservoir potential. To date, the Maxhamish gas pool with estimated gas in place values of 300 to 400 Bcf represents the only economically significant field within the Liard Basin. Production at Maxhamish is from sandstones of the Chinkeh Formation.
The Chinkeh Formation is Barremian to Aptian in age, and at Maxhamish, sits unconformably on tilted Triassic shales. The Chinkeh Formation represents the oldest Cretaceous rocks deposited within the Liard Basin.
Preliminary core descriptions have indicated that the producing Chinkeh zone consists of glauconite-rich, finegrained, quartz arenites to sublitharenites. The Chinkeh sands also contain abundant clays, in particular kaolinite, illite, chlorite and smectite, which complicate completion and production. Reservoir sands are interpreted to be shoreface deposits with permeabilities ranging from 5-80 millidarcies and porosities ranging from 15 to 20% (with an average of 15%).
The Chinkeh Formation within the Liard Basin contains
a full suite of trace fossils ranging from a poorly developed Zoophycos
ichnofacies, through to the much more abundant and diverse Skolithos ichnofacies.
AAPG Search and Discovery Article #90925©1999 AAPG Foundation Grants-in-Aid