GRAVITY CASE HISTORY: DAWN NO. 156 POOL, ONTARIO

Abstract

The Dawn No. 156 pool in southwestern Ontario was discovered by the Union Gas Company of Canada Limited, in January, 1952, by drilling on a gravity maximum. The drilling supported the original interpretation that this maximum was produced by a Silurian reef. Initial production of 6.5 million cubic feet per day was obtained from the upper fourteen feet of the Guelph in highly porous reef dolomite at a depth from 1,720 to 1,734 feet below the surface. The geology of the area is discussed as a background for the gravity interpretation. Bouguer and residual gravity maps of the original survey are presented.