The Leduc oil field, a major discovery in 1947, is near the center of the province of Alberta, Canada. The discovery well, completed in February, 1947, was located on the basis of reconnaissance seismic work by a Carter Oil Company crew and detail by a Heiland Exploration Company crew working for Imperial Oil Limited. By February 1, 1948, 37 flowing wells were producing 4,470 barrels of oil a day under Government allowables. The extent of the field has not been defined, but a probable area of at least 8,100 acres, with an estimated recoverable reserve well in excess of 100,000,000 barrels, is indicated.

With the exception of exposures of Upper Cretaceous continental beds along stream channels, the entire area is covered with glacial drift. In the stratigraphic section drilled to date in the field only two periods, the Cretaceous and Devonian, are represented.

The main producing zones are Upper Devonian dolomites, and are temporarily called the D-2 and D-3 zones. These occur at depths of 4,850-5,400 feet, or 500-900 feet below the top of the Devonian. The D-3 zone, from both its innate characteristics and its regional aspects, appears to be a coral reef. The D-2 zone is rich in coralline material but is a blanket-type deposit. It has an almost constant thickness but a variable porosity throughout a broad regional area. Development of the field is too incomplete to pemit a clarification of the structural picture, but the accumulation appears to be due to both stratigraphic- and structural-trap conditions. Development is proceeding rapidly, and, as of February, 1948, 1 year after discovery, 20 rigs were in operation. Spacing is set by the Pro incial Government at 40 acres per well, with twin wells being drilled in each 40-acre tract where both zones are productive.