ABSTRACT: The Geology of Venture, a Geopressured Gas Field, Offshore Nova Scotia

K. J. Drummond

The Venture gas field is a potential giant gas accumulation discovered in 1979 by the Mobil et al Venture D-23 well drilled by Petro-Canada on a farm-in from Mobil. This well was completed at a total depth of 4945 m

(16,224 ft). The field is located on the Scotian Shelf, 5-16 km (3-10 mi) off the east end of Sable Island, 300 km (186 mi) east of Halifax, Nova Scotia. Water depths across the field range from 12 to 23 m (39 to 75 ft). Participants in the Venture field include Mobil, Texaco, Petro-Canada, and Nova Scotia Resources. Venture is the largest discovery on the Scotian Shelf, offshore Nova Scotia, with initial estimates of ultimate gas recovery exceeding 1.5 tcf.

The Venture structure is an elongate east-west anomaly on the downthrown side of a normal east-west-trending fault. Currently, five wells define a gas-bearing area of about 3000 ha (7400 ac) within structural closure. In the Venture field, gas occurs in multiple sandstone reservoirs, from Late Jurassic to Early Cretaceous age, over a stratigraphic interval of 1600 m (5250 ft). The Venture gas-bearing productive section consists of one to four hydropressured sandstones and up to 17 geopressured sandstones, with pressure-depth ratios of up to 0.8 psi/ft. Venture sandstones exhibit abnormally high porosities for their depth, possibly both preserved primary porosity and secondary solution porosity. The reservoirs are often characterized by high water saturations and very high-salinity for ation water.

AAPG Search and Discovery Article #91000©1990 AAPG Conference-Giant Oil and Gas Fields of the Decade 1978-1988 Conference, Stavanger, Norway, September 9-12, 1990