Petroleum geology of the United States Atlantic continental margin
Early hydrocarbon exploration on the U.S. Atlantic continental margin was concentrated in the shallow water depths of the Continental Shelf over Georges Bank Basin, Baltimore Canyon Trough, and the Southeast Georgia Embayment (Figs. 1, 2, and 3). Wildcat drilling started in March of 1978 when the Exxon 684-1 well was spudded-in near the shelf edge in the Baltimore Canyon Trough (Fig. 2). To date, industry has drilled 45 deep wildcat wells on the U.S. Atlantic Continental Shelf. Although significant natural gas discoveries and shows were reported from wells drilled in the Baltimore Canyon Trough area (Table 1), a commercial gas field has yet to be established. Crawford (1978) estimated that a daily flow of about 5.7 million m3 (200 million ft3) and reserves of about 34 billion m3 (1.2 trillion ft3) of natural gas would be required to warrant establishing an offshore production platform and pipeline. Since mid-1982, wildcat drilling on the shelf has come to a standstill, and leases for numerous blocks on the shelf have been relinquished by industry.
In 1983-84 exploration shifted from the shelf area to the slope. During this period, deep-water drilling tested the Jurassic- Cretaceous reef trend beneath the mid-Atlantic Continental Slope. It was hoped that the shales here, deposited in a reducing environment, might contain a high percentage of preserved marine organic matter and that reservoirs in backreef, reef, and forereef areas might have been charged with petroleum generated from the shales. To date, industry has completed 4 wells (93-1, 372-1,586-1, and 587-1) in water depths of about 2,000 m in the Baltimore Canyon Trough area (Fig. 2). Data from the 93-1 well has not bee released; the other three wells were reported to be dry holes.
Figures & Tables
The Atlantic Continental Margin
This synthesis covers stratigraphy, depositional processes, and geophysical interpretation of the major onshore and offshore marginal basins from Maine to the Bahamas, and includes an up-to-date review of thinking on regional tectonic history. Additional chapters discuss the theoretical aspects of thermal evolution, subsidence, and seismic stratigraphy as applied to this region. Geological resources including petroleum, water, sand and gravel, hard minerals, and heat flow are reviewed, and environmental hazards such as seismicity, coastal erosion, waste disposal and submarine instability as it relates to site of drilling platforms and mining are evaluated. A summary chapter reviews areas of controversy and suggests key topics for research.