The floor of the Gulf of Mexico slopes southward to a depth of about 600 feet. From there the Continental Slope plunges rather quickly to depths exceeding 2,000 feet. The Shelf is that area of less than 600 feet water depth. The edge of the Shelf is roughly 120 miles offshore at its broadest, south of the Texas/Louisiana line.

 

Shallower water means a less technically demanding, and hence cheaper, operating environment. Smaller reserve targets can be exploited because of the existing platforms and pipelines. The many thousands of wells that have been drilled to date mean that the chance of finding a large accumulation (that is, a world-class discovery), is very remote.  Consequently, the Shelf is considered to be a “very mature” petroleum province.

 

For the most part, the major oil companies, and even some of the large independents, have abandoned Shelf exploration.

 

The map above depicts the offshore Louisiana Shelf from the Texas border to almost the mouth of the Mississipi River.