Petroleum (Oil and Gas) Resources in the Marine Environment
Without question, the petroleum and natural gas industry is the largest source of jobs and revenue in the world, involving seven out of top ten of the world's largest corporations and is the largest source of wealth for countries around the world. Oil and gas reserves in marine and coastal regions is the largest natural resource. Almost all oil and gas resources occur in sediment-filled basins along continental margins or in regions within continents that were ocean-margin basins in the geologic past (Figure 17.2). The Middle East region has the greatest amount of oil & gas resources (Saudi Arabia, Iraq, Iran, and other countries around the Persian Gulf). Venezuela, Canada, Russia also have significant reserves. About 1/3 of world’s reserves occur on continental margins.
Sadly, petroleum consumption is at the heart of the environmental, economic, and social issues related to greenhouse gas/global warming, climate change, ocean acidification, and related issues.
What is the difference between a resource and a reserve?
The term resource applies to the total amount of material that occurs in a region. In the case of petroleum (oil and gas), this includes “fuel” that is both discovered and undiscovered, and may or may not be economically recoverable. In contrast, reserves are deposits of fossil fuels that are known to exist in a region with a reasonable level of certainty based on geologic and engineering research. A reserve is only a portion of a resource that is economically recoverable based on technologies that already exist. The value of an oil field is only based on the amount of petroleum that can be reasonably extracted over a period of time. The reserves of the world’s oil resources are constantly changing. For instance, the new technology associated with fracking has nearly doubled the amount of petroleum reserves in the United State in the last decade, whereas the resource assessments have remained essentially unchanged.
Unfortunately the easiest to access reserves on land and in shallow coastal areas have already been exploited and depleted, forcing ongoing exploration for future reserves into deeper water.