Gulf of Mexico seeps like a sieve, intrigues columnist - 6/18/2007 -
By Don G. Briggs, President – LOGA (Louisiana Oil & Gas Association)

For years, we have watched the successful CBS sitcom the Beverly Hillbillies. In the opening montage, Jed Clampett is an Ozarks mountaineer who, through sheer fortune, falls into unimaginable wealth with the discovery of oil bubbling beneath his poor farm land.

Clampett sells out for $25 million, moves his family to Beverly Hills, and the rest is history. The truth is that natural oil seepage to the surface does exist.

Fifteen years ago I found myself truly fascinated by a Texas A&M study on oil seepage in the Gulf of Mexico and then by a more recent study by U.S. Geological Survey, commissioned by the National Academy of Sciences.

The NAS study concluded that global estimates of crude-oil seepage rates suggest that about 47 percent of crude oil currently entering the marine environment is from natural seeps.

The remaining 53 percent is made up of spills or leaks from transportation, storage, extraction and urban runoff. The study estimates global seepage is 200,000 mt/a (metric tons), with oil seepage in the Gulf of Mexico being 150,000 mt/a.

I won't pretend to know what the conversion of a metric ton is to a gallon or barrel of oil; let's just say that it is a lot of oil.

Many of us at one time or another have walked on a beach and had the experience of feeling tar ooze between our toes, maybe even cursing beneath our breath something to the effect of "those darn oil companies."

Actually, very little to none of the oil found on beaches comes from the everyday exploration and extraction activities of oil companies, but rather from natural seepage. The US Geological Survey and Minerals Management Services concluded in a study of tar on the beaches of Santa Barbara County, Calif., that:

· All collected coastal tar residues and oils are derived from the Miocene Monterey Formation.

· Tar residues are geochemically distinct from crude oil collected from platforms in the study area.

· A preliminary conclusion is that tar is being transported north along the California coastline from sources in the southern California area.

In 2002, staff writer Robert Cooke of Newsday.com wrote in an article, "It has long been known by geologists and oil industry workers that seeps exist. In Southern California, for example, there are seeps near Santa Barbara, at a geologic feature called Coal Oil Point."

LSU marine geologist Harry Roberts said "it's clear that the Gulf of Mexico 'leaks like a sieve.' You can't take a submarine dive without running into an oil or gas seep. And on a calm day, you can't take a boat ride without seeing gigantic oil slicks on the sea surface."

Roberts also added that seepage in the Gulf of Mexico "far exceeds anything that gets spilled by oil tankers and other sources."

The natural seepage of oil and natural gas into the marine environment is an intriguing ongoing occurrence to scientists, geologists, petroleum engineers, marine biologists and to me.

Don Briggs is president of the Louisiana Oil and Gas Association. His column appears in The Advertiser twice a month.