This July 3, 2010 satellite photo released by NASA and processed by SkyTruth, shows a cluster of oil slicks caused by natural oil and gas seeps in the Gulf, highlighted by a detail box, about 120 miles off the Louisiana coast in deep water at the edge of the continental shelf. Neither industry nor government checks for leaks at the more than 27,000 oil and gas wells abandoned in the Gulf of Mexico since the late 1940s. AP Photo / NASA via SkyTruth

By JEFF DONN and MITCH WEISS (AP) – 6 July 2010  More than 27,000 abandoned oil and gas wells lurk in the hard rock beneath the Gulf of Mexico, an environmental minefield that has been ignored for decades. No one — not industry, not government — is checking to see if they are leaking, an Associated Press investigation shows. The oldest of these wells were abandoned in the late 1940s, raising the prospect that many deteriorating sealing jobs are already failing. The AP investigation uncovered particular concern with 3,500 of the neglected wells — those characterized in federal government records as “temporarily abandoned.” Regulations for temporarily abandoned wells require oil companies to present plans to reuse or permanently plug such wells within a year, but the AP found that the rule is routinely circumvented, and that more than 1,000 wells have lingered in that unfinished condition for more than a decade. About three-quarters of temporarily abandoned wells have been left in that status for more than a year, and many since the 1950s and 1960s — even though sealing procedures for temporary abandonment are not as stringent as those for permanent closures. As a forceful reminder of the potential harm, the well beneath BP’s Deepwater Horizon rig was being sealed with cement for temporary abandonment when it blew April 20, leading to one of the worst environmental disasters in the nation’s history. BP alone has abandoned about 600 wells in the Gulf, according to government data. There’s ample reason for worry about all permanently and temporarily abandoned wells — history shows that at least on land, they often leak. Wells are sealed underwater much as they are on land. And wells on land and in water face similar risk of failure. Plus, records reviewed by the AP show that some offshore wells have failed. … Despite warnings of leaks, government and industry officials have never bothered to assess the extent of the problem, according to an extensive AP review of records and regulations. That means no one really knows how many abandoned wells are leaking — and how badly. The AP documented an extensive history of warnings about environmental dangers related to abandoned wells. …

AP IMPACT: Gulf awash in 27,000 abandoned wells