Could the capped wellhead at the Deepwater Horizon site be leaking again? That’s the question some are asking after the discovery of oil sheens in the vicinity of the infamous BP disaster.

From this story in the Mobile (Alabama) Press-Register:

Oil is once again fouling the Gulf of Mexico around the Deepwater Horizon well, which was capped a little over a year ago. Tuesday afternoon, hundreds of small, circular patches of oily sheen dotted the surface within a mile of the wellhead. With just a bare sheen present over about a quarter-mile, the scene was a far cry from the massive slick that covered the Gulf last summer.

Floating in a boat near the well site, Press-Register reporters watched blobs of oil rise to the surface and bloom into iridescent yellow patches. Those patches quickly expanded into rainbow sheens 4 to 5 feet across. Each expanding bloom released a pronounced and pungent petroleum smell. Most of the oil was located in a patch about 50 yards wide and a quarter of a mile long. The source of the oil was unclear, but a chemical analysis by Louisiana State University scientists confirmed that it was a sweet Louisiana crude, and could possibly be from BP PLC’s well. The oil could be flowing from a natural seep on the seafloor near the wellhead, experts said.

Other possibilities include oil trapped within the wreckage of the Deepwater Horizon drilling rig, or oil deposited on the bottom during the spill that is slowly working its way to the surface. The most troubling possibility, according to petroleum engineers, is that oil is leaking up through the seafloor surrounding the sealed well pipe. Last week, in response to Internet postings by lawyers and environmental groups describing a leak, BP issued a blanket denial, stating, “None of this is true.”