Well head leaking at Cape Simpson well 31

Petroleum News Alaska

An old wellhead at the Cape Simpson 31 well in the National Petroleum Reserve-Alaska has been found to be releasing about a gallon of crude oil per day. The North Slope Borough was notified that the well was leaking crude oil and confirmed with a site visit June 4. The Bureau of Land Management, identified by DEC as the “potential responsible party,” was notified on June 7 and flew out to assess the release.

BLM concluded that the master valve had a pinhole size leak that was plugged by natural paraffin at the time of their visit. DEC said pressure was applied to the master valve and gas could be heard escaping. BLM plans to hire a contractor to install a second valve at the wellhead.

In a June 15 update, DEC said that a contractor for BLM and a representative from the Alaska Oil and Gas Conservation Commission traveled to the well to assess repair needs and observe condition of the oil that had been released. They concluded that the oil is leaking from the wellhead at a rate of about a gallon a day and that the oil leakage has been contained in two areas — a circle of about 4-5 foot diameter around the wellhead and an area of equal size at the end of the side arm. DEC said that local residents said this wellhead, on Cape Simpson near Sinclair Lake, has been leaking since March 2000.

DEC said there is also an active oil seep about 50 yards to the east of the wellhead that has covered an estimated 1,500 square yards of surface area with other small seeps in the general area.