BP Exploration (Alaska) has shut-in some 70 wells at the Prudhoe Bay and Endicott fields on Alaska’s North Slope following a review of all wells at the fields, taking some 20,000 barrels per day of production offline until identified risks at the wells have been remedied.
“This is a review that’s been going on for the last few months,” Andrew Van Chau, BP Exploration (Alaska)’s vice president of external affairs, told Petroleum News Sept. 29. He said experts from BP and its partners, ConocoPhillips Alaska and ExxonMobil Production, “literally reviewed all the wells that we had up there, producing and injection.”
The focus of the evaluation was on managing risk, Van Chau said.
They looked at the potential for the release of hydrocarbons or produced water in well houses. They looked at operating, start up and shut in conditions: “what elements raise and lower the risks of those activities.”
They looked at what contributes to a release, including the range of weather conditions from extremely cold in the winter to warm in the summer.
They looked at controls to mitigate risk, at the equipment on the wells itself and at administrative controls, the “processes and procedures employees follow” in starting up, operating and shutting down wells.
And they “looked at where could things go wrong” inside the well, such as the potential for corrosion in tubing or valve failure.
Of the 2,000 or so wells at Prudhoe Bay and Endicott, the review looked for wells with the potential for risk higher than acceptable. Seventy or so wells were identified; about 30 of those were already shut in; the balance of the wells are being shut in now, Van Chau said.
Shutting those wells in is the “right thing” to do, he said, because of focus on the workforce and on the safety of BP’s operations.
The next step is to look at what is needed to refurbish the wells, whether maintenance or equipment replacement, because the company plans to operate on the North Slope for decades to come. The focus, he said, is on “maintaining and enhancing reliability … and the safety of our operations.”
The priority will be on “bringing high-production wells back online sooner rather than later,” he said. Each well will be looked at individually to see what is needed. At least 75 percent of the wells are expected to be back online by mid-year 2006, Van Chau said.
Work on these wells will have to be balanced with the work program to drill new wells, he said.
Decisions on which wells to shut in were driven by “safety considerations” for BP’s workforce, and by operational experience both from the North Slope and from worldwide operations. Van Chau said BP also consulted with agencies such as the Alaska Oil and Gas Conservation Commission, the state agency responsible for downhole operations.
