Shell to eliminate mud discharge in Beaufort

Along with an application to drill a single well in its Beaufort Sea Sivulliq prospect in the 2011 open water season, Shell has submitted a revised Beaufort Sea exploration plan to the Bureau of Ocean Energy Management and Regulation. The revised plan is for the most part a carbon copy of Shell’s plan approved for the 2010 drilling season by the U.S. Minerals Management Service, the precursor agency to BOEMRE. But the plan does contain a significant new feature: a proposal by Shell to collect waste such as drilling cuttings and sanitary waste, and to transfer this waste out of the Arctic rather than discharge it into the sea.

Shell says that it plans to deploy a barge, towed into position by a tug, to collect drilling cuttings coated with drilling mud, for hauling out of the region, while other waste streams such as sanitary waste and bilge water would be held on the drillship or other support vessels, also for out-of-region disposal “in accordance with all applicable laws and regulations.” Shell spokesman Curtis Smith has told Petroleum News that the waste would probably be transferred to an appropriate disposal site on the U.S. West Coast.

Shell says that it does anticipate discharging some waste streams into the sea, in accordance with a National Pollutant Discharge Elimination System general permit. Those streams will include some well cuttings from operations involving the use of just seawater and viscous sweeps, and other harmless materials such as uncontaminated seawater.

The planned drilling operation will use non-toxic, water-based drilling mud that Shell had previously proposed discharging into the ocean along with all drilling cuttings, a practice that is normally allowed for exploration drilling.

BOEMRE is conducting a supplemental environmental assessment for Shell’s exploration plan, with public comments suggesting any new issues or information that may require consideration due by Dec. 22. As in Shell’s 2010 plan, the revised exploration plan includes provision to drill up \to two wells, although at this stage Shell has only indicated an intent to drill one of those wells.

—Alan Bailey