BP stemmed production declines in the Prudhoe Bay eld for the third year, company officials told us. Prudhoe produces about half of total North Slope oil output, so performance of the 40-year- old eld is critical to supporting overall slope production, which has shown small increases over the last two years. Prudhoe maintained an average of 280,000 barrels per day in 2017, down only slightly from 280,700 in 2016 and 281,800 in 2015. BP is the Prudhoe eld operator. With Prudhoe output as a base, total slope production rose 1.5 percent in 2017 over 2016 to an average of 526,000 barrels per day, Alyeska Pipeline Service Co. reported. Prudhoe experienced annual declines of about 5 percent yearly until BP developed strategies to mitigate the effective decline beginning in 2015.