U.S. energy companies this week added the most oil rigs in nearly four years, extending an eight-month recovery as drillers take advantage of a deal by OPEC to cut supplies that has boosted prices over $50 a barrel since early December. Drillers added 29 oil rigs in the week to Jan. 20, bringing the total count up to 551, the most since November 2015, energy services firm Baker Hughes Inc said on Friday. During the same week a year ago, there were 510 active oil rigs. Since crude prices first topped $50 a barrel in May after recovering from 13-year lows in February, drillers have added a total of 235 oil rigs in 30 of the past 34 weeks, the biggest recovery in rigs since […]