U.S. energy companies this week added oil rigs for a seventh week in a row, extending a seven-month drilling recovery as crude prices held near a 17-month high. Drillers added 12 oil rigs in the week to Dec. 16, bringing the total count to 510, the highest since January, but still below 541 rigs a year ago, energy services firm Baker Hughes Inc said on Friday. Since crude prices briefly recovered from 13-year lows to around $50 a barrel in May, drillers have added oil rigs in 26 of the past 29 weeks for a total of 194, the biggest recovery in rigs since a global oil glut crushed the market over two years. Almost two-thirds of the rigs added since May…