About 70 miles north of Pittsburgh, a pothole-pocked dirt road along the side of a warehouse leads to a solitary oil well, undisturbed by the recent plunge in crude prices. McClintock No. 1, the world’s oldest continually producing oil well, is still going after 153 years, quietly churning out about 1/10 of a barrel each day from a small spot in a clearing of trees. Crude bubbles up from this 625-foot chasm regardless of the swings in oil prices, which have slid 30 percent in the past five months amid a glut in global supply. On its best days, McClintock yielded about 175 barrels. It’s survived through all the industry’s highs and lows, from busts that sent prices below $1 per barrel during the Great Depression to booms that sent them over $140 in 2008. The well’s output today is sold to a fuel company to make motor oil, […]