Activity in the oil and gas sector accelerated in the first quarter as company outlooks improved, according to a survey of oil executives released on Wednesday by the Federal Reserve Bank of Dallas. U.S. crude will sell for an average of $93 a barrel by the end of the year and natural gas prices at the largest U.S. hub will average $4.57 per million British thermal units (mmBtu), according to the survey of oil executives from Texas, Louisiana, and New Mexico. An index of activity by oil and gas companies in the region rose to 56 from 42.6 in the fourth quarter, marking the highest reading since the survey began six years ago, the survey said. Still, executives lamented they are facing “unprecedented” supply chain and labor shortages that are affecting their ability to expand output and add employees despite sharply higher oil and gas prices. Oil prices are at …