Productivity levels in the US’ prime tight oil play began to fall last year, raising further questions over the sustainability of the current tight oil recovery as constraints on the shale sector mount, BP’s chief economist Spencer Dale said Wednesday.  With US tight oil and natural gas liquids (NGL) production surging by almost 2 million b/d since late 2016, shale drillers have been forced to spread out from the most productive areas, or sweet spots, in their acreage, Dale said presenting BP’s latest annual Statistical Review. Tight oil well productivity has now flattened out in the Permian Basin based on initial output per completed well, he said. But tight oil productivity from the basin fell last year when measured by output per lateral foot of each completed well, Dale said. “It does perhaps suggest that the very rapid increases in tight oil productivity that […]