Crude prices began to rise last week from near six-year lows, in part due to a reported downturn in U.S. rig activity that could eventually dampen rapid growth in shale oil production. “However, production from existing completed wells is currently unaffected and is contributing to consistent weekly stock builds,” analysts at BNP Paribas said in a note. “The resulting drop in demand for crude at refineries is likely to lead to further large crude inventory builds,” BNP Paribas said.