Operations at Essar Oil UK's Stanlow refinery on the same site were unaffected, Essar says. : LONDON, Aug 22 (Reuters) - A fire broke out at a Shell-owned chemical plant in northwestern England on Wednesday but operations at Essar Oil UK's Stanlow refinery on the same site were unaffected, Essar said. The Shell Higher Olefins Plant (SHOP) is separated from the refinery by a road and rail tracks. Essar operates the chemical plant as well as the refinery. "Earlier this afternoon, a fire occurred at the SHOP chemical plant," an Essar spokesman said.