They point to the Sakhalin-2 project off Russia's Far East coast, where Gazprom gained majority control from Royal Dutch Shell last year, after Russian authorities refused to give Shell environmental clearance for the scheme.

BBC: NEWS | Business | Gazprom talk lifts Centrica stock

Carter, looking slightly shell-shocked by now, repeated the error minutes later and watched helplessly from his chair as Ronnie made a clearance of 92.

BBC: What exactly goes on inside Ronnie O'Sullivan's head?