In Amenas road sign, Algeria.

It has been a harrowing start to 2013 for the global energy industry. BP, Statoil and the joint operators of the In Amenas natural gas plant in Algeria are slowly coming to terms with last week's brutal 4-day occupation of the isolated desert facility where 38 mainly foreign hostages were killed by Islamist militants.

Governments and the industry have a grim and arduous task ahead in the immediate aftermath - accounting for still missing personnel, clearing the site of explosives and munitions left by the attackers and finally returning to some semblance of normality by resuming production at the plant, which accounts for 10 percent of Algeria's natural gas.