That was fun little wiki-war!  Your next assignment: try adding Category Deepwater Horizon oil spill to Atlantis oil field and perhaps a one sentence link to it from Deepwater horizon drilling rig explosion, if latter makes sense to you and article structure.  Note well, when Discussing a particular Category, you need to place a semi-colon    just after first two square brackets to make it a visible link, without actually so categorizing the Discussion page.  A little trick not so easily learned.