Further problems hampered the Arctic project after the commencement of drilling in <answer>2012</answer>, as Shell dealt with a series of issues that involved air permits, Coast Guard certification of a marine vessel and severe damage to essential oil-spill equipment. Additionally, difficult weather conditions resulted in the delay of drilling during mid-<answer>2012</answer> and the already dire situation was exacerbated by the "Kulluk" incident at the end of the year. Royal Dutch Shell had invested nearly US$5 billion by this stage of the project.
In what year did drilling in the Arctic region begin?
2012