West Africa-focused oil and gas exploration group BowLeven has started drilling on the Sapele-2 well in its Douala Basin prospect off the coast of Cameroon.The main purpose of the Sapele-2 well is to appraise the Omicron discoveries encountered in the Sapele-1 exploration well. The Sapele-2 well will penetrate both the Lower and Deep Omicron discoveries at a location around five kilometres south west of the Sapele-1 location. Drilling is expected to take around 50 to 60 days (excluding testing).