The chargeable hydrocarbon tax for any accounting period of a company shall be a percentage of the aggregated chargeable profit for that period and it shall be —
(a)
30% of the profit from crude oil for petroleum mining leases selected under section 93 (6) (b) and (7) (b) of the Petroleum Industry Act with respect to onshore and shallow water areas ; and
(b)
15% of profit from crude oil for onshore and shallow water and for petroleum prospecting licences selected under section 93 (6) (a) and (7) (a) of Petroleum Industry Act.