For the purposes of this Act, the quantity of petroleum recovered by the registered holder of a petroleum exploration permit, petroleum retention lease or petroleum production licence from a well during a period is taken to be:
(a) the quantity measured during that period by a measuring device:
(i) approved by the State Minister ; and
(ii) installed at the wellhead or at such other place as the State Minister approves; or
(b) if:
(i) no such measuring device is so installed; or
(ii) the State Minister or the Joint Authority is not satisfied that the quantity of petroleum recovered by the registered holder from that well has been properly or accurately measured by such a measuring device;
the quantity determined by the State Minister as being the quantity recovered by the registered holder from that well during that period.