Petroleum production is—
(a) the extraction of petroleum from land for the purpose of producing it commercially;
(b) the injection and storage of petroleum in reservoirs for the purpose of later recovering it;
(c) the recovering of petroleum from reservoirs into which the petroleum was previously injected;
(d) any activity incidental to any activity listed in paragraph (a), (b) or (c), including the processing of petroleum and transportation of petroleum within the area in which the petroleum is being produced.