(1)In this Part of this Act—
" oil " means any substance won or capable of being won under the authority of a licence granted under either the [1934 c. 36.] Petroleum (Production) Act 1934 or the [1964 c. 28 (N.I.).] Petroleum (Production) Act (Northern Ireland) 1964, other than methane gas won in the course of operations for making and keeping mines safe;
" oil extraction activities " means any activities of a person—
in searching for oil in the United Kingdom or a designated area or causing such searching to be carried out for him ; or
in extracting or causing to be extracted for him oil at any place in the United Kingdom or a designated area under rights authorising the extraction and held by him or, if the person in question is a company, by the company or a company associated with it; or
in transporting or causing to be transported for him as far as dry land in the United Kingdom oil extracted at any such place not on dry land under rights authorising the extraction and held as aforesaid ; or
in effecting or causing to be effected for him the initial treatment or initial storage of oil won from any oil field under rights authorising its extraction and held as aforesaid ;
" oil rights " means rights to oil to be extracted at any place in the United Kingdom or a designated area, or to interests in or to the benefit of such oil.
(2)For the purposes of (d) in subsection (1) above—
(a)the expressions " oil field " and " initial treatment" have the same meaning as in Part I of this Act; and
(b)the definition of " initial storage " in section 12(1) above shall apply but, in its application for those purposes in relation to the person mentioned in (d) in subsection (1) above and to oil won from any one oil field, shall have effect as if the reference to the maximum daily production rate of oil for the field as there mentioned were a reference to that person's share of that maximum daily production rate, that is to say a share thereof proportionate to his share of the oil won from that field.
(3)For the purposes of this Part of this Act two companies are associated with one another if—
(a)one is a 51 per cent, subsidiary of the other ;
(b)each is a 51 per cent, subsidiary of a third company ; or
(c)one is owned by a consortium of which the other is a member;
and section 258(8) of the Taxes Act shall apply for the purposes of paragraph (c) above.