(1) In section 6(1) of the Principal Act insert the following definition—
""underground petroleum storage" means—
(a) the injection into and storage of petroleum in natural reservoirs from which petroleum was previously recovered for the purpose of later recovering it; and
(b) the recovery of petroleum from a natural reservoir into which it was previously injected under paragraph (a); and
(c) any activity incidental to an activity listed in paragraph (a) or (b);".
(2) In section 6(1) of the Principal Act, in the definition of good oilfield practice —
(a) in paragraph (b), after "operations;" insert "or";
(b) after paragraph (b) insert —
"(c) underground petroleum storage operations;".
(3) In section 6(1) of the Principal Act, in the definition of "petroleum"—
(a) in paragraph (f), after "both;" insert "and";
(b) after paragraph (f) insert —
"(g) for the purposes of underground petroleum storage, also includes any petroleum as defined by paragraph (a), (b), (c) or (d), where—
(i) one or more things have been added; or
(ii) one or more things have been wholly or partly removed—
or both; and
(h) for the purposes of underground petroleum storage, also includes any mixture that—
(i) has been recovered from a natural reservoir; and
(ii) includes petroleum as defined by paragraph (a), (b), (c) or (d)—
whether or not—
(iii) one or more things have been added; or
(iv) one or more things have been wholly or partly removed—
or both;".
(4) In section 6(1) of the Principal Act, in the definition of "well", after paragraph (b) insert —
"(ba) underground petroleum storage operations; or".