(a) The Oil and Gas Commission, upon the filing of a petition in a form complying with the requirements of § 15-72-308, may after notice and hearing require unit operation of a pool or portion thereof when the unit area newly established embraces a unit area within the same pool established by a previous order of the commission.

(b) In each case the petition shall be accompanied by a copy of the proposed unit operating agreement with respect to the operation of the unit as so enlarged in the form meeting the requirements of § 15-72-308(b)(3).

(c) In each instance the unit operating agreement shall be executed by persons owning interests in oil and gas in the entire unitized area so enlarged in sufficient numbers to comply with the requirements of § 15-72-309(a)(1). However, if the unit operating agreement then in effect with respect to the unit area to which an additional portion of a pool is to be added contains provisions under the terms of which additions to the unit area may be made, the application for enlargement of the unitized area need only be accompanied by an agreement executed by persons owning interests in oil and gas under the area to be added to the unit area in numbers sufficient to comply with the requirements of § 15-72-309(a)(1), for the inclusion, in accordance with the plan provided in the unit operating agreement involved, of the additional area to the unit area then existing.

(d) In either case, the new order, in providing for allocation of unit production from the enlarged unit area, shall first treat the unit area previously established as a single tract. The portion of unit production so allocated thereto shall then be allocated among the separately owned tracts included in the previously established unit area in the same proportion as those specified therefor in the previous order. In no event shall the new order alter the relative values of tract factors of the previously established unit area, except by consent of all parties owning interests in the tract affected.

(e) An order of the commission entered under this section shall be effective as to the enlarged unit area and to all persons owning interest in oil and gas therein to the same extent as an order entered under § 15-72-309. It shall contain provisions with respect to the enlarged unit area to meet the requirements of § 15-72-310, and the provisions of §§ 15-72-311 and 15-72-312 shall be applicable to obligations incurred in the operation of the enlarged unit area.