Upon filing of an application for an order providing for the unit operation of a pool, pools, or part thereof, and for the pooling of the interests in the oil and gas in the proposed unit area, the commission shall promptly set the matter for hearing and in addition to the notice otherwise required by section 57-911 or the commission rules shall cause notice of the hearing to be given by certified mail at least fifteen days prior to the date of hearing to all persons whose names are required to be set forth in such application.