The paper is drafted into aim to be a contribution, a clarification, towards the relationship between conventional and unconventional petroleum resources. Within of the content, they are presented general overview and remarks regarding the concepts and bank of raw data, geonatural informations, specific technologies in field and office investigations. As well are mentioned financial –investments ,and juridical aspects. The scenario of the gas resources, focussed on unconventional, it was adapted to Romania’ conditions. Could be found guides and recommendations to the progress and the optimizations of the Romania’ balance energy. The author , by his long and complex experience, as petroleum gelogist, was involved into the drafting, home and abroad, reports of reserves assessment, from global scale to national, regional levels.