Abstract: Oil/gas reservoirs are one of the objectives for the geological explorations in petroliferous basins. However, reservoir evaluation is directly related to the assessment of oil/gas in sedimentary basins. Not only the study is necessary throughout the activities of petroleum exploration, but even more important in the development of oil/gas fields. Nowadays, the understanding, analysis and evaluation of the reservoir become the foundamental topics in the study of oil/gas reservoirs. Therefore, it is suggested that the study consists of the following three fields (topics): the regional explorations, oil/gas exploration,and the development of reservoirs.