Exploitation and Development of Oil/Gas Marginal Fields in Nigeria and Romania: Technology, Rising Market Development Challenges & Sustainable Energy Transition

Development of petroleum marginal fields has inevitable become a crucial due to the continuous production decrease in mature and large fields. Although they may not have huge resources, they still can be economically developed and exploited using the available current technologies. Then, they will substitute the lackage of other sources of energy. Therefore, this paper's primary goal is to explore and develop Nigeria's marginal oil and gas reserves, one of which had a blowout during the process of reopening and developing. Nigerian offshore marginal gas condensate field with a blowout well called ‘’Well-1’’ is studied. Three approaches are firstly proposed in order to control and re-entry Well-1. Field development and evaluation were performed. Studies and analyses carried out on the marginal field, which is a gas condensate reservoir, showed valuable reserves. Also, a sensitivity study was done for various recovery factors that could be achieved during producing from the reservoir for each zone and for the total reserves. Afterthat, a cost study was done with changing the interest rate for the next five years. Plans, developments, policies and strategies that have been explored, marginal fields, and completed work are all assessed. Furthermore, gas field development and processing scheme were done and suggested. A thorough discussion and recommendation of problem-solving strategies, technologies, scientific methodologies, and simulation studies were provided. Finally, the situation of marginal fields in Romania is reviewed to know at which level is the development stage. Taken decisions, strategies and polices of the companies owned these fields are also presented. Recommendations to develop those fields are obviously presented.