The oil and gas production from Indian Offshore have been dominating with more than 60% of the total production coming from offshore fields. This scenario is expected to continue in the future also. Accordingly, greater emphasis is being laid in offshore exploration. In these exploration efforts, many small/marginal fields have been discovered off the Indian coast. To develop these fields economically cheaper and cost effective solutions are required which include subsea well completions. Further, due to marginal nature of these fields, artificial lift is required to improve vertical lift performance, sometimes right from the beginning. Various modes of lift which include rod pumping (RP), gas lift, electrical submersible pumps(ESP), hydraulic jet and turbine pumps have been analysed and reviewed for their application in four BR series marginal offshore fields where geological reserves are lower than 20 million tonnes (in most cases, less than 10 million tonnes). Among the available modes, gas lift is considered technically superior and economically cheaper alternative for its application in these marginal fields. This is planned to be implemented right from the beginning of the field development.
The marginal field is one that is on the borderline between economic and not being economic to develop. The marginal fields are normally smaller fields. The word "marginal" implies that the conventional technology for developing offshore fields may not be feasible and cheaper hardware designs and systems need to be adopted. The production and platform systems need to be made cheaper. Several redundancies in the systems and their controls for operational flexibility and safety need to be weighed and sacrificed to reduce cost.