This paper flows through a consideration of various industry standards for possible knowledge to promote the design of all-electric subsea production control system. All-electric subsea production control system is borne from the need to replace hydraulic pressure completely with electric power as the sole power source for subsea production system (SPS). Currently, there are developments involving the accumulation of electric power in batteries subsea for powering electrical actuators. The motivation for this paradigm shift in technology is improvement in the following: Safety, environmental-friendliness, cost (CAPEX and OPEX savings), performance and reliability.
A major contribution to the subsea system assurance is ensuring independence between the safety systems (emergency shutdown and process shutdown) and from the control system (basic process control system), which will provide guarantee against dependent failures. This paper aims to investigate independence in a subsea electrical/electronics actuator with emphasis on split logic and shared final element, with the objective of saving cost without compromising safety. The paper builds on an evaluation of existing standards and regulations, among other technical documents, where there exists a set of areas with difference in implementation between the subsea method and topside process industry method. In addition, the paper proposes a classification scheme for achieving independence, considering the fact that too frequent interventions subsea is very expensive. Furthermore, recommendations are also offered in relation to the concept of split logic and shared final element.