New Concepts for a Normally Unattended Installation NUI – Design, Operation, Automation, and Digitalization

This paper is based on an ongoing multi-participant study which focuses on the development of concepts for unmanned or "Normally Unattended Installations" (NUIs) that can be used for the economic recovery of stranded oil and gas reserves considered too small for traditional floating production storage and offloading (FPSO) vessels, and too far away from existing facilities for tie-backs. The primary objective of the study is to apply existing technologies in novel ways and to utilize recent advances in digitalization to develop low manning concepts by facilitating remote control, remote monitoring, and reducing maintenance requirements. The study engaged key technology vendors and operators, who provided operational expertise and defined future operation philosophies. Concepts are being validated by classification societies, yards and installation contractors. The specific NUI concept explored in this paper is an unmanned production buoy that proved to be technically and economically feasible for the recovery of small hydrocarbon pools in deeper water. The case study is a realistic approximation of a small deepwater offshore development in the North Sea, however, it is not based on any specific prospect. The case study Basis of Design (BoD) has been defined to cover a range of API gravities, ensuring that the resultant topsides design concept is robust and applicable to a range of real field developments in the future without significant re-configuration. The study into the technical and economic feasibility of the unmanned production buoy considered alternatives for gas compression, treatment, separation; heating and cooling, power generation, automation systems, and digitalization. This paper presents the outcomes with respect to production buoy design, operating philosophy, automation and digitalization.