Subsea All-Electric

Abstract

The trend in subsea development is heading towards simplification, industrialization, digitalization and commercial optimization in an environment of longer step-out and deep / ultra-deep water applications. With that the limitation of existing electro hydraulic systems as exposed. Statoil has launched an All-Electric Subsea (AES) initiative to prove the feasibility of new flexible, cost efficient subsea production system (SPS) to meet future demands. While most of the main technology elements are available and proven in use, full market and operator acceptance seems to be a challenge. However, in the current and future situation and with the experience gained from the Åsgard subsea compression system, all electric is considered as a feasible future option for SPS. The strategy for the AES initiate is to identify all electric concepts with SPS vendors in order to establish cost effective solutions and strive for standardization of products and interfaces. The AES initiative aims to have system approach and examine the impact on all elements of a subsea development, i.e. covering topside, umbilical, SPS and downhole etc. This will ensure the benefit of an all-electric implementation is presented. The intention is to present the advantages seen with an all-electric for all aspects, i.e. with respect to cost, project execution, operational flexibility, standardization. This paper will present the current status of the AES initiative covering: –the fundamental features of the AES technology and concepts–the potential of this technology for operation in production control systems–status of the all-electric initiative with respect to technology maturity–the activities required to close the identified technical gaps–the implementation of all electric SPS solutions

Digital Redundance for Compact Subsea Electro-Hydrostatic Actuators Using Sensor Fusion

“…The transition from conventional hydraulic and electro-hydraulic to electro-mechanical apparatus in subsea oil & gas exploitation fields is a growing trend, referred to as the "All-Electric Subsea" approach. This shift offers multiple advantages including reduced installation (CAPEX) and operation costs (OPEX), quicker system response, increased energy efficiency, reduced umbilical cable diameter (due to the elimination of hydraulic lines), enhanced operational flexibility, and environmentally sustainable design [1] [2]. Electro-hydrostatic actuators (EHAs) are integral to this approach, amalgamating the benefits listed above with those of traditional electro-hydraulic systems, such as compactness, robustness, high power density, high load capacity, and effective overload protection with fail-safe functions performed by springs [3] [4].…”