Electrification of Oil & Gas offshore installations can be performed by transmitting electrical energy over long length using high voltage direct current (HVDC) submarine cable systems. This paper describes the two commonly used technologies for HVDC submarine cable systems and the current state of the art. A technico-economical analysis has been performed for the supply and installation of an HVDC submarine cable system located in the Middle East, which shows that cable loss valuation should be considered together with the technology readiness level (TRL), in addition to the initial investment cost. Depending the voltage level, cross-linked polyethylene (XLPE) cables have a lower investment cost than mass impregnated (MI) cables, but considering the loss valuation and TRL, MI cables could be preferred considering the cable system only. This study gives an input to the full project value of an HVDC transmission system, where cost and losses of converter stations for different technologies and at various voltage levels should also be included.