Cathodic protection systems for offshore petroleum production platforms have commonly been designed for 20 years; however, because service life has been extended beyond this in many cases, retrofitting is required. A fundamental parameter needed for efficient, effective design of such retrofits is the structure current demand or maintenance current density at the time of the cp redesign. Five possible methods are identified for assessing this parameter, including 1) polarization of the structure, 2) anode potential measurements, 3) field gradient measurements, 4) the potential difference . modified Dwight equation .....
Keywords: cathodic protection, current demand, sea water, offshore structures, galvanic anode, retrofit.