Offshore marine structure with corrosion protection

Claim 1

In a marine structure having a deck and a rotatable drill string for drilling wellbores into the floor of a body of water, a jacket comprised of corrodible metallic members including support legs which are mutually interconnected with cross braces, and which jacket rests on the said floor and supports said deck above the water's surface, a drilling template incorporated into said jacket to accommodate drilling conductors for guiding said rotatable drill string which is lowered from the deck to form a vertical wellbore, said drilling template including vertically aligned elongated conductor guides arranged in a horizontal pattern to define a drill conductor array comprised of external conductors, which encompass at least one internal conductor, a cathodic protection system protecting said corrodible metallic members of said marine stucture comprising a first sacrificial anode system disposed on discrete submerged jacket members to afford corrosion protection to said jacket members as well as to submerged sections of the drill conductor array, and other sacrificial anodes removably carried on said at least one internal conductor to supplement the cathodic protection afforded by said first sacrificial anodes.