A Method of Selecting Protective Coatings For Offshore Drilling Structures^⋆

A general outline of the principal conditions of exposure encountered in marine operations associated with petroleum production. The high cost of marine or offshore wells makes a corrosion control program imperative. A major part of this program is the use of organic protective coatings. This type of application is relatively new for most paint manufacturers and consequently a laboratory testing program was set up to evaluate protective coatings. To further verify the laboratory results, panels coated with the various painting systems were exposed at a marine location in the Gulf Coast. A laboratory testing program is described in which quantitative measurements of the film characteristics are made. By using the moisture vapor transmission salt spray and adhesion tests, a laboratory rating is calculated by which coatings are rejected or further tested in the field. The better coatings together with some of the unsuitable ones were exposed on test panels at a marine test station in the atmospheric, tidal or splash zone and totally submerged. Correlation between the laboratory and the marine test station exposure is given as ninety-one percent. Some thirty systems have been tested to date and approximately sixty percent were totally unsuited for these exposure conditions. Twenty percent were of doubtful value leaving twenty percent that could be used with more or less effectiveness. It is concluded that petroleum companies engaged in this Work should outline a standard test program to be used in testing the materials submitted for the various exposures encountered.