American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
Baked phenol-formaldehyde formulations, commonly referred to as baked phenolics, have had varying degrees of success in H2S environments. The degree of success for a given baked phenolic used as an internal tubular coaling depends upon H2S concentration, pressure, and temperature of the environment. Laboratory tests of baked phenolic coatings indicate 5% H2S, 2,000 psi, and 200 degrees F to be the upper limits for satisfactory performance. Case histories have proven certain individual formulations are capable of performing satisfactorily above these limits.
Coating material formulations for H2S environments of high pressure and temperature are achieved by combining inert fillers with thermosetting phenolic resins. The type and amount of filler used in baked phenolic coating materials influence the temperature limit, acid resistance, flexibility, permeability and gas diffusion rate. A baked phenolic coating well balanced in the preceding five points will perform well in continuous service points will perform well in continuous service above the limits of most manufacturer recommendations. Extensive laboratory and field tests are necessary to determine the performance capability of a baked phenolic coating in an H2S environment.
Proper application is essential to produce a satisfactory coating performance in service The following are necessary steps to achieve proper coating application. proper coating application.
Adequate metal cleaning for internal tubular coating requires flint blasting to an SSPC-SP-5 (white metal finish).
An anchor pattern (1 1/2 to 2 mils)is required to obtain a satisfactory bond of coating material to the steelsubstrate.
A uniform coating film well balanced in adhesion and cohesion produces a product that will not delaminate or lose bond with the steel substrate.