Risk assesment pipa gas (piping) 6", 8", 12", 16", dan 18", terhadap serangan korosi di anjungan lepas pantai PT. X dengan menggunakan metode risk-based inspection (RBI) = risk assesment of 6", 8", 12", 16", and 18", gas piping from corrosion attack at PT. X offshore platform using risk-based inspection (RBI) methode