Corrosion Study of Steel API 5A, 5L and AISI 1080, 1020 in Drill-Mud Environment of Iranian Hydrocarbon Fields

摘要

API 5A and 5L (grades J55, H40, N80, and K55) are used in making drill pipe and well casing. In this paper after studying the rheological and chemical properties of the mud, the effective corrosion parameters were reviewed and studied. The drill pipe corrosion management, with reference to NACE PRO 502-2002 was made and showed that for 50 drilling rigs 120 million dollars is to be spent in 21 years for corrosion damage. Potentiodynamic polarization tests were made to study the drill-pipe (API 5A), well casing (API 5L), a connecting tube (AISI 1020), and drill cable (AISI 1080) corrosion behavior in different pH and mud chemistry; following these tests, the pitting potential at which wash-out of drill pipe occurs was determined.