By Gary Whelan
Nearly every Oil Country Tubular Goods (OCTG) manufacturer and producer is looking for solutions to sour service. It’s a perpetual issue that’s been hampering the oil and gas industry for as long as pipes have been underground.
High-strength, low-alloy carbon steels are the backbone of most oil and gas casing and tubing projects. However, these alloys are not necessarily equipped to operate for extended periods of time in sour environments that are prone to sulfide stress cracking. This is the type of cracking that occurs when hydrogen sulfide accelerates the absorption of hydrogen into the steel, which embrittles grain boundaries.
The oil and gas industry has traditionally handled sulfide stress cracking in one of two ways: Rely on significantly more expensive corrosion-resistant alloys (CRA) or replace the lower grade OCTG when sour conditions emerge in the operating environment.
While completely eradicating corrosion and cracking remains a pipe dream, advances in materials engineering provide opportunities for the oil and gas industry to increase the lifespan of the OCTG by developing better alloys. With the help of computational modeling and design, manufacturers can create casing and tubing materials that transport oil and gas over a longer service life and create cost savings.