The evolution of drilling programs has driven the industry to develop more suitable solutions adapted to extreme and aggressive conditions such as Sour Service environments. High strength drill pipe is necessary to achieve these deeper drilling targets because Sulfide Stress Cracking susceptibility is observed even in minimal concentrations of H2S partial pressure.
Due to the astringency of the sour environment, particular precautions have to be defined to select and characterize an adapted Sour Service steel grade. Controlling crucial manufacturing parameters is the key to successfully supplying products for these critical applications. Steel microstructure, chemical composition, cleanliness and heat treatment process control are all important to promote Sulfide Stress Cracking resistance in high strength drill pipe. Moreover, controlled yield strength, restricted hardness and improved fracture toughness are the mechanical parameters enhancing the ability of these drilling products to be used safely and efficiently by drilling contractors and operators in aggressive wells.
This paper presents the latest VAM Drilling solutions in terms of steel chemistries and manufacturing process controls highlighting key parameters that drilling engineers and specifiers should consider when planning sour gas wells. The paper also introduces further developments to be sought for deep and Extended Reach Drilling above current material limits.