Using API 5L-grade X70 seamless and welded pipes for wet sour applications—Part 2

High-strength pipes are required for oil and gas industries to transport high-pressure sour hydrocarbon crude and gas for both onshore and offshore pipeline applications. Material specifications and standard requirements of the majority of oil and gas operating companies allow the use of line pipes up to a maximum strength of API 5L Grade X65 (i.e., prohibiting the use of API 5L Grade X70 pipes for wet sour environments). The increase in pipe strength is associated with the addition of alloying elements, which mainly leads to centerline segregations, inclusions, high residual stresses and high micro-hardness locations. Hydrogen can permeate the steel and is entrapped mostly in large, elonga