The new, higher grade pipeline steels provide an opportunity to reduce pipeline costs by enabling a shift to higher pressure at reasonable wall thickness. However, these higher operating stresses place greater demands on the pipeline, particularly when a running fracture is considered. Several studies have shown that intrinsic arrest cannot be counted on for these grades under all operating conditions. In such cases, crack arrestors will be needed. This paper presents results obtained using CSM’s proprietary PICPRO® finite element code to predict the performance of crack arresters on X120 pipes, and shows that the predictions agree well with full-scale experimental results obtained in arrestor trials.

The incentive to use corrosion-resistant alloy (CRA) production tubing has grown as bottomhole temperatures have steadily increased above 325°F, as corrosion control costs have grown, and as many operations have sprung up in remote sites with limited accessibility.This paper discusses procedures to ensure acceptable manufacture of such tubing and also presents some operational experiences with these alloys.

This paper presents the results of corrosion and mechanical testing of welded high-nickel, corrosion-resistant-alloy (CRA)-lined pipes manufactured using various lining processes. The corrosion resistance of CRA-lined pipes for use as a flowline material in sour service was evaluated.The effects of the manufacturing process, CRA-lining material and welding on the corrosion performance of CRA-lined pipes were also determined.

No abstract

The mechanism of pitting corrosion in carbon steel in a simulated seawater environment was studied by obtaining data on the chemical changes which occur with time in the pit and cathode solutions. Quantitative measurements were made of pH; sodium, magnesium, calcium, iron, chlorine, sulfate concentrations, and weight loss. The solutions used in the analysis were generated by using a recently developed artificial pit which not only provided a sufficient amount of solution but also made it possible to obtain specimens from specific locations in the cell itself. The results show a depletion of magnesium, calcium, chlorine, and sulfate in the cathode region while sodium and hydroxyl ion concentrations increased. Inside the pit the chlorine, iron, and hydrogen ion concentrations rose while the calcium, magnesium, and sodium concentrations dropped. Based on the results of these tests, it is shown that the decrease in pH in the pit is greatly enhanced by the magnesium and calcium reactions occurring at the cathode and by the formation of iron colloids (Fe(OH)4− and Fe(OH)2+).