Corrosion Behavior and Mechanical Performance of Drill Pipe Steel in a CO2/H2S-Drilling-Fluid Environment

Abstract

Objectives: This article investigates the corrosion behavior and mechanical-property changes of S135, G105, and V150 drill pipe materials in a high-temperature-resistant, potassium amino poly-sulfonate drilling fluid, which has good lubrication performance and contains CO2/H2S, by applying an 80% yield-limit-load simulation. The results show that the CO2-corrosion behavior of G105, S135, and V150 drill pipes are obvious under the simulated constant-load-stress-corrosion environments at the wellhead, well-middle, and bottomhole positions. Compared to uncorroded drill pipes, S135 and V150 drill pipes have increased strength and yield ratios, decreased fracture elongation, and increased sensitivity to hydrogen embrittlement under H2S action, and V150 has a greater risk of stress-hydrogen embrittlement. The strength and yield ratios of G105-material drill pipes decrease, while the fracture elongation increases; the intensity-change amplitude levels are ranked V150 > G105 > S135, and the fracture-elongation-change amplitude is ranked G105 > S135 > V150. The tensile-performance-change amplitude and the SSCC (Sulfide-Stress-Corrosion Cracking) sensitivity of G105 and V150 drill pipes were the highest at the bottomhole. S135 drill pipe materials were most affected by pitting and tensile action at the wellhead, and they had the with the largest SSCC sensitivity.

Modification of Copper Benzene-1,3,5-tricarboxy Late (Cu-BTC) Composites with Multiwalled Carbon Nanotubes and Amino Groups for Enhanced CO2/CH4 Selective Adsorption Performance and Water Stability

“…Heat release associated with the combustion of methane (CH 4 ), which is the main component of biogas and natural gas, can reach 34,000 KJ/m 3 per unit volume. However, biogas, in which CH 4 and carbon dioxide (CO 2 ) account for 55-70% and 25-40%, respectively [1], and natural gas contain a large amount of CO 2 gas [2], which affects fuel utilization and reduces the calorific value of fuel combustion. Therefore, separation of CO 2 from fuel is essential to achieve carbon emission reduction and effective energy utilization, and adsorption stands out as a promising method for this purpose [3,4].…”