In recent years, Oil & Gas industry operators have begun to drill wells in increasingly challenging deepwater Complex High Pressure and High Temperature Wells conditions. As a result, these operators have found themselves facing new, and particularly demanding, mechanical requirements. Deepwater Complex High Pressure and High Temperature Wells require enhanced internal and external pressure resistance, sometimes combined with corrosive sour environments, and the performances offered by API products no longer suffice.Their well featured complex architecture and tight clearance between the strings, so they used World’s leading seamless pipe specialist Vallourec’s Dual Performance Baskets in VM125HCSS/XCSS, which increased the collapse rating by 8% with no need to increase the wall thickness. A burst load occurs when the internal pressure is higher than the external pressure on the pipe. The burst loads considered to be the most extreme occur during the high pressure test, gas kick and tubing leak load cases. The opposite scenario, a collapse load, occurs when the external pressure applied on the string is greater than the internal pressure. The most extreme load cases take place in the cementing operation and full evacuation scenarios.Annular pressure buildup, an increase of pressure due to the expansion of the fluid confined between two strings, is a particular case that combines both challenges. The inner string is subjected to collapse loads, while the outer string is subjected to burst loads.In the presence of hydrogen sulfide, common carbon steels can become more brittle, and therefore more susceptible to Sulfide Stress Cracking, a sudden and catastrophic corrosion mode. Furthermore, when increasing the Specified Minimum Yield Strength of a material, its toughness is reduced, and the risks of hydrogen embrittlement, and consequently of SSC, become greater. This represents a significant limitation for well designs that require both enhanced mechanical performance and hydrogen sulfide resistance.Vallourec has developed a range of high strength grades to help clients meet all of these challenges. Vallourec’s wide array of materials includes VM110HCMS/XCSS, VM125HCSS/XCSS and VM130HCMS/XCMS for mild sour conditions, and VM110HCXS/XCXS and VM125HCESS/XCESS for severe sour and extreme sour conditions. Vallourec can now enhance collapse resistance of tubulars even beyond common High Collapse grades with its eXtreme Collapse offer. This cutting-edge product line was developed in response to demand for ever higher collapse performance. The single basket option offers greater collapse ratings by increasing control of production variables, targeting even tighter values than for HC grades. Meanwhile, for Dual Performance Baskets, Individual Pipe Analysis is applied to identify and physically separate the highest performing pipes in a production lot, thus increasing the collapse rating for 50% of the string.