New regulatory requirements and design conditions introduced in recent years have led to the use of higher strength tubulars in the majority of Deepwater wells in the Gulf of Mexico. To achieve the new design requirements, the use of non-conventional casing sizes, grades and weights different than those traditionally used and available in the industry are required. The use of thicker wall tubular has consequently resulted in geometrical constraints and tighter annuli clearances in the wellbore driving new connection design requirements and selection criteria to meet overall well objectives. The new design conditions require innovative connection design to meet or exceed the collapse strength of pipe body rating. As part of the Shell Mars B project, the Olympus TLP DVA team championed the development and qualification of multiple connection types to meet the project requirement and for overall portfolio usage. As the number of connections to be designed and qualified is substantial, a pragmatic and systematic testing philosophy and strategy was developed for the Mars-B project TLP DVA wells.

This paper provides a high level overview of the connection selection challenges, the systematic process adopted to streamline connection development, testing and qualification. It will also discuss some of the challenges in connection design to meet well requirements and qualification process. The scope includes static connection design for strings installed below the subsea well head, as well as, dynamic connection design on strings that are installed in the water column. Both connection designs require sealability qualification and assurance. Dynamic connections require additional fatigue design and qualification. Rigorousness of sealability and fatigue testing is appropriate to the environment of which it will be subjected throughout the well and the 50 year field life.

You can access this article if you purchase or spend a download.