A Major Advancement in Expandable Connection Performance, Enabling Reliable Gastight Expandable Connections

摘要

Since the introduction almost 15 years ago of today's solid-expandable-liner systems, threaded-connection technologies have advanced very little compared with the development of sophisticated, state-of-the-art expansion tools and systems. The severity of damage caused to threaded connections during the downhole expansion process leaves some threads unengaged and badly deformed, reducing the connections' mechanical dependability. Even worse, traditional metal seals incorporated into most proprietary premium connections are destroyed during the expansion process or damaged to the point of being undependable. Even though solid-expandable-liner systems offer a large number of important and valuable solutions, connection performance is obviously a problem. For more than a decade, engineers have worked on the development of connection features that are more resistant to damage caused during expansion. Although there has been some advancement, today most or all expanded connections share little resemblance to unexpanded connections when subjected to ISO 13679 (2002) qualification tests with gas. This paper details new expansion-cone technology that eliminates the majority of damage caused to connections when expanded with traditional cones. This paper will provide finite-element analyses and physical-testing verification to show how this new technology leaves connections with minimal visible damage to the threads and metal seals after expansion.