Traditionally, a wellhead system requires a drilling lockdown sleeve (LDS) during drilling operations to ensure that the seal assembly is rigid and prevents dynamic movement. By eliminating the LDS, however, the operator will save multiple trips into the well. Because of a seal-assembly design outlined in the complete paper, development of a single-trip LDS was possible for wellhead systems requiring extremely high lockdown requirements, allowing the user to save trips required by legacy designs.
New Subsea Challenges
In high-pressure/high-temperature subsea wells, annular pressure buildup, caused by thermal expansion of fluid, endangers well integrity. This phenomenon is caused by the increase of pressure during the production phase, temperature differential during the drilling phase, and fluid parameters.
