Abstract
<jats:title>Abstract</jats:title> <jats:p>This paper outlines a novel technology for aligning the tubing hanger (TH) within the wellhead, using the tubing hanger orientation spool (THOS) in subsea installations. This paper also details the results and lessons learned during actual project deployment of THOS system across various subsea projects.</jats:p> <jats:p>The THOS is an innovative system used to accurately align the TH inside the wellhead, ensuring the successful installation of the vertical Monobore tree system. It differs from the traditional method of TH alignment using the tubing hanger orientation joint (THOJ) system, which requires blowout prevent (BOP) specific interfaces, equipment and modifications. These can be prohibitive to project cost and delivery schedule. The THOS is installed between the wellhead and BOP, directly locking onto the wellhead profile. It contains an orientation key that engages with a double helix on the tubing hanger running tool, enabling accurate orientation of the TH inside the wellhead.</jats:p> <jats:p>The THOS system is compatible with guideline and guideline-less installation methods and can also use the conductor housing castellation slots as a positional reference. These installation methods were successfully checked and verified during the execution of various subsea projects. The structural integrity of the THOS system was validated, confirming its ability to withstand with a landing velocity of up to 0.3 m/s. The main advantage of the THOS system over the THOJ system is that it does not require rig-specific BOP details, which are often not known at the start of a project, and this lack of information can delay project delivery.</jats:p> <jats:p>The traditional method of orienting the TH inside the wellhead using the THOJ system requires complicated modifications to the rig BOP system. However, the THOS system works independently of the BOP system; hence, it does not require any BOP modifications. Furthermore, the THOS and the tree are assembled onto the wellhead using the same method, which also helps to ensure accuracy. In comparison with the THS method, the THOS method can reduce embodied carbon emissions by up to 300 tCO2e, estimated for a 5-well project.</jats:p>