Abstract
Spacing out production tubing and landing the tubing hanger in subsea completions is particularly challenging in wells with extreme well depths or in highly deviated well bores, as rig heave can significantly challenge space-out operations. Another problem also can occur when attempting to enter the casing at the subsea blowout preventer (BOP) in deep water, since the subsea currents can initiate a bending motion to the riser, causing the bottom of the completion to enter the subsea blowout preventer (BOP) at an angle. If the angle is too high, set-down weight or compression must be applied to push the completion through, placing shearable travel joints at risk of prematurely shearing. Even after pushing the travel joint through the subsea BOP, the completion design must manage friction induced by well deviations or ‘S’ curve well bores. Also, the travel joint must remain rigid enough to land seals into production packers at the formation. Often, these challenging scenarios with high angles can be further complicated by limited available slack-off weight. This paper will discuss how the development of new travel-joint designs were capable of resolving challenges such as those mentioned above that were encountered on the the first deepwater subsea development for an operator in Malaysia. This was also the first entirely deepwater subsea development in Malaysia, and at the time of the commencement of its development, an average production of 135,000 barrels per day of hydrocarbon was expected from the project.
To address the completion obstacles discussed above, a service/engineering company developed a long, space-out travel joint (LSOTJ) designed to telescope downward in response to a timed application of a compressive load rather than a shearing event as in standard designs. The LSOTJ slowly scopes downward during lowering of the production tubing until the hanger is landed. Equipment development was comprised of two versions of the long space-out travel joint; one version is a non-continuous sealing (NCS-LSOTJ) version, and the other is a continuous sealing (CS-LSOTJ) version
This paper will discuss the design and development of the two LSOTJ versions, and the first usage of the continuous sealing version in Malaysia, which was also its first usage world-wide.
