BACKGROUND

This invention relates to coiled tubing being utilized to intervene in a pipeline or well subsea while maintaining pressure integrity from the hydrostatic and dynamic conditions.

In a subsea environment, performing an intervention with coiled tubing to a pipeline, or oil/gas well historically used a semi-submersible rig or DP Monohull vessel with a riser conduit from surface to the subsea tree or pipeline.

When utilizing a riser or flexible conduit the pressure control equipment (such as blow out preventers (BOP's) and stripper assemblies) are mounted at surface to control any release of fluids or gases from the well/pipeline during the intervention program.

However, when operating riserless conduits utilizing open water coiled tubing (OWCT), the well control package including the strippers for dynamic control have to be modified to operate subsea and control both hydrostatic and wellbore conditions simultaneously.

Normally this equipment is hydraulically controlled to function subsea. Methods are needed for dynamic/static sealing of coiled tubing subsea for pipeline and well access with hydrostatic conditions up to 10,000 ft water depth while maintaining wellbore or pipeline pressures up to 10,000 psi. Current systems exist for surface application only and seal coiled tubing from wellbore or pipeline pressure with only ambient pressure at surface.

