ConocoPhillips
SEALED CONCENTRIC COILED TUBING

Abstract:

Implementations described and claimed herein provide systems and methods for extending reach in a wellbore in oil well operations. In one implementation, a first coiled tubing string has a first coil interior surface, and a second coiled tubing string is disposed within the first coiled tubing string and has a second coil exterior surface. An annulus is defined by the first coil interior surface and the second coil exterior surface. The annulus is sealed proximal to a top end of the first coiled tubing string via a first seal and sealed proximal to a bottom end of the first coiled tubing string via a second seal. A fluid is sealed within the annulus at a pressure.