Alternate Path* (shunt-tubes) technology has been available to the petroleum industry for well more than a decade. Its applications have expanded over time around the world ranging from single-zone cased-hole gravel packs to multizone gravel packs or frac packs and openhole gravel packs. The recent advances have expanded applicability from specialty gravel packing to a general, all-purpose technology with huge benefits. Its flexibility permits use in extremely challenging environments, allowing completions previously considered difficult or impossible.
Development of multizone packers (cup type or swellable) has helped to push the envelope for Alternate Path technology both for cased-hole and openhole applications. This technology has enabled operators to not only perform multizone gravel-pack and frac-pack completions, but also provide solutions for gravel packing in exceptional conditions such as gravel packing a new zone in presence of open perforations in the zone above, isolating unwanted zones while completing new intervals, or gravel packing in exceptional well geometry.
This paper provides a review of the recent unique completions using a shunt-tube system to overcome complicated well completion challenges and expand the limits of using this technology further.