Many deepwater formations are quite shallow in geological terms, resulting in unconsolidated, highly permeable sands. A vast majority of deepwater wells therefore require some form of sand control.
Sand control has evolved to include systems and devices appropriate to the reservoir zone, providing efficient connections to the reservoir, maximizing reservoir conductivity and optimizing production. It has become necessary to complete longer intervals with tighter pressure windows, preferably all at one time or to directly isolate and complete multiple zones separately in a single trip.
To maximize well productivity with minimum solids production, deepwater wells often require completions with gravel packs or cased hole frac packs.
The use of shunt tubes for sand control in deepwater fields helps to place gravel more effectively. The longevity of openhole gravel packs and cased hole frac packs is dependent on successfully filling the entire annulus volume between the screens and the formation with gravel; the shunt tubes placed around the screens are designed to increase the probability of achieving this. Shunt tube screen technology is a key enabler for successful single-trip, open-hole gravel-pack operations. Shunt tube diversions ensure uniform gravel pack and help prevent premature screen out and erosion hot spots.
Alternate path systems use shunt tubes and nozzles to bypass bridges and fill in voids that can occur when gravel and frac packing.
In-flow control devices help create a balanced flow and effective draining across the reservoir layer. This assists for optimum sweep and effective draining without premature gassing out or watering out of the well (important for improving ultimate recovery).