Some are completion tools that remain in the well after the gravel pack is complete. On the other hand, service tools are used while placing the gravel pack but then are removed. Sand is introduced using a Pot Machine or specialized gravel infuser. Although more costly, the Infuser system offers several advantages, including more precise mixing, lower completion fluid volumes, and reduced rig time. Non-viscous completion fluids are more economical, but higher volumes are required and filtration requirements are more critical with the higher leakoff.
Experience indicates that cleanliness is critical to job success.
Cleanliness covers the entire system casing, tubing, tanks, lines, completion fluid, equipment and gravel. Frac Packs are a combination of a fracture treatment and an annular gravel pack. A successful Frac Pack must not only stop sand movement, but must create a wide fracture that is held open by a high permeability proppant extending through the nearwellbore zone, importantly not making contact with nearby zones that contain unwanted fluids. Treating pressures may or may not exceed fracture pressure. HRWPs are typically used where the completion is near water or gas contacts and there is a shallow radius of near wellbore damage combined with relatively uniform sand quality and permeability.