Operators developing reservoirs and producing them from deep and ultra-deepwater wells are pushing the technical limits regarding horizontal extension. Deepwater wells completed in uncosilidated formations usually have low fracture gradients, severe leak-off zones and/or significant wash outs. Long horizontal open holes, therefore, may become technically difficult or economically unfeasible to gravel pack using conventional fluids and gravels.
Typical completions offshore Brazil start from a 9 5/8-in. or 10 3/4-in. casing, where a 5 1/2-in. premium screen and tubular string is hung along an open hole drilled with 8 1/2-in. or 9 1/2-in. bit. Horizontal extensions range from 980 to 4,000 ft.
Ultra-lightweight proppants have enabled gravel packing in these longer horizontal open holes. The reduced gravel density allows a significant reduction in pumping rate, which avoids fracturing the formation, minimizes fluid losses and eliminates the risk of premature screen out due to excessive gravel settling.
This paper summarizes the procedures and results of almost 60 wells that have been gravel packed using ultra-lightweight proppants technology pumped for a local operator.