The mode of gravel transportation in openhole packing is determined by the deviation angle of the interval – typically a gravity assisted (bottom up) mode occurs for deviations less than 50 degrees and alpha-beta mode for deviations exceeding 60 degrees. Experience in various fields in Brunei indicates a lower success rate when gravel packing intervals in the 50-60 degree deviation range using conventional gravel packing techniques. In fishhook wells, the critical 50-60 degree deviation range is equivalent to the uphill wellbore geometry 120-130 degree deviation range.
This paper discusses the technique used to gravel pack two fishhook wells with deviations of 126 and 131 degrees respectively. The objectives of the completions were threefold:
a) Achieve a complete annular pack,
b) Provide the capability for zonal isolation
c) Maintain bottomhole pressures below the fracturing pressure.
d) Deliver a low skin completion.
The world’s first successful Shunt tube uphill gravel pack in a fishhook well was executed in September 2010. The same type of completion was performed for a second time a few months later. Completion design, component optimization, fluid design, gravel pack simulation and downhole gauge analysis for these wells are discussed.