Gravel packing is increasingly used in long horizontal wells and challenging environments. Key to executing the gravel-pack job successfully is selecting an appropriate gravel-carrier fluid. Frictional pressure loss exhibited by gravel-packing fluids is an important consideration in their selection. This paper discusses the friction pressure performance of commonly used gravel-packing fluids in the industry today, which include the viscoelastic surfactant (VES) types of fluids, xanthan, and hydroxyethyl cellulose (HEC).
In wells with a long horizontal section or narrow margin between pore pressure and fracture gradients, the frictional pressure loss exhibited by these fluids in the wash pipe and wash-pipe/base-pipe annulus governs whether these wells can be gravel packed without fracturing the formation. In gravel packs with alternative-path configuration (shunts), the frictional pressure loss through the shunts controls the maximum length that can be gravel packed.
This paper discusses in detail the fluid friction pressure performance while pumping these fluids through various conduits including circular pipe, eccentric annuli, and rectangular tubes (shunts). These data were generated in field-scale yard tests under controlled conditions, for both ambient and elevated temperatures. The paper also discusses the rheological properties of these fluids at ambient and elevated temperatures. The effect of factors such as surfactant/polymer concentration, addition of gravel, and temperature on the frictional pressure loss of these fluids is presented, which will help in fluid selection/optimization under different scenarios.