•Drill cuttings that settle during static conditions can cause bridges and fill, which in turn can cause stuck pipe or lost circulation.
•Weight material which settles is referred to as sag and causes a wide variation in the density of the well fluid.
•Sag occurs most often under dynamic conditions in high-angle wells, where the fluid is being circulated at low annular velocities
•High viscosity shear thinning fluids (thixotropic) and required to suspend cuttings during connections and other interruptions in circulation.
•Thixotropic fluids have properties that thin when stress is applied (such as circulation of the fluid) and thicken up or gel when static
•Most drilling fluids are thixotropic, polymers added to the fluid increase the low end rheology of the fluid and help to suspend cuttings and barite
.•Weight material which settles is referred to as sag and causes a wide variation in the density of the well fluid.
•Sag occurs most often under dynamic conditions in high-angle wells, where the fluid is being circulated at low annular velocities
•High viscosity shear thinning fluids (thixotropic) and required to suspend cuttings during connections and other interruptions in circulation.
•Thixotropic fluids have properties that thin when stress is applied (such as circulation of the fluid) and thicken up or gel when static
•Most drilling fluids are thixotropic, polymers added to the fluid increase the low end rheology of the fluid and help to suspend cuttings and barite
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