Experimental investigation of solids transport in horizontal concentric annuli using water and drag reducing polymer-based fluids

When drilling long horizontal wells, drilled solids tend to settle down on the low side of the welibore and form a stationary bed. Presence of stationary cuttings bed causes operational difficulties such as pack-off, excessive torque and drag, slow drilling rate, and in severe cases, stuck pipe, lost circulation, and even loss of the well control. Despite significant progress made in drilling fluids, tools, and field practices, along with more than 50 years of university and industry research, field experience indicates that cuttings transport is still a major problem in most horizontal wells.