GRAVEL PLACEMENT IN WELLS

Several gravel-placement techniques are available for prepacking and g ravel packing wells where sand control is required. Water and viscous fluids have been used effectively to prepack gravel outside perforatio ns; however, when an annulus is gravel packed, advantages and disadvan tages of each fluid become more apparent. Research and field experienc e have shown that water is a more general-purpose transport fluid for gravel packing than viscous fluids, which are best suited for low well deviations and relatively short completion intervals.