The requirement for screened and gravel packed completions in horizontal wells has led to the development of alternative stimulation fluids and placement techniques.
This paper describes a common damage mechanism in this type of completion and the remedial cleanup procedures developed.
While horizontal wells do not normally require stimulation for primary production reasons, it is often necessary to clean up the drill in fluid (DIF) filtercake.
A placement technique was developed that includes a coiled tubing, controlled injection technique (CIT) in combination with a true fluidic oscillator (TFO) to aid in placing a modified propriatory scale and DIF filtercake solvent (PSDS) fluid behind the screen into the gravel packed annulus.
The placement technique is supported with surface testing results of two standard jetting tools vs. a TFO for the placement of the stimulation fluid.
This PSDS fluid was specifically modified to improve the effectiveness of removing filtercakes layed down with a drill solids-laden DIF mud sample from the field. The presence of formation-drilled solids results in a much more tenuous filtercake than one created with a clean DIF.
The technique was developed for a long horizontal gravel-packed North Sea well, however the procedure has global applications.