A gravel pack equipped with sand screen completion is commonly used in deepwater Gulf of Mexico. Over time, fines migration and asphaltenes clog the screens of the completion, which negatively affects the well production. In order to remediate the damage, openings are created in the concentric base pipe inside the screen (Fig. 1). This process creates a flow path that allows for cleaning of debris from the screens through jetting and bull heading of stimulation fluids. The combination of these operations restores the productivity of the well.
In the conventional method, the cuts are machined one at a time with a blade spinning in the horizontal plane. To achieve sufficient flow area, this step is repeated approximately hundred times to distribute the cuts along the target screen interval. Such an operation can require up to 14 days including the downhole cutting time as well as trips in and out of the well to replace the blades.
The blades protrude only slightly from the base pipe to avoid damaging the screen. The screens are separated from the base pipe with standoff to maintain a constant clearance. Thus, the blades cannot damage the screen.