Chapter 9. Filter Cake Removal
Well drill-in and servicing fluids are employed in the course of drilling, which typically include fluid loss control fluids. These fluids make up a comparatively small portion of the total, but sufficient to form a filter cake so as to plug off thief zones.
In general, well drill-in and servicing fluids are formulated to form a fast and efficient filter cake on the walls of a wellbore within a producing formation, in order to minimize leak-off and damage, which often contains an inorganic and an organic portion. This arises because drill-in fluids are typically composed of either starch or cellulose polymers, xanthan polymers, and sized calcium carbonate or salt particulates.
Before the production starts, the filter ...