Casing Scratchers Overview In Wells Cementing
Scratching devices as casing scratchers are external devices designed to remove immobile mud from the wellbore and mud cake from the wellbore wall (Fig. 1). These devices are categorized by how aggressive they are.

Casing Scratchers Types

Fig. 1. Scratching devices (photographs courtesy of Weatherford International).

The basic springloaded bristle scratcher is more aggressive than the cable scratcher (also known as a wellbore wiper).
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