Cased Hole: Pressure Operated

Cased hole drill stem tests (DST) are conducted after the well has been cased and the formation of interest is behind casing. The casing is perforated by wireline perforating guns or with tubing conveyed perforating (TCP) guns connected to the bottom of the DST string to open the casing to the formation. The DST tool assembly is run at the bottom of the temporary production tubing or drill pipe (work string) and used for downhole well testing (inflow testing) and stimulation (injection).