Cased Hole DST
Cased Hole DST is the process of testing the wells after running production casing or liner. Once a well is drilled to the target reservoir, various logs are run for evaluating reservoir characteristics. Based on log evaluation, prospective zones are identifies. Formation type is identified through Gamma Ray signatures, potentials of oil and gas are identified through resistivity logs and porosity is identified through porosity log etc. The prospective zone is identified through positive combination of these logs. Well is cased with production casing or liner cemented in place to provide zonal isolation. Casing / Liner and well are perforated across selected potential zone and is tested by running DST string inside cased hole.