Wireline formation test tool with jet perforator for positively establishing fluidic communication with subsurface formation to be tested

摘要

A wireline tool, and process for its use, for lowering into wellbores for testing the gas pressure, and connate fluid flow rates, in low permeability oil or gas producing subsurface formations. The tool features a jet charge perforator for detonation to perforate through the wall and positively establish fluidic communication with the non damaged portion of the subsurface formation to be tested. It also includes, in the combination, a mechanism for affixing and stabilizing the tool in the wellbore at the wall of the subsurface formation to be tested, inclusive of a packer assembly for isolating from wellbore fluids the opening between the subsurface formation, created by the jet perforator, and tool test components. On blasting into the wall of the subsurface formation, the pressure in the flowline is maintained at formation pressure, avoiding formation damage. The pressure is recorded during the flow of gas and connate fluids from the subsurface formation, and analysis is made of a specimen taken into a chamber of the test tool.