The scientific plan for the Mt. Elbert Prospect includes multiple tests using Schlumberger’s Modular Formation Dynamics Tester (MDT) tool. This device is deployed on wireline and will be used to sample formation fluids, and measure formation pressure and permeability.

The tool’s design involves extension of a sampling probe pad against the borehole wall by backup pistons and the insertion of a smaller test probe a small distance into the formation. The probe is then opened to a sampling chamber within the tool, where fluids from the formation can flow, free of contamination by the borehole fluid. The formation pressure is measured using an extremely accurate gauge that can resolve small pressure differences. The pressure and the rate of fluid flow into the sample chamber can be used to calculate reservoir permeability. Multiple probes can also be used to determine both vertical and horizontal permeability data, which can be used to assess near-wellbore permeability anisotropy (i.e., the degree to which vertical and horizontal permeability within the same reservoir differ). All of these data are useful to engineers interested in predicting the productive capability of a reservoir. Various configurations of the MDT tool can be used to accomplish specific testing goals.

Modular Formation Dynamics Tester (MDT) Tool
photo courtesy Schlumberger