A new 3D probe module has been added to the Schlumberger MDT modular formation dynamics tester arsenal. The probe expands radially to achieve a positive seal with four elliptical probes spaced at 90° intervals and covering more than 79 in² of flow area. Ideal for tight, low-permeability formations, where it dramatically reduces sampling time, the new probe also benefits unconsolidated formations, where it can achieve valid, high-quality tests with minimal drawdown. Called the Saturn 3D radial probe, it complements all the features of the wireline-deployed MDT service including downhole fluid analysis using the InSitu Fluid Analyzer system, pumpout module, and multiple pressure-volume-temperature sample chambers. Although the probes cover a large total area, testing is narrowly focused on a 6-in formation interval. Successfully testing a wide variety of formations around the world, the Saturn probe is acquiring high-quality representative fluid samples from formations previously deemed impossible to test. Recently, its 650% greater flow rate and faster cleanup capability allowed the tool to obtain two low-mobility oil samples in the range of 1.5 to 2.2 mD/cP. In West Africa, stabilized formation pressure measurements were achieved in fluid mobilities down to 0.01 mD/cP.