Wireline And While-Drilling Formation-Tester Sampling With Oval, Focused, And Conventional Probe Types In The Presence Of Water- And Oil-Base Mud-Filtrate Invasion In Deviated Wells

Speculation about the potential of developing new fluid sampling methods with probe-type formation testers has existed since the introduction of formation pressure testing to the drilling environment in 2002. Extending the existing wireline technology requires a new pumping system capable of removing invasion fluids and then filling single-phase sample chambers. Several technology advances are necessary before this is commercially possible. Although wireline pumpout tools may require hours to retrieve representative fluid samples, spending hours obtaining samples in the drilling environment may not be considered a practical alternative. The objective of this paper is to quantify the viability of sampling in the drilling environment by way of numerical simulations. The study considers the dynamic nature of invasion while drilling when using both new and conventional probe configurations to retrieve fluid samples.