Formation Testing –

Supercharge, Pressure Testing and Contamination Models



December 2018



Wilson C. Chin, Ph.D., M.I.T.













This volume, possibly the third and final of three, summarizes new and important methods and approaches for wireline and LWD/MWD formation tester pressure transient interpretation. Two prior monographs, Formation Testing: Pressure Transient and Contamination Analysis (2014) and Formation Testing: Low Mobility Pressure Transient Analysis (2015), had developed essential models and algorithms for exact forward analysis; rapid, real-time, inverse mobility and pore pressure prediction methods in low mobility environments with non-negligible flowline volume effects; steady-state and transient forward and inverse techniques; miscible, multiphase flow contamination modeling for sample quality control; fast "phase-delay" methods for real-time kh and kv prediction in tight zone applications, and other useful mathematical methods.

The present book tackles two additional challenges. The first deals with high overbalance pressures, which "supercharge" the pressure fields surrounding tool probes, and addresses specific questions. How do we extrapolate mobility, compressibility and pore pressure accurately in the presence of possibly overwhelming borehole effects which have not yet dissipated? How can we use this model to obtain error bounds on the usual downhole predictions? And how does supercharging evolve dynamically, as a function of formation, borehole and mud filtration properties? Second, we consider "multiple drawdown and buildup" sequences, actually any combination of piecewise constant, positive, negative or zero flowrates, calculate their exact pressure response, and importantly, show how any three time-pressure data points taken during the final flowrate cycle can be accurately inverted to produce mobility, compressibility and pore pressure – and that’s rapidly, in the presence of flowline volume distortions and low mobility environments.

Detailed theory, validations and engineering applications are given for both new models. But just as important, the present book summarizes all of our collective results obtained over the years, and highlights their application to day-to-day activities. This perspective is invaluable especially to a researcher reflecting on his path to discovery in dealing with what appeared to be an endless array of random challenges. Out of this, a number of "best practices" were developed which focus on uses of our models, which apply to all manufacturers’ formation testing tools. It is difficult to believe that almost two decades have elapsed since the author’s first introduction to formation testing and sampling – it’s been immensely challenging and enjoyable, particularly in seeing these methods used in oil exploration – and, I suppose, an intellectual labor of love, that’s finally coasting to a satisfying ending. I think.


Wilson C. Chin, Ph.D., M.I.T.

Houston, Texas









The author is indebted to his friends and colleagues at Halliburton Energy Services and China Oilfield Services who strongly shaped and influenced his initial approaches to formation testing. Over the past twenty years, the freedom to pursue new ideas and a continual exposure to state-of-the-art technology have led to innovative interpretation and oilfield planning methods that have positively impacted our industry. This third book in our trilogy on formation testing summarizes modeling approaches that address operational concerns raised by petroleum engineers, for example, interpretation in supercharged environments, modeling contamination under overbalanced pressures, gas pumping, and applications to reservoir treatment and enhanced hydrate production.

The author gratefully acknowledges the United States Department of Energy for its support through its Small Business Innovation Research (SBIR) program for Contracts DE-FG03-99ER82895, DE-FG02-04ER84082, DE-FG02-04ER84083 and DE-FG02-06ER84621, and through its Research Partnership to Secure Energy for America (RPSEA) Ultra-Deepwater Program, for assistance under Contract 08121-2502-01. Such programs are essential in supporting new, high-risk ideas that may make a difference – and, certainly, to entrepreneurs dedicated to science and wanting of the chance to make the world just a bit better. Finally, thanks to Mark Proett, formation testing guru, Xiaoying Zhuang, friend and facilitator, and last but not least, Phil Carmical, Acquisitions Editor and Publisher, for their interest and continuing support over the years. Without their unwavering faith and confidence, this author’s frustrations and disappointments may have remained just that.