Supercharge, Invasion, and Mudcake Growth in Downhole Applications

Mysterious "supercharge effects," encountered in formation testing  pressure transient analysis, and reservoir invasion, mudcake growth,  dynamic filtration, stuck-pipe remediation, and so on, are often  discussed in contrasting petrophysical versus drilling contexts.   However, these effects are physically coupled and intricately related.  The authors focus on a comprehensive formulation, provide solutions for  different specialized limits, and develop applications that illustrate  how the central ideas can be used in seemingly unrelated disciplines.  This approach contributes to a firm understanding of logging and  drilling principles. Fortran source code, furnished where applicable, is  listed together with recently developed software applications and  conveniently summarized throughout the book. In addition, common  (incorrect) methods used in the industry are re-analyzed and replaced  with more accurate models, which are then used to address challenging  field objectives.

Sophisticated mathematics is explained in  "down to earth" terms, but empirical validations, in this case through  Catscan experiments, are used to "keep predictions honest." Similarly,  early-time, low mobility, permeability prediction models used in  formation testing, several invented by one of the authors, are extended  to handle supercharge effects in overbalanced drilling and near-well  pressure deficits encountered in underbalanced drilling. These methods  are also motivated by reality. For instance, overpressures of 2,000 psi  and underpressures near 500 psi are routinely reported in field work,  thus imparting a special significance to the methods reported in the  book.

This new volume discusses old problems and modern  challenges, formulates and develops advanced models applicable to both  drilling and petrophysical objectives. The presentation focuses on  central unifying physical models which are carefully formulated and  mathematically solved. The wealth of applications examples and  supporting software discussed provides readers with a unified focus  behind daily work activities, emphasizing common features and themes  rather than unrelated methods and work flows. This comprehensive book is  "must" reading for every petroleum engineer.