Read e-book online Resistivity Modeling: Propagation, Laterolog and Micro-Pad PDF

Resistivity logging represents the cornerstone of recent petroleum exploration, delivering a quantitative evaluation of hydrocarbon bearing capability in newly came across oilfields.  Resistivity is measured utilizing AC coil instruments, in addition to via concentrated DC laterolog and micro-pad units, and later extrapolated, to supply oil saturation estimates concerning fiscal productiveness and money flow.  Interpretation and modeling tools, hugely profitable, are shrouded in secrecy via oil provider businesses – frequently those types are mistaken and error perpetuate themselves over time.

This booklet develops math modeling equipment for layered, anisotropic media, delivering algorithms, validations and various examples.  New electrical present tracing instruments also are built which exhibit how good (or poorly) DC instruments probe meant anisotropic formations at diverse dip angles.  The methods mentioned supply readers with new insights into the restrictions of traditional instruments and strategies, and provide useful and rigorous suggestions to numerous sessions of difficulties explored within the book.

Traditionally, Archie’s legislations is used to narrate resistivity to water saturation, yet purely on small core-sample spatial scales.  the second one half this publication introduces how you can calculate field-wide water saturations utilizing smooth Darcy move methods, after which, through Archie’s legislations, develops field-wide resistivity distributions that could differ with time.  How large-scale resistivity distributions can be utilized in additional exact instrument interpretation and reservoir characterization is taken into account at length.  The publication additionally develops new equipment in “time lapse logging,” the place timewise alterations to resistivity reaction (arising from fluid hobbies) can be utilized to foretell rock and fluid stream properties.