Method for optimizing the selection of points to obtain formation static pressure based on the relation between the permeability index and the effective

Abstract

A method for marking out which intervals are most suitable for carrying out pressure measurements with wireline testers, comprising: charts divided into four intervals of flow capacity regimes, wherein the third interval houses the inflection point of the sigmoidal function, that is, it corresponds to the highest rate of variation in permeability versus porosity; from this point onwards, a slowdown in the accumulation of permeability begins to occur, due to the increase in effective porosity; wherein the point of interest for effective porosity cutoff, to mark out pressure measurement operations, corresponds to the lower limit of said third interval; wherein, in order to obtain this point, it is necessary to find the first derivative of the sigmoidal function fitted to the effective porosity distribution versus the normalized sum of the permeability index, and the first inflection point of the first derivative of the sigmoidal function corresponds to the lower limit of the third interval, so that this effective porosity value is the minimum cutoff for pressure measurement operations.

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