METHOD FOR DETERMINING POROSITY, ASSOCIATED WITH ORGANIC SUBSTANCE, IN A WELL OR IN A PRODUCTIVE STRATA Russian patent published in 2019 - IPC E21B49/08 G01N15/08 G01V5/08 G01V5/14 

FIELD: measurement technology.

SUBSTANCE: invention relates to method and system for determining amount of porosity associated with organic matter in a well or in productive strata. Method includes (a) obtaining images using scanning electron microscope (SEM) or scanning electron microscope with a focused ion beam (FIB-SEM) for a variety of rock samples obtained from well or reservoir, (b) determination of amount of porosity associated with organic matter (PAOM), total porosity (PHIT) and content (TOC) of organic matter (OM) using SEM or FIB-SEM images, (c) determining maximum value of apparent transformation coefficient (ATR) for a variety of rock samples using equation (1): ATR=PAOM/(PAOM+OM), in which the PAOM and OM values are determined in (b), (d) fitting the fitting PAOM to PHIT and TOC ratios for at least three experimental points obtained in (b) for obtain at least one of the following: equation of mathematical function or graph of their dependence (2), (e) determining total porosity (PHIT) and organic matter content (TOC) (OM) for a sample at location along the length of borehole or core sample being logged, (f) calculating first PAOM value for a sample of borehole or core sample to be logged using a mathematical function equation or a dependency graph (2) obtained using total porosity (PHIT) value and the organic matter content (TOC) defined in (e), (g) calculating second PAOM value for borehole or core sample to be logged using equation (3): PAOM=ATR×OM/(1-ATR), in which the ATR value is defined in (c), and the OM value is defined in (e), (h) comparing the first PAOM value calculated from (f) with the second PAOM value calculated in (g), and (i) selecting the first calculated PAOM value, if the condition that the first PAOM value exceeds the second PAOM value is not met, and when the condition is met, the second PAOM value is selected.

EFFECT: technical result is creation of improved method for estimating the value of porosity associated with the organic matter of geological material.

16 cl, 5 dwg