A method comprising: a) acquiring a reservoir rock sample from a reservoir of interest; b) obtaining scanning electron microscopy image data in back-scattered electron mode and energy dispersive spectral data of said reservoir rock sample, c) generating a mineral map from said EDS spectral data; d) assigning a chemical mineralogy in said mineral map; and e) determining a spatial profile of chemical mineralogy of one or more pore walls in said reservoir rock sample; f) evaluating said reservoir rock sample's response to one or more enhanced oil recovery laboratory tests on said reservoir rock sample; and g) comparing said spatial profile with results from said evaluating step f) to identify the composition of one or more critical region of pore walls, wherein a critical region is a region that influences fluid-rock interactions and is located near the interface between distinct mineral grains and void or pore space and is sufficiently large enough that sub-areas of grain and pore can be identified such that the interface between the two is recognisable; characterised in that the method is a method for forecasting an enhanced oil recovery process for a reservoir; steps c) and d) comprise: generating a mineral map by combining said SEM image data and said EDS spectral data on an individual pixel basis; and assigning a chemical mineralogy of each pixel in said mineral map; and the method further comprises: h) forecasting enhanced oil recovery for one or more regions in said reservoir of interest having the same critical region of pore walls composition as said reservoir rock sample based on said response in step f. a) acquiring a reservoir rock sample from a reservoir of interest; b) obtaining scanning electron microscopy image data in back-scattered electron mode and energy dispersive spectral data of said reservoir rock sample, c) generating a mineral map from said EDS spectral data; d) assigning a chemical mineralogy in said mineral map; and e) determining a spatial profile of chemical mineralogy of one or more pore walls in said reservoir rock sample; f) evaluating said reservoir rock sample's response to one or more enhanced oil recovery laboratory tests on said reservoir rock sample; and g) comparing said spatial profile with results from said evaluating step f) to identify the composition of one or more critical region of pore walls, wherein a critical region is a region that influences fluid-rock interactions and is located near the interface between distinct mineral grains and void or pore space and is sufficiently large enough that sub-areas of grain and pore can be identified such that the interface between the two is recognisable; the method is a method for forecasting an enhanced oil recovery process for a reservoir; steps c) and d) comprise: generating a mineral map by combining said SEM image data and said EDS spectral data on an individual pixel basis; and assigning a chemical mineralogy of each pixel in said mineral map; and generating a mineral map by combining said SEM image data and said EDS spectral data on an individual pixel basis; and assigning a chemical mineralogy of each pixel in said mineral map; and the method further comprises: h) forecasting enhanced oil recovery for one or more regions in said reservoir of interest having the same critical region of pore walls composition as said reservoir rock sample based on said response in step f.