A computer implemented method for estimating amounts of hydrocarbon recoverable from porous reservoir rock by one or two or more enhanced oil recovery, i.e., EOR, techniques, the method comprising: retrieving by a computing system a representation of a physical porous reservoir rock sample, i.e., porous reservoir rock, the representation including pore space and grain space data corresponding to the porous reservoir rock, subsequent to an execution of a multiphase flow simulation to obtain predictions of flow behavior of oil in the presence of a waterflood of the porous reservoir rock; locating substantially immobile oil blobs or patches in the retrieved representation of the porous reservoir rock; and for N number of substantially immobile oil blobs or patches, i.e., blobs, i) evaluating changes in mobility of the blobs for one or two or more iterations of a given EOR technique, with a first one of the one or two or more iterations expending a first level of effort and a second one of the one or two or more iterations expending a second, higher level of effort, to estimate an amount of change in mobilization of the blob between the first and the second iterations for the given EOR technique, and, ii) integrating all iterations at different levels of effort including the first and second levels of effort, for the given EOR technique to provide an approximation of an incremental amount of recoverable oil for the given EOR technique according to the levels of effort. retrieving by a computing system a representation of a physical porous reservoir rock sample, i.e., porous reservoir rock, the representation including pore space and grain space data corresponding to the porous reservoir rock, subsequent to an execution of a multiphase flow simulation to obtain predictions of flow behavior of oil in the presence of a waterflood of the porous reservoir rock; locating substantially immobile oil blobs or patches in the retrieved representation of the porous reservoir rock; and for N number of substantially immobile oil blobs or patches, i.e., blobs, i) evaluating changes in mobility of the blobs for one or two or more iterations of a given EOR technique, with a first one of the one or two or more iterations expending a first level of effort and a second one of the one or two or more iterations expending a second, higher level of effort, to estimate an amount of change in mobilization of the blob between the first and the second iterations for the given EOR technique, and, ii) integrating all iterations at different levels of effort including the first and second levels of effort, for the given EOR technique to provide an approximation of an incremental amount of recoverable oil for the given EOR technique according to the levels of effort. i) evaluating changes in mobility of the blobs for one or two or more iterations of a given EOR technique, with a first one of the one or two or more iterations expending a first level of effort and a second one of the one or two or more iterations expending a second, higher level of effort, to estimate an amount of change in mobilization of the blob between the first and the second iterations for the given EOR technique, and, ii) integrating all iterations at different levels of effort including the first and second levels of effort, for the given EOR technique to provide an approximation of an incremental amount of recoverable oil for the given EOR technique according to the levels of effort.