초록 ▼

A method is provided of determining saturation values corresponding to particular locations in a sample of a porous media, whereby such saturation values can be used in conjunction with corresponding capillary pressures to derive a capillary pressure curve. The method of the invention involves the u

A method is provided of determining saturation values corresponding to particular locations in a sample of a porous media, whereby such saturation values can be used in conjunction with corresponding capillary pressures to derive a capillary pressure curve. The method of the invention involves the use of nuclear magnetic resonance (NMR) imaging to obtain NMR intensity values corresponding to the locations of interest. Intensity is related to saturation by an appropriate function which is employed to determine the saturation values from the intensity values.

대표청구항 ▼

A method comprising (a) substantially saturating a sample of a porous media with at least one liquid, wherein said sample has a first end, a second end, and an axis which passes through each of said ends; (b) subjecting the sample, after step (a), to a substantially constant acceleration in a predet

A method comprising (a) substantially saturating a sample of a porous media with at least one liquid, wherein said sample has a first end, a second end, and an axis which passes through each of said ends; (b) subjecting the sample, after step (a), to a substantially constant acceleration in a predetermined direction with respect to the sample so as to cause at least some of said liquid to flow from the sample, this step being performed for such a time until a state of equilibrium is reached wherein liquid flow from the sample terminates, wherein the sample is oriented during this step so as to extend along said axis in said direction from said first end to said second end and so that said axis is generally parallel to said direction; (c) positioning the sample after step (b) in a static magnetic field; (d) exposing the thus positioned sample to a pulsed radio frequency field, having a resonant frequency for which nuclear magnetic resonance occurs with respect to atomic nuclei associated with said liquid, such that at least one NMR signal results for each of a plurality of locations in the sample which are spaced a plurality of different distances from the first end of the sample, where distance is defined as being measured along lines generally parallel to said axis and wherein the at least one signal corresponding to each location has at least one amplitude associated therewith; (e) detecting said at least one amplitude for each location; (f) determining the saturation corresponding to each of said plurality of locations based on said at least one amplitude corresponding to each location; and (g) determining the capillary pressure corresponding to each of said plurality of locations.