Patent ID: 9176251
Filing Date: 2015-11-03
Classification: E21B,G01N,G01V

Abstract:
1. A method of asphaltene evaluation of a hydrocarbon-bearing rock sample from a subterranean rock formation comprising: making a first NMR measurement representative of the hydrocarbon-bearing rock sample at temperature and pressure conditions prior to asphaltene precipitation onset; lowering temperature and/or pressure of the hydrocarbon-bearing rock sample below an expected asphaltene precipitation onset condition; subsequently raising the temperature and/or pressure conditions above the expected asphaltene precipitation onset condition; making a second NMR measurement on the hydrocarbon-bearing rock while at conditions above the expected asphaltene precipitation onset condition; and evaluating asphaltene content of oil in the hydrocarbon-bearing rock sample based at least in part on a comparison of the first and second NMR measurements.