US 9,176,251 B2 · Asphaltene evaluation based on NMR measurements and temperature / pressure cycling

Abstract

Asphaltene content and its spatial distribution in a reservoir containing crude oil is an important factor in determining the potential for formation damage and pipeline impairment, as well as planning for processing and refining of the oil. Exemplary uses include: reservoir modeling, development and depletion planning, pressure maintenance, and surface facilities management. A convenient method has been developed which uses two-dimensional NMR techniques during a temperature and/or pressure cycle to quantify the asphaltene content of the crude oil without the need for extracting the oil from the reservoir rock. The technique can be applied to core, down-hole logs, or, a combination of both.

Claims23

Dependent claims

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.

3 more elements

Dependencies are inferred from the claim text.

Asphaltene evaluation based on NMR measurements and temperature / pressure cycling

Life of this patent

Asphaltene evaluation based on NMR measurements and temperature / pressure cycling

Life of this patent

Abstract

Claims23