MEASURING CONNECTIVITY BETWEEN DIFFERENT PORE TYPES IN POROUS MEDIA

摘要

The connectivity between different pore types in porous media is measured by using low-field nuclear magnetic (NMR) and fast field cycling NMR techniques. Due to the fluid exchange between connected pores, T1(T2) NMR relaxation times of proton nuclei of fluids in the different pore types are shifted. By comparing the T1(T2) NMR relaxation times of porous media samples which are 100% brine saturated with relaxation times for the samples containing brine and hydrocarbon in the different pore systems of the samples, the connectivity between the pores can be measured.

主权项

1. A method of obtaining a measure of connectivity between pores in a rock sample from a subsurface hydrocarbon reservoir, comprising the steps of:
obtaining nuclear magnetic resonance relaxation times of the rock sample fully saturated with water; obtaining a nuclear magnetic resonance dispersion profile of the rock sample at irreducible water saturation; obtaining nuclear magnetic resonance relaxation times of the rock sample at irreducible water saturation; obtaining nuclear magnetic resonance relaxation times of the rock sample fully saturated with a hydrocarbon liquid; and obtaining measure of connectivity between pores of pores in the rock sample based on the obtained measures of nuclear magnetic resonance relaxation times of the rock sample: when fully saturated with water; when at irreducible water saturation; when fully saturated with a hydrocarbon liquid; and the nuclear magnetic resonance dispersion profile.