Method for determining the resistivity index, as a function of the water saturation, of certain rocks of complex porosity
US6879154B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 2003 |
| Grant date | Apr 12, 2005 |
| Priority date | — |
| Expiry date | Oct 13, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A90/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the variations of the resistivity index (RI) of a family of rock samples of complex pore structure with at least two pore networks, as a function of the water saturation (Sw), and in the presence of a non-oil conducting fluid. The volume fraction (f1, f2, f3) occupied by each pore network and the distribution of the pore throats in the various pore networks are determined for each sample of the family. The values of coefficients relating the variation of its electrical resistivity as a function of its water saturation (Sw) are experimentally determined on a sample of the family used as a reference sample. The resistivity index (RI) of all the samples of the family is then determined on the basis of the variation of parameters describing the layout of the pore network, and using the values of the coefficients measured on the reference sample. The method allows measurement of a continuous resistivity index curve which is not obtained, as in conventional techniques, from only a limited number of points at capillary equilibrium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.