Method of determining the permeability of sedimentary strata using NMR data
US6047595A · kind A · utility
7Cited by
2References
2Claims
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Key dates
| Filing date | Dec 12, 1997 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Dec 12, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
There is provided a method of accurately estimating the permeability of sedimentary rock formations from well logging data. The method involves a short relaxation time strategy with the identification of the key k-Lambda parameter S/V.sub.p, which is the surface-to-pore ratio. The inverse of T.sub.2 is related to this ratio by the surface relaxivity, .rho.2. The k-Lambda estimator is given by: ##EQU1## where: .DELTA.V.sub.1 represents the volume elements of the T.sub.2 distribution and the sum over i=1 to n represents some set of early to later volume elements; and V.sub.p is the total pore volume.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.