NMR logging of natural gas in reservoirs
US5498960A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1994 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Oct 20, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lithology-independent method of well logging the gas saturation in a reservoir containing natural gas. The method makes use of a pulsed NMR logging tool utilizing a recovery time that is greater than the relaxation time of hydrocarbon gas within the formation. In a preferred embodiment, two different NMR logs are obtained: one with a recovery time significantly shorter than the longitudinal relaxation time, T1, of the gas and one with a recovery time equal to or longer than T1. The amplitudes of the two logs are subtracted and the remainder divided by the hydrogen index of the gas at reservoir conditions to determine the pore volume occupied by gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.