Methods and apparatus for optically measuring fluid compressibility downhole
US6474152B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2000 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Dec 8, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3536
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The compressibility of a formation hydrocarbon sample is determined downhole by using a borehole tool to obtain the sample downhole, and, at two different pressures, subjecting the sample to near infrared illumination and conducting spectral absorption measurement of peaks at and/or around about 6,000 cm−1 and/or at and/or about 5,800 cm−1 (the absorption peaks of methane and crude oil respectively). The compressibility of the sample is determined from the change in the peak areas, the change in pressure, and the measured peak area itself. According to a preferred embodiment of the invention, the pressure is changed at least 2000 pounds per square inch (psi), and preferably 4000 or more psi between measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.