Microwave electromagnetic logging with mudcake correction
US4300098A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1979 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | May 24, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A90/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosure is directed to a technique used for determining the mudcake-corrected water-filled porosity of formations surrounding a borehole, and which can also be used for determining the thickness of the mudcake formed on the borehole. Microwave electromagnetic energy is transmitted into the formations. Near and far receiving antennas are employed for receiving microwave electromagnetic energy from the formations. Means responsive to the outputs of the receiving antennas are provided for obtaining a travel-time-dependent differential measurement. Further means, responsive to the output of one of the antennas, are provided for obtaining a travel-time-dependent direct measurement. Finally, means are provided for determining the mudcake-corrected water-filled porosity of the formations from the differential and direct measurements. The mudcake thickness may also be determined from the differential and direct measurements. In the preferred embodiment of the invention, the means for obtaining the travel-time-dependent differential measurement is operative to measure the phase difference between the electromagnetic energy received at the near and far receivers, and the means for obt…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.