Decoupling tensor components without matrix inversion
US11035976B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 2019 |
| Grant date | Jun 15, 2021 |
| Priority date | — |
| Expiry date | Mar 6, 2039 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Numerical and/or semi-analytical methods are leveraged to decouple a complete set of nonzero electromagnetic field tensor components (118) from detected signal data (119). Nine nonzero components can serve as inputs for a three-dimensional inversion process to determine formation properties. A resistivity tool (100) containing at least one transmitter (111) and at least one receiver (108, 109) at tilted angles receives an electromagnetic signal throughout a rotation. A difference in the azimuthal positions of the transmitter(s) and receiver(s) during rotation of the resistivity tool can result in an azimuthal offset between resistivity tool subs. The components (118) are decoupled from the detected signal data (119) numerically or semi-analytically according to whether the azimuthal offset angle is known. If the azimuthal offset angle is known, the nine components are determined numerically through curve fitting. If the azimuthal offset angle is unknown, a semi-analytical process is used to solve for the nine components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.