Methods for determining formation and borehole parameters via two-dimensional tomographic reconstruction of formation slowness
US5081611A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1991 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | Mar 6, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods are provided for determining the axial and radial slowness of a formation traversed by a borehole via utilization of sonic data obtained from a sonic borehole tool having a plurality of detectors. The methods utilize first arrival time information, ray tracing techniques, and backprojection techniques. The differences between the actually measured first arrival times and the theoretical first arrival times as calculated by ray tracing through an initial slowness model of the formation, are backprojected along the theoretical ray paths of first arrival in order to modify the initial slowness model of a formation. The methods utilized are preferably iterative, such that the modified slowness model is then utilized for additional ray tracing and backprojection. Secondary arrivals may also be utilized to refine slowness determinations made from first arrival information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.