Enhanced-resolution rock formation body wave slowness determination from borehole guided waves
US11550073B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2016 |
| Grant date | Jan 10, 2023 |
| Priority date | — |
| Expiry date | Mar 26, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/6222
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus, method, and system for determining body wave slowness from guided borehole waves. The method includes selecting a target axial resolution based on the size of a receiver array, obtaining a plurality of waveform data sets corresponding to a target formation zone and each acquired at a different shot position, computing a slowness-frequency 2D dispersion semblance map for each waveform data set, stacking the slowness-frequency 2D dispersion semblance maps to generate a stacked 2D semblance map, and determining a body wave slowness from the extracted dispersion curve. The method may also include generating a self-adaptive weighting function based on a dispersion model and the extracted dispersion curve, fitting the weighted dispersion curve and the dispersion model to determine a body wave slowness that minimizes the misfit between the weighted dispersion curve and the dispersion model. The method can be applied to both frequency-domain and time-domain processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.