Data compression method for use in wellbore and formation characterization
US6405136B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2000 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Jun 23, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/30
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method is disclosed for compressing a frame of data representing parameter values, a time at which each parameter value was recorded, and an orientation of a sensor at the time each parameter value was recorded. Generally the method includes performing a two-dimensional transform on the data in the orientation domain and in a domain related to the recording time. In one embodiment, the method includes calculating a logarithm of each parameter value. In one embodiment, the 2-D transform includes generating a Fourier transform of the logarithm of the parameter values in the azimuthal domain, generating a discrete cosine transform of the transform coefficients in the time domain. This embodiment includes quantizing the coefficients of the Fourier transform and the discrete cosine transform. One embodiment of the method is adapted to transmit resistivity measurements made by an LWD instrument in pressure modulation telemetry so that while-drilling images of a wellbore can be generated. The one embodiment includes encoding the quantized coefficients, error encoding the encoded coefficients, and applying the error encoded coefficients to the pressure modulation telemetry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.