System and method of petrophysical formation evaluation in heterogeneous formations
US5675147A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1996 |
| Grant date | Oct 7, 1997 |
| Priority date | — |
| Expiry date | Jan 22, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V11/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for evaluating a geological formation is described which compares actual wireline log measurements from a number of wireline logging tools to predicted tool response logs. The system and method uses a forward model of each tool response, given a formation description, to predict a set of wireline logs. Comparing the predicted logs with the actual measured logs yields a mismatch error. The system and method iteratively adjusts the formation description to minimize the mismatch error to obtain a "best" formation description. In one form, the formation description includes petrophysical properties (porosity, density, saturation) and geometry properties (dip, bedding, invasion). In a more complicated form, the formation description also includes a model of petrophysical mixing laws and formation material content. In the special case of a horizontally layered formation and linear tool response models, there exists a computationally efficient version of the system and method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.