Downhole depth computation methods and related system
US8528637B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2012 |
| Grant date | Sep 10, 2013 |
| Priority date | — |
| Expiry date | Feb 28, 2032 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for determining depth in a wellbore uses inertial navigation in conjunction with a database having one or more measured parameters correlated with depth. The measured parameter may be the lengths of stands forming a drill string, prior survey data relating to a naturally occurring feature such as formation lithology, or data relating to a human made feature such as collars in a casing string. The downhole processor may use accelerometer measurements to calculate a measured depth of a BHA and access the database to retrieve a predicted depth that corresponds with one or more sensor measurements (e.g., motion indicating the addition of a stand to a drill string). Thereafter, if the downhole processor determines that the predicted depth is in agreement with the calculated depth, the processor stores the predicted depth and/or associates the predicted depth with directional surveys taken along the wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.