Downhole pressure calculation based on strain gauge measurements
US12264577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2021 |
| Grant date | Apr 1, 2025 |
| Priority date | — |
| Expiry date | Nov 26, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L1/2206
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
As a wellbore is extended into a formation, hydrostatic and hydrodynamic pressures change due to variations in drilling mud weight, fluid density, etc. Strain gauges downhole measure forces experienced by drilling equipment. During drilling, a strain gauge measures strain applied between the drill string and the formation. When off bottom, the strain gauge measures forces experienced by the drill string other than drilling forces. A pressure calculator converts off bottom strain gauge measurements into measurements of hydrostatic pressure for periods without fluid flow (i.e., when drilling motors are paused) and into measurements of hydrodynamic pressure for periods with fluid flow (i.e., when mud motors are operating). The pressure calculator correlates strain measurements (usually in voltages) to pressure based on a predetermined relationship for a given wellbore geometry (e.g., hole diameter, drill bit diameter, drill pipe diameter, etc.).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.