Formation resistivity measurement sensor contained onboard a drill bit (resistivity in bit)

US6850068B2 · kind B2 · utility

Assignee

• Baker Hughes Holdings LLC · US

Inventors

• Roland E. Chemali · Humble, US
• Paul E. Pastusek · Diemelstraße, US
• Friedhelm Makohl · Hermannsburg, DE
• Rene Ritter · Celle, DE
• Martin Evans · Norwich, GB
• Stanley T. Hewitt · Slidell, US

Key dates

• Filing date: Jun 16, 2003
• Grant date: Feb 1, 2005
• Expiry date: Jun 16, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A90/30
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus for obtaining a resistivity measurement of an earth formation surrounding a borehole in an MWD device uses an electrode for injecting current into the earth formation and an electrode for obtaining a responsive signal from the borehole. The electrodes are located on the drill bit arm or blade. Measured resistivity values are obtained at the location of the drill bit. Measurements can be taken in both oil-based mud and water-based mud environments. Maximum or minimum resistivity can be used to best represent the resistivity of the surrounding formation.