Apparatus and method for resistivity measurements during rotational drilling

US7576543B2 · kind B2 · utility

Assignee

• Baker Hughes Holdings LLC · US

Inventors

• Rene Ritter · Celle, DE
• Matthias Gorek · Hannover, DE
• Volker Krueger · Celle, DE
• Martin Evans · Norwich, GB

Key dates

• Filing date: May 15, 2007
• Grant date: Aug 18, 2009
• Expiry date: May 15, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01V3/30
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A resistivity sub including a resistivity sensor forms part of a bottom hole drilling assembly. The sensor is maintained at a substantially fixed offset from the wall of a borehole during drilling operations by, for example, a stabilizer. In WBM, galvanic sensors may be used, with or without commonly used focusing methods, for obtaining a resistivity image of the borehole wall. In OBM, capacitive coupling may be used. The apparatus is capable of using other types of sensors, such as induction, MPR, shielded dipole, quadrupole, and GPR sensors. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).