Apparatus for weight on bit measurements, and methods of using same

• Main Authors: BOUCHER MARCEL LUKE, IVIE CRAIG ROBERT, SCHEN AARON, JARVIS BRIAN PETER
• Format: Patent
• Language: English
• Published: 25.10.2005
• Edition: 7
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The present invention is generally directed to a tool for obtaining downhole measurements and methods of using such a tool. In one illustrative embodiment the tool comprises a body, at least one strain gauge cavity in the body, the strain gauge cavity having a strain gauge mounting surface that is located at a position such that a region of approximately zero strain due to at least one downhole operating condition exists on the mounting surface when the tool is subjected to downhole operating conditions, and a strain gauge operatively coupled to the mounting face above the region of approximately zero strain. In another illustrative embodiment, the method comprises providing a measurement tool comprised of a body, at least one strain gauge cavity in the body, the strain gauge cavity having a strain gauge mounting surface that is located at a position such that a region of approximately zero strain due to at least one downhole operating condition exists on the mounting surface when the tool is subjected to downhole operating conditions, and a strain gauge coupled to the mounting face above the region of approximately zero strain. The method further comprises positioning the tool in a subterranean well bore and obtaining measurement data using the strain gauge in the tool.