The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 1995
Filed:
Apr. 25, 1994
Hwa-Shan Ho, Spring, TX (US);
Other;
Abstract
A method determining a tool face angle of a downhole drilling assembly in a well bore including the steps of determining an apparent tool face angle, measuring torque at least at one downhole axial location along the drillstring in the well bore, correlating a change in the apparent tool face angle relative to a change in the torque so as to produce a graphical curve of the correlation, and identifying a slope discontinuity along the graphical curve. The slope discontinuity is indicative of a contact resistance between the drillstring and the well bore. This method further includes the steps of determining a differential twist angle from the graphical curve and inferring a true tool face angle by subtracting the differential twist angle from the apparent tool face angle. The step of determining the apparent tool face angle includes measuring the inclination angle and azimuth angle of the well bore. The torque is measured at substantially the same axial location as the apparent tool face angle. The torque or rotation applied to the drillstring is adjusted so as to obtain a desired true tool face angle.