Patent ID: 8010290
Filing Date: 2011-08-30
Classification: E21B

Abstract:
1. A method for obtaining a list of survey points for a subterranean borehole while drilling, the list defining a well path and including a plurality of survey points at a corresponding plurality of measured depths, each survey point including at least one of a borehole inclination and a borehole azimuth, the method comprising: (a) deploying a drill string in a drilling well; (b) estimating at least one of a borehole inclination and a borehole azimuth of the drilling well at a particular measured depth; (c) processing the at least one of the borehole inclination and borehole azimuth estimated in (b) to calculate a value of at least one parameter at the measured depth; (d) measuring a value of the parameter at substantially the measured depth; (e) adjusting at least one of the borehole inclination and the borehole azimuth estimated in (b) to obtain a survey point, the survey point selected so that a difference between the value of the parameter calculated in (c) and the value of the parameter measured in (d) is less than a predetermined threshold; and (f) recording the survey point in the list of survey points.