Patent ID: 8095317
Filing Date: 2012-01-10
Classification: E21B,G01V

Abstract:
1. A drill string, comprising: a downhole portion adapted to move within a wellbore, the downhole portion hag a first portion at a first position within the wellbore and oriented at a first angle relative to the wellbore at the first position and a second portion at a second position within the wellbore and oriented at a second angle relative to the wellbore at the second position, wherein at least one of the first and second angles is non-zero; a first acceleration sensor mounted within the first portion, the first acceleration sensor adapted to generate a first signal indicative of an acceleration of the first acceleration sensor; and a second acceleration sensor mounted within the second portion, the second acceleration sensor adapted to generate a second signal indicative of an acceleration of the second acceleration sensor, wherein a difference between the first angle and the second angle is due to gravity induced sag and is less than about one degree.