| 摘要 |
An adjustable bent sub for use in directional drilling in earth formations comprises a first body member having a first body portion defining a first primary axis and a second body portion defining a first secondary axis disposed at a first offset angle with respect to the first primary axis, a second body member having a first body portion defining a second primary axis and a second body portion defining a second secondary axis disposed at a second offset angle with respect to the first primary axis, the second body member being adapted to be secured to the first body member such that the first secondary axis and the second primary axis are coaxial and define a common axis and the second body member is rotatable about the common axis. A device is provided for non-rotatably coupling the second body member to the first body member in predetermined angular relation about the common axis so as to provide a predetermined angular relationship between the first primary axis and the second secondary axis.
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