Corientator Core Barrels

Comprises a wireline core barrel incorporating a special core orientation device in the head assembly. This "Corientator" mechanism maintains the same the rotational position as the inner tube, and contains an indicating device that marks the position of the inner tube when the core is broken from the strata. Once the inner tube assembly is removed from the borehole, the original rotation of the drilled core can be determined by reference the indicator.

The technique depends on boreholes being drilled at an angle of at least 5 degrees to the vertical. The Corientator mechanism consists of a steel ball on a circular race track within the head assembly. Gravity causes the ball to rest on the lowest side of the inclined borehole. When the overshot is lowered, it latches onto the head assembly triggering a clamp that traps the steel ball where it is resting. Thus, when the inner tube is extracted, it is possible to determine its original rotational position by reference to the steel ball.

These core barrels are available for hole sizes N, H. Except for the head assembly all parts are fully interchangeable with Longyear "Q" series and Boyles "O" series wireline core barrels.

To convert an existing wireline corebarrel to a "Corientator" core barrel the following parts are required:

• Corientator head assembly
• Outer tube extension
• Alignment kit
• Modified overshot

See also:
Core Barrel Selector