PAJARI

 INSTRUMENTS LTD

Directional Surveying

Instrumentation and Accessories

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The principle in surveying with the Tropari instrument in wireline drilling is to raise the rod train 8 - 9 meters so that the complete survey train will extend beyond the drill bit.

This will place the Tropari Instrument beyond the magnetic influence of the drill bit and rods.

The connector is identical in all dimensions to a core-lifter casing for the wireline size being drilled, except that it will have a pin thread protruding on the bottom end that threads into the top of the non-magnetic survey train.

The inner-tube is threaded onto the bottom end of the inner-tube (core-barrel) in place of the core lifter casing. The normal inner-tube assembly used in drilling lowers the Tropari train attached to the bottom of the inner-tube. When the assembly locks in place at the landing ring, the complete survey train will have passed through the bit. Since the survey train has to pass through the bit, the non-magnetic rods, container and centralizer must have a smaller diameters than the core. The inner-tube sub must be specific to the wireline system being drilled so that it will thread onto the core-barrel being used.

The inner-tube sub method, and the Tropari instrument, are capable of surveying holes drilled at any angle since standard procedures used in drilling are used to place the survey train at the survey site.

(not to scale)