Pajari Instruments Ltd., since 1945




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   Wireline Surveying with the Overshot Method

Diagram - not to scale


Surveying with the instrument installed into a wireline drilling overshot saves time and therefore money by measuring the inclination of the hole while you are retrieving the core.


A very time efficient configuration for this type of surveying is to simply install the instrument into a spare overshot. Normal drilling and core retrieval procedures can be performed. When you would like to perform a survey, simply connect the overshot with the instrument installed to the overshot already being used to retrieve the core. If you do not have a spare overshot then let us know and we will provide other options.


The instrument can be threaded directly into overshots which have a 1" 16TPI thread and can be used with other overshots that have a different thread configuration by adding thread adapters. Standard and custom thread adapters are available.

This method is 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.


Information to provide when requesting a quotation:

If available, please includes details about your surveying application so we can provide a detailed quotation and/or additional information. Common details to include are:

  • What is the core size(s)?

  • What is the direction (upward, downward, horizontal, etc) of the hole?

  • What is the length of the hole?

  • Is the hole water filled?



Pajari Instruments Ltd. 2015

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