Introduction to wellbore positioning


This industry standard publication on directional drilling (accepted by the ISCWSA board) is published through the UHI Research Office ( , the full eBook is available to view or download below. This publication is constantly updated as techniques change or newer technology is employed, please check this page regularly if it is important to you to have the latest version of the publication. Version information is at the bottom of this page.


Wellbore e-book cover

Copyright notice

This eBook is provided, and may be used, free of charge. Selling this eBook in its entirety, or extracts from it, is prohibited. Obtain permission from the author before redistribution.

In all cases this copyright notice and details of the authors and contributors (pages 1 & 2) must remain intact.

Permission is granted to reproduce this eBook for personal, training and educational use, but any extract should be clearly attributed to the author giving the name and version of this publication.

Commercial copying, hiring, lending of this eBook for profit is prohibited.

At all times, ownership of the contents of this publication remains with Prof Angus Jamieson.

Copyright © University of the Highlands and Islands

See the related video presentation Making the Most of Borehole Surveying.

As this publication develops, we post all version update information below:

VERSION: V06.02.17

Updates from the below version include;

Renumbering references to figures in the body of the document to match the number in the figures.

VERSION: V05.08.16

Updates from the below version include

Reference to figure 33 on p.39 has been updated to figure 35, The first column in Table 2 has been centred, The photos in Figure 67 have been replaced, Figure 68 has been updated to acknowledge Digi-Tally, Table 4 has been updated to acknowledge Sandvik, Table 5 has been enlarged, The arrows in Figure 72 have been repositioned, The second column in Table 7 has been expanded, Table 7 has been updated to read St Coeff, Figure 75 has been updated to acknowledge Pegasus Vertex, Figure 76 has been tidied up.

VERSION: V04.05.16

Updates from the below version include;

Chapter 8 ‘Survey Frequency’ has been replaced, A new chapter 15a ‘Along Hole Depth Measurements’ by Harald Bolt has been added, Chapter 24 ‘Tortuosity’ has been replaced with a new chapter called 'Combined Surveys', Appendix D ‘Some Useful Mathematics’ has been added.

A new contents page has been inserted, A new table of figures has been inserted therefore figure numbers have changed, A new table of tables has been inserted.

Page 47 ‘either in real time’ has been reworded ‘either close to real time’, ‘In the days when there were no personal computers the average angle was the preferred method of calculating surveys and it produces results similar to the more recent minimum curvature method currently in use’ has been added to Page 47, Page 60 ‘This gives them an enormous dynamic range, of as much as 109.’  Has replaced ‘This gives them an enormous dynamic range, of as much as 10^9’ has replaced with, Page 115 ‘survey tool that will be or has been run’ has replaced ‘survey tool that has been run’, Page 130 ‘many different ways’ has replaced ‘main different ways’, Page 143 ‘at a rather coarse level’ has replaced ‘at a rather course level’, Page 161 ‘-2.12°’ has replaced ‘-2.12o&rsquo

VERSION: V01.05.14

Updates from the below version include; A small but important update to page 25, example 4, which has been amended. It was noticed that the line "And if the convergence was +2" was wrong and should have read "And if the convergence was -2".

VERSION: V18.9.13

Updates from the below version include; addition of chapters 26 (Relief Well Drilling) and 27 (Subsea Positioning), amendment to the formula on page 69 regarding vector dot products, minor spelling/grammar corrections

VERSION: V01.7.12

Original version


ISCWSA: Well Intercept Sub-committee eBook

"On behalf of the ISCWSA I would like to thank the authors of this excellent resource on ranging which has been put together by a strong and dedicated team of experts in the subject. I highly commend this book for its simple explanations of what has been a somewhat arcane specialism and yet of crucial importance to our industry."

Prof Angus Jamieson, University of the Highlands and Islands
Former chairman of ISCWSA