Patent ID: 7047653
Filing Date: 2006-05-23
Classification: E21B

Abstract:
1. A method of determining the depth of equipment in an underground borehole, the equipment being suspended in the borehole by means of a cable extending from the surface into the well, comprising: (i) determining the amount of cable introduced into the well at the surface; (ii) dividing the cable in the borehole into a series of elements; (iii) defining each element in the series as a portion of the cable for which the tension can be considered as effectively constant; (iii) determining the tension in each element of the cable in the borehole; (iv) determining the stretch of the cable in the borehole for the determined tension in all elements; and (v) determining the depth of the equipment from the determined amount of cable introduced into the well from the surface and from the determined stretch of the cable in the borehole.