Patent ID: 9581018
Date: 2017-02-28
CPC Classifications: E21B,G01V

Claim:
1. A method for determining soil characteristics within a borehole made via horizontal directional drilling, the method employing a drilling rig, a drillstring, and a drilling head, the method comprising the following steps: performing the horizontal direction drilling; determining the position of the drilling head along the (y) and (z) axes and the angular orientation of the drilling head (φ) by way of navigational sensors positioned proximate to the drilling rig and the drilling head, respectively; determining the length of the borehole (s); and computing a coefficient of soil characterization (α) as a function of the position of the drilling head (y, z), the angular orientation of the drilling head (φ), and the length of the borehole (s), all over a drillstring relaxation length L, which is a length of thrust of the drill rig; wherein the coefficient of soil characterization (α) is computed in accordance with the following equations: where s