Patent ID: 6732816
Filing Date: 2004-05-11
Classification: E21B

Abstract:
A method of drilling a flowline below the surface, the method comprising the steps of:establishing a first sight relief hole and a second sight relief hole along the linear path; positioning a directional drilling machine on the surface, the directional drilling machine having a boring tool, the position of the boring tool relative to the surface being variable under the control of the directional drilling machine; boring a first portion of a pilot hole from the surface to the first sight relief hole; determining the elevation of the tool at the first sight relief hole; adjusting the position of the tool at the first sight relief hole to a first desired depth; boring a second portion of the pilot hole from the first sight relief hole to the second sight relief hole; determining the elevation of the tool at the second sight relief hole; and adjusting the position of the boring tool to a second desired depth, the second desired depth being different from the first desired depth.