System and method for employing alternating regions of magnetic and non-magnetic casing in magnetic ranging applications

摘要

A system and methods for facilitating drilling and/or drilling a well in an orientation with respect to an existing well are provided. Specifically, one method in accordance with present embodiments is directed to producing a magnetic field with a magnetic field source positioned in a non-magnetic region of casing within a first well, wherein the first well is cased with alternating regions of magnetic casing and non-magnetic casing. The method may also include producing at least one output from at least one magnetic field sensor capable of sensing directional magnetic field components, wherein the at least one output is based on detection of the magnetic field and wherein the at least one magnetic field sensor is positioned in a second well.

主权项

1. A method for determining a geometric relationship of a second well with respect to a first well, comprising the steps of:
producing a magnetic field with a magnetic field source positioned in a non-magnetic region of casing within the first well, wherein the first well is cased with alternating regions of magnetic casing and non-magnetic casing wherein each magnetic region has a length, the length of each of the magnetic regions is based on an accuracy value for related drilling measurements, values relating to a desired geometric relationship between the first well and the second well, or a value associated with drilling consistency; and producing at least one output from at least one magnetic field sensor capable of sensing directional magnetic field components, wherein the at least one output is based on detection of the magnetic field, and the at least one magnetic field sensor is positioned in the second well.