Abstract: A method and apparatus are provided for making directional measurements toward a formation of different resistivity that is proximate to the borehole, but which is not penetrated by the borehole. The methods and apparatus include the use of at least one insulated gap and at least one magnetometer positioned within a non-magnetic housing that is disposed within a non-magnetic tubular. An electric current is applied across the insulated gap, which results in current leaking into the surrounding formations. When a formation of contrasting resistivity is proximate to the logging apparatus, the magnetometer detects a secondary magnetic field due to the contrasting formation. The direction of the secondary magnetic field can be used to determine the direction to the contrasting formation. The magnitude of the secondary magnetic field can be used to determine the distance position to the contrasting formation.

Abstract: The present disclosure is directed to systems and methods for relative positioning of wells. A method in accordance with an exemplary embodiment may include drilling a new well in a field having at least three completed wells using a drilling tool that includes a magnetometer. The method may further include driving current on a first pair of the at least three completed wells and then driving current on a second pair of the at least three completed wells, wherein the current is driven on each of the first and second pairs in a balanced mode. The method may also include measuring a direction of a first magnetic field generated by the current on the first pair using the magnetometer, measuring a direction of a second magnetic field generated by the current on the second pair using the magnetometer, and determining a location of the drilling tool relative to the completed wells based on the direction of the first magnetic field and the direction of the second magnetic field.

Abstract: Methods for drilling wells using magnetic ranging while drilling to position the wells with respect to one another are provided. In accordance with one embodiment, a method of drilling a well includes leaving a drill string in position within a primary well, and drilling a secondary well using the drill string as a target for magnetic ranging while drilling such that the secondary well is positioned with a specified orientation relative to the drill string.

Abstract: Systems and methods for drilling a multilateral well using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a multilateral well includes drilling and casing a mother wellbore, installing a multilateral junction, drilling and casing a first lateral well from the multilateral junction, and drilling a second lateral well from the multilateral junction using magnetic ranging while drilling such that the second lateral well has a controlled relationship relative to the first lateral well. The first and second lateral wells may form a SAGD well pair, in which case the first lateral well may be a producer well and the second lateral well may be an injector well.

Abstract: Systems and methods for drilling a multilateral well using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a multilateral well includes drilling and casing a mother wellbore, installing a multilateral junction, drilling and casing a first lateral well from the multilateral junction, and drilling a second lateral well from the multilateral junction using magnetic ranging while drilling such that the second lateral well has a controlled relationship relative to the first lateral well. The first and second lateral wells may form a SAGD well pair, in which case the first lateral well may be a producer well and the second lateral well may be an injector well.

Abstract: A method and apparatus are provided for making directional measurements toward a formation of different resistivity that is proximate to the borehole, but which is not penetrated by the borehole. The disclosed methods and apparatus include the use of at least one insulated gap and at least one magnetometer positioned within a non-magnetic housing that is disposed within a non-magnetic tubular. An electric current is applied across the insulated gap, which results in current leaking into the surrounding formations. When a formation of contrasting resistivity is proximate to the logging apparatus, the magnetometer detects a secondary magnetic due to the contrasting formation. The direction of the secondary magnetic field can be used to determine the direction to the contrasting formation. The magnitude of the secondary magnetic field can be used to determine the distance position to the contrasting formation.

Abstract: A method for determining the distance and/or direction of a second earth borehole with respect to a first earth borehole, includes the following steps: providing, in the first borehole, first and second spaced apart magnetic field sources; providing, in the second borehole, a magnetic field sensor subsystem for sensing directional magnetic field components; activating the first and second magnetic field sources, and producing respective first and second outputs of the magnetic field sensor subsystem, the first output being responsive to the magnetic field produced by the first magnetic field source, and the second output being responsive to the magnetic field produced by the second magnetic field source; and determining distance and/or direction of the second earth borehole with respect to the first earth borehole as a function of the first output and the second output.

Abstract: The present disclosure is directed to systems and methods for relative positioning of wells. A method in accordance with an exemplary embodiment may include drilling a new well in a field having at least three completed wells using a drilling tool that includes a magnetometer. The method may further include driving current on a first pair of the at least three completed wells and then driving current on a second pair of the at least three completed wells, wherein the current is driven on each of the first and second pairs in a balanced mode. The method may also include measuring a direction of a first magnetic field generated by the current on the first pair using the magnetometer, measuring a direction of a second magnetic field generated by the current on the second pair using the magnetometer, and determining a location of the drilling tool relative to the completed wells based on the direction of the first magnetic field and the direction of the second magnetic field.

Abstract: A method for determining the distance and/or direction of a second earth borehole with respect to a first earth borehole, includes the following steps: providing, in the first borehole, first and second spaced apart magnetic field sources; providing, in the second borehole, a magnetic field sensor subsystem for sensing directional magnetic field components; activating the first and second magnetic field sources, and producing respective first and second outputs of the magnetic field sensor subsystem, the first output being responsive to the magnetic field produced by the first magnetic field source, and the second output being responsive to the magnetic field produced by the second magnetic field source; and determining distance and/or direction of the second earth borehole with respect to the first earth borehole as a function of the first output and the second output.

Abstract: Methods for drilling wells using magnetic ranging while drilling to position the wells with respect to one another are provided. In accordance with one embodiment, a method of drilling a well includes leaving a drill string in position within a primary well, and drilling a secondary well using the drill string as a target for magnetic ranging while drilling such that the secondary well is positioned with a specified orientation relative to the drill string.

Abstract: Systems and methods for drilling a multilateral well using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a multilateral well includes drilling and casing a mother wellbore, installing a multilateral junction, drilling and casing a first lateral well from the multilateral junction, and drilling a second lateral well from the multilateral junction using magnetic ranging while drilling such that the second lateral well has a controlled relationship relative to the first lateral well. The first and second lateral wells may form a SAGD well pair, in which case the first lateral well may be a producer well and the second lateral well may be an injector well.