Modular electromagnetic ranging system for determining location of a target well

A method for electromagnetic ranging of a target wellbore, comprising:

• disposing a modular electromagnetic ranging tool in a wellbore;
• transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool to induce an eddy current in the target wellbore;
• measuring at least one component of a secondary electromagnetic field generated by the eddy current from the target wellbore with at least one receiver coil disposed on the modular electromagnetic ranging tool, wherein the at least one transmitter coil and the at least one receiver coil are disposed on different modular sections of the modular electromagnetic ranging tool;
• and
• determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil.

A method for electromagnetic ranging of a target wellbore, comprising:

• disposing a modular electromagnetic ranging tool in a wellbore;
• transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool to induce an eddy current in the target wellbore;
• measuring at least one component of a secondary electromagnetic field generated by the eddy current from the target wellbore with at least one receiver coil disposed on the modular electromagnetic ranging tool, wherein the at least one transmitter coil and the at least one receiver coil are disposed on different modular sections of the modular electromagnetic ranging tool;
• measuring a phase difference or amplitude ratio between a first module and a second module, wherein the measured phase difference or amplitude ratio is used in determining the relative location of the conductive member;
• and
• determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil.

A method for electromagnetic ranging of a target wellbore, comprising:

• disposing a modular electromagnetic ranging tool in a wellbore;
• transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool to induce an eddy current in the target wellbore;
• measuring at least one component of a secondary electromagnetic field generated by the eddy current from the target wellbore with at least one receiver coil disposed on the modular electromagnetic ranging tool, wherein the at least one transmitter coil and the at least one receiver coil are disposed on different modular sections of the modular electromagnetic ranging tool;
• determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil;
• and
• selecting the at least one receiver coil for use in the determining the relative location from receiver coils disposed on the modular electromagnetic ranging tool, wherein the at least one receiver coil is selected based on spacing from the at least one transmitter coil.

A method for electromagnetic ranging of a target wellbore, comprising:

• disposing a modular electromagnetic ranging tool in a wellbore;
• transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool to induce an eddy current in the target wellbore;
• measuring at least one component of a secondary electromagnetic field generated by the eddy current from the target wellbore with at least one receiver coil disposed on the modular electromagnetic ranging tool, wherein the at least one transmitter coil and the at least one receiver coil are disposed on different modular sections of the modular electromagnetic ranging tool;
• determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil;
• and
• selecting the at least one receiver coil for use in the determining the relative location from receiver coils disposed on the modular electromagnetic ranging tool, wherein the at least one receiver coil is selected based on spacing from the at least one transmitter coil, wherein the at least one receiver coil determines the relative location of the target wellbore with a gradient measurement.