Patent ID: 9739122
Date: 2017-08-22
CPC Classifications: E21B,G01V

Claim:
1. A method of bulk heating of a subsurface formation with a first electrode assembly in the subsurface formation, a second electrode assembly in the subsurface formation, and a third electrode assembly in the subsurface formation, the method comprising: electrically connecting the first electrode assembly to a first alternating voltage having a frequency and a first phase angle; electrically connecting the second electrode assembly to a second alternating voltage having the frequency and a second phase angle different from the first phase angle and forming a first in situ resistive heater in a first subsurface region between the first electrode assembly and the second electrode assembly; electrically connecting the third electrode assembly to a third alternating voltage having the frequency and a third phase angle different from the second phase angle and forming a second in situ resistive heater in a second subsurface region between the second electrode assembly and the third electrode assembly; concurrently applying the first, second, and third alternating voltages to the first, second, and third electrode assemblies, respectively; and upon determining a presence of a subsurface shunt between the first electrode assembly and the second electrode assembly, electrically connecting the first electrode assembly to the second alternating voltage and applying the second alternating voltage to the first and second electrode assemblies while applying the third alternating voltage to the third electrode assembly.