Mitigating The Effects Of Subsurface Shunts During Bulk Heating Of A Subsurface Formation

摘要

Systems and methods for mitigating the effects of subsurface shunts during bulk heating of a subsurface formation are disclosed. The methods may include electrically connecting, and concurrently applying, first, second, and third alternating voltages to respective first, second, and third electrode assemblies within the subsurface formation. The first, second, and third alternating voltages may have the same frequency and respective first, second, and third phase angles. The second phase angle may be different than the first phase angle, and the third phase angle may be different than the second phase angle. The methods may include, 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.

主权项

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.