Abstract:
Methods are provided for mitigating thief zone losses during hydrocarbon recovery by thief zone pressure maintenance through downhole radio frequency (RF) radiation heating. A thief zone situated near a hydrocarbon reservoir poses a risk of losing valuable components from the reservoir to the thief zone. In addition to the risk of loss of diluent, heat, or steam to the thief zone, valuable hydrocarbons may also be lost to the thief zone. One way to mitigate these losses is by maintaining thief zone pressure. RF radiation may be used to heat a thief zone fluid to maintain pressure in the thief zone, decreasing the driving force for losses to the thief zone. In some cases, steam generated thusly may be used to enhance hydrocarbon thermal recovery. Advantages of methods herein include: lower costs, higher efficiencies, higher hydrocarbon recovery, less hydrocarbon contamination, increased hydrocarbon mobility, and fewer thief zone losses.
Abstract:
Heavy oil recovery using downhole radio frequency radiation heating accelerates SAGD thermal recovery processes. In one embodiment, one or more SAGD well pairs traverse a subterranean formation for recovering heavy oil. The SAGD well pairs each create a steam chamber which, over time, expands to allow each steam chamber to interact with one another and in this way, increases the recovery heavy oil from the formation. One or more antennas may be interposed between the steam chambers to introduce electromagnetic radiation into the formation to heat the fluids therein to accelerate expansion of the steam chambers, particularly where antennas are judiciously situated to optimize steam chamber expansion. Where an infill production well is present, the antennas may be situated to accelerate steam chamber communication with the infill production well. Advantages include lower cost, higher efficiencies, quicker and increased hydrocarbon recovery.