Thermal and thermo-chemical methods of heavy oil recovery Alexander Babchin, PhD Emeritus Distinguished Scientist Heavy Oil Recovery Department Alberta Research Council (Alberta Innovates) Edmonton, Alberta, Canada

Buckley – Leverett Solution of Oil Displacement by Water Oil saturated zone Water flooded zone Injecting Well

Buckley – Leverett Solution is Unstable for the Displacement of Heavy Oils (Viscous Fingering)

Cyclic Steam Stimulation is historically the first method for significant heavy oil recovery Modern Cyclic Steam Stimulation Main Phases

Finger of Miscible Gas Injected into Heavy Oil

Steam Assisted Gravity Drainage

Mechanism of Heavy Oil Recovery within SAGD Steam Chamber

Reasons for High Oil Recovery (50.0 – 70.0 %) by SAGD SAGD is run by forces of Capillarity and Gravity, this leads to stability of steam / condensate – oil front; No SAGD is possible in hydrophobic reservoirs; SAGD test failed in the Grossmont carbonate reservoir in Alberta, Canada

Special Case – Heavy Oil Recovery from Carbonate Reservoir Over 50.0 % of world oil proved reserves are located in carbonate reservoirs; Less than 10.0 % of oil is recovered from carbonate reservoirs; Major difference of oil recovery is Hydrophobicity of carbonate reservoirs; Major task is thermal – chemical floods aiming wettability change of carbonate rocks

Heavy Oil Recovery from Fractured Carbonate Reservoir Without chemical additives Imbibition of Water Drainage of Oil With chemical additives Water imbibition Oil drainage

Imbibition into Carbonate Matrix Induced by Chemical Additives (Wettability Change) Micro core preparation

Micro Core Saturated by Oil in Contact with Water After 1 month

Oil Recovery from Carbonate Core by Acidic Solution 0.36 M HCl

Oil Recovery from Carbonate Core by Weak Acid Mixed with Surfactant 0.25 M H3PO4 + 1.0 % SPI 2400 Surfactant

Heat Transfer from the Fracture into the Matrix in Carbonate Rocks Differential Equation of Convective Heat Transfer: With V = 0, = 0 and the equation converts into that is the equation of the molecular heat transfer. Thus, chemical additives give the rise to the convective heat transfer increasing the temperature of the matrix and decreasing oil viscosity.

Analytical Formula for Pc

Conclusions Technology of Heavy Oil recovery from hydrophilic reservoirs is well developed and successfully works in Alberta, Canada and in Russia (the Yarega field) at the depth deposit up to 500 m. Deeper deposits are subject to the technology development and extension; Special and very important case is recovery of Heavy Oil from Carbonate reservoirs; Heavy Oil recovery from Carbonates is negligible; Wettability change from oil wet to water wet is the crucial for Heavy Oil recovery from Carbonate rocks.