Khosrow Naderi

Influence of intensity and frequency of ultrasonic waves on capillary interaction and oil recovery from different rock types

Oil saturated cylindrical sandstone cores were placed into imbibition cells where they contacted with an aqueous phase and oil recovery performances were tested with and without ultrasonic radiation keeping all other conditions and parameters constant. Experiments were conducted for different initial water saturation, oil viscosity and wettability. The specifications of acoustic sources such as ultrasonic intensity (45-84W/sqcm) and frequency (22 and 40kHz) were also changed. An increase in recovery was observed with ultrasonic energy in all cases. This change was more remarkable for the oil-wet medium. The additional recovery with ultrasonic energy became lower as the oil viscosity increased. We also designed a setup to measure the ultrasonic energy penetration capacity in different media, namely air, water, and slurry (sand+water mixture). A one-meter long water or slurry filled medium was prepared and the ultrasonic intensity and frequency were monitored as a function of distance from the source. The imbibition cells were placed at certain distances from the sources and the oil recovery was recorded. Then, the imbibition recovery was related to the ultrasonic intensity, frequency, and distance from the ultrasonic source.

Clarifications on Oil/Heavy Oil Recovery Under Ultrasonic Radiation Through Core and 2D Visualization Experiments

Our previous research on the effects of ultrasonic waves on oil recovery conducted at the University of Alberta had shown that capillarity and interfacial tension (IFT) might be responsible for the observed improvements in incremental oil recovery. Although the results seem encouraging, questions about the mechanism and effective parameters causing additional recovery still remain. To analyze the influence of parameters other than IFT and capillary forces, we conducted capillary imbibition experiments on cylindrical Berea sandstone core samples under ultrasonic radiation, and the results are presented in this paper. Through this experimental scheme, we focused on: a) the effect of initial water saturation for rocks with different wettability; b) oil viscosity; and c) matrix wettability. The cores were placed into imbibition cells where they were contacted with an aqueous phase. Every experiment was conducted with and without ultrasonic radiation for comparison. Different intensities of ultrasonic waves were tested as well. To investigate the acoustic interaction between rock and fluid, we performed certain visualization experiments. We used 2D glass bead models to clarify the effects of ultrasonic waves on the oil displacement process for different oil viscosities and matrix wettability through comparative analysis. The qualitative and quantitative observations and analyses presented are expected to provide additional understanding regarding investigations in the use of in situ recovery of oil/heavy oil, as well as surface extraction.

Use of Biodiesel as an Additive in Thermal Recovery of Heavy-Oil and Bitumen

Bitumen extraction in oil sands-ore water slurry systems was studied by using lipids and lipid derivatives such as biodiesel (BD) as surfactant additive to promote bitumen recovery efficiency. Performance of BDs (i.e., canola and tall oil, a byproduct of pulp mills using the bleached Kraft process) fatty acids methyl ester and food-grade fatty acids monoglycerides were evaluated as surfactant additives. Experimental findings suggest that BDs such as fatty acids methyl esters could also be used as surfactant additives to increase the efficiency of bitumen recovery in thermal in-situ processes such as steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) processes. The required dosage for the surfactant additive is about 0.1 % of bitumen by mass. Also, interfacial tension measurements between bitumen and process water (γ B, W ) and BD and process water (γ BD,W ) support the surfactant behavior of BD.

Use of Biodiesel as an Additive in Thermal Recovery of Heavy Oil and Bitumen

Bitumen extraction in oil sands-ore water slurry systems was studied by using lipids and lipid derivatives such as biodiesel (BD) as surfactant additive to promote bitumen recovery efficiency. Performance of BDs (i.e., canola and tall oil, a byproduct of pulp mills using the bleached Kraft process) fatty acids methyl ester and food-grade fatty acids monoglycerides were evaluated as surfactant additives. Experimental findings suggest that BDs such as fatty acids methyl esters could also be used as surfactant additives to increase the efficiency of bitumen recovery in thermal in-situ processes such as steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) processes. The required dosage for the surfactant additive is about 0.1 % of bitumen by mass. Also, interfacial tension measurements between bitumen and process water (γ B, W ) and BD and process water (γ BD,W ) support the surfactant behavior of BD.