Improvement of Heavy Oil Recovery by Nonionic Surfactant/Alcohol Flooding in Light of the Alkane Carbon Number and Interfacial Tension Properties.

In this work, we prepared nonionic surfactants from waste cooking oil materials. Hydrolysis was carried out for palm and palm kernel waste cooking oils to get a mixture of free fatty acids. The mixture of free acids was esterified with sorbitan and then ethoxylated at different ethylene oxide units.

Recent applications of ultrasonic waves in improved oil recovery: A review of techniques and results.

Ultrasound technique is an inexpensive and ecofriendly technology commonly used in oil and gas industry to improve oil recovery and its applications have been successfully tested in both laboratory and field scales. In this technique, high-power ultrasonic waves are utilized downhole to improve oil recovery and reduce formation damage in near wellbore region that causes a reduction in hydrocarbon production rate due to the penetration of mud, scale deposition, etc. In most of the cases, barriers for the oil flow to the wellbore are effectively removed by using the ultrasound technique and the effect of improved oil recovery may last up to several months.

Ultrasound-assisted CO flooding to improve oil recovery.

CO flooding process as a common enhanced oil recovery method may suffer from interface instability due to fingering and gravity override, therefore, in this study a method to improve the performance of CO flooding through an integrated ultraosund-CO flooding process is presented. Ultrasonic waves can deliver energy from a generator to oil and affect its properties such as internal energy and viscosity. Thus, a series of CO flooding experiments in the presence of ultrasonic waves were performed for controlled and uncontrolled temperature conditions.

Characterization of scale-dependent dispersivity in fractured formations through a divergent flow tracer test.

Scale-dependency of dispersivity has been reported from field tracer tests. We present a simple methodology for characterization of dispersivity as a linear function of scale around an injection well using divergent flow tracer test data conducted in fractured formations. Results show that the slope of this linear dispersivity function can be estimated using tracer concentration measurements in a monitoring well.

Advective-diffusive mass transfer in fractured porous media with variable rock matrix block size.

Traditional dual porosity models do not take into account the effect of matrix block size distribution on the mass transfer between matrix and fracture. In this study, we introduce the matrix block size distributions into an advective-diffusive solute transport model of a divergent radial system to evaluate the mass transfer shape factor, which is considered as a first-order exchange coefficient between the fracture and matrix. The results obtained lead to a better understanding of the advective-diffusive mass transport in fractured porous media by identifying two early and late time periods of mass transfer.