Sharif Digital Repository

Enhancing oil extraction from oil sands with a hydraulic fracturing technique has been widely used in practice. Due to the complexity of the actual process, modelling of hydraulic fracturing is far behind its application. Reproducing the effects of high pore pressure and high temperature, combined with, complex stress changes in the oil sand reservoir, requires a comprehensive numerical model which is capable of simulating the fracturing phenomenon. To capture all of these aspects in the problem, three partial differential equations, i.e., equilibrium, flow, and heat transfer, should be solved simultaneously in a fully implicit (coupled) manner. A fully coupled thermo-hydro-mechanical... 

Hydraulic fracturing is a widely used and efficient technique for enhancing oil extraction from heavy oil sands deposits. Application of this technique has been extended from cemented rocks to uncemented materials, such as oil sands. Models, which have originally been developed for analyzing hydraulic fracturing in rocks, are in general not satisfactory for oil sands. This is due to a high leak-off in oil sands, which causes the mechanism of hydraulic fracturing to be different from that for rocks. A thermal hydro-mechanical fracture finite element model is developed, which is able to simulate hydraulic fracturing under isothermal and non-isothermal conditions. Plane strain or axisymmetric... 

It is generally accepted that a hydraulically induced fracture in the reservoir is approximately a plane fracture perpendicular to the direction of the in situ minor principal stress. However, field observations, in some cases, do not support the above traditional assumption. This is especially true when hydraulic fracturing technique is applied to the uncemented porous materials such as oil sands. In this article, the pattern of hydraulically induced fractures in oil sands and other geomaterials is discussed. Field observations and experimental investigation results are combined with the outcomes of the numerical simulations of hydro-fracturing in oil sands conducted by the authors to... 

Application of organic−inorganic nanocomposite membranes for water treatment is exceptionally growing owing to their tunable functionalities in addition to their enhanced permeation and antifouling propensity. In the present work, novel nanocomposite polyethersulfone (PES) membrane was synthesized using antimony-doped tin oxide (ATO) nanoparticles (NPs) via phase separation technique. It was found that the modified PES-ATO nanocomposite membranes exhibited significantly higher fouling resistance and larger permeate flux recovery ratio when tested with oil sands produced water than unmodified PES membranes. Furthermore, the PES-ATO membranes provided 40% more organic matter removal compared...