Sharif Digital Repository

Red tide, an impermanent natural phenomenon including harmful algal blooms, causes changing the color of the sea generally to red or almost brown, and has a serious impact on environment along the coast and aquatic ecosystem. Due to recent extensive steady harmful algal blooms events that cause adverse impacts on human healthsome, aquaculture and tourism industry, and the entire economy of the coastal region, the need of society for realizing these phenomena is much greater than the past. In the recent decades, consideration of algal blooms and determination of bloom-former species and fundamental researches about dynamics of blooms are increased worldwide. Development in technology has... 

The top-down in situ combustion (ISC) involves the stable propagation of the combustion front from the top vertical injector to the bottom horizontal producer. Apart from laboratory studies in conventional sandstones, no application of the process in fractured carbonates has been addressed yet. The authors modified a successful combustion tube history matched model of an Iranian low-permeable heavy oil reservoir called Kuh-E-Mond to investigate the feasibility of ISC in fractured carbonate reservoirs mimicking block-scale combustion cells. Effects of fractured geometrical properties such as orientation, location, extension, density, spacing, and dispersion were considered. Results confirmed... 

Microbial enhanced oil recovery (MEOR) is receiving renewed interest worldwide in recent years as a viable method while not damaging the reservoir is proven to be remarkably effective, however to some extent costly. This method is based on microorganisms' activities to reduce residual oil of reservoirs, which is dependent on behavior of inherent microorganisms or injection of bioproduct of external microorganisms. In this work, five bacterial species were taken from MIS crude oil that is one of the aging Persian fractured reservoirs. These microorganisms are substantially strong in increasing oil recovery especially by reducing IFT and other MEOR mechanisms such as change of wettability of... 

Gas injection is the second largest enhanced oil recovery process being applied in many reservoirs around the world. Simulation of these processes is necessary for implementation, management, and decision making. Relative permeability is one of the most important factors in numerical reservoir simulation. In this study, several core flood experiments are done and the relative permeability in carbon dioxide (CO2) injection is compared with nitrogen (N2) injection. Oil relative permeability in CO 2 injection is found to be higher than in N2 injection, but gas relative permeability in CO2 injection is found to be lower than in N2 injection. Higher oil relative permeability in CO 2 injection... 

The small-strain shear modulus, Go, is an important fundamental soil property. Although many studies have been conducted on this property for clean sands and pure clays, small-strain behavior for mixtures of sand and fines has been less addressed. This paper presents the results of a comprehensive laboratory study on G0 value of sand containing various amounts of different fines. To this aim, bender elements were integrated into a conventional triaxial apparatus, and shear wave velocity was measured on samples of sand with different amounts of highly-plastic, medium-plastic, low-plastic, or non-plastic fines at different void ratios. Measuring the shear wave velocity and thus...