Sharif Digital Repository

The Low salinity water flooding is one of the important methods of secondary and tertiary oil production in which many expert petroleum-production engineering working on it in recent two decades. There are some basis mechanisms for low salinity method presented in the literatures including fine migrations, alkaline flooding, multicomponent ionic exchange, electrical double-layer expansion and pH-driven wettability alteration. The main approach is generating low salinity mechanism especially wettability alteration in OpenPNM framework. OpenPNM is a python base framework developed by Jeff Gostick for porous media modeling. OpenPNM has paved the way for extracting pore network models (PNM) from... 

Various studies have confirmed that water salinity and its composition significantly affect the efficiency of the waterflooding process. Field-scale operation of low-salinity water injection has been proven to be a cost-effective enhanced oil recovery (EOR) method which is also compatible with the environmental regulations. Although this method has satisfactory results, it faces some challenges, such as in-situ mixing of the injection low-salinity water with the saline water in the host reservoir. The salinity of the injected water increases, as it contacts the high-salinity reservoir brine in the pores. This phenomenon significantly impairs the efficiency of this technique, and increases... 

Excessive water production in highly heterogeneous mature reservoirs (water flooded or affected by water zones) leads to increased production costs. Water production causes sediment formation, creation of corrosion, water treatment and disposal, and finally due to the inefficiency of production, it leads to closure of the well.Among the methods introduced to reduce water production, the use of polymers and gels as an affordable and effective method has been widely used in enhanced oil recovery processes. The main mechanism in this method is blocking or limiting the major paths of water flow (fractures or high permeability zones) and thereby increasing sweep efficiency in water injection.... 

Microbial electrolysis cell is a novel technology for hydrogen production. The biggest challenges for this new technology are low rate of hydrogen production and high investment cost.
In this research, catholite condition was investigated for increasing the rate of hydrogen production. Low price stainless steel was used as cathode electrod. The microbial electrolysis cell operated applying 1.3 v external voltage. Basic pH was found to be the best condition for maximum rate of hydrogen production, where the average rate of hydrogen production was 100.006 1.866 L/m3.d. However, the hydrogen production rate for the acidic and neutral cathodic condition, were 92.89 1.13 and 91.845 1.485... 

Error concealment is one of the effective ways to alleviate the effect of packet loss in video communication over error-prone environments. In order to estimate lost macro-blocks, we have employed Bayesian estimation as an efficient and robust framework. Gaussian process regression has been used as the modeling approach through this framework. Considering luminance component as Gaussian process,a minimum mean squared error estimation of the lost macro-block is obtained. This estimator, as a function of the existing data, is only determined by the covariance matrix defined over them. Therefore,the main step in Gaussian process regression, is construction of the convenient covariance matrix... 

The effects of biosurfactants on sandstone rocks are known in the literature. However, there are few examples of experimental works in Iranian carbonate reservoirs dealing with the effects of biosurfactants under reservoir conditions. This thesis discusses the effect of an efficient biosurfactant produced from Pseudomonas aeroginosa MRo1, a bacterial strain isolated from oil excavation areas in southern Iran, on the recovery of residual oil trapped within carbonate rocks was investigated. The MRO1 could reduce surface tension from 72 to 28 dyne/cm. It also could reduce Interfacial tension from 18.382 to 5.646 dyne/cm.
In a core holder set-up bearing four limestone- and... 

As producing and consuming of natural gas has increased in recent years, improving natural gas distribution and transfer network systems has become vital. Pressure reduction station (PRS) is an important part of the natural gas network. Common PRSs are facing two issues: first is the pressure reduction technology, which is throttling valve that destroys the exergy of the high pressure flow. The solution is to utilize turbo-expander instead which can recover the energy. Second is the preheating technology which is boiler and water bath heater in the common systems that cause environmental problems. Using solar collectors is one of the best solution based on the literature. Since the solar... 

The ever increasing usage of modified binders in road construction requires that the effect of different modifiers on the performance characteristics of the asphalt binder be determined through laboratory testing. The current Superpave protocol for performance grading asphalt binders has proven to be insufficient to properly characterize modified binders, thus researchers have searched for other testing methods to complement or possibly replace some of the Superpave tests. Most notable are the time sweep test for fatigue resistance, the multiple stress creep and recovery test (MSCR) for rutting resistance and the direct tension test (DTT) for low temperature cracking characteristics. In the... 

Back then and still now natural calamities have been a serious threat for energy systems. On that front, this thesis constitutes a three-stage mixed integer linear programming (MILP) model to enhance the resilience of power distribution systems to deal with disas-trous events. The proposed model involves in pre-, mid-, and post-event stages. In this con-text, to increase the preparedness of the power distribution system, system operator recon-figures the system by taking benefit of remote-control switches (RCSs), manual switches (MSs), and distributed generations (DGs) before the natural calamity hits. The proposed model contemplates the traveling time of crew teams to the MS sites in order... 

Water injection is known as one of the most efficient and affordable techniques to displace the oil in the reservoirs. To increase oil recovery efficiency through water injection operation, recently low salinity water injection or water containing a certain amount of effective ions (engineered/low salinity water) is proposed. Besides, improving this technique is also adopted in the oil industry using certain chemicals like surfactants to change the interfacial tension or rock wettability for more oil recovery. In order to study and model the mechanisms involved during surfactant flooding, molecular dynamics simulation is utilized here as a novel technique. The advantage of this method over... 

Chemical flooding such as surfactant flooding in oil reservoirs can change the wettability and interfacial tension between oil and water and so reduce the residual oil saturation in the reservoir. Some of these materials can be adsorbed a lot on the surface of carbonate rocks, so it is difficult to predict the oil recovery factor in such process. Therefore it is necessary to survey the adsorption amount of surfactants in chemical EOR injections.In this thesis, the adsorption of a nonionic surfactant on the surface of carbonate rock is experimented and the proper model is obtained. Then the surfactant is injected in a core saturated with oil to observe the efficiency of this surfactant in... 

Nowadays, application of ultrasonic wave technology as a novel method of enhancing oil recovery and also gas and oil well stimulation is prevailing. Not only this method is environment friendly, but also it is economic. Although the application of this method is proved to be of outstanding positive influences in field operations. In this study, it is intended to investigate the effect of ultrasonic waves on the rate and final recovery of miscible and immiscible injection of fluids as Enhanced Oil Recovery (EOR) methods by using the Micro model apparatus and Although the effect of the waves on fluid flow through the porous media can be studied. The results of this work are a good guidance to... 

Increasing complexity of modern embedded systems has caused tasks with different criticality levels to run on a shared hardware platform, called mixed-criticality systems. In these systems, it is important to use fault tolerant techniques to achieve reliability targets. Moreover, the limited battery life in many applications and real-time requirements make energy-aware reliability management and guaranteeing deadline constraints a major challenge. Checkpointing with rollback recovery is a good option to ensure reliability of these sys- terns because of its low cost and relatively low time overhead. However, improper use of this technique can impose high energy overhead and cause deadline... 

Oil and gas reservoirs in various parts of the world have declined over time, despite a high percentage of oil. Due to the increasing need for hydrocarbon resources, the need for more cost-efficient harvesting methods and less environmental damage is felt. Injection of saline water is one of the most cost-effective ways of harvesting due to the need for no expensive additives. On the other hand, microscopic glass modeling can be used to better understand and understand the performance of saline water at the microscopic scale. In this study we have been able to visualize the effective factors in infusion of saline water. Improved interfacial tensile and particle migration in kaolin-coated... 

Utilization of RAP in HMA reduces the initial costs, conserves natural sources and avoids disposal problems. Aged binder from RAP will have some effects on resultant binder. To date, solvent extraction and recovery is the only method that physically separates the RAP binder from the RAP aggregate for characterization. Time consuming for recovery, altering the physical properties of the recovered asphalt binder like binder hardening and the possibility that Asphalt binder is not completely extracted from the aggregate are the weak points of this method. Addressing the need for non-solvent based RAP binder characterization; procedures for low temperature characterization of RAP binder... 

Heavy oil reservoirs contain huge amount of initial oil in place in the world. Thus, enhancement of their production attracts lots of attention. Primary and secondary oil recovery methods have just little effects on the production of these reservoirs, thus, using innovative chemical methods which lead them to increase their mobility is recommended to improve their oil recovery efficiency. One of these proper and novel methods which has been established recently to enhance oil recovery is ASP1 flooding that can significantly increase oil recovery from petroleum heavy oil reservoirs. In addition, considerable numbers of reservoirs especially heavy oil reservoirs are fractured reservoirs. In... 

Ground Source Heat Pumps (GSHP), as a renewable source heating, ventilating, and air conditioning (HVAC) technology, has the highest energy efficiency among different heat pump types. One of the major drawbacks of GSHPs is the long-term ground temperature variations as a result of heat accumulation or depletion in the ground. This contribution puts forward a novel ground thermal recovery system for horizontal ground heat exchangers in a hot climate. The proposed recovery system consists of open-loop horizontal Ground-Air Heat Exchangers (GAHEs) that are buried between the horizontal Ground-Water Heat Exchangers (GWHEs). A fan supplies ambient air to the GAHE pipes when the soil around GWHE... 

Waste management is one of the essential and basic utility services in 21st century, especially in rural areas. It includes different environmental, technical, economic, legal and social aspects which need to be considered in levels of waste generation, transport, treatment and disposal. Therefore, considering economic criterion in waste management programs, as the only one criterion, will result in environmental impacts in long-term and impose high costs to the society and the economy overall. The main purpose of this study is to develop a multi-criteria mathematical model, which take into account both economic and environmental criteria in order to present an integrated municipal solid... 

One of the most important production mechanisms of fractured reservoirs is wettability alteration. Since most fractured reservoirs are carbonate, and thus are often oil-wet; production of these reservoirs is facing their special challenges. Since most of our country reservoirs are fractured carbonate type, determination of the exact mechanisms of their production is necessary. Thermal EOR methods traditionally have been welcomed by big oil companies. Also, these methods of enhanced oil recovery techniques, have a much greater share in the production history of all EOR methods, rather than other EOR methods. Exponentially decreasing of oil viscosity on heating, is the main reason for using... 

Results showed that 9 factors of “Brand Equity”, “Product Quality”, “Service Quality”, “Service Recovery”, “Perceived Value”, “Relationship”, “Employee Satisfaction”, “Physical Environment” and “Distribution Channel” are most effective factors by researchers that have effect on customer satisfaction. Thus, the Macromodel of this research was designed based on these factors. Due to limitations and context of the research, “Service Quality”, “Service Recovery” and “Relationship” were chosen in the final model. Results of questionnaire showed that the 5 parameters of “Service Recovery Speed”, “Reliability”, “Responsiveness”, “Empathy” and “Seller-focused antecedents” was the most important...