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hydraulics
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Hydraulic Fracturing Modeling in Conventional and Unconventional Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Badakhshan, Amir (Supervisor) ; Ghotbi, Siroos (Supervisor) ; Taghikhani, Vahid (Supervisor)
Abstract
Unconventional fracturing applications such as long-term waterflooding at fracturing pressure, produced water re-injection and waterfracs, etc., are characterized by very high fluid leakoff velocity, long operation time and significant changes in stress, pore pressure, and/or permeability and porosity, affecting possibly large regions around the wellbore and/or fracture. These special characteristics make fracturing modeling methods developed for conventional fracturing applications inadequate. Some of the problems encountered include grid effects resulting in oscillation of fracture growth with time (limiting the stability of conventional fracture modeling models), singularity of material...
Investigation of Hydraulic Fracturing Effect on Production of Natural Reservoir Fractures
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeeid (Supervisor) ; Pak, Ali (Co-Advisor)
Abstract
Hydraulic fracturing process as one of the most important ways to inhanse of production requires careful study and investigation and due to its importance has been studied for decades. The effect of this process on the production at oil and gas industry has many complexities and these complexities with the complex structure of natural gaps, would be multiplied. In this thesis effect of hydraulic fracturing operation on the production of natural fractures at naturaly fractured reservoirs from two aspects of hydraulic and geomechanics will be investigated. First we provide models for fractures network by using UDEC software after that investigate the effect of hydraulic farcture on the natural...
Hydraulic Fracturing Simulation in Iranian Carbonate Reservoir
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeed (Supervisor) ; Pak, Ali (Supervisor)
Abstract
This paper presents finite-element simulation results for hydraulic fracture’s initiation, propagation at reservoirs with damaged zone and naturally fractured reservoirs that likely finds in Iranian oil fields. To address this objective, a two-dimensional poro-elastic model was solved and cohesive zone modeling was used as the methodology for simulation fractures. This enables us to assign individual criteria for fracture initiation and propagation in each model. Our results demonstrate that hydraulic fracturing is not useful in reservoir with strongly damaged zone around the wellbore, because pore pressure increases at that zone and plastic flow of fracture wall happens, so it is better to...
Underbalanced Drilling Hydraulics Modeling and Optimization
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeid (Supervisor) ; Pishvaie, Mahmoud Reza (Co-Advisor)
Abstract
Due to the underbalanced drilling advantages compared to the overbalanced drilling, this drilling method usage is on rise day to day. In this method, the well pressure has to be lower than formation pressure. To achieve this goal, we have to use light fluids such as air, foam, aerated mud, etc. Because of the compressible nature of these fluids, their hydraulics calculation is more complicated than overbalanced drilling fluids. Due to this complexity, a simulator which can predict and optimize the well conditions is very important in designing drilling schedule. In this thesis, by combination of different rheology and pressure drop equations for the foam, a simulator is developed to model...
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor)
Abstract
The aim of this project is Industrial Solvents (White Spirit) producing in Tehran Refinery. For this manner “Wild Naphtha” from Gasoil Hydrotreater and Kerosene Hydrotreater Units was chosen as feed stock for solvents preparation. In addition, Pentane Recovery Column is selected for Simulation and Optimization based on Wild Naphtha. As a Result, Abadan White Spirit 402 and 410 has been produced and a side stream which is full of Aromatic is obtained. Simultaneously, Tray Hydraulics and Solvents production in different cases (Various Pressure and different Split Ratio of Feed Stock) are evaluated, so optimum Tower process conditions such as pressure, Temperature and Split Ratio of Feed Stock...
Investigation of Petroleum Pollutant Removal in a Membrane Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamid Reza (Supervisor) ; Moslehi Moslehabadi, Parivash (Supervisor)
Abstract
In this study, the performance of Convectional activated sludge reactor (CAS), moving bed biofilm reactor (MBBR) and coupled MBBR-membrane bioreactor (MBR) for diesel removal was investigated.
Hydrocarbon quantification was conducted based on a photometery method at 250 nm after extraction with n-hexane.
Experiments with MBBR was conducted in a batch mode using the sludge obtained from a municipal wastewater treatment plant. In order to adapt microorganisms with diesel as carbon sourse, diesel concentration was gradualy increased from 100 to 3400 ppm where diesel removal efficiency decreased from 62/1 to 26/6 %. However, after addition of diesel degrading bacteria (previously...
Hydrocarbon quantification was conducted based on a photometery method at 250 nm after extraction with n-hexane.
Experiments with MBBR was conducted in a batch mode using the sludge obtained from a municipal wastewater treatment plant. In order to adapt microorganisms with diesel as carbon sourse, diesel concentration was gradualy increased from 100 to 3400 ppm where diesel removal efficiency decreased from 62/1 to 26/6 %. However, after addition of diesel degrading bacteria (previously...
Experimental Study the Treatment of Oily Wastewater by Thermophilic External Membrane Bioreactor(MBR)
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamidreza (Supervisor) ; Vosoughi, Manouchehr (Supervisor) ; Hesampour, Mehrdad (Co-Advisor)
Abstract
The membrane bioreactor (MBR) as an alternative method for simultaneous biodegradation and separation of oily water has received more attention, recently. Normally the MBR works at ambient temperature; therefore, the yield of biodegradation recalcitrant components is low. Increasing temperature improves the efficiency of degradation and reduces the amount of produced sludge. In this study the performance of an aerobic thermophilic and mesophilic membrane bioreactor (MBR) for treating oily wastewater has been investigated. In batch conditions (without applying the membrane), a comparison between COD removal in mesophilic and thermophilic conditions was done. In thermophilic conditions COD and...
Performance Analysis and Design of Spectral Noise Logging Tool
, M.Sc. Thesis Sharif University of Technology ; Movahedian, Hamid (Supervisor)
Abstract
Today, one of the most important concerns of oil and gas wells is to increase the efficiency of wells. To increase efficiency, well integrity must be monitored. One of the factors that destroy the integrity of the well is the creation of hydraulic fractures inside the oil and gas wells, which is one of the main factors that reduce the efficiency of the well. Hydraulic fractures cause water, gas and other materials to leak into the well or oil and gas to leak out of the fracture, which in both cases reduces the efficiency of the well. One of the most important technologies for identifying hydraulic fractures is the use of SNL tools from oil and gas wells. The oil and gas well SNL tool listens...
Simultaneous/sequential alkaline-surfactant-polymer flooding in fractured/non-fractured carbonate reservoirs
, Article Canadian Journal of Chemical Engineering ; Vol. 92, issue. 5 , May , 2014 , p. 918-927 ; ISSN: 00084034 ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
Abstract
Alkaline-Surfactant-Polymer flooding is one of the most novel chemical enhanced oil recovery methods in the petroleum industry. This method has attracted interest due to its remarkable advantages. In this work, a series of ASP floods are conducted on fractured/non-fractured carbonate rocks. The performance of the tests was investigated by various ASP floods consisting of five types of polymers, two surfactants and one common alkaline. ASP was flooded simultaneously and sequentially in four defined scenarios after water flooding. The results showed that although using hydrolysed polymers increases the recovery factor in the fractured medium, sulfonated polymers increase oil recovery even more...
Field Scale Characterization of Geological Formations Using Percolation Theory
, Article Transport in Porous Media ; Vol. 92, issue. 2 , March , 2012 , p. 357-372 ; ISSN: 1693913 ; Masihi, M ; Shojaei, A ; Pishvaie, M ; King, P. R ; Sharif University of Technology
Abstract
The connectivity of high conductivity pathways in geological formations depend on the spatial distribution of geological heterogeneities that may appear on various length scales. Appropriate modeling of this is crucial within in hydrology and petroleum systems. The approach taken in this study is to use percolation theory to quantify the connectivity, hydraulic conductivity, and breakthrough time behavior between an injector and a producer within such systems. In particular, a three-dimensional overlapping sandbody model is considered which assumes that the geological formation can be split into either conductive flow units (i. e., good sands) or non-conductive units (i. e., poor sands). The...
Numerical simulation of high voltage electric pulse comminution of phosphate ore
, Article International Journal of Mining Science and Technology ; Volume 25, Issue 3 , 2015 , Pages 473-478 ; ISSN: 20952686 ; Rezai, B ; Irannajad, M ; Ravanji, M. H ; Sharif University of Technology
Abstract
Numerical simulation of the electrical field distribution helps in-depth understanding of the mechanisms behind the responses and the benefits of the high voltage pulse comminution. The COMSOL Multiphysics package was used to numerically simulate the effect of ore compositions in this study. Regarding phosphate ore particles shape and composition, the effects of mineral composition, particle size, particle shape and electrodes distance were investigated on the electrical field intensity and distribution. The results show that the induced electrical field is significantly dependent on the electrical properties of minerals, the feed particle size and the location of conductive minerals in...
An investigation of fracture geometry in hydraulic fracturing on a gas reservoir well production enhancement
, Article Petroleum Science and Technology ; Vol. 32, issue. 2 , 2014 , pp. 150-157 ; ISSN: 10916466 ; Parvazdavani, M ; Abbasi, S ; Rahnama, A. R ; Sharif University of Technology
Abstract
Utilizing improved production methods have been always challenging in upstream industries. Nowadays, hydraulic fracturing is one of the most prestigious mechanical methods. Application of this method is in wells with low productivity index. Hydraulic fracturing efficiency depends on various factors, such as fracture geometry, fluid composition, and stress distribution. But some of them would be ignored, such as fracture geometry, which is neglected due to nongravity and lack of investigation of DFN statistical population assumption. The authors develop a more comprehensive methodology based on fracture geometry and aim to model one of the gas reservoirs in Iran that is naturally fractured by...
Designing a multi-echelon supply chain network: A car manufacturer case study
, Article Journal of Intelligent and Fuzzy Systems ; Vol. 27, Issue. 6 , 2014 , pp. 2897-2914 ; ISSN 1875-8967 ; Modarres, M ; Tavakkoli-Moghaddam, R ; Sharif University of Technology
Abstract
A multi-echelon supply chain design problem concerns the structure of the network and allocation of resources of the company to meet the demand forecast. This paper tries to design a multi-echelon supply chain network with five echelons including supplier, cross-dock, plant, distribution center and representative (customer). For this purpose, a mixed-integer mathematical model is developed to investigate the location of cross-docks, distribution centers, and also allocation between each pair of parties in order to minimize total cost of location and transportation. Due to the complexity of the model, a novel genetic algorithm is developed and applied on a real-world case study of Iran Khodro...
Theoretical and experimental investigation of density jump on an inclined surface
, Article Scientia Iranica ; Vol. 21, Issue. 5 , 2014 , pp. 1655-1665 ; ISSN :1026-3098 ; Sarnie, M ; Firoozabadi, B ; Afshin, H ; Sharif University of Technology
Abstract
The density jump on an inclined surface is analyzed using an integral method by applying mass and momentum conservation equations. The jump occurs in a two-layered fluid flow in which the upper layer is stagnant and very deep. A relation is derived, which gives the conjugate depth ratio as a function of inlet densimetric Froude number, inlet concentration ratio, bed slope and entrainment. A set of experiments are performed to verify the relation. The theory and the measurements are in good agreement. The analysis reveals that increasing the surface inclination results in a decrease in the conjugate depth ratio. This analysis also shows that the densimetric Froude number just after the jump...
An investigation on the dynamic response of the shaking table steel deck using finite element
, Article 11th World Congress on Computational Mechanics, WCCM 2014, 5th European Conference on Computational Mechanics, ECCM 2014 and 6th European Conference on Computational Fluid Dynamics, ECFD 2014 ; 2014 , pp. 1330-1340 ; ISBN: 9788494284472 ; Farzanian, K ; Taheri, E ; Sharif University of Technology
Abstract
This paper presents the results of an analytical study on the dynamic characteristics of the Shaking Table facilities at Sharif University. This 3 degree of freedom shaking table is driven by 3 servo-control hydraulic actuators, and consists of a 12 ton, 4m×4m×0.6m steel deck. The main objective of this investigation is to identify the degree of flexibility of the deck, and its adverse effects in causing errors in the simulation of seismic effects on different structural specimens. Many frame specimens of different weights and configurations are subjected to seismic motions, and their responses are calculated using FE models. Some of these models were designed to account for eccentric...
An evolvable self-organizing neuro-fuzzy multilayered classifier with group method data handling and grammar-based bio-inspired supervisors for fault diagnosis of hydraulic systems
, Article International Journal of Intelligent Computing and Cybernetics ; Vol. 7, issue. 1 , 2014 , p. 38-78 ; Fathi, A ; Behzadipour, S ; Sharif University of Technology
Abstract
Purpose: The purpose of this paper is to apply a hybrid neuro-fuzzy paradigm called self-organizing neuro-fuzzy multilayered classifier (SONeFMUC) to classify the operating faults of a hydraulic system. The main motivation behind the use of SONeFMUC is to attest the capabilities of neuro-fuzzy classifier for handling the difficulties associated with fault diagnosis of hydraulic circuits. Design/methodology/approach: In the proposed methodology, first, the neuro-fuzzy nodes at each layer of the SONeFMUC are trained separately using two well-known bio-inspired algorithms, i.e. a semi deterministic method with random walks called co-variance matrix adaptation evolutionary strategy (CMA-ES) and...
A coupled hydro-mechanical analysis for prediction of hydraulic fracture propagation in saturated porous media using EFG mesh-less method
, Article Computers and Geotechnics ; Vol. 55, issue , January , 2014 , p. 254-266 ; Pak, A ; Soga, K ; Sharif University of Technology
Abstract
The details of the Element Free Galerkin (EFG) method are presented with the method being applied to a study on hydraulic fracturing initiation and propagation process in a saturated porous medium using coupled hydro-mechanical numerical modelling. In this EFG method, interpolation (approximation) is based on nodes without using elements and hence an arbitrary discrete fracture path can be modelled.The numerical approach is based upon solving two governing partial differential equations of equilibrium and continuity of pore water simultaneously. Displacement increment and pore water pressure increment are discretized using the same EFG shape functions. An incremental constrained Galerkin...
Specific surface and porosity relationship for sandstones for prediction of permeability
, Article International Journal of Rock Mechanics and Mining Sciences ; Vol. 71, issue , October , 2014 , p. 25-32 ; Jamshidi, S ; Sharif University of Technology
Abstract
Porosity and specific surface are two prominent factors in describing the hydraulic properties of porous media. Determination of these two important parameters leads to identify the capability of porous media to conduct the fluids. In the present study, a new relationship between porosity and specific surface of sandstones has been developed. Micro-CT data from 10 types of sandstones has been utilized in order to present a porosity-specific surface correlation. This correlation also contains the average grain radius of each rock obtained by image processing algorithms. Finally, the correlation is tested on the provided data to evaluate its precision. The simplicity and applicability of the...
A mesh-independent finite element formulation for modeling crack growth in saturated porous media based on an enriched-FEM technique
, Article International Journal of Fracture ; Vol. 188, issue. 1 , 2014 , p. 79-108 ; Vahab, M ; Haghighat, E ; Moallemi, S ; Sharif University of Technology
Abstract
In this paper, the crack growth simulation is presented in saturated porous media using the extended finite element method. The mass balance equation of fluid phase and the momentum balance of bulk and fluid phases are employed to obtain the fully coupled set of equations in the framework of u - p formulation. The fluid flow within the fracture is modeled using the Darcy law, in which the fracture permeability is assumed according to the well-known cubic law. The spatial discritization is performed using the extended finite element method, the time domain discritization is performed based on the generalized Newmark scheme, and the non-linear system of equations is solved using the...
Sea-level rise impact on fresh groundwater lenses in two-layer small islands
, Article Hydrological Processes ; Vol. 28, issue. 24 , 2014 , p. 5938-5953 ; Mahmoodzadeh, D ; Ataie-Ashtiani, B ; Werner, A. D ; Simmons, C. T ; Sharif University of Technology
Abstract
The fresh groundwater lenses (FGLs) of small islands can be highly vulnerable to climate change impacts, including sea-level rise (SLR). Many real cases of atoll or sandy islands involve two-layer hydrogeological conceptualizations. In this paper, the influential factors that affect FGLs in two-layer small islands subject to SLR are investigated. An analytical solution describing FGLs in circular islands, composed of two geological layers, is developed for the simplified case of steady-state and sharp-interface conditions. An application of the developed model is demonstrated to estimate the FGL thickness of some real-world islands by comparison with existing FGL thickness data. Furthermore,...