Sharif Digital Repository

Wellbore storage effect is one of the biggest problems of petroleum engineers in analyzing the reservoir properties. In this phenomenon, at the beginning time of production from a reservoir, the fluid is initially produced from the well and not from the reservoir. Due to this effect, the pressures are distorted and could not be used in reservoir analysis. In this thesis the wellbore storage effect would be removed in naturally fractured reservoirs using deconvolution method. Using this method the range of data used could be increased. In this method special techniques are used in order to determine reservoir behaviour.
Using the method presented in this thesis, petroleum engineers could... 

A critical property in designing drilling fluids is the concerns for environmental damages and cost efficiency of mud additives used to complete a well safely and economically. Designing drilling fluids for harsh environments such as high temperature, high salinity formation water, lime and cement contamination demands proper selection of deflocculant (thinner) materials to achieve a successful drilling operation. This study presents a novel thinner material that satisfies the goal of an environmentally and economically acceptable mud in drilling lime contamination areas where drilling carbonate formations with high concentration of calcium ions tends to flocculate clay particles in... 

Matrix acidizing treatment are performed to enhance the permeability of oil and gas formations by removing pore plug. Numerous additives have been introduced to aid the penetration of the acid or to perform other important tasks. To be able to pump the reactive fluid from the surface through the tubing and into the formation, corrosion inhibitors usually is necessary to protect the metal from attack by the fluid itself. In this work the Henna extract introduced as a pre flush additive and corrosion inhibitor in acidizing operation. It also enters the formation and effect on the matrix permeability and acidizing performance. The effect of Henna extract on permeability of rock will be... 

Well-Testing is a one of the usual methods in petroleum engineering for evaluating reservoir and well parameters. This method is based on measuring downhole pressure verses time in different production conditions and then drawing these data in different pressure-time graphs and evaluating reservoir characteristics and calculating reservoir parameters. This thesis describes the development of techniques for the automation of the model identification and parameter estimation of a well test interpretation, using Artificial Intelligence. The computer programs which are written in MATLAB software use Neutral Network toolbox to detect a model that is based on the pressure derivative curve, and... 

Nowadays, foaming agents have wide applications in drilling, cementing, fracturing and oil displacement in the petroleum industry. Typical applications are to make light fluids for drilling operations in naturally fractured reservoirs where lost circulation is a problem. Compared with conventional and aerated drilling fluids, foamy mud is a compressible and relatively homogeneous mixture. A great flexibility for pressure control is thus possible. In this study, a new foaming agent of Yas-Khorramshahr Company is introduced to drilling fluids. Stability of this agent at different concentration and in presence of Salt and crude oil is tested. Also common drilling muds are lightened and... 

Transport of drilling cutting to the surface is the most important function of drilling fluid. Insufficient hole cleaning leads to accumulation of cuttings in the annulus especially of a Horizontal wellbore. This may cause severe drilling problems including reduction in rate of penetration, stuck pipe, premature bit wear, increase the mud lost, high drag and torque. In this research work a mathematical model is developed to simulate cutting transport process in the horizontal drilling wells. A three-layer model was used to simulate cutting transport process in horizontal wellbores: a stationary at the bottom of hole, a moving bed and a suspension layer on top of these layers. In this model,... 

In this paper we have tried to mention a proper method of upscaling permeability data in a typical Iranian reservoir. Firstly a literature review is made on some common upscaling methods witch have been used so far. We introduced common upscaling methods like full tensor method, streamline method, stone method , vertical equilibrium method and also Kyte & Berry method. Additionally we have explained their advantages and also disadvantages. After selecting two upscaling methods, Kyte & Berry method and vertical equilibrium method, we applied these algorithms for upscaling of permeability data of Soroosh Oil Field. Soroosh oilfield is a heavy oil, Iranian reservoir located in Persian Gulf.... 

Confining nematic liquid crystal between two curved boundary conditions while the nematic molecules have a degenerate planar anchoring leads to complex and beautiful textures of molecular disparagement(defect) in the bulk and on the surfaces. Such the liquid crystal shells are made with double-emulsion techniques in microfluidic devices have provided applications for micro-scale colloidal linkers.In this work, we have numerically minimized the elastic energy in one-constant approximation in present of Fournier’s degenerate surface potential with finite element method. The nematic shell is confined between two spherical surfaces that we have studied the final energies and their related... 

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... 

Analytic hierarchy process (AHP) is a structured technique for organizing and analyzing complex decision. This process is used around the world in a wide variety of decision situation, in fields such as government, business, industry, healthcare, and education. In this method, decision problem first is decomposed into a hierarchy of more easily comprehended sub-problems, each of which can be analyzed independently. Once the hierarchy is built, the decision makers systematically evaluate its various elements by comparing them to one another two at a time, with respect to their impact on an element above them in the hierarchy. In this thesis we will study the hierarchy process and also study a... 

In recommender systems, the available data structure is mostly in the form of a graph; Therefore, during the past years, graph based recommendation methods, especially Graph neural networks, have received a lot of attention. These networks obtain the representation of user nodes and items by aggregating multi-hop neighbors in different ways. Unfortunately, the existing methods are part of the Supervised learning scenario and due to the lack of data in recommender systems, they have faced serious challenges. These challenges reduce the ability to learn to representation nodes and the accuracy of recommendations. Recently, knowledge graph based recommendations have achieved excellent... 

Effective stress variation is one of the main issues in petroleum and gheothermal reservoir development. These stress variation could cause formation damage, sand production, sloughing shale and various modes of borehole instability like induced fractures and borehole wall shearing. In petroleum engineering, drilling a borehole is the first step in reservoir development. The wellbores are implemented to produce or inject fluids such as water, oil, gas and chemical fluids used during secondary and tertiary recovery processes. Upon drilling a borehole, reservoir pore pressure, rock and fluid temperature and mechanical stresses change which induces borehole instability and variations in rock... 

Polycarbonate (PC) is known as one of the engineering plastics with remarkable mechanical properties, but the application of this polymer is limited due to its high notch sensitivity. Blending polycarbonate with other polymers such as acrylonitrile butadiene styrene (ABS) is a method to resolve this disadvantage. PC/ABS blends are commonly used in automotive industry, electrical and electronic devices. As PC and ABS are not completely miscible, a variety of compatibilizers are used to achieve a suitable microstructure and high engineering properties. Considering crucial applications of PC/ABS blends, different flame retardants are also used to reduce the flammability. These flame retardants... 

In recent years, due to greater attention scientific communities to environment and environmental friendly material, use of natural fibers as reinforcing the polymers has increased significantly. High specific strength, low density, cheap, stiffness and recycled by nature, are including promotional items using natural fibers as reinforcing in the polymer composites. In This study has tried in the first place an appropriate method for producing polypropylene composites reinforced with short jute fibers should be presented and then the physical and mechanical properties of composites will be investigated. Used MAPP and Silane for compatibility took improved between natural jute fibers as a... 

Recently, Polypropylene has been extensively used in a variety of applications in the polymer industry, but its quite low stiffness and toughness limit this polyolefin’s application in the engineering functions; thus, the market of polymer blend and composite manufacturing has grown noticeably in the last few years. In the current project, short Flax fibers are used in order to reinforce the PP matrix. Firstly, Flax fibers were washed with the gentle and harsh condition during the alkalization process, then the optimized alkalization condition was determined through comparison of results from X-ray Diffraction (XRD ), Attenuated Total Reflectance FTIR (ATR-FTIR) and microscopic surface... 

The discovery of oil and gas resources in deep waters led to the invention of various platforms adapted to these waters. As the search for oil and gas resources is advanced to deep water, it is impossible to use fixed platforms in these depths. Hence, the idea of using floating platforms that can be used in deep waters has been increasingly considered. An option for the exploration and extraction of offshore oil resources is semi-submersible platforms. Under wave, wind, and current forces, a floating structure moves from its initial location. Types of mooring systems are used to maintain the position of the platform. During the life of a platform, mooring lines may be damaged under... 

Dye sensitized solar cells are one of the cheap and available technologies that have attracted the attention of many researchers. Many factors such as morphology, microstructure, phase composition and the arrangement of photoanode electrode layers have an effect on the photovoltaic properties of DSSCs. Different approaches have been used to improve the efficiency of this type of cells. Among these approaches, we can mention the use of a mixture of different phases of titanium dioxide and the use of perovskite titanate structures as photoanodes. In the current study, the performance of nickel titanate on light absorption and electron-hole separation in titanium dioxide-based dye-sensitized... 

It is common to inject gas in naturally fractured reservoirs to maintain the reservoir pressure. Recovery will be the result of the complex interplay of several mechanisms such as viscous flow, extraction by molecular diffusion, gravity drainage, oil swelling and capillary force. Generally the main mechanism is gravity drainage However in many cases like low permeability of matrix, small matrix block size and high capillary pressure; gravity drainage may be very low or ineffective. Low permeability results inefficient viscous displacement too. Therefore in these cases the main mechanism is diffusion. The parameters influences the diffusion are: The nature of the injected gas, the composition... 

Studying the interaction of active particles with walls and obstacles has a great importance for practical purposes. Using this knowledge, it is possible to control the motion of active particles in different environments.Experimental evidences show that after encountering with a wall, most of the active particles slide along the wall for some time and then detach in a certain direction, independent of their incoming angle. This special collision is considered to guide, sort or trap active particles.In this dissertation, using Brownian dynamics simulations and theories, we study how different selfpropelled particles and walls influence each other. We explore the behavior of two important... 

Discontinuously reinforced aluminum matrix composites (DRA) are candidates as a substantial class of materials for improved strength, stiffness, and wear resistance. However, the low fracture resistance of DRA's has restricted the widespread use of these materials as structural components. Consequently, intrinsic and extrinsic mechanisms have been considered in order to enhance the damage tolerance of composite materials based on microstructural and architectural modification, respectively. The intrinsic toughening technique has shown to elevate fracture resistance to some extent; usually at the expense of reducing several other properties such as strength. The more recent approach to...