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To have a deeper understanding of Hydraulic fracturing operation, in this study four important parts in this field was developed and simulated. In the first part, continuity and momentum equations for a single phase flow in a propagating penny-shaped fracture inside an impermeable matrix was revisited based on a fixed coordinate system. Its correctness was validated against experimental data and its features were compared with the well-known lubrication theory in analytical form. The new derived continuity equation caused the fracture tip to have a positive and finite pressure while, the conventional model predicted negative infinity for that. In the second part, Finite Volume method was... 

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... 

Investigation about Hydraulic Fracturing phenomenon in fractured porous medium which was occurred by in-situ fracture pressure upon the crack wings, owes the fact that creating enormous damages. However, it might include advantages such as increasing the rate of crude oil production from deep and high pressure/ high temperature reservoirs. On account of the fact that, existence of cracks and natural discontinuities and heat sources such as boundary of geo thermal reservoirs in porous mediums it is undeniable fact. Also, cross sectioning hydraulic fracturing cracks with natural cracks it is an obvious impact. Actually, investigation and analyzing the break throw of HF crack with natural... 

Hydraulic fracture propagation occures in fractured saturated porous media due to fluid leakage from the crack faces and the consequent fluid pressure. In many cases, hydraulic fracturing may be considered as a detrimental phenomenon which endangers stability of human made structures like rock-fill dames. However, in recent decades the hydraulic fracturing has been an appealing method for increasing the production rate of low-permeability oil and gas reservoirs in petroleum industries.
In order to efficiently assess the behavior of saturated madia one needs to consider the coupling between the solid and fluid phases of the medium. To do so, the coupled formulation refered to as u-p... 

In this thesis, a fully coupled numerical model is developed for the modeling of dynamic cohesive crack propagation and hydraulic fracture in saturated porous media using extended finite element method. Many engineering structures like concrete or soil dams and buildings foundation are built with porous materials like concrete, rock and soil. Behavior of these materials in which void among the solid particles are filled with one or more fluids are so complicated rather than single solid phase. Dynamic analysis of porous mediums containing a discontinuity has many applications in various civil engineering fields including structure, earthquake, hydraulic structures, etc. For instance... 

In this study, a fully coupled three-dimensional numerical analysis of two-phase fluid flow and heat transfer through deformable porous media is presented in the context of extended element free Galerkin method. By coupling momentum balance equation for the whole mixture, continuity equations of wetting and non-wetting fluid phases and energy balance equation, the developed numerical algorithm is capable of simulating a wide range of engineering problems such as CO2 sequestration, nuclear waste disposal in deep underground strata, hydraulic fracturing in oil and gas reservoirs and so on.By taking the advantages of partition of unity property of MLS shape functions, weak and strong... 

Hydraulic fracturing is a process during which a viscous fluid under relatively high pressure and flow rate is injected into a wellbore to induce and propagate a system of cracks in the ground.Hydraulic fracturing of underground formations has been widely used in different fields of
engineering, such as petroleum engineering, geotechnical engineering, environmental engineering, mining engineering,and so on.Despite the technological advances in the techniques of in-situ hydraulic fracturing, the industry lacks a realistic and reliable numerical model to design cost - effective and efficient hydraulic fracturing treatment.This is due to the complex interaction and strong coupling between... 

Hydraulic fracturing, as an industry-leading technology, has proven to be very efficient in increasing the productivity of oil and gas wells. Therefore, this technology has been taken into attention in recent years and the number of hydraulic fracturing operations has been increasing. In order to enhance the efficiency of this technology, the final transmissibility of the fracture needs to be at the maximum possible value. To do so, proppant injection is the most common way to maintain a fracture open. To achieve a successful hydraulic fracture operation, detailed knowledge of the particle's transport and distribution inside the fracture is needed.In this study, a static fracture geometry... 

In this thesis, a fully coupled numerical model is developed for the modeling of the cohesive crack propagation and hydraulic fracturing in porous media using the extended finite element method in conjunction with the cohesive crack model. The governing equations, which account for the coupling between various physical phenomena, are derived within the framework of the generalized Biot theory. The solid phase displacement, the wetting phase pressure and the capillary pressure are taken as the primary variables of the three-phase formulation. The other variables are incorporated into the model via the experimentally determined functions that specify the relationship between the hydraulic... 

Transport phenomena in porous media play important role in many areas of subsurface hydrology, geo-physics, environment, energy and petroleum. The work in the field of numerical modeling of fractured porous media is yet an open area of research. The classic finite element method (FEM) has some limitations in modeling of discontinuities like fracture. FEM mesh should conform with the geometry of the fracture. Presence of fracture imposes discontinuity in pressure field of fluid phases and displacement field of solid phase (rock). To represent the fractures, the extended finite element method (X-FEM) can be used in which the standard finite element approximation of the field variables is... 

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... 

In the last decades, Hydraulic Fracturing has been found widespread applications. One of its main applications is fracture producing in hydrocarbon reservoirs and increasing the outflow of oil and gas. Thus, control and prediction of crack path is really necessary. One of the major parts in any model is an appropriate crack propagation criteria. Many criterion has been proposed in literature. These models often assume some simplifying assumptions. They often consider isotropic media. In fact, this assumption is not applicable in geo-mechanics. In other words, there are many inhomogenities such as micro-cracks and microdefects. These appear in the flow characteristics (e.g. permeability) and... 

Fractured rock masses contain fractures facilitating the fluid movement and storage. Permeability and material behavior of this particular material is poorly understood. Hence, there would be a great need of determining the characteristics of such materials. In this paper, an equivalent approach has been implemented at first in order to equivalently determine the hydro-mechanical and geomechanical characteristics of the fractured rock masses in the form of anisotropic tensors. The equivalent permeability and compliance tensors are derived based upon fluid dissipation energy and linear elasticity, respectively. In addition, the effect of derived characteristics on a single-phase (solid... 

With the production from the reservoirs, the amount of in-situ oil storage has decreased and there is a need to increase oil recovery (EOR) from the reservoir. Increased oil recovery (EOR) includes operations such as acidizing and hydraulic fracturing. Considering the economic and high operational costs and geomechanical complexities, as well as the technical progress of hydraulic fracturing and its future; It is necessary to manage hydraulic fracturing operations optimally. This research is about hydraulic fracturing and its main goal is to optimize the parameters of the fracture or the geometry of the fracture. The research study was carried out on the Bangistan Reservoir located in the... 

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... 

In the oil industry, after drilling an oil well and laying pipes, it is time for the hydraulic fracturing process. In the process of hydraulic fracturing, a fracture must be created in the casing pipe of the well. The reason for this is that the oil from the existing reservoir enters the well so that it can be extracted. The end of the well must be blocked to cause a fracture in the well body. The reason is that after creating a fracture in the casing pipe, proppant particles are pumped together with water inside the well to keep it open. For the proppant particles to be placed inside the cracks, it is necessary to create pressure in the fracture area. To create pressure in the fracture area... 

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... 

The exploitation of oil and gas were changed dramatically with the advent of hydraulic fracturing. By using enhanced oil recovery methods in unconventional reservoirs, USA could raise the rate of production in comparison with the rate of consumption. Hydraulic fracturing is one of the enhanced oil recovery methods.The purpose of this research is the study of the effects of geomechanical parameters in the characteristics of the cracks induced by hydraulic fracturing in unconventional oil reservoirs. The minimum in-situ stress and tensile stress of rock can be overcome by injecting fluid and thus the rock will be cracked. Changes in geomechanical parameters such as modulus of elasticity,... 

Increasing the permeability of hydrocarbon reservoirs by creating artificial cracks that are induced by injection of fluids under high pressures is called Hydraulic Fracturing operation. This method is widely used in petroleum reservoir engineering. For design of Hydraulic Fracture operations, a number of methods have been developed. KGD and PKN are the first and most used methods in this area and despite the development of advanced softwares in recent years, these methods are still popular and are used in a number of softwares. KGD is commonly used for induced fractures where the height of fracture is greater than its length, and PKN is normally used where the length of the fracture is... 

The exploitation of oil and gas has been changed dramatically since the advent of hydraulic fracturing. Hydraulic fracture is one of the enhanced oil recovery methods in which high-pressure injecting fluid is pumped into the well to overcome the lowest in-situ stress and rock resistance to create cracks in the deep-rock formations. It is estimated that the benefits of the mentioned method lead to a net economic profit of $48 billion per year in the world’s oil and gas industry.While there are various analytical models for predicting hydraulic fracture characteristics, KGD and PKN are amongst the most popular Models. The conditions of plane strain in two-dimensional space are taken into...