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The Effect of Different Stresses in the Three Principal Directions on Horizontal Fractured Formation
, M.Sc. Thesis Sharif University of Technology ; Goodarznia, Iraj (Supervisor)
Abstract
Nowadays, we know that many hydrocarbon reservoirs are fractured regarding this, the investigation of the properties of these reservoirs is necessary to predict the storage, production and the drilling methods. To identify fractured reservoirs, the fracture properties and their geometries under different conditions should be investigated. Besides, the evaluation of the behavior of induced fractures in distinct under ground conditions is very important. The Mechanical properties of the drilling bed like crack propagation, layer and mass rock is impactful in planning of drilling process and hydraulic fracturing operation. In this research, at first we introduce natural and induced fractures...
Investigation of underground gas storage in a partially depleted naturally fractured gas reservoir
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 29, Issue 1 , 2010 , Pages 103-110 ; 10219986 (ISSN) ; Azin, R ; Nasiri, A ; Bahrami, H ; Sharif University of Technology
Abstract
In this work, studies of underground gas storage (UGS) were performed on a partially depleted, naturally fractured gas reservoir through compositional simulation. Reservoir dynamic model was calibrated by history matching of about 20 years of researvoir production. Effects of fracture parameters, i.e. fracture shape factor, fracture permeability and porosity were studied. Results showed that distribution of fracture density affects flow and production of water, but not that of gas, through porous medium. However, due to high mobility of gas, the gas production and reservoir average pressure are insensitive to fracture shape factor. Also, it was found that uniform fracture permeability...
Estimating the properties of naturally fractured reservoirs using rate transient decline curve analysis
, Article Journal of Earth Science ; Volume 28, Issue 5 , 2017 , Pages 848-856 ; 1674487X (ISSN) ; Joukar, M ; Fathinasab, M ; Da Prat, G ; Kharrat, R ; Sharif University of Technology
Abstract
Transient rate decline curve analysis for constant pressure production is presented in this paper for a naturally fractured reservoir. This approach is based on exponential and constant bottom-hole pressure solution. Based on this method, when ln (flow rate) is plotted versus time, two straight lines are obtained which can be used for estimating different parameters of a naturally fractured reservoir. Parameters such as storage capacity ratio (ω), reservoir drainage area (A), reservoir shape factor (CA), fracture permeability (kf), interporosity flow parameter (λ) and the other parameters can be determined by this approach. The equations are based on a model originally presented by Warren...
Experimental study on enhanced oil recovery by low salinity water flooding on the fractured dolomite reservoir
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 40, Issue 5 , 2021 , Pages 1703-1719 ; 10219986 (ISSN) ; Gerami, S ; Safekordi, A. A ; Bahramian, A. R ; Ganjeh Ghazvini, M ; Sharif University of Technology
Iranian Institute of Research and Development in Chemical Industries
2021
Abstract
Enhanced Oil Recovery from carbonate reservoirs is a major challenge especially in naturally fractured formations where spontaneous imbibition is a main driving force. The Low Salinity Water Injection (LSWI) method has been suggested as one of the promising methods for enhanced oil recovery. However, the literature suggests that LSWI method, due to high dependence on rock mineralogy, injected and formation water salt concentration, and complexity of reactions is not a well-established technology in oil recovery from carbonate reservoirs. The underlying mechanism of LSWI is still not fully understood. Due to lack of LSWI study in free clay dolomite fractured reservoir, and to investigate of...
Comparison of dual Porosity-Dual Permeability Models in 2D Two-Phase Immiscible Flows under Gravitational Effect
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Advisor)
Abstract
Physics of the present work is 2D two-phase immiscible flow under gravitational effect through fractured porous media and the most practical formulas for transfer function in dual porosity-dual permeability models have been implemented for numerical simulation of naturally fractured reservoir. The models are: Kazemi et al. (1976), Gilman (1986), Sonier et al. (1988), Quandalle and Sabathier (1989), Lim and Aziz (1995), and Rangel-German and Kovscek (2006), which are compared using a benchmark problem and the effects of gravity, capillary, number of matrix block subdomains and dual continuum media model are studied. The benchmark problem was adopted from Gilman (1986) and involves water...
Horizontal Well Modeling in Naturally Fractured Reservoirs Using Dual Porosity-Dual Permeability Model
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor)
Abstract
In this article, we investigate the transient pressure response and production rate of horizontal wells in a dual porosity-dual permeability naturally fractured reservoir.First, the point source solution is derived in Laplace transform space and then pressure distribution and horizontal well response is obtained using the principle of superposition. In our model, despite of dual porosity model, matrix system is directly connected to horizontal wellbore as well as fracture system and has an influence on type curves characteristics. We also showed that type curves characteristics are affected by horizontal well length, well eccentricity, external boundary conditions, permeability and storavity...
Modeling of Two Phase Flow in Horizontal Well Coupling Natural Fracture Reservoir
, M.Sc. Thesis Sharif University of Technology ; Shad, Saeed (Supervisor)
Abstract
Today due to increasing demand of using energy and petroleum products, finding optimum ways to produce more oil and gas in a way which petroleum reservoirs faces less pressure drop is very necessary. Therefore, petroleum engineers face multiphase flow proportionally more than other issues. So, they have to comprehend this issue in a complete manner in order to discover the best practical ways for maximum utilization. Researchers in different ways tried to model multiphase flow, but many of provided models are so complicated and sometimes have low accuracy. In this project we tried to present a model that in simplicity has high accuracy and works in a way that apperceiving it, is very...
Analytical Modeling of Oil Production from a Matrix Block by Free Fall Gravity Drainage
, M.Sc. Thesis Sharif University of Technology ; Masihi, Mohsen (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor) ; Kharrat, Reyaz (Supervisor)
Abstract
Free fall gravity drainage is one of the most effective mechanisms of producing the oil from the matrix blocks in the gas invaded zone of the naturally fractured reservoirs. Although several analytical models have been proposed to characterize this mechanism in a matrix block, but these models suffer from the practical or theoretical viewpoints. In this study, a new analytical model was presented to predict the oil production rate versus time from a homogeneous matrix block under free fall gravity drainage mechanism. The model was developed by considering the balance between involved forces in the gas-oil gravity drainage process. By simplifying the equation derived from the momentum...
Multirate Transfer Functions in Dual Porosity-Dual Permeability Models in Simulation of Naturally Fractured Reservoirs in 2D Two Phase Water-Oil System
, M.Sc. Thesis Sharif University of Technology ; Taghi Zade Manzari, Meherdad (Supervisor) ; Afshin, Hossein (Co-Advisor) ; Kazemzadeh Hannani, Siamak (Co-Advisor)
Abstract
Naturally Fractured Reservoirs (NFRs) play an important role in petroleum industry and the global economy.. The reservoirs of the most complex geological structures in petroleum engineering science, on the other hand the largest sources of hydrocarbons are considered throughout the world and especially in our country. Therefore, characterization and modeling them frst step to develop best practices for hydraulic fracturing gap, optimal design of production Method and evaluate potential reservoirs. Physics of the present work is 2D two-phase immiscible flow under gravittational effect through fractured porous media and the most practical formulas for transfer function in dual porosity-dual...
Modification of vogel's inflow performance relationship (IPR) for dual porosity model
, Article Petroleum Science and Technology ; Volume 31, Issue 16 , 2013 , Pages 1633-1646 ; 10916466 (ISSN) ; Gerami, S ; Sharif University of Technology
2013
Abstract
The performance of a solution gas-drive reservoir can be predicted using Vogel inflow performance relation (or IPR), which simply relates the deliverability of a well to bottom-hole pressure and average reservoir pressure. While many studies have shown the success of Vogel-type IPR for single porosity reservoirs, the applicability of this method for naturally fractured reservoirs (NFRs), is under question mainly because of the complex flow behavior in matrix and fracture systems. The present study is undertaken to determine if the relation between NFR flowing wellbore pressure and oil production rate could be described by Vogel's IPR. For this purpose, a synthetic dual porosity fractured...
Application of the recovery curve method for evaluation of matrix-fracture interactions
, Article Journal of Natural Gas Science and Engineering ; Volume 22 , January , 2015 , Pages 447-458 ; 18755100 (ISSN) ; Masihi, M ; Heinemann, Z. E ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier
2015
Abstract
The Discrete Fracture Network and Dual Continuum concept are two common methods to model naturally fractured reservoirs. Each has specific limitations. The newly introduced recovery curve method is believed to be a compromise between these two current methods. In the recovery curve method, two recovery curves for water and gas displacements are used to more realistically calculate matrix-fracture mass exchanges. This paper presents a new approach to determine appropriate recovery curves by using the recovery curve method and production data. In particular, two recovery curves were determined for a column model by matching phase contact positions throughout the production data. Hybrid genetic...
Simulation analysis of the effects of fractures' geometrical properties on the performance of vapour extraction process
, Article Journal of Canadian Petroleum Technology ; Volume 49, Issue 7 , 2010 , Pages 47-59 ; 00219487 (ISSN) ; Bahonar, M ; Sharif University of Technology
2010
Abstract
Vapour extraction (VAPEX), a newly developed heavy oil recoveiy (HOR) method, has been extensively studied, both theoretically and experimentally, in conventional sandstone models. However, the applicability of this process to naturally fractured reservoirs has not yet been addressed. The objective of this work is to evaluate the effects of fractures' geometrical properties, such as orientation, length of extension, discontinuity in both the upper well region (UWR) and the far well region (FWR) and vertical fracture location on VAPEX performance. Additionally, the effects of horizontal and vertical fracture dispersion in various density, dispersion scheme and networking on the performance of...
Factors affecting the gravity drainage mechanism from a single matrix block in naturally fractured reservoirs
, Article Special Topics and Reviews in Porous Media ; Volume 2, Issue 2 , 2011 , Pages 115-124 ; 21514798 (ISSN) ; Ghazanfari, M. H ; Mashayekhizadeh, V ; Kamyab, M ; Sharif University of Technology
2011
Abstract
Despite numerous experimental and numerical studies, fundamental understanding of how the matrix block height, the density difference between petroleum and gas, and matrix capillary pressure could affect the oil recovery from a single matrix block in naturally fractured reservoirs remains a topic of debate in the literature. In this work a one-dimensional gravity drainage model developed by Firoozabadi and Ishimoto (1994) is considered and numerically solved. The Fourier series method is applied for a numerical Laplace inversion of the dimensionless mathematical model; this type of inversion method has rarely been used in petroleum applications. The obtained results revealed that by...
History matching of naturally fractured reservoirs based on the recovery curve method
, Article Journal of Petroleum Science and Engineering ; Volume 126 , 2015 , Pages 211-221 ; 09204105 (ISSN) ; Masihi, M ; Heinemann, Z. E ; Ghazanfari, M. H ; Sharif University of Technology
Abstract
The discrete fracture network (DFN) and Multiple-Continua concept are among the most widely used methods to model naturally fractured reservoirs. Each faces specific limitations. The recently introduced recovery curve method (RCM) is believed to be a compromise between these two current methods. In this method the recovery curves are used to determine the amount of mass exchanges between the matrix and fracture mediums. Two recovery curves are assigned for each simulation cell, one curve for gas displacement in the presence of the gravity drainage mechanism, and another for water displacement in the case of the occurrence of the imbibition mechanism. These curves describe matrix-fracture...
Fracture characterizing and modeling of a porous fractured carbonate reservoir
, Article Society of Petroleum Engineers - SPE/EAGE Reservoir Characterization and Simulation Conference 2009 - Overcoming Modeling Challenges to Optimize Recovery, 19 October 2009 through 21 October 2009 ; Volume 1 , 2009 , Pages 303-319 ; 9781615677443 (ISBN) ; Bagheri, M. B ; Ulhaq, S ; Sharif University of Technology
Abstract
Anisotropy and heterogeneity in reservoir properties introduce challenges during the development of hydrocarbon reservoirs in naturally fractured reservoirs. In reservoir simulations, grid-block properties are frequently assigned to obtain reasonable history matches. Even then, accuracy with regard to some aspects of the performance such as water or gas cuts, breakthrough times, and sweep efficiencies may be inadequate. In some cases, this could be caused by the presence of substantial flow through natural fractures. In this work the fracture characterization and modeling was performed in a highly fractured carbonate reservoir in SW Iran. It was observed that reservoir simulation based on...
Microfluidics experimental investigation of the mechanisms of enhanced oil recovery by low salinity water flooding in fractured porous media
, Article Fuel ; Volume 314 , 2022 ; 00162361 (ISSN) ; Fatemi, M ; Masihi, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Spontaneous imbibition of water from fracture into the matrix is considered as one of the most important recovery mechanisms in the fractured porous media. However, water cannot spontaneously imbibe into the oil-wet rocks and as a result oil won't be produced, unless the capillary pressure barrier between fracture conduits and matrix is overcome. Wettability alteration is known as the main affecting mechanism for low salinity water flooding (LSWF), however, its effectiveness in fractured porous media has been less investigated, especially in the case of possible pore scale displacement mechanisms. In this study, the effectiveness of LSWF (diluted seawater) on oil recovery is compared to the...
Comparison of Transfer Functions in Dual Porosity-Dual Permeability Model in Simulation of Naturally Fractured Reservoirs in Two Phase Water-Oil Systems
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor)
Abstract
In this study, simulation of two-phase water-oil compressible flow in naturally fractured reservoirs is studied. The studied reservoir has a 1D and horizontal ge-ometry that its properties such as porosity and permeability are homogeneous.Dual Porosity and Dual Porosity-Dual Permeability models are employed for simulation of reservoir. Reservoir descriptive equations are conservation of mass and momentum. Conservation of momentum equation is simplified by Darcy law and two-phase fluid flow is simulated with Black-oil model. Discretization of equations is done by finite volume method. In order to solve the equations of two-phase compressible fluid flow, the so-called IMPES (Implicit Pressure...
Dual Porosity Modeling of Oil-Gas Systems under the Effects of Gravity and Capillary Forces
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor) ; Shamloo, Amir (Supervisor)
Abstract
In this thesis, two types of two-phase flow are studied in one dimension. The first type is oil-gas two-phase flow which is miscible and compressible. The second one is oil-water two-phase flow which is immiscible and incompressible. Oil wet and water wet conditions are studied in the second type of flow. Two approaches, i.e. double porosity and double porosity-double permeability, are used to study naturally fractured reservoirs. In these approaches, the matrix and fracture are modeled as two separate media that exchange mass via a transfer function. Black oil model is applied to simulate the fluid system. The governing equations consist of the conservation of mass equations for each...
Wel Test Analysis Using Deconvolution Method in Naturally Fractured
Reservoirs
,
M.Sc. Thesis
Sharif University of Technology
;
Taghikhani, Vahid
(Supervisor)
;
Shadizadeh, Seyed Reza
(Supervisor)
;
Jamshidi, Saeid
(Co-Advisor)
Abstract
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...
Using the method presented in this thesis, petroleum engineers could...
Evaluation of Transfer Functions of Dual Porosity-dual Permeability Model Using Discrete Fracture Model
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor) ; kazemzadeh Hannani, Siamak (Co-Advisor)
Abstract
Physics of present work is 2D and two phase immiscible flow under gravity and capillary effect through fractured porous media. Rock properties such as porosity and permeability are homogenous. Discrete fracture model and dual porosity-dual permeability model are used to simulate this problem. Governing equations for such reservoirs are conservation of mass and conservation of momentum. Evaluations are performed in two seperate parts. in the first part, geometry, boundary conditions and initial conditions which important models of transfer functions were calculated are provided by using discrete fracture model and results are compared with results of corresponding reference. Following...