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fractured-reservoirs
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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...
Modeling fluid flow under sonic wave field in fractured porus media-with an approach to capillary forces
, Article 4th International Conference and Exhibition: New Discoveries through Integration of Geosciences, 5 April 2010 through 8 April 2010 ; 2010 ; Ghazanfari, M ; Ghotbi, C ; Kharrat, R ; Sharif University of Technology
European Association of Geoscientists and Engineers, EAGE
Abstract
Till now, no mathematical model is presented to model the flow under sonic field be applied in fractured reservoirs. This will be more noticeable when we bear in mind that several reservoirs in Middle East region are fractured. In this work the effects of elastic waves on capillary trapping and mobility of Bingham plastic fluids in fractures have been investigated. Eventually, a model for predicting the influence range of the wave in fractured reservoirs is presented. The results of this study clarified that radiation of wave with low frequency and intensity extremely increases the flow rate and decreases the minimum pressure gradient required for flow of Bingham plastic fluids in fractured...
An improvement of the matrix-fracture transfer function in free fall gravity drainage
, Article Petroleum Science and Technology ; Vol. 31, issue. 24 , Apr , 2011 , Pages. 2612-2620 ; 10916466 (ISSN) ; Masihi, M ; Sharif University of Technology
Abstract
The simulation of fractured reservoir is conventionally performed by using dual porosity formulation in which the type of transfer function may be critical. Over the past few years, various models with their strength and weakness have been developed to account for matrix-fracture interporosity flow. However, some of them are unable to simulate some mechanisms like gravity drainage. In this work, the most well-known transfer functions have been examined for simulation of the gravity drainage in a single block model and an improvement has been introduced to modify them. The validation of the developed approach have been done by using fine grid simulation
An adaptive CPR-AMG based linear solver for simulating geometrically complicated and fractured reservoirs
, Article Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2020, ADIP 2020, 9 through 12 November ; 2020 ; Eslahi, R ; Bakhtiari, M ; Alizadeh, A ; Zeinali, M ; Madani, M ; Rajabi, H ; Sharifi, E ; Mortezazadeh, E ; Mahdavifar, Y ; Sharif University of Technology
Society of Petroleum Engineers
2020
Abstract
A great deal of computational power and time is necessary for simulating highly heterogeneous fractured reservoirs with complex geometry; the efficiency of these computations is a major subject especially in large-scale heterogeneous and fractured reservoirs. So, simulating large scale, complex and fractured reservoirs with both minimum time and maximum accuracy is the scope of current work. The BiCG-Stabilized solver preconditioned by CPR-AAMG has been developed to achieve acceptable results of high efficiency and robustness for large heterogeneous fractured Black-Oil models. The solver's efficiency is demonstrated in an Iranian fractured field model with heterogeneity. As an observation,...
Laboratory studies of MEOR in micromodel as a fractured system
, Article Society of Petroleum Engineers Eastern Regional Meeting 2007: Unbridling Energy's Future, Lexington, KY, 17 October 2007 through 18 October 2007 ; October , 2007 , Pages 39-46 ; 9781604239362 (ISBN) ; Panahi, H ; Biria, D ; Roosta, R ; Haghighi, M ; Mohebbi, A ; Sharif University of Technology
2007
Abstract
Microbial EOR (MEOR) is receiving renewed interest worldwide. The method is based on microorganisms' activities to reduce residual oil of reservoirs, which is dependent on behavior of inherent microorganisms or injection of bioproduct of external microorganisms. Five bacterial species were taken from MIS crude oil that is one of the aging Persian fractured reservoirs. Visualization experiments were carried out to examine the behavior of MEOR in micromodels designed to resemble the fractured system: static and dynamic. A new surface sample of the MIS oil was taken at the well head and physical specifications were measured at the lab. This was fairly light oil with API gravity of 42.5. The...
Estimation of naturally fractured oil reservoir properties using the material balance method
, Article Scientia Iranica ; Volume 21, Issue 3 , 2014 , Pages 781-791 ; ISSN: 10263098 ; Jamshidi, S ; Gholinezhad, S ; Sharif University of Technology
Abstract
In fractured reservoirs, a large variation of permeability due to the presence of fractures leads to changes in the production mechanism compared to conventional reservoirs. Hence, an appropriate model with the ability to describe the reservoir properly can provide a more confident prediction of its future performance. One of the features of a representative model is the number and height of the matrix blocks. The determination of these two parameters is one of the decisive steps in the calculation of an accurate amount of oil production from these reservoirs. In fact, matrix height shows its effect as a gravity force, which is one of the driving mechanisms. If the matrix height is less than...
New expert system for enhanced oil recovery screening in non-fractured oil reservoirs
, Article Fuzzy Sets and Systems ; 2015 ; 01650114 (ISSN) ; Ayatollahi, S ; Bozorgmehry Boozarjomehry, R ; Sharif University of Technology
Elsevier
2015
Abstract
As the oil production from conventional oil reservoirs is decreasing, oil production through Enhanced Oil Recovery (EOR) processes is supposed to compensate for both the oil production reduction in matured oil reservoirs and the worldwide dramatic increase in oil demand. Therefore, developing a strategy to choose an optimized EOR technique is crucial to find a resolution for production decline in oil reservoirs. A screening tool recommending the most appropriate EOR method is proposed in this study. An expert fuzzy logic system is employed to screen four well-known EOR methods including miscible CO2 injection, miscible HC gas injection, polymer flooding and steam injection based on the...
An experimental investigation of the effect of fracture dip angle on oil recovery and drainage rate in free fall gravity drainage in fractured reservoirs using a glass micromodel (A pore level investigation)
, Article Petroleum Science and Technology ; Volume 31, Issue 4 , 2013 , Pages 355-367 ; 10916466 (ISSN) ; Kharrat, R ; Ghazanfari, M ; Sharif University of Technology
2013
Abstract
Gravity drainage is the main production mechanism in the gas invaded zone in naturally fractured reservoirs. However, there are large ambiguities and complexities, resulting from the dynamic of oil depletion from matrix blocks toward the fracture network. Visualization of drained oil at pore scale using glass micromodels provides the opportunity to better understand the effects of different parameters which might affect oil recovery from fractured reservoirs. In this work a micromodel apparatus generated by laser etching is used to perform some gravity drainage tests on the network patterns. The experiments were performed on double block systems using crude oil. The block to block...
Toe-to-heel air injection: Investigation of the effect of fractures geometrical properties on process performance
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 33, Issue 22 , Sep , 2011 , Pages 2067-2077 ; 15567036 (ISSN) ; Kharrat, R ; Ghotbi, C ; Sharif University of Technology
Abstract
Toe to heel air injection has been studied on non-fractured sandstone models and is found to be a promising enhanced oil recovery method for certain heavy oil reservoirs, such as those in Canada, but its applicability on fractured reservoirs, such as those in the Middle East, is not investigated yet. The objective of this article is to evaluate the effect of fractures geometrical parameters, such as fracture density, orientation, and location, on the performance of the process in laboratory scale. Simulation results showed that toe-to-heel air injection is more applicable on highly networked fractured reservoirs, such as those that occur in Persian Gulf coast compared to lower density...
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...
Experimental study of some important factors on nonwetting phase recovery by cocurrent spontaneous imbibition
, Article Journal of Natural Gas Science and Engineering ; 2015 ; 18755100 (ISSN) ; Mirzaei Paiaman, A ; Masihi, M ; Harimi, B ; Sharif University of Technology
Elsevier
2015
Abstract
Spontaneous imbibition, defined as the displacement of nonwetting phase by wetting phase in porous media by action of capillary forces, is important in many applications within earth sciences and in particular in naturally fractured oil and gas reservoirs. Hence, it is critical to investigate the various aspects of this process to correctly model the fractured reservoir behavior. In this study, twenty four experiments were conducted to study the effect of rock properties, lithology of porous medium, brine viscosity and boundary conditions on displacement rate and final recovery by cocurrent spontaneous imbibition (COCSI) in brine-oil systems. The results can be extended to brine-gas systems,...
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...
New expert system for enhanced oil recovery screening in non-fractured oil reservoirs
, Article Fuzzy Sets and Systems ; Volume 293 , 2016 , Pages 80-94 ; 01650114 (ISSN) ; Ayatollahi, S ; Bozorgmehry Boozarjomehry, R ; Sharif University of Technology
Elsevier
2016
Abstract
As the oil production from conventional oil reservoirs is decreasing, oil production through Enhanced Oil Recovery (EOR) processes is supposed to compensate for both the oil production reduction in matured oil reservoirs and the worldwide dramatic increase in oil demand. Therefore, developing a strategy to choose an optimized EOR technique is crucial to find a resolution for production decline in oil reservoirs. A screening tool recommending the most appropriate EOR method is proposed in this study. An expert fuzzy logic system is employed to screen four well-known EOR methods including miscible CO2 injection, miscible HC gas injection, polymer flooding and steam injection based on the...
An efficient and robust method for optimizing the number of non-linear iterations for simulating highly heterogeneous naturally fractured reservoirs
, Article Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2020, ADIP 2020, 9 through 12 November ; 2020 ; Eslahi, R ; Bakhtiari, M ; Alizadeh, A ; Zeinali, M ; Madani, M ; Rajabi, H ; Sharifi, E ; Mortezazadeh, E ; Mahdavifar, Y ; Sharif University of Technology
Society of Petroleum Engineers
2020
Abstract
For speeding up the complex fractured reservoir simulating, we have given more attention to reducing runtime and improving efficiency of the solver. In this work, we describe an improved and computationally efficient version of Newton's method, which reduces the non-linear iteration count, increases time steps, and furthermore reduces time spent in nonlinear loops of reservoir simulating. Safeguarded variants of Newton's method which have used in current reservoir simulators cannot guarantee convergence of the solution, especially in highly heterogeneous, detailed and fractured reservoirs. In such simulators time step chopping is often observed. From other hand, with growing complexity,...
Static and dynamic evaluation of the effect of nanomaterials on the performance of a novel synthesized PPG for water shut-off and improved oil recovery in fractured reservoirs
, Article Journal of Petroleum Science and Engineering ; Volume 189 , June , 2020 ; Fatemi, M ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier B. V
2020
Abstract
Among different methods which are introduced to reduce unwanted water production, “Preformed Particle Gel” (PPG) is a recently developed type of these gels that can have important advantages such as temperature resistance and long-term stability. The aim of the present work is to synthesize a new type of PPG in which the above specifications are improved even further with the advantage of the Nano-material (here after called N-PPG) and then investigate its effectiveness via static bulk tests as well as dynamic Hele-Shaw and Micromodel tests. In static tube tests, the swelling performance of N-PPG samples was evaluated under different conditions. The examined parameters include various pH of...
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...