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fractured-reservoir
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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...
Experimental and modelling study of gravity drainage in a three-block system
, Article Transport in Porous Media ; Volume 136, Issue 2 , 2021 , Pages 471-494 ; 01693913 (ISSN) ; Karimi Malekabadi, A ; Ghazanfari, M. H ; Rostami, B ; Sharif University of Technology
Springer Science and Business Media B.V
2021
Abstract
Gravity drainage is known as the controlling mechanism of oil recovery in naturally fractured reservoirs. The efficiency of this mechanism is controlled by block-to-block interactions through capillary continuity and/or reinfiltration processes. In this study, at first, several free-fall gravity drainage experiments were conducted on a well-designed three-block apparatus and the role of tilt angle, spacers’ permeability, wettability and effective contact area (representing a different status of the block-to-block interactions between matrix blocks) on the recovery efficiency were investigated. Then, an experimental-based numerical model of free-fall gravity drainage process was developed,...
An insight into the formation of liquid bridge and its role on fracture capillary pressure during gravity drainage in fractured porous media
, Article Canadian Journal of Chemical Engineering ; Volume 99, Issue S1 , 2021 , Pages S212-S231 ; 00084034 (ISSN) ; Masihi, M ; Ghazanfari, M. H ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
The formation of liquid bridges can maintain capillary continuity between matrix blocks during gas/oil gravity drainage in fractured reservoirs. A travelling oil drop draining into a fracture either forms a liquid bridge or breaks into detached drops. However, the different characteristics of a travelling drop during its elongation and required conditions for transformation into a liquid bridge are not well described in the published literature. In this work, a one-dimensional model based on slender-drop theory is employed that holds gravity, viscosity, and surface tension forces but ignores inertia. This model, together with Young-Laplace equation, gives the fracture capillary pressure....
Analysis of evaporating liquid bridge in horizontal fractures
, Article Journal of Petroleum Science and Engineering ; Volume 202 , 2021 ; 09204105 (ISSN) ; Ghazanfari, M.H ; Masihi, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The formation of liquid bridge is pertinent to many fields including seepage into underground fractured rocks as an environmental issue and capillary continuity between matrix blocks which controls oil recovery in fractured reservoirs. Evaporation from the surface of liquid bridge into the surrounding gas could affect the stability of liquid bridge and fracture capillary pressure, which is not well discussed in the available literatures. In this research, by the aid of analogy between the diffusive flux and electrostatic potential, a new model for predicting evaporation rate from a liquid bridge inside a horizontal fracture is presented. The proposed model is then coupled with Young-Laplace...
Experimental and modelling study of gravity drainage in a three-block system
, Article Transport in Porous Media ; 2020 ; Karimi Malekabadi, A ; Ghazanfari, M. H ; Rostami, B ; Sharif University of Technology
Springer Science and Business Media B.V
2020
Abstract
Gravity drainage is known as the controlling mechanism of oil recovery in naturally fractured reservoirs. The efficiency of this mechanism is controlled by block-to-block interactions through capillary continuity and/or reinfiltration processes. In this study, at first, several free-fall gravity drainage experiments were conducted on a well-designed three-block apparatus and the role of tilt angle, spacers’ permeability, wettability and effective contact area (representing a different status of the block-to-block interactions between matrix blocks) on the recovery efficiency were investigated. Then, an experimental-based numerical model of free-fall gravity drainage process was developed,...
Modeling of capillary pressure in horizontal rough-walled fractures in the presence of liquid bridges
, Article Journal of Petroleum Science and Engineering ; Volume 185 , 2020 ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Capillary continuity between adjacent matrix blocks through formation of liquid bridge controls the recovery factor of gravity drainage process in fractured reservoirs. However, stability of liquid bridges as well as related capillary pressure in horizontal rough fractures is not well discussed in the available literature. In this work, new models of rough-walled fracture are developed and the role of roughness size and frequency on formation of liquid bridge and fracture capillary pressure are investigated. The Young-Laplace equation is numerically solved to characterize the liquid bridge formed in the proposed models of rough fractures. Critical fracture aperture for a range of liquid...
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,...
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,...
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...
Possible pitfalls in pressure transient analysis: Effect of adjacent wells
, Article Journal of Petroleum Exploration and Production Technology ; Volume 9, Issue 4 , 2019 , Pages 3023-3038 ; 21900558 (ISSN) ; Eyvazi Farab, A ; Sharifi, M ; Sharif University of Technology
Springer Verlag
2019
Abstract
Abstract: Well testing is one of the important methods to provide information about the reservoir heterogeneity and boundary limits by analyzing reservoir dynamic responses. Despite the significance of well testing data, misinterpreted data can lead us to a wrong reservoir performance prediction. In this study, we focus on cases ignoring the adjacent well’s production history, which may lead to misinterpretation. The analysis was conducted on both homogeneous and naturally fractured reservoirs in infinite-acting and finite-acting conditions. The model includes two wells: one is “tested well” and the other is “adjacent one.” By studying different scenarios and focusing on derivative plots, it...
A new insight into pore body filling mechanism during waterflooding in a glass micro-model
, Article Chemical Engineering Research and Design ; Volume 151 , 2019 , Pages 100-107 ; 02638762 (ISSN) ; Sadatshojaie, A ; Mohebbi, A ; Riazi, M ; Sharif University of Technology
Institution of Chemical Engineers
2019
Abstract
By displacing oil in porous media with other fluid, different mechanisms of fluid displacing occur. The importance of understanding the trapping mechanisms like pore body filling is irrefutable. Pore body filling mechanism with a coordination number of four has different events like I0, I1, I2 and I3. Previous studies showed that the event of I0 occurs when the pore is only filled by a compressible non-wetting phase, but this study showed that this event could also occur by an incompressible non-wetting phase. Trapping mechanisms can be examined in a glass micro-model. In this research, a glass micro-model with three different patterns was used. Results showed that at two spots of the...
Experimental study of dynamic imbibition during water flooding of naturally fractured reservoirs
, Article Journal of Petroleum Science and Engineering ; Volume 174 , 2019 , Pages 1-13 ; 09204105 (ISSN) ; Masihi, M ; Mirzaei Paiaman, A ; Hamidpour, E ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Capillary imbibition is an important recovery mechanism in naturally fractured reservoirs when water-filled fractures surround water-wet matrix blocks. A large amount of studies of imbibition process is simply total or partial immersion of nonwetting phase saturated rock in aqueous wetting phase. However, water advance in fractures during water flooding or water encroachment from an active aquifer introduces time dependent boundary conditions where invariant exposure of rock surface to water is not representative. In this work, a laboratory simulated matrix-fracture system was used to investigate different aspects of imbibition in the presence of fracture fluid flow (namely dynamic...
Phase-field simulation of counter-current spontaneous imbibition in a fractured heterogeneous porous medium
, Article Physics of Fluids ; Volume 29, Issue 6 , 2017 ; 10706631 (ISSN) ; Akhlaghi Amiri, A ; Sharif University of Technology
American Institute of Physics Inc
2017
Abstract
Spontaneous imbibition is well-known to be one of the most effective processes of oil recovery in fractured reservoirs. However, the detailed pore-scale mechanisms of the counter-current imbibition process and the effects of different fluid/rock parameters on this phenomenon have not yet been deeply addressed. Thiswork presents the results of a newpore-level numerical study of counter-current spontaneous imbibition, using coupled Cahn-Hilliard phase field and Navier-Stokes equations, solved by a finite element method. A 2D fractured medium was constructed consisting of a nonhomogeneous porous matrix, in which the grains were represented by an equilateral triangular array of circles with...
Multi-criterion based well placement and control in the water-flooding of naturally fractured reservoir
, Article Journal of Petroleum Science and Engineering ; Volume 149 , 2017 , Pages 675-685 ; 09204105 (ISSN) ; Boozarjomehry Bozorgmehry, R ; Pishvaie, M. R ; Sharif University of Technology
Elsevier B.V
2017
Abstract
In the optimization of naturally fractured reservoirs, it is required to take into account their complex flow behavior due to high conductivity fractures. In this regard, the possible effects of fractures must be included in the optimization procedure. In a water-flooding project, fast water breakthrough from injection to production wells may be occurred because of high permeability fractures. To consider the effect of the fracture system, a multi-criterion optimization procedure is proposed in this work. For this contribution, Non-dominated Sorting Genetic Algorithm version II (NSGA-II) is implemented for the optimization purposes. Considering the effect of the fracture system on the flow...
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...
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...
Free fall and controlled gravity drainage processes in fractured porous media: Laboratory and modelling investigation
, Article Canadian Journal of Chemical Engineering ; Volume 93, Issue 12 , October , 2015 , Pages 2286-2297 ; 00084034 (ISSN) ; Ayatollahi, S ; Masihi, M ; Sharif University of Technology
Wiley-Liss Inc
2015
Abstract
Gravity drainage is known to be one of the most effective methods for oil recovery in fractured reservoirs. In this study, both free fall and controlled gravity drainage processes were studied using a transparent fractured experimental model, followed by modelling using commercial CFD software. The governing equations were employed based on the Darcy and mass conservation laws and partial pressure formulation. Comprehensive examination was done on variables such as fluid saturation, velocity, and pressure distribution in the matrix and fracture, as well as fluid front level and production rate. Additionally, effects of the model parameters on the gravity drainage performance were...
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,...
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...
Analytical modeling of oil production from a matrix block by free fall gravity drainage mechanism
, Article Energy Exploration and Exploitation ; Volume 31, Issue 6 , October , 2013 , Pages 821-832 ; 01445987 (ISSN) ; Ardakany, M ; Ghazanfari, M ; Sharif University of Technology
2013
Abstract
Free fall gravity drainage is the most effective mechanism in gas invaded zone of fractured reservoirs. Although several analytical models have been proposed to characterize this mechanism, most of them suffer from inadequate reality, such as neglecting capillary pressure. In this study, a new analytical model was proposed to predict the oil recovery versus time for a homogeneous matrix block under a free fall gravity drainage mechanism. Considering the effect of viscous, gravity as well as capillary forces, the model was developed. This model is applicable to different conditions of gravity and capillary force, as well as when both forces are active. Along with core scale experimental data...