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oil-reservoirs
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Wettability Alteration of Reservoir Rocks to Super Gas-Wet Condition Using Nanocomposite by Applying Contact Angle Measurement for Gas-Crude Oil System
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossien (Supervisor) ; Fatemi, Mobeen (Supervisor) ; Esmaeilzadeh, Pouriya (Co-Supervisor)
Abstract
Today, increasing the productivity of reservoirs is more important than in the past, while the use of nanoparticles to change the wettability of rock and increase the recovery factor from the reservoir has been considered by many researchers. Despite previous studies on the use of nanoparticles to change the wettability of rock to gas-wet, the use of nanocomposites with super gas-wet at high temperature and pressure in the crude oil-gas system has rarely been considered. In this research, several nanocomposites with different structures have been synthesized in the laboratory and nanofluids with different formulations have been used to coat the rock thin sections and measure droplet contact...
Parallel Simulation of Petroleum Reservoir on Clusters
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
The main goal of petroleum reservoir simulation is finding of Pressure (P) and Saturation (S) of fluid in different places of prose media environment of the reservoir in a specific time interval. In this project we will implement a distributed reservoir simulator of a cluster. In fact parallelization of reservoir simulator is finding a method to decompose the reservoir domain into some region and assigning each region to a computer in a cluster of parallel computers in order to minimize the total amount of dependency of regions to each other and messages between nodes in the parallel network according to fluid equation in the system and finaly minimize' the duration of simulation. In this...
Water-flooded On-line Reservoir Management Using Multi-variable Multi-model Predictive Controllers
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor)
Abstract
High efficiency and low-emission fuel cells have the capacity to replace fossil fuels for energy supply concerns. Solid oxide fuel cells operate in relatively high temperature and have power plant applications. Hence, they are acquainted to be coupled with cycle gas turbine to reduce the cost and increase the overall system efficiency. The control of these hybrid systems is so important. Due to the system nonlinearity and having more than one controlled variable, its control with classic methods would be difficult. The model based predictive control is used as an alternative to mitigate these difficulties. In addition to their high performance, their extension to the multivariate case would...
Toward mechanistic understanding of heavy crude oil/brine interfacial tension: The roles of salinity, temperature and pressure
, Article Fluid Phase Equilibria ; Vol. 375, issue , August , 2014 , p. 191-200 ; ISSN: 03783812 ; Hemmati-Sarapardeh, A ; Ghazanfari, M. H ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
Abstract
Injecting low salinity brines is regarded as an enhanced oil recovery (EOR) process through IFT reduction. However, the exact mechanism behind this process is an unsettled and complex issue that has not been well understood yet, especially for heavy crude oil system. Besides, limited information is available regarding the key heavy oil/brine interfacial tension (IFT). The present study aims to investigate the sensitivity of dead heavy crude oil/brine IFT to a wide range of properties/conditions and to reveal the underlying physicochemical mechanisms involved in enhanced oil recovery and IFT reduction by low salinity water injection into heavy oil reservoir. IFT was measured as a function of...
Well Placement optimization using hybrid optimization technique combined with fuzzy inference system
, Article Petroleum Science and Technology ; Vol. 31, issue. 5 , Dec , 2009 , p. 481-491 ; ISSN: 10916466 ; Masihi, M ; Sharif University of Technology
Abstract
Decision on the location of new wells through infill drilling projects is a complex problem that depends on the reservoir rock and fluid properties, well and surface facilities specifications, and economic measures. Conventional approach to address this is a direct optimization that uses the numerical flow simulation. However, this is computationally very extensive. In this study the authors use a hybrid genetic algorithm (HGA) optimization technique based on the genetic algorithm (GA) with helper functions based on the polytope algorithm and the neural network. This hybridization introduces hill-climbing into the stochastic search and makes use of proxies created and calibrated iteratively...
Investigation of the effect of water based nano-particles addition on hysteresis of oil and-water relative permeability curves
, Article Society of Petroleum Engineers - SPE International Oilfield Nanotechnology Conference 2012 ; June , 2012 , p. 267-277 ; Masihi, M ; Ghazanfari, M. H ; Sherafati, M ; Mashayekhi, L ; Sharif University of Technology
Abstract
It has been shown that one kind of poly silicon particles with sizes ranging from 10-500 nm, can be used in oilfields to enhance the oil recovery of water injection by 15-20%. The contributing mechanism might be reducing the interfacial tension which appears through improving relative permeability of the oil-phase. However, fundamental understanding of how hysteretic behavior of relative permeability curves affected by nanosilica particles remains a topic of debate in the literature. In this study, water as well as water dispersed nanosilica particles floods was performed on sandstone rock sample saturated by light crude oil supplied from one of Iranian oil reservoir, and the relative...
Experimental study of miscible displacement with hydrocarbon solvent in shaly heavy oil reservoirs using five-spot micromodels: The role of shale geometrical characteristics
, Article Journal of Porous Media ; Vol. 15, issue. 5 , 2012 , p. 415-427 ; ISSN: 1091028X ; Ghazanfari, M. H ; Masihi, M ; Kharrat, R ; Sharif University of Technology
Abstract
Most of the heavy oil reservoirs contain discontinuous shale which affects fluid flow through porous media as well as recovery efficiency during enhanced oil recovery processes. However, the role of shale geometrical characteristics (including orientation, length, discontinuity, and spacing of the shale) on oil recovery remains a topic of debate in the literature, especially during miscible injection of heavy oils and five-spot systems. Here, a series of hydrocarbon solvent injection tests have been performed on various five-spot glass micromodels containing barriers which are initially saturated with heavy oil under fixed flow rate conditions. Oil recoveries as a function of pore volumes of...
Recovery improvement using water and gas injection scenarios
, Article Petroleum Science and Technology ; Vol. 29, issue. 3 , Sep , 2009 , p. 290-300 ; ISSN: 10916466 ; Masihi, M ; Momeni, A ; Sharif University of Technology
Abstract
Water and miscible gas injection scenarios are considered in an Iranian oil reservoir for the purpose of recovery improvement. Firstly reservoir fluid modeling and modeling of a slim tube test were performed. Then, water alternating gas (WAG) injection was evaluated by optimizing the WAG half cycle and WAG ratio. Alternatively, hybrid WAG and separate injection of water and gas in the top and bottom of the reservoir were also investigated. The numerical simulation results showed that the optimum WAG, with half cycle of 1.5 years and WAG ratio of one, gave the highest recovery factor. Moreover, economic evaluation of these scenarios indicated that WAG had the highest net present value and was...
The impacts of aqueous ions on interfacial tension and wettability of an asphaltenic-acidic crude oil reservoir during smart water injection
, Article Journal of Chemical and Engineering Data ; Vol. 59, issue. 11 , 2014 , pp. 3624-3634 ; ISSN: 00219568 ; Ayatollahi, S ; Riazi, M ; Sharif University of Technology
Abstract
The use of adjusted/optimized saline water categorized into two different classes namely smart water (SW) and low salinity (LoSal) water injection has been proposed for more oil recovery from specific types of oil reservoirs. There are possible mechanisms concerning SW flooding that have been proposed in the literature, some of them are still subject to more examination. In this study, an experimental investigation is performed to determine the influence of type and amount of salt to the surface properties including interfacial tension (IFT) and contact angle (CA) of aqueous solution + acidic and asphaltenic crude oil + carbonate rock systems. For this purpose, the concentration of different...
Toward mechanistic understanding of heavy crude oil/brine interfacial tension: The roles of salinity, temperature and pressure
, Article Fluid Phase Equilibria ; Vol. 375, issue , 2014 , Pages 191-200 ; ISSN: 03783812 ; Hemmati-Sarapardeh, A ; Ghazanfari, M. H ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
Abstract
Injecting low salinity brines is regarded as an enhanced oil recovery (EOR) process through IFT reduction. However, the exact mechanism behind this process is an unsettled and complex issue that has not been well understood yet, especially for heavy crude oil system. Besides, limited information is available regarding the key heavy oil/brine interfacial tension (IFT). The present study aims to investigate the sensitivity of dead heavy crude oil/brine IFT to a wide range of properties/conditions and to reveal the underlying physicochemical mechanisms involved in enhanced oil recovery and IFT reduction by low salinity water injection into heavy oil reservoir. IFT was measured as a function of...
Experimental investigation of water alternating CH4-CO 2 mixture gas injection in light oil reservoirs
, Article International Journal of Oil, Gas and Coal Technology ; Vol. 8, issue. 1 , 2014 , p. 31-40 ; Ghazanfari, M. H ; Taghikhani, V ; Badakhshan, A ; Sharif University of Technology
Abstract
This paper studies a WAG process for improving the recovery efficiency in light oil reservoirs. Until now, few references have reported the role of CO2 mole percent on recovery improvement in light oil reservoirs. The injected gas was changed, and the effect of composition changes on performance of core flood experiments were conducted at fixed flow rate. Five series of experiments (varied in methane mole percentages, 0, 25, 50, and 75, 100) were systematically examined. The results indicated that the oil recovery efficiency improved with the increasing of CO2 mole ratio and there was also maximum recovery efficiency in this work. That would be helpful to better understanding the role of CO2...
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...
Asphaltene precipitation due to natural depletion of reservoir: Determination using a SARA fraction based intelligent model
, Article Fluid Phase Equilibria ; Volume 354 , September , 2013 , Pages 177-184 ; 03783812 (ISSN) ; Alipour Yeganeh Marand, R ; Naseri, A ; Safiabadi, A ; Gharagheizi, F ; Ilani Kashkouli, P ; Mohammadi, A. H ; Sharif University of Technology
2013
Abstract
Precipitation of asphaltene leads to rigorous problems in petroleum industry such as: wettability alterations, relative permeability reduction, blockage of the flow with additional pressure drop in wellbore tubing, upstream process facilities and surface pipelines. Experimentally determination of the asphaltene precipitation is costly and time consuming. Therefore, searching for some other quick and accurate methods for determination of the asphaltene precipitation is inevitable. The objective of this communication is to present a reliable and predictive model namely, the least - squares support vector machine (LSSVM) to predict the asphaltene precipitation. This model has been developed and...
Application of fast-SAGD in naturally fractured heavy oil reservoirs: A case study
, Article SPE Middle East Oil and Gas Show and Conference, MEOS, Proceedings, Manama ; Volume 3 , March , 2013 , Pages 1946-1953 ; 9781627482851 (ISBN) ; Hashemi Kiasari, H ; Alizadeh, N ; Mighani, S ; Kamari, A ; Baker Hughes ; Sharif University of Technology
2013
Abstract
Steam injection process has been considered for a long time as an effective method to exploit heavy oil resources. Over the last decades, Steam Assisted Gravity Drainage (SAGD) has been proved as one of the best steam injection methods for recovery of unconventional oil resources. Recently, Fast-SAGD, a modification of the SAGD process, makes use of additional single horizontal wells alongside the SAGD well pair to expand the steam chamber laterally. This method uses fewer wells and reduces the operational cost compared to a SAGD operation requiring paired parallel wells one above the other. The efficiency of this new method in naturally fractured reservoir is not well understood....
Application of multi-criterion robust optimization in water-flooding of oil reservoir
, Article Journal of Petroleum Science and Engineering ; Volume 109 , September , 2013 , Pages 1-11 ; 09204105 (ISSN) ; Pishvaie, M. R ; Khorasheh, F ; Salahshoor, K ; Kharrat, R ; Sharif University of Technology
2013
Abstract
Most of the reported robust and non-robust optimization works are formulated based on a single-objective optimization, commonly in terms of net present value. However, variation of economical parameters such as oil price and costs forces such high computational optimization works to regenerate their optimum water injection policies. Furthermore, dynamic optimization strategies of water-flooding often lack robustness to geological uncertainties. This paper presents a multi-objective while robust optimization methodology by incorporating three dedicated objective functions. The goal is to determine optimized and robust water injection policies for all injection wells. It focuses on reducing...
Temperature and composition effect on CO2 miscibility by interfacial tension measurement
, Article Journal of Chemical and Engineering Data ; Volume 58, Issue 5 , March , 2013 , Pages 1168-1175 ; 00219568 (ISSN) ; Escrochi, M ; Ayatollahi, S ; Sharif University of Technology
2013
Abstract
Crude oil reservoirs have different temperatures, compositions, and pressures, therefore oil recovery performance by CO2 injection varies from one case to another. Furthermore, it is predicted that lower interfacial tension between injected CO2 and reservoir fluid results in more oil recovery. In this study, we investigate the effect of temperature on the equilibrium interfacial tension between CO2 and three different oil fluids at different pressures. Also minimum miscible pressure (MMP) is measured by the vanishing interfacial tension (VIT) technique to determine the temperature effect on the CO2 miscible gas injection. The results on different pure and mixtures of hydrocarbon fluids show...
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...
Toward reservoir oil viscosity correlation
, Article Chemical Engineering Science ; Volume 90 , 2013 , Pages 53-68 ; 00092509 (ISSN) ; Khishvand, M ; Naseri, A ; Mohammadi, A. H ; Sharif University of Technology
2013
Abstract
Oil viscosity plays a key role in reservoir simulation and production forecasting, as well as planning thermal enhanced oil recovery methods and these make its accurate determination necessary. In this communication, the most frequently used oil viscosity correlations are evaluated using a large databank of Iranian oil reservoirs which were measured using a Rolling Ball viscometer (Ruska, series 1602). To evaluate the performance and accuracy of these correlations, statistical and graphical error analyses have been used simultaneously. Three of the most accurate correlations for each region, including dead oil viscosity, viscosity below bubble point, viscosity at bubble point and the...
An experimental investigation of silica nanoparticles effect on the rheological behavior of polyacrylamide solution to enhance heavy oil recovery
, Article Petroleum Science and Technology ; Volume 31, Issue 5 , 2013 , Pages 500-508 ; 10916466 (ISSN) ; Mohebbi, A ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
2013
Abstract
The use of polymer flooding as one of enhanced oil recovery methods has recently increased. The occurrence of high shear rates in reservoir and near well bore through perforation nozzles during polymer flooding cause shear degradation of polymers and therefore polymer viscosity has decreased. Rheological behavior of polymer solution in different conditions of oil reservoir is one of the key factors to develop use of polymer solutions. A few researches are available regarding improving rheological behavior of polymeric solution. In this study, to investigate the effect of nanoparticles on rheological behavior of polymer solutions two samples were prepared: polyacrylamide solution in water and...