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fractured-carbonate-reservoir
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Selecting a Surfactant for Wettability Alteration In Iranian Carbonate Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Badakhshan, Amir (Supervisor)
Abstract
Fractured carbonate reservoirs are mostly oil-wet to intermediate-wet. Due to the negative capillary pressure of the matrix poor spontaneous imbibition of reservoir brine occurs in such reservoirs, and water flooding leads into early break through due to the high conductivity of the fracture network. Some surfactants have the ability to change the wettability of rock matrix toward water-wet state by adsorbing onto the rock surface. The phenomenon can result in spontaneous imbibition improvement and thereby increasing water flooding efficiency and recovery from fractured carbonate reservoirs. In this thesis the effect of some surfactants on the wettability of Iranian carbonate reservoir rocks...
Experimental Investigation of Acidizing in Natural Fractured Carbonates to the Optimum Injection Condition
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabodin (Supervisor)
Abstract
In many cases, oil and gas extraction from reservoirs due to damage and permeability reduction near wellbore is lower than optimum level and reduces the flow of oil into the well. In fact, formation damage is the collapse of natural condition of reservoirs, In addition to delaying production and increasing costs, it causes early desertification of wells. Well stimulation methods are used to solve this problem and increase production. One of the most effective ways to increase the production of wells is well acidizing. In this study, the acid performance of the fractured carbonate reservoirs has been investigated. In this type of reservoirs, due to the existence of high permeable paths of the...
A Carbonate Reservoir Characterization Using AVO Analysis on 3D Seismic Data
, Ph.D. Dissertation Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor) ; Javaherian, Abdolrahim (Supervisor) ; Nabi Bidhendi, Majid (Co-Advisor)
Abstract
In this project, some issues facing the application of AVO in carbonate reservoirs were studied,reviewed and discussed: physical relationships between elastic and reservoir rock properties to estimate compressional and shear wave velocities both on core measurements and well logging data, sensitivity analysis for Gassmann‐Biot and Kuster‐Toksoz rock physics models on the representative carbonate samples, lithology discrimination and reservoir characterization in carbonate intervals using AVO seismic attributes and specifically LambdaRho‐MuRho approach.The studied area (Azadegan Oil Field) is an area about 1174 km2 of 3D seismic data and was containing of six wells in the time of study. In...
Investigation of Rheological Behavior of Polymer on EOR in Carbonate Reservoir
, Ph.D. Dissertation Sharif University of Technology ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Emadi, Mohammad Ali (Supervisor)
Abstract
The major objectives of this study are to analytically and experimentally investigate the rheological behavior of polymers in the fractured carbonate medium based on the polymer solution properties and operational conditions. The intrinsic and apparent viscosity of high molecular weight-partially hydrolyzed poly (acrylamide) which is mainly used in enhanced oil recovery (EOR) processes hasbeen investigated in reservoir conditions. Since, the EOR efficiency of hydrolyzed poly (acrylamide) is very sensitive to the temperature and salinity of petroleumreservoirs; investigations have been carried out at different possible reservoirtemperatures using high saline polymer solutions. The parameters...
Investigating the Role of Molecular Diffusion on the Performance of Non-Equilibrium Gas Injection in One of the Fractured Reservoirs in Iran
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein (Supervisor) ; Fatemi, Mobin (Supervisor)
Abstract
Major parts of Iran's oil reservoirs are fractured carbonates, which need time to produce oil due to their much lower permeability than sandstone reservoirs. Molecular diffusion mechanism is an efficient mechanism in oil recovery from fractured reservoirs under gas injection conditions. The main subject of this work is to investigate the role of molecular diffusion mechanism in the non-equilibrium gas injection project and its role in increasing the oil recovery rate in two southern fractured reservoirs located in the west of Iran, taking into account the capillary pressure, as well as the change of interfacial tension closely miscible conditions is also investigated through simulation. The...
Comparison of wellbore stability of UBD in the case of laser drilling and conventional operation
, Article 76th European Association of Geoscientists and Engineers Conference and Exhibition 2014: Experience the Energy - Incorporating SPE EUROPEC 2014 ; 2014 , Pages 1736-1740 ; ISBN: 9781632666949 ; Nakhaee, A ; Koohian, A ; Irawan, S ; Habibpour, M ; Shahvar, M ; Sharif University of Technology
Abstract
In recent years, growing interest in underbalanced drilling has resulted in the rapid development of its associated equipment technology, practices, and procedures. Underbalanced drilling is used to avoid lost circulation, formation damage, and decreasing weight on bit. However, the risk of wellbore collapse due to lake of hydrostatic mud pressure is high; therefore, using good geo-mechanical model may avoid wellbore instability problems. In order to evaluate the potential for wellbore instability, it is necessary to use an elastoplastic model to compute the stresses and strains around the bore hole. Furthermore, it should be mentioned that the laser drilling process depends extremely on the...
The operational and reservoir parameters influencing the performance of top-down in situ combustion in fractured reservoirs: 2D block-scale simulation of networked fractures
, Article Petroleum Science and Technology ; Volume 30, Issue 3 , 2011 , Pages 256-270 ; 10916466 (ISSN) ; Kharrat, R ; Vossoughi, S ; Sharif University of Technology
2011
Abstract
Top-down in situ combustion (ISC) involves the stable propagation of a combustion front from the top vertical injector to the bottom horizontal producer. With the exception of laboratory studies of conventional sandstones, no application of the process in fractured carbonates has been addressed. The aim of the present work is to study ISC in the presence of a system of networked fractures using a thermal reservoir simulator from the Computer Modeling Group (CMG; Calgary, AB, Canada). The performance of ISC is compared with nonfractured system under similar conditions. To obtain more realistic results, a history-matched and validated combustion model of an Iranian naturally fractured...
The assessment of fracture geometrical properties on the performance of conventional in situ combustion
, Article Petroleum Science and Technology ; Volume 29, Issue 6 , Feb , 2011 , Pages 613-625 ; 10916466 (ISSN) ; Kharrat, R ; Ghotbi, C ; Sharif University of Technology
Abstract
The aim of the present work is to evaluate the effect of fractures geometrical properties such as orientation, density, location, and networking on the conventional fire flooding (CFF) process performance through simulation analysis. Combustion parameters of a fractured low-permeable carbonate heavy oil reservoir in Iran called Kuh-E-Mond (KEM); applied for simulation study and simulator has been validated with KEM combustion tube experimental data. The validated model was modified to study CFF in 3D semi-scaled combustion cells. Simulation results confirmed that CFF is more feasible in the case of densely fractured reservoirs such as those in the Middle East
The effect of fractures' geometrical properties on the recovery mechanism of the top-down in situ combustion process
, Article Petroleum Science and Technology ; Volume 30, Issue 2 , Feb , 2011 , Pages 147-158 ; 10916466 (ISSN) ; Kharrat, R ; Sharif University of Technology
2011
Abstract
The top-down in situ combustion (ISC) involves the stable propagation of the combustion front from the top vertical injector to the bottom horizontal producer. Apart from laboratory studies in conventional sandstones, no application of the process in fractured carbonates has been addressed yet. The authors modified a successful combustion tube history matched model of an Iranian low-permeable heavy oil reservoir called Kuh-E-Mond to investigate the feasibility of ISC in fractured carbonate reservoirs mimicking block-scale combustion cells. Effects of fractured geometrical properties such as orientation, location, extension, density, spacing, and dispersion were considered. Results confirmed...
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...
The synergic effects of anionic and cationic chemical surfactants, and bacterial solution on wettability alteration of carbonate rock: an experimental investigation
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 513 , 2017 , Pages 422-429 ; 09277757 (ISSN) ; Lashkarbolooki, M ; Ayatollahi, S ; Hashemi, A ; Sharif University of Technology
Abstract
Changing the wettability of reservoir rock towards strongly water-wet state is effective way to enhance oil recovery from fractured carbonate reservoirs which are typically oil-wet. Regarding this fact, the injection of surfactant and the bacterial solution as EOR agents is proposed in the current work as a potential method to alter the wettability of rock surface reservoir. Nevertheless, there is a definite lack of experimental data regarding this method and the synergistic effect of both chemical and bacterial solutions on this process. In this study, the sole and combined effects of the bacterial solution using an Enterobacter cloacae strain as a biosurfactant-producer are compared with...
Microorganisms’ effect on the wettability of carbonate oil-wet surfaces: implications for MEOR, smart water injection and reservoir souring mitigation strategies
, Article Journal of Petroleum Exploration and Production Technology ; Volume 10, Issue 4 , 2020 , Pages 1539-1550 ; Ayatollahi, S ; Sharif University of Technology
Springer
2020
Abstract
In upstream oil industry, microorganisms arise some opportunities and challenges. They can increase oil recovery through microbial enhanced oil recovery (MEOR) mechanisms, or they can increase production costs and risks through reservoir souring process due to H2S gas production. MEOR is mostly known by bioproducts such as biosurfactant or processes such as bioclogging or biodegradation. On the other hand, when it comes to treatment of reservoir souring, the only objective is to inhibit reservoir souring. These perceptions are mainly because decision makers are not aware of the effect microorganisms’ cell can individually have on the wettability. In this work, we study the individual effect...
An experimental investigation of foam for gas mobility control in a low-temperature fractured carbonate reservoir
, Article Petroleum Science and Technology ; Volume 30, Issue 10 , 2012 , Pages 976-985 ; 10916466 (ISSN) ; Kharrat, R ; Motealleh, M ; Khanamiri, H. H ; Nematzadeh, M ; Ghazanfari, M. H ; Sharif University of Technology
2012
Abstract
This work concerns the experimental investigation of surfactant alternating CO 2 injection in carbonate rocks. The core samples provided from a low-temperature fractured light oil reservoir, located in southwest Iran. The experiments were designed to observe the effect of CO 2-foam injection on gas mobility and oil recovery at different surfactant concentrations. The core samples were initially saturated with synthetic/field brine, 5,000 ppm, and then flooded with live oil to reach connate water saturation at reservoir condition, 115F and 1,700 psia. The commercial surfactant used was sodium lauryl sulfate as an anionic surfactant. The results of this work, along with field-scale simulation...