Search for: asphaltene-deposition
Total 51 records
Article Journal of the Japan Petroleum Institute ; Volume 47, Issue 1 , 2004 , Pages 27-31 ; 13468804 (ISSN) ; Rashtchian, D ; Tohidi, B ; Jamialahmadi, M ; Sharif University of Technology
Asphaltene precipitation and deposition is one of the main problems in some of the oil fields. The deposited asphaltene results in partial or total blockage of the wellstring and reducing or completely seizing oil production. Asphaltene deposition problems have been experienced in the field for a long time. Although, the asphaltene precipitation has been studied thoroughly and different parameters that effects this process has been investigated but little work has been carried out in the asphaltene deposition across the production system of flowing oil well. This paper introduces a new comprehensive model for description of asphaltene deposition behavior in wellstring. The mechanisms of...
Article Petroleum Science and Technology ; Vol. 32, Issue. 18 , 2014 , Pages 2183-2194 ; ISSN: 10916466 ; Dabir, B ; Asghari, K ; Shahvaranfard, A ; Sharif University of Technology
The authors present the results of numerical tests and simulations to investigate and analyze the likelihood of asphaltene precipitation and deposition during CO2 flooding in a reservoir. The effects of asphaltene precipitation on oil properties such as oil viscosity and density during miscible CO2 flooding process were elaborated by using Winprop software of Computer Modeling Group. Also oil properties change during CO 2 miscible flooding by numerical slim tube were investigated by a compositional simulator (GEM). A fluid sample of Saskatchewan Reservoir that had been flooded miscibly with CO2 was chosen for performing the sensitivity analyses. The results showed that asphaltene...
Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 29, Issue 2 , 2010 , Pages 131-142 ; 10219986 (ISSN) ; Rashtchian, D ; Tohidi, B ; Jamialahmadi, M ; Sharif University of Technology
Asphaltene precipitation and deposition is a serious problem in many Iranian fields. The deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. This paper studies the asphaltene problem and mitigation methods in wellstring systematically. It presents new approach based on the combination of thermodynamic modeling of asphaltene precipitation with hydrodynamic well modeling. The developed model is capable to determine the asphaltene precipitation and deposition interval through the wellstring. Therefore, it could study the effect of hydrodynamic parameters such as wellhead pressure, well flow-rate and tubing size...
M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid ; Ayatollahi, Shahabodin
Asphaltene, known as the heaviest and the most polar component of the crude oil, can precipitate because of the changes in the fluid condition such as pressure, temperature and composition. Asphaltene deposition causes major problems during oil production, in the form of fluid viscosity changes, wellbore damage and fouling in pipelines. The remediation of these problems is very expensive and needs to halt down the crude oil production. The use of electric field has been proposed recently as clean and cheap technique that could also be applied during the production period. In this work, the effect of electric potential on asphaltene precipitation in both static and dynamic modes has been...
Article Petroleum Science and Technology ; Volume 36, Issue 9-10 , February , 2018 , Pages 632-639 ; 10916466 (ISSN) ; Ayatollahi, S ; Vafaie Seftie, M ; Sharif University of Technology
Taylor and Francis Inc 2018
In this study, asphaltene deposition from crude oil has been studied experimentally using a test loop and prediction using theoretical study under turbulent flow (Reynolds numbers below 5000). The effects of many parameters such as oil velocity, surface temperature and concentration of flocculated asphaltene on the asphaltene deposition were investigated. The results showed that asphaltene deposition thickness increases with increasing both surface temperature and concentration of flocculated asphaltene and decreasing oil velocity. Thermal approach was used to describe the mechanisms involved in this process and the results of data fitting showed that there are good agreements between the...
Mechanistic study to investigate the effects of different gas injection scenarios on the rate of asphaltene deposition: An experimental approach, Article Fuel ; Volume 262 , 2020 ; Zanganeh, P ; Kord, S ; Ayatollahi, S ; Amiri, A ; Sharif University of Technology
Elsevier Ltd 2020
Asphaltene deposition during enhanced oil recovery (EOR) processes is one of the most problematic challenges in the petroleum industry, potentially resulting in flow blockage. Our understanding of the deposition mechanism with emphasis on the rate of the asphaltene deposition is still in its infancy and must be developed through a range of experiments and modelling studies. This study aims to investigate the rate of asphaltene deposition through a visual study under different gas injection scenarios. To visualise the asphaltene deposition, a high-pressure setup was designed and constructed, which enables us to record high-quality images of the deposition process over time. Present research...
Experimental and Modeling Investigation of the Near Wellbore Asphaltene Deposition Damage Removal by Ultrasonic Waves, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus ; Ghazanfari, Mohammad Hossein
This work concerns with experimental and modeling investigation of the asphaltene damage removal using ultrasonic wave irradiation. A specific core holder apparatus was designed and utilized for in situ ultrasonic exposure to damaged core plug at different conditions of exposure time, ultrasound power and distances between sound source and plug. Injection of many pore volumes of an asphaltenic crude oil was used for creating asphaltene induced damaged in porous media through permeability measurements. The deposited asphaltene during oil injection as well as asphaltene removal due to ultrasonic exposure was evaluated using IP-143 analysis. The results revealed that ultrasound application...
Article Energy and Fuels ; Vol. 28, Issue. 6 , 2014 , Pages 3594-3603 ; ISSN: 08870624 ; Panuganti, S. R ; Taghikhani, V ; Pishvaie, M. R ; Chapman, W. G ; Sharif University of Technology
This paper is a continuation of our previous paper (part 1; 10.1021/ef401857t), which discussed the roles of different phenomena effecting the deposition of asphaltene from model oil systems and before the onset of asphaltene precipitation. The study in this paper is to understand the depositional tendency of asphaltene using a quartz crystal microbalance with dissipation (QCM-D) measurements and their corresponding modeling for real crude oil systems with emphasis after the onset of asphaltene precipitation
Investigating the Effects of Different Parameters on Asphaltene Deposition Using Electrodeposition Technique, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabeddin ; Taghikhani, Vahid
Additional to Temperature, Pressure and Compositional changes of crude oils, Electro-kinetics and Electrical potential effects are also known as the most influencing parameters on Asphaltene deposition during oil production and processing.Mechanisms of electro-kinetics and asphaltene charge generation are very complex and unclear. In the previous studies on asphaltene precipitation and deposition, mostly electro-kinetics effects are ignored.While, recent studies show the great effects of electrical filed on asphaltene deposition during production and processing phase of crude oils.At reservoir porous medium and crude flow line, an electrical field can be developed along the length of the...
Development of a Simulator to Simulate Multi-phase Flow with Asphaltene Precipitation in the Wellbore, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid ; Bozorgmehri, Ramin
Asphaltene, the heaviest and most polarizable fraction of crude oil, has a potential to precipitate, deposit and plug pipelines, causing considerable production costs. The main objective of this study is to contribute to the thermodynamic and transport modeling of asphaltene in order to predict its precipitation, segregation and deposition. Potential calculation of some thermophysical properties of asphaltene is also explored. Predicting the flow assurance issues caused by asphaltene requires the ability to model the phase behavior of asphaltene as a function of pressure, temperature and composition. It has been previously demonstrated that the Perturbed Chain form of Statistical Association...
Ph.D. Dissertation Sharif University of Technology ; Ghotbi, Cyrus ; Taghikhani, Vahid ; Shahrabadi, Abbas
In this work, a new model based on the multilayer adsorption kinetic mechanism and four material balance equations for oil, asphaltene, gas and water phase has been developed to account asphaltene deposition in porous media under dynamic condition and the model was verified using experimental data obtained in this work and also with those reported in the literature. The results showed that the developed model can correlate more accurately the oil flooding experimental data in comparison to the previous models based on the mechanical plugging mechanism, in particular in carbonate core samples. Also, a series of experiments was carried to determine the permeability reduction of carbonate,...
M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabodin ; Dehghani, Farzaneh
Given the decreasing trend of light petroleum reserves and the necessity to produce heavy and extra-heavy oil resources, the challenge of dealing with existing asphaltene related problems, which is the heaviest and the most complex component of crude oil, has become increasingly tangible. Asphaltene precipitates and deposits due to pressure, temperature or composition alterations which leads to obstruction of porous media and production facilities. Set the costly methods aside, one of the available approaches to prevent asphaltene precipitation, is to apply an electric field upon the suspected zone, which is cheap and uncomplicated. Besides, utilizing nano-particles while applying electric...
M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein ; Taghikhani, Vahid
Asphaltene deposition, the heaviest and most polar component of crude oil, which causes great economic damage inside the reservoir, near wells, pipelines and well equipment, is an important challenge in the production of oil reservoirs. The main purpose of this study is to prob the adsorption kinetics and the mechanism of asphaltene adsorption on the metal surface by a quartz crystal microbalance device under different conditions of temperature, flow rate and degree of asphaltene instability. In this study, indirect uv-vis spectroscopic method was used to determine the onset of asphaltene precipitation, then experiments were designed using Taguchi method. A new QCM device has been designed...
Improving the Remediation Process of Asphaltene Deposits in the Well Facility of Koupal-Bangestan Oil Reservoir, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahaboddin ; Ghotbi, Cyrus
Crude oil production could cause the thermodynamic equilibrium of the crude oil to be disturbed in the well column which results in asphaltene precipitation and deposition. The thickness of the deposited material grows over time until it completely blocks the well column.Due to the hard and insoluble nature of deposited asphaltene, the two main chemical and mechanical methods are found to be more effective. It should be noted that the actual organic sediments in the piping are not pure and consist of three components: asphaltene, resin and paraffin. Therefore, it is very important to know the composition of the deposited material before selecting the appropriate chemical solvent.The samples...
Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 36, issue. 13 , 2014 , pp. 1395-1405 ; ISSN: 15567036 ; Ghoodjani, E ; Sharif University of Technology
In this article, dynamic core flood experiments in miscible CO2 condition were carried out to investigate core damage due to asphaltene deposition. Carbonate and sandstone cores were used to study of effect of core characteristic on permeability and porosity reduction. The experimental results show asphaltene deposition preferentially in sandstone core type takes place in the first half of the core while in the carbonate one it occurs in the second half. In spite of asphaltene content measurement results (IP-143) that show higher asphaltene deposition in sandstone cores, permeability impairment compared to the carbonate one is severe. Also, permeability-porosity reduction models are affected...
Article Energy and Fuels ; Vol. 28, Issue. 3 , 2014 , pp. 1617-1628 ; ISSN: 08870624 ; Panuganti, S. R ; Vargas, F. M ; Taghikhani, V ; Pishvaie, M. R ; Chapman, W. G ; Sharif University of Technology
Among the asphaltene flow assurance issues, the most major concern because of asphaltene is its potential to deposit in reservoir, well tubing, flow lines, separators, and other systems along production lines causing significant production losses. Hence, the focus of this study is to understand the depositional tendency of asphaltene using quartz crystal microbalance with dissipation (QCM-D) measurements. The results are presented in two consecutive papers, with this paper (part 1) dealing with model oil systems. The depositing environment is varied by changing the system temperature, asphaltene polydispersity, solvent (asphaltene stability), depositing surface, and flow rate. This paper...
Article Petroleum Science and Technology ; Volume 31, Issue 2 , 2013 , Pages 129-141 ; 10916466 (ISSN) ; Schaffie, M ; Kharrat, R ; Ghazanfari, M. H ; Ghoodjani, E ; Sharif University of Technology
The authors studied deposition and entrainment of asphaltene particles as major mechanisms that occur in porous media. Deposition mechanisms that contribute to permeability reduction and entrainment of deposited particle improve the damaged permeability value. While in most previous works the effects of entrainment mechanism are considered negligible, in this study miscible CO2 injection tests were conducted by core flood apparatus to investigate the effect of asphaltene deposition on permeability and porosity alterations. Results indicated that proposed model for entrainment mechanism is affected by deposition mechanism. The asphaltene deposition core's characteristics have undeniable roles...
Development of a New Simulation Tool to Study the Asphaltene Precipitation and Deposition in Oil Well Column Based on Particle Scaling, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saied ; Taghikhani, Vahid
Formation, precipitation and deposition of heavy organic compounds of petroleum fluids including, but not limited to, asphaltene in oil reservoirs and production systems have been by far the most important and challenging flow assurance problems. Therefore, preventative actions to control organic deposits in oil formations and production systems which can lead inevitably to reduction or cessation in production, have always been a main challenge for oil producers.In this thesis, a one dimensional simulator have been developed to study asphaltene precipitation, aggregation and deposition in an oil well column at isothermal and non-isothermal conditions. While the previously proposed PC-SAFT...
M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahaboddin
In this thesis, by focusing on the hydraulics of three phase flow in vertical tubing to investigate asphaltene deposition problem, the solid particles behaviors in a turbulent flow is fully studied. Reasonable size distribution for particles (based on previous works and researches) was assumed and a model for 2 sections of a Marrat oil field well to evaluate their asphaltene deposition problem was developed. Three phase liquid-gas-solid flow in the well tubing was simulated. Asphaltene deposition profile on the well tubing, mean and maximum of the deposition rate and particle concentrations in the flow regime were calculated and compared with real field data. Better agreement with field data...
Modeling of Asphaltene Transport and Deposition under the Effect of Flow Regime in Production oil well, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid ; Ayatollahi, Shahab
Asphaltene deposition, considered as the heaviest and the most polarizable fraction of crude oil, can cause severe problems in oil production and extraction systems. Oil production companies annually bear huge reduction or even cessation in production and, in turn, costs due to asphaltene precipitation and deposition in wellbore or production tubings. To gain more and better insight into asphaltene formation in production systems, the conceptual investigation on the mechanisms of asphaltene adsorption and deposition on a solid surface is indispensable. In this study Asphaltene's particle adsorption and deposition onto the metal surface under the effect of flow is investigated by experimental...