Mahmut Parlaktuna

Mahmut Parlaktuna
Middle East Technical University | METU · Department of Petroleum and Natural Gas Engineering

PhD

About

58
Publications
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Publications

Publications (58)
Article
Full-text available
Heat generation during gas hydrate formation is an important problem because it reduces the amount of water and gas that become gas hydrates. In this research work, we present a new design of an impeller to be used for hydrate formation and to overcome this concern by following the hydrodynamic literature. CH4 hydrate formation experiments were per...
Article
Full-text available
This study examines the impact of three amino acids such as proline, methionine and tryptophan on methane (95%)-propane (5%) hydrate formation with the use of different impellers. The concentration of amino acids was 1 wt% at 24.5 bar and 2 °C. Based on experimental outcomes proline behaves as inhibitor and methionine and tryptophan perform as prom...
Article
Full-text available
The kinetics of methane gas hydrate formation was obtained by different dual and dual mixed impeller experiments with surface baffle at 42.5 bars pressure and 2 °C temperature. The outcomes indicated that induction time is lower in radial flow experiments compared to mixed flow experiments due to better gas liquid contact, uniform shear stress and...
Article
Full-text available
The formation of gas hydrates blocks oil and gas transportation in pipelines, nevertheless sufficient comprehension of gas hydrate behavior is the key to its prolepsis. Thus this study reports the impact of three amino acids such as asparagine, threo-nine and aspartic acid on methane (95%)-propane (5%) hydrate formation. Based on experimental outco...
Article
Full-text available
The motivation for this study is the potential of environmental friendly amino acids such as alanine, histidine, phenylalanine and valine to be examined as inhibitors on methane (95%)—propane (5%) hydrate formation together with the hydrodynamic examination of three different flows in hydrate formation process. The outcomes indicated that valine an...
Article
Full-text available
The motivation for this study was the potential of arginine, glycine and valine to be examined as promoter or inhibitor on methane (95%)-propane (5%) hydrate formation and the examination of which flow is better for hydrate formation. The experimental outcomes indicated that glycine can be used as inhibitor while valine and arginine can be used as...
Article
Full-text available
The kinetics of methane gas hydrates formation was obtained by different dual impeller (DI) experiments with full baffle (FB) at 42.5 bar pressure and 2 °C temperature. There were 18 (dual and dual mixed) experiments by the use of pitched blade turbine upward trending (PBTU), pitched blade turbine downward trending (PBTD), rushton turbine (RT) and...
Article
Full-text available
The growing oil and gas industry is projected to prominently impact the lives and economies of modern communities around the world. Safety at work must be an implementation rather than a goal directed conduct. Accidents that arise from occupational health hazards have human, economic and social costs. This must not be a concern at only the individu...
Article
Full-text available
This study investigates the effects of types of impellers with the use of full baffle in carbon dioxide gas hydrate formation. In single impeller experiments initial hydrate formation rate is higher with the use of rushton turbine showing the better interaction between gas and liquid in radial flow due to better pumping capacity and good shear fiel...
Article
Full-text available
In the present study, the effect of four amino acids is studied for inhibition or promotion of hydrate formation in methane (95%)–propane (5%) mixture-water system. Thus this study reports the impact of leucine, serine, histidine and phenylalanine on mixture hydrate formation with the use of impellers such as: rushton turbine (RT) which has radial...
Article
Full-text available
Hydrate formation characteristics and hydrodynamic behavior have been investigated for mixture of methane-propane hydrate formation with pure water and with the amino acid of lysine 1.5 wt% at 24.5 bars and 2 °C. There were total 12 experiments with full and no baffle estimating the induction time, rate of hydrate formation, hydrate productivity an...
Article
Full-text available
Natural gas hydrates (NGH) are proposed as gas storage and transportation media owing to their high gas content and long-term stability of hydrate crystal structure at common refrigeration temperatures and atmospheric pressure. Technically feasible, cost efficient hydrate production is one of the crucial items of the whole chain of storage and tran...
Article
Full-text available
This study investigates the effects of types of impellers and baffles on methane hydrate formation. Induction time, water conversion to hydrates (hydrate yield), hydrate formation rate and hydrate productivity are components that were estimated. The initial hydrate formation rate is generally higher with the use of Ruston turbine (RT) with higher v...
Article
Full-text available
In the present study, the effect of different kinds of impellers with different baffles or no baffle was investigated. Up-pumping pitched blade turbine (PBTU) and Rushton turbine (RT) were the two types of impellers tested. The reactor was equipped with different designs of baffles: full, half and surface baffles, or no baffles. Single (PBTU or RT)...
Article
Full-text available
In the present study, the effect of different kinds of impellers with different baffles or no baffle was investigated. Up-pumping pitched blade turbine (PBTU) and Rushton turbine (RT) were the two types of impellers tested. The reactor was equipped with different designs of baffles: full, half and surface baffles or no baffles. Single (PBTU or RT)...
Conference Paper
Full-text available
During the past 50 years, there has been a growing awareness of environmental issues related with energy technologies and natural resource utilization. A growing global population demands augmenting amounts of energy, goods without big discovery of conventional resources (apart from Zohr offshore field in Mediterranean Sea-Egypt), leading companies...
Conference Paper
Full-text available
Greece together with Cyprus is believed that will be the next big thing in the upstream sector of Eastern Mediterranean sea while there is no any school or department of petroleum and natural gas engineering. Apart from Metallurgical and Mining Engineering School in N.T.U.A and Resources Engineering in T.U.C, which are the most, close schools compa...
Conference Paper
Full-text available
In Iran, occupational accidents and injuries are one of the most substantial economic and social issues for employees and their families, employers, and government and its institutions. Such accidents can cause disabilities and, in some cases, deaths, which directly affects the workers' families. Moreover, loss of skilled workers and healthcare exp...
Technical Report
Full-text available
This MIGRATE report presents an overview of current technologies that are being used, and could be used, with relation to gas hydrate exploration (Chapter 2), production (Chapter 3) and monitoring (Chapter 4), with an emphasis on European activity. This requires covering various activities within different disciplines, all of which contribute to th...
Conference Paper
Full-text available
In a developing world, the spreading and progress of industry, agriculture and social service is a necessity. Such a progress is often associated with an increase of occupational accidents. Unfortunately, occupational accidents are destined to reiterate itself and the reasons are in very case the same (human mistake, poor regulatory enforcement, et...
Technical Report
Full-text available
This MIGRATE report presents an overview of current technologies related to gas hydrate exploration (Chapter 2), production (Chapter 3) and monitoring (Chapter 4), with an emphasis on European activity. This requires covering various activities within different disciplines, all of which contribute to the technology development needed for future cos...
Conference Paper
Balçova geothermal field is located in a densely populated area which makes direct heat applications very efficient and economical. Heat produced from Balçova geothermal field is utilized for three main purposes: greenhouse heating, balneology and residential heating. Among these three applications, the latter one is the main application throughout...
Article
The Edremit geothermal field is located in the Edremit Graben, which forms an integral part of the Western Anatolian Graben System in Turkey. In the field, the geothermal energy is currently used in heating 5000 houses. A total of 21 wells were sampled in this study for the purpose of hydrogeochemical conceptual modeling. Chemical analyses results...
Article
Polymer Gel Injection is an efficient method for Water Shut-Off (WSO) application in naturally fractured carbonate oil reservoirs with high water cuts. The application of WSO extends the economic life of the field is extended with the decline in water production. Polymer gel injection has become a common application to remediate high water rates in...
Article
Full-text available
The large amount of CO2 that can be mitigated by geologic storage had gained interest during the last 15 years. Acceptance of CCS under CDM is still under discussion(IEA, 2008) however there are several pilot or field scale projects and monitoring surveys that are underway which will make the technology better known and resolve the risks involved....
Article
l-Aspartic acid (l-Asp) was produced using Escherichia coli (ATCC 11303), and its recovery from the reaction mixture was studied using reverse micelle and gas hydrate methods. The effect of initial substrate concentration on l-Asp production was also investigated, and inhibition was shown to occur above 0.75 mol L−1. The values of the kinetic const...
Article
The back extraction of amino acids from reverse micelle phase was investigated through gas hydrate formation. Three amino acids, namely l-aspartic acid, l-serine and l-phenylalanine having different hydrophobicity were used to model the amino acid solution. Back extraction of these amino acid solutions were studied with the help of CO2 hydrate form...
Article
A study on recovery of gas from a Class 1G hydrate deposit (mobile gas in the hydrate zone) and a Class 1W hydrate deposit (mobile water in the hydrate zone) is presented in this text. During the production from these reservoirs, a second dissociation front appears at the top of the hydrate interval. This front develops and advances downward in add...
Article
Full-text available
Kizilcahamam is a low temperature (~ 80°C) geothermal field located 70 km far from Ankara, Turkey. The produced geothermal water is used to heat more than 2500 houses. In order to characterize the reservoir a tracer-test was planned using the efficient hydrologic tracer-test design technique. The test was carried out by injecting a slug of fluoresc...
Article
Full-text available
A numerical modeling study was carried out to simulate Kizildere geothermal field of Turkey. Three different reservoir models were developed: isothermal, non-isothermal and non-isothermal with CO 2 . While developing the reservoir models, permeability values from build-up tests that indicated a double porosity behavior and log-derived porosities we...
Article
The hydrate inhibition potential of four different polymers has been tested in a high-pressure apparatus at high pressures and low temperatures. Aqueous polymer solutions were prepared at 1 wt % concentration. Methane (99.5% purity) was used as hydrate former gas. Hydrate formation rates of the tests were calculated to decide the best inhibitors. A...
Article
The promotion effect of two polymers and three surfactants on methane hydrate formation was investigated in a high-pressure system. For all of the tested chemicals, 1 wt % aqueous solutions were prepared and methane hydrate was formed in those media to detect their effect on hydrate formation rate. It was determined that Igepal-520 is the most effe...
Article
In this study, methane and gas mixture (including 88.17% propane) hydrates were produced from the anionic surfactant solutions of 0.00, 0.01 and 0.05 wt.% to investigate the effect of surfactant on the hydrate formation rate. Hydrate formation rate increases (promotion effect) with surfactant concentration, but the extent of the surfactant effect i...
Article
Full-text available
Kizildere field is the first and only geothermal field of Turkey producing electricity from geothermal steam. Although it produces energy since 1984, it has some operational problems such as fluid disposal and decline in reservoir pressure. The best solution for these two operational problems seems to be the re- injection of produced fluid. A numer...
Article
Full-text available
Build-up measurements from five wells (KD-6, KD- 15, KD-16, KD-21, and KD-22) of Kizildere Geothermal field were analyzed. The main focus was to investigate the effect of calcite scaling on reservoir and wellbore parameters such as permeability, skin factor, wellbore storage coefficient. Several buildup tests from the same well before and after cle...
Article
A computer program, SPECIATION, was developed to determine the detailed composition of an aqueous solution and the concentrations and activities of all species. Once the detailed composition of an aqueous solution is known, it is possible to determine the saturation level of the solution with respect to any mineral, which is silica for this study....
Article
Thermally efficient production of natural gas from a hydrate reservoir by the use of cyclic steam injection process was modeled. The model was considered as a three-phase process: an injection phase, a soak phase, and a production phase. Using energy and mass balances, heat transfer equations, and steam properties, wellbore heat losses, heat losses...
Article
Natural gas hydrates from different types and concentrations of surfactant solutions were produced and dissociated in a high-pressure cell. The Clausius-Clapeyron equation was utilized to derive the enthalpy related to the phase transition of the gas component from dissociation data. The results indicated that the phase change enthalpy of the nonio...
Article
Natural gas hydrates from different types and concentrations of surfactant solutions were produced in a high-pressure cell. An anionic, a cationic, and a nonionic surfactant were used to prepare different concentration of surfactant solutions from deionized water. Although the thermodynamics of hydrate formation from a gas mixture is not affected w...
Article
Natural gas hydrate technology is an attractive alternative for storing and transporting natural gas. A high-pressure laboratory has been built to provide experimental data for use in the design and development of hydrate-based processes for the oil and gas industry. In the laboratory, hydrate is produced from liquid water-and water-in-oil emulsion...
Article
Natural gas hydrate (NGH) technology is an attractive alternative to capture associated gas on FPSO's to solve the stranded and marginal gas problem in the oil industry. Based on estimates for land-based plants, the capital cost of hydrate technology is considerably lower than LNG, methanol and syncrude technologies. Offshore-based hydrate plants a...
Article
Experiments were conducted to determine the hydrate formation conditions of Deǧirmenköy field natural gas. Hydrate equilibrium temperature decreased with decrease in pressure. The use of methanol at low concentrations (< 5 wt %) increased the hydrate equilibrium temperature, while higher concentrations of methanol decrease the hydrate equilibrium t...
Article
The stability of a natural gas hydrate during storage at atmospheric pressure and below-freezing temperatures was studied in the laboratory. The gas hydrate was produced in a stirred vessel at 2- to 6-MPa pressure and temperatures from 0 to 20°C. The hydrate was refrigerated and stored in deep freezers at −5, −10, and −18°C for up to 10 days. The n...
Article
An experimental study on calcium carbonate scaling and prevention by chemical inhibitors was carried out in a laboratory model. In order to study the inhibiting capacities of the chemicals, experiments were performed with four different inhibitors by flashing 350 cc of 0.1 M Ca++ solution to atmospheric pressure at a temperature of 144 °C. The part...
Article
Full-text available
In the development of geothermal sources for power generation, production of geothermal fluids as well as reinjection becomes an important aspect for significant heat extraction from the reservoir rock. The purpose of this work was to understand how cold water injection in five spot pattern affected the temperature distributions and production pres...
Article
Kizildere Geothermal Field is the first and the only field of Turkey utilized for electricity generation. Although the field was discovered in 1968, electricity generation was started in 1984 with an installed capacity of 20.4 MW e . Since then, the power plant is producing with an average of 10 MW e . The field has some operational problems such a...
Article
One of the most applicable methods of low-temperature geothermal resource assessment is volumetric method. While applying volumetric method, the values of uncertain parameters should be determined. An add-in software program to Microsoft EXCEL, @RISK, is used as a tool to define the uncertainties of the parameters in volumetric equation. In this st...
Article
Introduction Gas hydrates are ice-like crystalline compounds that are formed by the combination of water molecules with gas molecules under suitable conditions of pressure and temperature. Water molecules form a lattice structure with cavities that are occupied by gas molecules. There is no chemical union between the water and gas molecules. The wa...

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Project (1)
Project
*Numerical modelling by using Tough+Hydrate *Reservoir modeling and gas in place estimations *Experimental investigations to understand the gas hydrate formation and dissociation processes under predefined conditions