Serhat Akin

Serhat Akin
Middle East Technical University | METU · Department of Petroleum and Natural Gas Engineering

Professor

About

161
Publications
45,826
Reads
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Introduction
Serhat AKIN is a professor of Petroleum and Natural Gas Engineering at the Middle East Technical University (METU), Ankara, Turkey, where he has Bsc, Msc and a PhD degree in petroleum and natural gas engineering. He has served on the faculty since 1998. Prior to joining METU, Dr. Akin was a post-doctoral researcher in Petroleum Engineering Department, Stanford University between 1997 and 1998. He was Blaustein Visiting Professor in Petroleum Engineering Department, Stanford University at 2006. Dr. Akin has published more than 130 technical articles, reports, and conference proceeding papers. His research interests include reservoir engineering, EOR especially thermal, geothermal, reservoir simulation, tracer, and well test analyses. He received the Society of Petroleum Engineers Outstanding Technical Editor award in 2001, 2002, 2004 and 2014. He also received Prof. Dr. Tarik Somer award in 2004 and the Middle East Technical University Academic Achievement award between 2001 and 2015. He was an associate editor of the SPE Reservoir Evaluation and Engineering between 2007 and 2013. He is currently an editorial board member in Computers & Geosciences. Dr Akin served in several SPE committees including Education and Accreditation, STAR Award and International Faculty Award committees.
Additional affiliations
January 2006 - June 2006
Stanford University
Position
  • Blaustein Visiting Professor
July 2005 - August 2005
Bulgarian Academy of Sciences
Position
  • Professor
June 2004 - July 2004
French National Centre for Scientific Research
Position
  • Professor

Publications

Publications (161)
Article
Full-text available
Imaging the distribution of porosity, permeability, and fluid phases is important to understanding single and multiphase flow characteristics of porous media: X-ray computed tomography (CT) has emerged as an important and powerful tool for non-destructive imaging because it is relatively easy to apply, can offer fine spatial resolution and is adapt...
Article
Full-text available
Although there are a number of mathematical modeling studies for carbon dioxide (CO2) injection into aquifer formations, experimental studies are limited and most studies focus on injection into sandstone reservoirs as opposed to carbonate ones. This study presents the results of computerized tomography (CT) monitored laboratory experiments to anal...
Article
A systematic investigation of fluid flow characteristics within diatomite (a high porosity, low permeability, siliceous rock) is reported. Using an X-ray computerized tomography (CT) scanner, and a novel, CT-compatible imbibition cell, we study spontaneous cocurrent water imbibition into diatomite samples. Air–water and oil–water systems are used a...
Technical Report
Full-text available
Turkey has a good potential for geothermal power production. Geothermal sources in Turkey are characterised by a relatively high and continuous CO2 release, which results in high carbon intensity of the energy produced in geothermal power plants. To reduce the direct CO2 emissions from this geothermal capacity and reduce the climate impact there is...
Conference Paper
Full-text available
Tracer tests are commonly carried out in geothermal fields in order to model certain parameters of the reservoir part between the production and injection wells and to predict the response of the reservoir to production. To obtain meaningful data in wells with weak hydraulic connection to each other, tracer tests need to be performed over long peri...
Conference Paper
Full-text available
Predictive modeling of flow and transport processes in geothermal reservoirs is difficult due to the complex nature of fracture networks. Tracer tests are traditionally used to characterize geothermal reservoirs for sustainable injection and production strategies. Interpretation of tracer tests to obtain accurate flow parameters is usually carried...
Article
Interpretation of tracer tests in geothermal reservoirs is carried out by fitting the measured data either with simplified two-dimensional (2-D) analytical solutions or with complex numerical models. Available analytical solutions commonly only describe isotropic conditions in 1-D or 2-D, which is generally unsatisfactory to construct realistic res...
Conference Paper
Accurate estimation of annular friction pressure loss is necessary to perform drilling and well completion operations without lost circulation, pipe sticking or more serious well control problems. Determination of friction pressure loss for Newtonian and non-Newtonian fluids has been investigated in several experimental and theoretical works by con...
Conference Paper
Full-text available
Directional drilling in naturally fractured geothermal reservoirs is a challenging task due to unexpected changes in inclination and azimuth of the well axis, which cause inefficient weight on bit transfer, decrease in penetration rate, increasing the risk of stuck pipe and problems while running casings. To predict the sudden changes in inclinatio...
Article
The aim of this work is to examine and estimate the ultimate recovery from Turkey's largest oil reserve (1.85 billion barrels) utilizing a new approach called mining-assisted heavy oil production (MAHOP) and conventional steam injection horizontal production (CSHP) method. In MAHOP, declines (tunnels) are excavated from the surface to the reservoir...
Article
Geothermal energy is commonly recognized as an environmentally friendly source of energy. However, geothermal fluids have unusually high CO2 content, particularly, in carbonated geothermal reservoirs. An efficient method to mitigate the CO2 emissions of geothermal power plants is to re-inject the captured CO2 with the effluent fluid to mineralize m...
Article
Full-text available
Turkey began tapping its hightemperature geothermal resources to generate electricity in 1984, and geothermal energy remains an important option in the country’s clean energy transition. At the time of commissioning, CO2 emission factors from Turkish geothermal plants have been measured in the 400 to 1,300 g/kWh range, significantly higher than the...
Conference Paper
Full-text available
Typically, geothermal wellbore model is used to predict the production performance of wells using a wellbore simulator based on flow tests. An iterative procedure is used to calibrate NCG content. In this study, a predictive modelling approach harnessing the power of machine learning is proposed. Several deep well data in Kizildere Geothermal Field...
Article
Full-text available
An experimental and numerical study was carried out to investigate matrix-fracture thermal transport in fractured rock. Two different synthetically fractured core plugs were used during the flow-through experiments while core plugs’ outer surface was maintained at two different constant temperatures. To investigate the matrix-fracture thermal trans...
Article
The shape-factor concept provides an elegant and powerful upscaling method for fractured reservoir simulation. Many different shape-factors, among which the well-known Warren and Root, and Kazemi shape-factors have been proposed in the past. Since different shape-factors can lead to totally different reservoir behavior, selection of the appropriate...
Conference Paper
Reinjection of gas free of brine into the peripheries of a geothermal reservoir may gradually decline non-condensable gas (NCG) concentration in the reservoir fluid during the operation of geothermal power plants. As a result, gradually decreasing gas emissions can be observed. In this study, we use separator data to calculate produced CO2 amount i...
Conference Paper
Full-text available
Geothermal fields in Turkey have substantially higher carbon dioxide content compared to a typical geothermal field in the world. Geothermal Emission Control (GECO) project aims to reduce carbon emissions by reinjecting produced carbon dioxide from a pilot reinjection well. A high-resolution CO2 flux meter is used to measure the surface carbon diox...
Article
Alaşehir geothermal area located in Alaşehir Graben, West Anatolia, is the latest target for geothermal field development in Turkey. Seven different operators are developing the power capacity in this geothermal field on a strictly competitive and largely confidential basis without the significant exchange of resource information among them. Curren...
Conference Paper
Full-text available
Due to the attractive feed-in-tariff mechanism, Turkish geothermal producers operate geothermal power plants at their maximum capacity. As a result, many geothermal reservoirs in Turkey have been exploited with an aggressive production strategy by multiple operators. A significant amount of production targeted natural fractures associated with norm...
Article
Estimating reservoir pressure and temperature is one of the challenges of geothermal reservoir engineering. A new proxy model has been developed to estimate reservoir pressure and temperature using wellhead pressure, temperature and non-condensable gas (NCG) amount. An exhaustive set of wellhead data covering a range of possible wellhead pressure,...
Poster
Full-text available
The result of our full-field model of Kızıldere Geothermal Field, Turkey, and workflow and preliminary results of the reactive transport modeling of CO2 injection into the field with TOUGHREACT.
Conference Paper
Full-text available
Use of a comprehensive reservoir simulation is essential for an effective geothermal reservoir management. TOUGH2 has become a widely used simulator for this purpose. In this study, one of the most exploited geothermal fields in Turkey, Alaşehir geothermal field has been modeled by using TOUGH2 reservoir simulator. The study includes more than 100...
Conference Paper
Full-text available
Emissions of greenhouse gases such as CO2 emitted at Turkish geothermal power plants are an obstacle to call geothermal energy as green power. However, recent advances in carbon capture and storage technologies have enabled low emissions by re-injecting produced CO2. The phase of injected CO2 is crucial for the success and safety of the operation....
Article
Re-injection, the key factor in the success or failure of a geothermal field, is an integral part of any geothermal field development. Modified Hall integral - derivative plot and Hearn plot are analytical injection surveillance methods that may be used to identify sub-par injection behavior due to problems such as scaling. Plotting injection volum...
Conference Paper
Full-text available
The Umurlu geothermal reservoir located in Buyuk Menderes Graben, Turkey initially contained around 2% by weight CO2 dissolved in geothermal reservoir fluid. The produced CO2 rate declined over one year of production time due to dilution of reservoir gas by degassed injectate. Since CO2 has a considerable role on Umurlu reservoir performance and en...
Conference Paper
Full-text available
Germencik Geothermal Field, which is one of the oldest high enthalpy geothermal fields in Turkey, is operational since 2009. As of 2017, two 47.4 MWe dual flash and four 22.5 MWe binary power plants have been constructed to exploit liquid dominated reservoir with feed zone temperatures as high as 234C. In order to optimize re-injection a tracer te...
Conference Paper
Full-text available
Alaşehir geothermal area that is located in southern part of the Alaşehir Graben is one the important geothermal areas in Turkey. Currently, more than 6 operators are exploiting this field on a strictly competitive, and largely confidential, basis without significant exchange of resource information among them. This paper discusses monitoring of th...
Conference Paper
Full-text available
Tracer testing of flow between injection and production wells is an effective tool to map fluid flow pathways in a geothermal reservoir. Tracer concentration curves can be used to provide insight into projected thermal drawdown in the reservoir or thermal breakthrough of re-injected fluids, estimating inter-well volumes and flow geometries. Althoug...
Conference Paper
Accurate numerical modeling of surge and swab pressures in concentric annuli is proposed. The numerical scheme is developed for the laminar flow occurring during the drillstring axial movement. The model incorporates Yield Power Law (YPL) fluids, which is a good representation of the most of the drilling fluids. A commercial computational fluid dyn...
Article
Full-text available
In this paper, the direct liquefaction of Turkish Niǧde-Ulukışla oil shale in noncatalytic and catalytic conditions was studied. The effects of pressure, tetralin/oil shale ratio, catalyst type and concentration, reaction time and temperature and oil shale/waste paper ratio on the process were investigated. It was found that tetralin/oil shale rati...
Conference Paper
CO2 emissions can be reduced by storing it in underground geologic formations such as coal seams, mature or depleted hydrocarbon reservoirs and deep saline aquifers. The combination of carbon dioxide enhanced oil recovery and permanent CO2 storage in mature oil reservoirs has the advantage to project economics. In this research, CO2 storage capacit...
Article
The combination of carbon dioxide enhanced oil recovery (CO2-EOR) and permanent CO2 storage in mature oil reservoirs has the potential to provide a critical near-term solution for reducing greenhouse gas (GHG) emissions. This solution involves the combined application of carbon capture and storage from power generation and other industrial faciliti...
Presentation
Full-text available
Presented at International Geothermal Conference İzmir 2017
Conference Paper
Full-text available
Alaşehir geothermal area located in Alaşehir Graben, West Anatolia – Turkey is the current target for geothermal field development. Currently, more than 6 operators are developing the power capacity in this field on a strictly competitive, and largely confidential, basis without significant exchange of resource information among them. Although ther...
Conference Paper
Reservoir parameters from the well test data are essential for reservoir management. Especially the identification the presence of the reservoir boundaries is important for an appraisal well testing. Providing reserve estimation, identifying new well locations and well placement and avoiding dry holes are some important outcomes. However more work...
Conference Paper
Full-text available
Jeotermal sahalarda jeotermal potansiyel hesaplanırken rezervuar hacmi en önemli parametrelerden biridir. Doğru bir rezervuar hacmi için gözeneklilik değeri ve dağılımının bilinmesi gerekir. Batı Anadolu’da bulunan jeotermal rezervuarlar çatlaklı sistemlerden oluşmaktadır. Bu tip sistemlerde depolama ve akış doğal çatlak ağı içinde olmaktadır. Ç...
Conference Paper
Full-text available
Alaşehir geothermal field located in Alaşehir Graben, West Anatolia – Turkey is the current target for geothermal field development. Several wells drilled in Alasehir geothermal reservoir were below expectations. Static and dynamic pressure – temperature, pressure transient tests and a short term flow test were conducted to characterize the problem...
Conference Paper
Full-text available
Conventional interference tests conducted in geothermal reservoirs are used to assess bulk transmissivities and storativities as well as the productivity and size of a geothermal reservoir. Hydrological heterogeneities such as no-flow and pressure support boundaries can also be identified using such tests. In a typical interference test a pressure...
Conference Paper
Full-text available
The heterogeneous nature of oil shale resources associated to the depositional environments, lithology, and organic content make the reserve estimation complex and unpredictable. However, comprehensive laboratory studies on organic rich shale samples collected from different regions can increase the understanding about the organic content of oil sh...
Conference Paper
The heterogeneous nature of oil shale resources associated to the depositional environments, lithology, and organic content make the reserve estimation complex and unpredictable. However, comprehensive laboratory studies on organic rich shale samples collected from different regions can increase the understanding about the organic content of oil sh...
Chapter
Aiming at analyzing the impact of Training Image (TI) uncertainty on simulated reservoir models; this study presents a novel approach for parameterizing channelized TIs. First, the channel structure is represented mathematically in two dimensions (2D) with a Sine function. Then, the parameters of the function (i.e. amplitude and phase) and the numb...
Article
Full-text available
Conventional EOR methods like steam-injection are usually not cost effective for deep wells and wells producing from thin pay zones, due to excessive heat loss to the overburden. For such wells minimizing heat losses can be achieved by using microwave heating assisted gravity drainage. In this study, the feasibility of this method was investigated....
Conference Paper
Full-text available
Knowing locations, distributions and apertures of fractures crossing a geothermal well is of vital importance in order to minimize costs and increase efficiency of drilling. Complete or small losses of drilling fluid flowing from wellbore to the surrounding formations have been used to identify fracture zones in the past. An analytical model based...
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
CO2 injection into deep saline aquifers is a preferred method for mitigating CO2 emission. Although deep saline aquifers are found in many sedimentary basins and provide very large storage capacities, several numerical simulations are needed before injection to determine the storage capacity of an aquifer. Since numerical simulations are expensive...
Article
Full-text available
Matrix–fracture transfer functions are the backbone of any dual-porosity or dual-permeability formulation. The chief feature within them is the accurate definition of shape factors. To date, there is no completely accepted formulation of a matrix–fracture transfer function. Many formulations of shape factors for instantly-filled fractures with unif...
Article
This research proposes a framework for determining the optimum location of an injection well using an inference method, artificial neural networks and a search algorithm to create a search space and locate the global maxima. A complex carbonate geothermal reservoir (Kizildere Geothermal field, Turkey) production history is used to evaluate the prop...
Article
Full-text available
Electrical heating for heavy-oil recovery is not a new idea, but the commercialization and wider application of this technique require detailed analyses to determine optimal application conditions. In this study, applicability of electrical heating for heavy-oil recovery from two heavy-oil fields in Turkey (Bati Raman and Camurlu) was tested numeri...
Article
Conventional enhanced oil recovery (EOR) methods, such as steam injection, are usually not cost-effective for deep wells and wells produced from thin pay zones, because of excessive heat loss to the overburden. For such wells, minimizing heat losses can be achieved using microwave heating. In this study, the feasibility of this method was investiga...
Article
The effect of microwave irradiation on the recovery of three different oil shale samples was studied. To enhance the microwave efficiency, three different iron powders (Fe, Fe2O3, and FeCl3) and their three different doses (0.1, 0.5, and 1% by weight, each) were added to the samples as microwave receptors. The doses of each receptor were optimized...
Article
Steam injection in naturally fractured formations has drawn considerable interest recently. It is believed that the steam or water heats the rock, which then undergoes a thermally induced wettability reversal. Hot water can then spontaneously imbibe into the water wet rock matrix, resulting in favorable oil recoveries. In this study, the applicabil...
Article
Full-text available
The vapour extraction process, or ‘ VAPEX’ has attracted a great deal of attention in recent years as a new method of heavy oil or bitumen recovery. The VAPEX (vapour extraction) can be visualized as energy efficient recovery process for unlocking the potential of high viscosity resources trapped in bituminous and heavy oil reservoirs. A total of 2...
Article
Full-text available
Electrical heating for heavy-oil recovery is not a new idea but commercialization and wider application of this technique require detailed analyses for determination of optimal application conditions. In this study, applicability of electrical heating for heavy-oil recovery from two heavy-oil fields in Turkey (Bati Raman and Camurlu) was tested exp...
Article
The recovery characteristics of four different oil shale samples were tested experimentally using the retort technique. To accomplish efficient temperature distribution, the thermal conductivity of the oil shale samples was increased by the addition of three different iron powders. The doses of iron powders were optimized for each oil shale sample...
Article
Carbonate reservoirs have more complex structures than silicate reservoirs because of depositional and diagenetic features. Secondary porosity enhancements due to fracturing or dissolution processes result complex porosity systems and thus complex flow patterns. Carbonates may contain not only matrix and fracture but also the vugs and cavities that...
Article
Full-text available
The productivity of most gas condensate wells is reduced significantly due to condensate banking when the bottom-hole pressure falls below the dew point. The liquid drop-out such gas wells leads to reduced gas relative permeability and thus to low recovery problems. An understanding of the characteristics of the high-velocity gas-condensate flow an...
Article
Carbonate reservoirs have more complex structures than silicate reservoirs because of depositional and digenetic features. Secondary porosity enhancements due to fracturing or dissolution processes result complex porosity systems and thus complex flow patterns. Carbonates may contain not only matrix and fracture but also the vugs and cavities that...
Article
A fast and accurate method for distribution of multiphase flow functions across the productive interval of a reservoir volume is proposed. When coupled with artificial neural networks (ANN) to correlate pore-type data (pore size, shape, and roughness) with well log measurements, network modeling is useful to generate relative permeability and capil...
Article
Full-text available
Drilling bit optimization is one of the key concepts in drilling engineering. It is considered as one of the economical factors in an overall well budget. Computers are strictly used as decision-making systems in the optimization calculations. Formation parameters are easily processed according to drilling bit selection criteria by the help of comp...