Search for: well-testing
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    Estimating the properties of naturally fractured reservoirs using rate transient decline curve analysis

    , Article Journal of Earth Science ; Volume 28, Issue 5 , 2017 , Pages 848-856 ; 1674487X (ISSN) Daryasafar, A ; Joukar, M ; Fathinasab, M ; Da Prat, G ; Kharrat, R ; Sharif University of Technology
    Transient rate decline curve analysis for constant pressure production is presented in this paper for a naturally fractured reservoir. This approach is based on exponential and constant bottom-hole pressure solution. Based on this method, when ln (flow rate) is plotted versus time, two straight lines are obtained which can be used for estimating different parameters of a naturally fractured reservoir. Parameters such as storage capacity ratio (ω), reservoir drainage area (A), reservoir shape factor (CA), fracture permeability (kf), interporosity flow parameter (λ) and the other parameters can be determined by this approach. The equations are based on a model originally presented by Warren... 

    A combined wavelet transform and recurrent neural networks scheme for identification of hydrocarbon reservoir systems from well testing signals

    , Article Journal of Energy Resources Technology, Transactions of the ASME ; Volume 143, Issue 1 , 2021 ; 01950738 (ISSN) Moghimihanjani, M ; Vaferi, B ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2021
    Oil and gas are likely the most important sources for producing heat and energy in both domestic and industrial applications. Hydrocarbon reservoirs that contain these fuels are required to be characterized to exploit the maximum amount of their fluids. Well testing analysis is a valuable tool for the characterization of hydrocarbon reservoirs. Handling and analysis of long-term and noise-contaminated well testing signals using the traditional methods is a challenging task. Therefore, in this study, a novel paradigm that combines wavelet transform (WT) and recurrent neural networks (RNN) is proposed for analyzing the long-term well testing signals. The WT not only reduces the dimension of... 

    Application Of Artificial Intelligence In Well Test Data Interpretation

    , M.Sc. Thesis Sharif University of Technology Salim Mehr, Mahdi (Author) ; Masihi, Mohsen (Supervisor) ; Shadizadeh, Reza (Supervisor)
    Well-Testing is a one of the usual methods in petroleum engineering for evaluating reservoir and well parameters. This method is based on measuring downhole pressure verses time in different production conditions and then drawing these data in different pressure-time graphs and evaluating reservoir characteristics and calculating reservoir parameters. This thesis describes the development of techniques for the automation of the model identification and parameter estimation of a well test interpretation, using Artificial Intelligence. The computer programs which are written in MATLAB software use Neutral Network toolbox to detect a model that is based on the pressure derivative curve, and... 

    Analysis of well testing results for single phase flow in reservoirs with percolation structure

    , Article Oil and Gas Science and Technology ; Volume 76 , 2021 ; 12944475 (ISSN) Shahrian, E ; Masihi, M ; Sharif University of Technology
    Editions Technip  2021
    Constructing an accurate geological model of the reservoir is a preliminary to make any reliable prediction of a reservoir's performance. Afterward, one needs to simulate the flow to predict the reservoir's dynamic behaviour. This process usually is associated with high computational costs. Therefore, alternative methods such as the percolation approach for rapid estimation of reservoir efficiency are quite desirable. This study tries to address the Well Testing (WT) interpretation of heterogeneous reservoirs, constructed from two extreme permeabilities, 0 and K. In particular, we simulated a drawdown test on typical site percolation mediums, occupied to fraction "p"at a constant rate Q/h,... 

    Pressure Transient Analysis of Variable-rate Well Test Data

    , Ph.D. Dissertation Sharif University of Technology Mansoori Habib Abadi, Mehdi (Author) ; Rashtchian, Davood (Supervisor) ; Van den Hof, Paul (Supervisor) ; Jansen, Jan Dirk (Supervisor)
    This study presents a novel perspective on pressure-transient analysis (PTA) of downhole-pressure and flow-rate data by use of system-identification (SI) techniques as widely used in advanced process engineering. Key features of the algorithm are that it considers the classic PTA process from a system-theoretical perspective; derives the causal structure of the flow dynamics; proposes a method to deal with continuously varying pressure and flow-rate signals contaminated with correlated noise, which estimates physical reservoir parameters through a systematic matching procedure in the frequency domain; and can cope with arbitrary (i.e., not necessarily piecewise constant) flow-rate signals.... 

    Pressure Response Analysis of Naturally Fractured Condensate Reservoirs Regarding the Effect of Permeability Anisotropy

    , M.Sc. Thesis Sharif University of Technology Haji Seyedi, Hamed (Author) ; Jamshidi, Saied (Supervisor) ; Masihi, Mohsen (Co-Advisor)
    Producing from Gas Condensate Reservoirs under dew point pressure and at constant temperature may have a complex behavior because of existing two phase system and liquid around the well. Zones with different mobility generate as a zone away from the well containing only gas, a zone having liquid around the well and finally a zone with capillary effect. Existence of condensate around well reduces gas relative permeability and as a result productivity index of well decreases. In fact these condensate acts like an additional skin and because of some complex processes, investigating of these behaviors can be difficult.
    Well testing analysis in Natural Fractured reservoir is generally based... 

    The application of numerical Laplace inversion methods for type curve development in well testing: A comparative study

    , Article Petroleum Science and Technology ; Volume 29, Issue 7 , 2011 , Pages 695-707 ; 10916466 (ISSN) Mashayekhizadeh, V ; Dejam, M ; Ghazanfari, M. H ; Sharif University of Technology
    In this work the Fourier series and Zakian and Schapery methods are considered to numerically solve the Laplace transform of a pressure distribution equation for radial flow and to generate the type curves for three different boundary conditions. The results show that the Schapery method leads to approximate solutions for small values of dimensionless time. For large values, however, this method is almost accurate and hence is recommended because it is fast to apply compared to other algorithms. It has been found that the accuracy of the Schapery method for early time prediction can be improved to almost a perfect match with analytical results through multiplying the Schapery relation by a... 

    Perturbative algorithm for rotational decoherence

    , Article Physical Review A ; Volume 103, Issue 3 , 2021 ; 24699926 (ISSN) Carlesso, M ; Naeij, H.R ; Bassi, A ; Sharif University of Technology
    American Physical Society  2021
    Recent advances in levitated optomechanics provide new perspectives for the use of rotational degrees of freedom for the development of quantum technologies as well as for testing fundamental physics. As for the translational case, their use, especially in the quantum regime, is limited by environmental noises, the characterization of which is fundamental in order to assess, control, and minimize their effect, in particular decoherence. Here, we present a general perturbative approach to compute decoherence for a quantum system in a superposition of its rotational degrees of freedom. The specific cases of the dipole-dipole and quadrupole-quadrupole interactions are solved explicitly, and we... 

    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) Dashti, R ; Bagheri, M. B ; Ulhaq, S ; Sharif University of Technology
    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... 

    A new method in well test interpretation using temperature transient analysis for gas wells

    , Article International Petroleum Technology Conference 2007, IPTC 2007, Dubai, 4 December 2007 through 6 December 2007 ; Volume 2 , 2007 , Pages 1151-1160 ; 9781615673360 (ISBN) Bahrami, H ; Siavoshi, J ; Sharif University of Technology
    Society of Petroleum Engineers  2007
    Interpretation of temperature logs has been done successfully in wells to identify water or gas entries location, detect casing leaks, and evaluate cement placement. This paper shows how knowledge of the Joule-Thomson cooling effect and frictional heating effect can be applied for well test interpretation. Many analysts rely on pressure derivative curve to diagnose wellbore storage period and radial flow regime on pressure transient data. However, there are field examples that flow regimes can't be accurately determined. During transient tests, both pressure and temperature are changed depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating... 

    Reservoir Characterization and Parameter Estimation Using Ensemble Kalman Filter

    , M.Sc. Thesis Sharif University of Technology Ebrahimkhani, Mohammad Javad (Author) ; Pishvaei, Mahmood Reza (Supervisor) ; Bozorgmehri Boozarjmehri, Ramin (Supervisor)
    Management decisions, enhanced oil recovery, and reservoir development plans in petroleum industries are based on predictions by reservoir simulation. Due to uncertainties in model parameters or engineering assumptions, the simulation results are not accurate, while they are correct. For more accurate estimation of unknown production quantities, it is required to characterize the unknown parameters and its uncertainty. By using static data alone the result of characterization is unreliable and unsure, therefore dynamic data use practically. In reservoir engineering literature, this is called “History Matching”.The ensemble Kalman filter is an optimal recursive data processing algorithm based... 

    Multi-Resolution Denoising of Well Test Data

    , Ph.D. Dissertation Sharif University of Technology Khadivi, Kourosh (Author) ; Soltanieh, Mohammad (Supervisor) ; Farhadpour, Farhad Ali (Co-Advisor)
    Permanent Downhole Gauge (PDG) has been employed since 1990s to acquire more information and better access to well and control production. PDG provides huge amount of pressure transient data during well test operation and production. However, such data are encountering with various noise and outliers. The noise and outliers can cause misleading and misinterpretation results. Therefore, denoising and outlier removal are two imperative steps before pressure transient analysis. The conventional denoising methods are mostly based on wavelet thresholding methods that preserve mean of data and have good performance when noise distribution is Gaussian distribution. However, noise distribution... 

    Wel Test Analysis Using Deconvolution Method in Naturally Fractured

    , M.Sc. Thesis Sharif University of Technology Soleimani, Payam (Author) ; Taghikhani, Vahid (Supervisor) ; Shadizadeh, Seyed Reza (Supervisor) ; Jamshidi, Saeid (Co-Advisor)
    Wellbore storage effect is one of the biggest problems of petroleum engineers in analyzing the reservoir properties. In this phenomenon, at the beginning time of production from a reservoir, the fluid is initially produced from the well and not from the reservoir. Due to this effect, the pressures are distorted and could not be used in reservoir analysis. In this thesis the wellbore storage effect would be removed in naturally fractured reservoirs using deconvolution method. Using this method the range of data used could be increased. In this method special techniques are used in order to determine reservoir behaviour.
    Using the method presented in this thesis, petroleum engineers could... 

    Optimization of gas allocation to a group of wells in gas lift in one of the Iranian oil fields using an efficient hybrid genetic algorithm (HGA)

    , Article Petroleum Science and Technology ; Volume 31, Issue 9 , 2013 , Pages 949-959 ; 10916466 (ISSN) Ghaedi, M ; Ghotbi, C ; Aminshahidy, B ; Sharif University of Technology
    A hybrid genetic algorithm (HGA) was introduced to allocate optimum amount of gas. This method was applied to a group of wells in gas lift in the case of availability limited amount of gas. For testing the ability of the proposed HGA, the results of this work with those of previous works in a field with six wells were compared. Then for an Iranian southern west oil field with nine wells, gas allocation is performed using different amount of available gas. The results show that the introduced method (HGA) is very efficient tool in gas allocation issue  

    Application of a mathematical method in calculation of the skin variation during a real field acidizing operation

    , Article Chemical Engineering Science ; Volume 192 , 2018 , Pages 829-839 ; 00092509 (ISSN) Shabani, A ; Jamshidi, S ; Jahangiri, H. R ; Sharif University of Technology
    Elsevier Ltd  2018
    The efficiency of an acidizing operation is usually assessed through ordinary well testing methods. These methods are performed only after the acidizing operation, and it is difficult to monitor and evaluate real-time efficiency of acidizing operation. Understanding the performance of the acidizing during the service, by analysis of the acidizing data is a viable approach to this costly and challenging process. The estimation of the skin changes needs an appropriate mathematical method that can handle the main aspects of an acidizing operation. It is tedious to model a real acidizing operation due to the heterogeneity of the reservoir, an unknown reaction rate of acid in reservoir condition,... 

    Possible pitfalls in pressure transient analysis: Effect of adjacent wells

    , Article Journal of Petroleum Exploration and Production Technology ; Volume 9, Issue 4 , 2019 , Pages 3023-3038 ; 21900558 (ISSN) Mirzaalian Dastjerdi, A ; Eyvazi Farab, A ; Sharifi, M ; Sharif University of Technology
    Springer Verlag  2019
    Abstract: Well testing is one of the important methods to provide information about the reservoir heterogeneity and boundary limits by analyzing reservoir dynamic responses. Despite the significance of well testing data, misinterpreted data can lead us to a wrong reservoir performance prediction. In this study, we focus on cases ignoring the adjacent well’s production history, which may lead to misinterpretation. The analysis was conducted on both homogeneous and naturally fractured reservoirs in infinite-acting and finite-acting conditions. The model includes two wells: one is “tested well” and the other is “adjacent one.” By studying different scenarios and focusing on derivative plots, it... 

    Mixed oxide nanotubes in nanomedicine: A dead-end or a bridge to the future?

    , Article Ceramics International ; Volume 47, Issue 3 , 2021 , Pages 2917-2948 ; 02728842 (ISSN) Sarraf, M ; Nasiri Tabrizi, B ; Yeong, C. H ; Madaah Hosseini, H. R ; Saber-Samandari, S ; Basirun, W. J ; Tsuzuki, T ; Sharif University of Technology
    Elsevier Ltd  2021
    Nanomedicine has seen a significant rise in the development of new research tools and clinically functional devices. In this regard, significant advances and new commercial applications are expected in the pharmaceutical and orthopedic industries. For advanced orthopedic implant technologies, appropriate nanoscale surface modifications are highly effective strategies and are widely studied in the literature for improving implant performance. It is well-established that implants with nanotubular surfaces show a drastic improvement in new bone creation and gene expression compared to implants without nanotopography. Nevertheless, the scientific and clinical understanding of mixed oxide... 

    Application of temperature transient analysis for welltest interpretation and well productivity evaluation

    , Article Society of Petroleum Engineers - SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, Indonesia,October 30–November 1, 2007 ; 2007 ; 9781613990407 (ISBN) Bahrami, N ; Siavoshi, J ; Sharif University of Technology
    During transient tests, both pressure and temperature are changed depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating effects are the main dynamic factors causing flowing bottomhole temperature to differ from the static formation temperature at that depth. When a gas well is shut in, JT cooling effect is vanished and this causes a sharp increase in sandface temperature. As effect of wellbore storage ends, wellbore temperature gradually cools down due to heat conduction with near wellbore region. This paper demonstrates a new technique for using temperature transient data in gas wells in order to determine end of wellbore storage. Also, effect... 

    Monitoring the influence of dispersed nano-particles on oil-water relative permeability hysteresis

    , Article Journal of Petroleum Science and Engineering ; Vol. 124, issue , December , 2014 , p. 222-231 ; ISSN: 09204105 Parvazdavani, M ; Masihi, M ; Ghazanfari, M. H ; Sharif University of Technology
    In recent years, polysilicon nanoparticles are used to enhance the oil recovery through the water injection process in oilfields. The contributing mechanisms are the reduction of interfacial tension and wettability alteration which lead to improving or decreasing the oil phase relative permeability and can be traced by change of relative permeability curves. However, profound understanding of the effect of dispersed nano-silica particles on the hysteretic behavior of relative permeability curves remains a controversy topic in the literature.The current study illustrates the influence of dispersed silica particles on hysteretic trend of two-phase curves of oil-water relative permeability.... 

    Simultaneous calculation of pore size distribution, capillary pressure, and relative permeability from injection-fall off-production test data

    , Article Special Topics and Reviews in Porous Media ; Vol. 5, issue. 1 , 2014 , p. 41-51 Keshavarzi, B ; Jamshidi, S ; Salehi, S ; Sharif University of Technology
    This work concerns simultaneous determination of relative permeability, capillary pressure, pore size distribution (PSD), and residual oil saturation data by optimization of well testing data, and introduces a new capillary pressure relationship, based on the Weibull distribution function, for direct determination of the PSD function from capillary pressure parameters. Three consecutive injection, fall off, and production well tests are performed on a predefined synthetic reservoir through simulation, and an optimization algorithm is used to find the parameters of relative permeability and capillary pressure curves as well as the value of residual oil saturation. The PSD function is also...