Day 1 Tue, September 17, 2019最新文献

{"title":"Comparison of Lanczos Decomposition Method LDM and Conventional Implicit Time-Stepping Method ITSM for Numerical Reservoir Simulation","authors":"Koray Yılmaz, T. Calisgan, Melike Dilsiz","doi":"10.2118/196735-ms","DOIUrl":"https://doi.org/10.2118/196735-ms","url":null,"abstract":"\u0000 Reservoir simulations constitute a cornerstone to predict the flow of fluids through porous media. Various numerical models called simulators are developed to simulate the performance of hydrocarbon reservoirs. These models are used in field development since production forecasts are necessary to make investment decisions. Nowadays, numerical simulators are widely used by reservoir engineers.\u0000 In recent times, machine learning applications have garnered the interest of the oil and gas industry due their unorthodox approach to creating complex models. The more historical data that can be provided in the training phase of the computation, the more accurate the predictions utilizing less time and computational power required by the alternative. The alternative, reservoir simulation applications, require more robust hardware for processing large amounts of data in sophisticated ways. This will require several iterations and may require long computation to validate the model. Running time for a simulation is dependent on software, which can be dependent on hardware. This creates a matrix of time and resources needed to complete simple to complicated simulations.\u0000 A few studies have proposed the use of the Lanczos decomposition method in reservoir simulation studies. The attractiveness of this method appears to be the avoidance of time stepping in simulation and allows the computation of reservoir pressures at any given time directly.\u0000 In this study, two new simulators were developed using Lanczos Decomposition Method (LDM) and Conventional Implicit Time-Stepping Method (ITSM). The study focuses on 2-D flow for slightly compressible fluid of constant viscosity with multiple wells. Derivation of the model equations was performed using the continuity equation for both methods through the use of MATLAB. The simulators were written using the MATLAB programming language. The simulators developed in this study are capable of assigning uniform and non-uniform gridblock distribution; porosity and permeability distributions, as well as developing various production and injection scenarios for single or multiple wells depending on different areas of application. Validity and accuracy of the 2D flow simulator were examined by comparing simulation results with that obtained from the commercial software called ECRIN. The results of the simulator were almost identical with the results obtained from the commercial software. During the model runs, the CPU time of the two simulators were compared. A special case was also studied for a single well with variable rate history using both ITSM and LDM written with FORTRAN.\u0000 To date, in petroleum engineering literature, there is no work published that compares the performances (in terms of computational aspects as well as CPU times) of the Lanczos method and the conventional implicit-time stepping method.","PeriodicalId":318637,"journal":{"name":"Day 1 Tue, September 17, 2019","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115220060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of H2S Production Risks in Heterogeneous Reservoirs Using Laboratory-Calibrated Compositional Thermal Reactive Simulations","authors":"Julien Gasser-Dorado, S. Ayache, V. Lamoureux-Var, C. Preux, P. Michel","doi":"10.2118/196644-ms","DOIUrl":"https://doi.org/10.2118/196644-ms","url":null,"abstract":"\u0000 SAGD is commonly used as a thermal EOR method to produce heavy oil. However it suffers from the production of acid gases formed by aquathermolysis chemical reactions that occur between the steam, the sulfur-rich oil and the mineral matrix. The objectives of this paper are to take advantage of a comprehensive chemical model coupled to compositional thermal reservoir simulations to predict and understand the H2S production variation at surface according to the type of reservoir.\u0000 Thermal reservoir simulations coupled to both a SARA based 10-component / 5-reaction chemical model fully calibrated against laboratory data and a compositional PVT are used to simulate SAGD processes on heavy oil fields in Athabasca, Canada. Numerical results are then analyzed to provide a comprehensive analysis of the mechanisms leading to in-situ H2S generation and its production at wellheads based on compositional thermal simulations coupled to a fully laboratory calibrated SARA-based chemical model. Composition of the pre-steam, post-steam and produced oil are compared to understand the effect of the aquathermolysis reactions. The impact of heterogeneities on H2S production both in-situ and at surface can also be observed and explained, especially the variations in vertical permeability. Then simple reservoir models with two facies are used to further understand the impact of heterogeneities on H2S production at surface. Overall heterogeneous cases show important changes in the temperature distribution, fluid flows, reactions kinetics and steam chamber shape that lead to H2S production variations at surface. This detailed description of the involved mechanisms in acid gases production will allow operators to better forecast their H2S risks according to their reservoir properties.","PeriodicalId":318637,"journal":{"name":"Day 1 Tue, September 17, 2019","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128558341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of Non-Equilibrium Phase Behavior of Hydrocarbons for Modeling Oil and Gas Fields with Gas Injection","authors":"F. Al-Jenaibi, K. Bogachev, S. Milyutin, S. Zemtsov, E. Gusarov, Maksim Kuzevanov, I. Indrupskiy","doi":"10.2118/196633-ms","DOIUrl":"https://doi.org/10.2118/196633-ms","url":null,"abstract":"\u0000 This paper deals with the issues related to the modeling of non-equilibrium phase transition in isothermal compositional models. Based on a real case of oil and gas field in the Middle East, the importance to take into account the effects of thermodynamic non-equilibrium are demonstrated with the help of mathematical models proposed earlier.\u0000 Theoretical and experimental studies, as well as actual field development data, show that not all phase transition processes take place in the forward and reverse directions at the same rate. For example, the dissolution of gas is much slower than the gas liberation from oil. Non-equilibrium processes are those whose characteristic time is comparable to or exceeding the characteristic time of variation of external conditions. In the classical formulation, it is supposed that thermodynamic processes are equilibrium, but the effect of non-equilibrium in addition to large grid cell sizes of the dynamic model and small-time steps can significantly affect the simulation results. In the case of black oil models, there are extensions of the mathematical model that are often used to describe the non-equilibrium behavior. At the moment, the rate of establishment of thermodynamic equilibrium is not taken into account in the majority of compositional models, the neglection of which in some cases might question the reliability of the simulation results. The practical implementation of the ideas (Indrupskiy et al, 2017), which were stated about how to take into account the non-equilibrium of thermodynamic processes occurring in the reservoir for compositional models, is performed.\u0000 The paper presents the results of modeling gas and water injection as a method of pressure support after development under depletion. In the equilibrium approach gas dissolves in oil at gas-oil contact simultaneously with increasing pressure. In practice, gas dissolution in oil occurs extremely slowly, and the dissolution rate decreases as the pressure approach the saturation pressure of the oil. According to laboratory studies, the modeling of such phase transitions requires the implementation of non-equilibrium models. At the same time, usage of the equilibrium models for this type of field leads to dramatic errors in estimates of the oil recovery.","PeriodicalId":318637,"journal":{"name":"Day 1 Tue, September 17, 2019","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131656204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of CO2-EOR Project for an Oil Field in Abu Dhabi, UAE Based on Industry Best Practices","authors":"M. Chirkov, Matthew Kent Coughlin, Wuilmer Jose Ponte Pineda","doi":"10.2118/196660-ms","DOIUrl":"https://doi.org/10.2118/196660-ms","url":null,"abstract":"\u0000 Enhanced oil recovery (\"EOR\") by means of CO2 injection has become a globally-used method of increasing oil recovery. Interest in the UAE has increased in recent years due to the proven effectiveness of the process, and due also to government plans to initiate a world-class CO2 capture campaign.\u0000 EOR by means of CO2 injection is associated with many challenges. The majority of EOR projects are conducted in onshore fields since offshore EOR experience is limited by technical and operational challenges, as well as by higher economic hurdles. A larger resource base is required to justify an offshore EOR project than a project that is located onshore. Apart from that, the decision to embark on a CO2 injection project is often complicated by the lack of multidisciplinary integration. Uncertainty analysis should be included in the evaluation since it is critical to understanding pilot objectives, identifying model limitations, proper scaling of results from the pilot area to the field, and managing expectations. The economics of the proposed project are strongly dependent on proper baseline definition – possible only by means of advanced methods of reservoir characterization – and by state-of-the-art methods of dynamic reservoir simulation using a fully-compositional model and robust equations of state to characterize the process physics.\u0000 The oilfield discussed in this paper is a digital multi-reservoir field being developed by horizontal and highly-deviated wells equipped by inflow control devices (ICD). Primary depletion will be augmented by reservoir-specific water injection and hydrocarbon gas injection. Field characterization is being done based on data from comprehensive open- and cased-hole log suites, seismic data, MDT runs, PTA, and an array of SCAL and PVT tests necessary to fully describe the process physics.\u0000 The purpose of this paper is to describe the workflow and methods used to design, and estimate the efficiency of a CO2 injection project for a carbonate reservoir complex in the offshore area of the UAE. Recommendations for pilot project and surveillance program designs based on best practices and lessons learned from prior projects, developed to overcome the challenges described above, are discussed.","PeriodicalId":318637,"journal":{"name":"Day 1 Tue, September 17, 2019","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129032995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}