Day 2 Thu, April 11, 2019最新文献

{"title":"Quasi-K-Orthogonal Grid Generation","authors":"S. Manzoor, M. Edwards, A. Dogru","doi":"10.2118/193927-MS","DOIUrl":"https://doi.org/10.2118/193927-MS","url":null,"abstract":"\u0000 Quasi K-orthogonal grid generation is presented, to improve grid quality and method stability with respect to flux approximation in the presence of strongly anisotropic full-tensor permeability fields.K-orthogonal grid generation is only possible for low anisotropy ratios. Quasi K-orthogonal grid generation involves satisfying the K-orthogonal condition approximately, resulting in grids that place less demand on an approximation with respect to stability conditions, and therefore improve grid quality with respect to flux approximation in the presence of anisotropic permeability fields. The method employed enables Delaunay grid generation principles to be employed in a locally transformed system according to local permeability tensor variation. The resulting method has great flexibility for handling complex geometries and can handle jumps in permeability tensor principal axes orientation and jumps in coefficients and details will be presented. Results are presented that demonstrate the benefit of a quasi K-orthogonal grid. Highly challenging cases involving strong full-tensor permeability fields where control-volume distributed multi-point flux approximation (CVD-MPFA) schemes exceed their stability limits and yield solutions with spurious oscillations when using conventional grids, are solved using the new grid generation method. CVD-MPFA schemes are still required as the grids are only approximately K-orthogonal in such cases, however the schemes retain a discrete maximum principle on the new quasi-K-orthogonal grids and yield well resolved solutions that are free of spurious oscillations. While the two-point flux approximation (TPFA) requires strict K-orthogonality, results using both CVD-MPFA and TPFA will be presented. New Quasi K-orthogonal grid generation methods are presented that satisfy the K-orthogonal condition approximately, resulting in practical grids that restore a discrete maximum principle (stability) for the CVD-MPFA schemes when applied to cases involving general full-tensor permeability fields. Results are presented for a variety of test cases that confirm the validity of the grids.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123855010","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":"Insights into Development and Application of a Reservoir Simulator: A Study on Agile Processes to Enhance Simulator Testing, Benchmarking, and Deployment","authors":"Sarwesh Kumar, M. Talpallikar, E. Valbuena, P. Nguyen, Baskar Velusamy","doi":"10.2118/193903-MS","DOIUrl":"https://doi.org/10.2118/193903-MS","url":null,"abstract":"\u0000 Increased complexity in reservoir models, advanced understanding of fluid flow physics, and improved computational capabilities continuously push E&P companies to improve their reservoir simulation tools and associated workflows. This paper describes a robust framework to handle two critical steps in the development of the integrated simulation workflows: simulator testing and release process to end-users companywide. Selection of benchmark models, coverage of functionalities and stress testing of the simulator, are also discussed.\u0000 Ideally, the simulation results should not change with new versions of the simulation software, but this is hardly the case. With the addition of new features, bug fixes and updates, some of the existing functionalities could behave differently - sometimes an improvement over previous results and at other times, an unintentional side-effect leading to errors. The simulator testing process starts with the automated regression test covering a wide range of features and functionalities, which is evaluated through comprehensive benchmark criteria and metrics for success/failure. Regression tests are followed by different levels of investigation to identify and resolve potential problems within each individual software component, the integrated workflows, or the simulation model itself. The web-based continuous integration tool (to collect code changes and create new builds) along with the automation helped to reduce the turnaround time for identification of issues with any code changes. This also helped to streamline and prioritize the scheduling and investigation of the regression tests based on the criticality of features under development and perform focused testing for user-preferred workflows.\u0000 Due to the increase in operational requirements, reservoir complexities, and the need to share the models with the partners, several types of simulation workflows are in practice within the company, all of which require proper testing before each new release version. Previously, sheer volume and monotonicity of the regression test process caused frequent incidences of human error; therefore, automation has not only reduced those errors but also made quality time available for in-depth analysis of the issues shortlisted by the automated process.\u0000 The paper details the testing and release framework using several real field simulation models, where the automated process resulted in timely resolution of issues, seamless transition to newer version of software/workflows, and reliable results from simulation tools. This framework also facilitated the collaboration and coordination among the cross-functional teams and provided updates on the release status and software changes to ensure a smooth and successful release.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124880662","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":"Investigation of the Correlation Between the Quality of History Matching and that of Forecasting","authors":"A. T. Tinni, P. King","doi":"10.2118/193926-MS","DOIUrl":"https://doi.org/10.2118/193926-MS","url":null,"abstract":"\u0000 The aim of this study is to determine to what extent the quality of a history matched model is a good predictor of future production. The background is the common assumption that the better a model matches the production data is the better it is for forecasting, or, at the very least, it leads to an improved estimate of the uncertainty in future production. We demonstrate that the validity of this assumption depends on the length of the history match period and that of the forecasting period. It also depends on how heterogeneous the reservoir is.\u0000 The correlation between the quality of history match and quality of forecast depends on various factors. For the same level of heterogeneity one of the strongest factors is the water breakthrough time for the base and compared cases.\u0000 Broadly if both the base and compared case have water breakthrough before the end of the history match period then the forecasts are reasonable. However, there appears to be a very rapid transition from a reasonably good history match leading to a good forecast to a moderately good history match leading to a very poor forecast. If water breakthrough has not occurred there is a very poor correlation between the quality of the history match and the quality of the forecast. So, the traditional belief that a good history matched model will also produce a good forecast is not always true.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128379042","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":"Robust Multi-Objective Field Development Optimization for the Mariner Asset","authors":"R. Hanea, O. P. Bjorlykke, Yastoor Hashmi, T. Feng, R. Fonseca","doi":"10.2118/193883-MS","DOIUrl":"https://doi.org/10.2118/193883-MS","url":null,"abstract":"\u0000 In this paper we present our results, challenges and learnings, over a two-year period wherein robust multi-objective optimization was applied at the Mariner asset which is being currently developed. Many different problems were solved with different objectives. These problems were formulated based on the phases of planning and development at the asset. The optimization problems include drilling order and well trajectory optimization as the main objectives with reduction in water cut and reduction of gas production to minimize flaring as secondary objectives. We use the efficient stochastic gradient technique, StoSAG, to achieve optimization incorporating geological and petrophysical uncertainty. For some problems computational limitations introduced challenges while for other problems operational constraints introduced challenges for the optimization.\u0000 Depending on the problems significant increases between 5% and 20% in the expected value of the objective function were achieved. For the multi-objective optimization cases we show that non-trivial optimal strategies are obtained which significantly reduce (40% decrease) gas production with minimal loss (less than 1%) in the economic objective. Our results illustrate the importance of flexible optimizations workflows to achieve results of significant practical value at different stages of the planning and development cycle at an operational asset.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133572549","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":"Reduced-Order Modeling of Coupled Flow-Geomechanics Problems","authors":"Zhaoyang Larry Jin, Timur Garipov, O. Volkov, L. Durlofsky","doi":"10.2118/193863-MS","DOIUrl":"https://doi.org/10.2118/193863-MS","url":null,"abstract":"\u0000 A reduced-order modeling framework is developed and applied to simulate coupled flow-geomechanics problems. The reduced-order model is constructed using POD-TPWL, in which proper orthogonal decomposition (POD), which enables representation of the solution unknowns in a low-dimensional subspace, is combined with tra jectory piecewise linearization (TPWL), where solutions with new sets of well controls are represented via linearization around previously simulated (training) solutions. The over-determined system of equations is pro jected into the lowdimensional subspace using a least-squares Petrov-Galerkin procedure, which has been shown to maintain numerical stability in POD-TPWL models. The states and derivative matrices required by POD-TPWL, generated by an extended version of Stanford's Automatic-Differentiation-based General Purpose Research Simulator, are provided in an offline (pre-processing or training) step. Offline computational requirements correspond to the equivalent of 5-8 full-order simulations, depending on the number of training runs used. Runtime (online) speedups of O(100) or more are typically achieved for new POD-TPWL test-case simulations. The POD-TPWL model is tested extensively for a 2D coupled problem involving oil-water flow and geomechanics. It is shown that POD-TPWL provides predictions of reasonable accuracy, relative to full-order simulations, for well-rate quantities, global pressure and saturation fields, global maximum and minimum principal stress fields, and the Mohr-Coulomb rock failure criterion, for the cases considered. A systematic study of POD-TPWL error is conducted using various training procedures for different levels of perturbation between test and training cases. The use of randomness in the well bottom-hole pressure profiles used in training is shown to be beneficial in terms of POD-TPWL solution accuracy. The procedure is also successfully applied to a prototype 3D example case.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132060348","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 Matrix Acidizing in Fractured Carbonate Reservoirs Using Adaptive Enriched Galerkin Method","authors":"Rencheng Dong, Sanghyu Lee, M. Wheeler","doi":"10.2118/193862-MS","DOIUrl":"https://doi.org/10.2118/193862-MS","url":null,"abstract":"\u0000 Acidizing in un-fractured carbonate reservoirs has been well studied through modeling and simulation. Since carbonate reservoirs are often naturally fractured, fractures should be modeled for realistic acidizing operations. We present adaptive enriched Galerkin (EG) methods to simulate acidizing in fractured carbonate reservoirs. We adopt a two-scale continuum model for the acid transport. The coupled flow and reactive transport systems are spatially discretized by EG methods. Fractures are introduced using local grid refinement (LGR) technique. Adaptive mesh refinement (AMR) is implemented around wormhole interfaces. Simulation results show that acidizing in fractured carbonate reservoirs is largely dependent on the fracture system while acidizing in unfractured carbonate reservoirs is mainly determined by operation parameters such as acid injection rate. Computationally, the proposed EG scheme has less numerical dispersion and grid orientation effects than standard cell center finite difference/volume methods. AMR is very efficient to track the wormhole growth and speed up acidizing simulations.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129677925","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 Error Quantification of Agent-Based Models as Applied to Oil Reservoir Simulation","authors":"Bryan Doyle, B. Rivière","doi":"10.2118/193935-MS","DOIUrl":"https://doi.org/10.2118/193935-MS","url":null,"abstract":"\u0000 Agent-based models (ABMs) provide a fast alternative to traditional partial differential equation (PDE)-based oil reservoir models by applying localized inexpensive simulations, rather than solving a partial differential equation at every time-step. However, while there have been theoretical and numerical results obtained with ABMs in social science applications, the accuracy of ABMs has not been analyzed in the context of oil reservoir modeling. This paper quantifies the accuracy of a specific ABM by comparing its results to a single-phase flow reservoir. We show that the proposed ABM matches results given by the PDE-based model with less than 5.4% difference. Results are obtained for reservoirs with single and double producers, with varying permeability and with impermeable barriers.","PeriodicalId":246878,"journal":{"name":"Day 2 Thu, April 11, 2019","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125365426","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}