Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | Springer Nature Link |
|---|---|
| Author | Zhao, Hui Li, Gaoming Reylds, Albert C. Yao, Jun |
| Copyright Year | 2012 |
| Abstract | Due to the limited availability of adjoint code in commercial reservoir simulators for gradient calculations, there is a need to explore the applicability of derivative-free optimization algorithms for large-scale history matching. This paper tests the utility of three derivative-free optimization algorithms (stochastic Gaussian search direction (SGSD), new unconstrained optimization algorithm (NEWUOA), and quadratic interpolation model-based algorithm guided by approximate gradient (QIM-AG)) for history matching. The SGSD method uses a negative stochastic gradient which is obtained by simultaneously perturbing all the model parameters using a Gaussian random vector. For a continuous objective function and a sufficiently small perturbation size, the stochastic gradient is always uphill and the expectation of the stochastic gradient converges to the true gradient as the perturbation size goes to zero. NEWUOA is a quadratic interpolation model-based optimization algorithm. At each iteration, the objective function is first approximated by a quadratic interpolation model. The quadratic model is then minimized to obtain an updated reservoir description for the next iteration. The number of interpolation points (reservoir simulation runs) required by NEWUOA must be larger than the dimension of reservoir model parameter space in order to construct the initial quadratic model. QIM-AG reduces the required number of interpolation points by replacing the first-order coefficients that appear in the quadratic model by an approximate gradient. The approximate gradient used in this study is an average of several stochastic gradients from SGSD. To reduce the dimension of the optimization problem, a simple parameterization method based on the prior covariance matrix is applied. The prior covariance matrix is approximated using an ensemble of unconditional realizations. The parameterization avoids the calculation of the inverse of the prior covariance matrix during optimization and may further regularize the ill-posed inverse problem. |
| Starting Page | 117 |
| Ending Page | 138 |
| Page Count | 22 |
| File Format | |
| ISSN | 14200597 |
| Journal | Computational Geosciences |
| Volume Number | 17 |
| Issue Number | 1 |
| e-ISSN | 15731499 |
| Language | English |
| Publisher | Springer Netherlands |
| Publisher Date | 2012-10-19 |
| Publisher Place | Dordrecht |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | SGSD NEWUOA Parameterization History matching Uncertainty quantification Earth Sciences Geotechnical Engineering & Applied Earth Sciences Hydrogeology Mathematical Modeling and Industrial Mathematics Soil Science & Conservation |
| Content Type | Text |
| Resource Type | Article |
| Subject | Computers in Earth Sciences Computational Theory and Mathematics Computer Science Applications Computational Mathematics |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|