Abstract
The layering in reservoir simulation grids is often based on the geology, e.g., structure tops. In this paper we investigate the alternative of using horizontal layers, where the link to the geology model is by the representation of the petrophysics alone. The obvious drawback is the failure to honor the structure in the grid geometry. On the other hand, a horizontal grid will honor the initial fluid contacts perfectly, and horizontal wells can also be accurately represented. Both these issues are vital in thin oil-zone problems, where horizontal grids may hence be a viable alternative. To investigate this question, a number of equivalent simulation models were built for a segment of the Troll Field, both geology-based and horizontal, and various combinations of these. In the paper, it is demonstrated that the horizontal grid was able to capture the essentials of fluid flow with the same degree of accuracy as the geology-based grid, and near-well flow was considerably more accurate. For grids of comparable resolution, more reliable results were obtained by a horizontal grid than a geo-grid. A geo-grid with local grid refinement and a horizontal grid produced almost identical results, but the ratio of computing times was almost 20 in favor of the horizontal grid. In the one-phase regions of the reservoir, relatively coarse cells can be used without significant loss of accuracy.
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References
Bagheri, M., Settari, A.: Methods for modeling full tensor permeability in reservoir simulators. J. Can. Pet. Technol. 46(3), 31–38 (2007)
Bowen, G.R., Leiknes, J.: Parallel processing applied to local grid refinement. In: Paper SPE 30203 Presented at Petroleum Computer Conference, Houston, 11–14 June 1995
Durlofsky, L.J.: Numerical calculation of equivalent grid block permeability tensors for heterogeneous porous media. Water Resour. Res. 27(5), 699–708 (1991)
Fantoft, S., Krogh, P.K., Pollen, S.: Evaluation of oil recovery from a thin oil column by a horizontal well in the Oseberg gamma north reservoir. In: Paper SPE 18341 Presented at SPE European Petroleum Conference, London, 16–19 Oct 1988
Henriquez, A., Apeland, O.J., Lie, Ø., Cheshire, I.: Novel simulation techniques used in a gas reservoir with a thin oil zone: Troll field. SPE Reserv. Eng. 7(4), 414–418 (1992)
Hsu, H.-H.: Use of new horizontal grids in reservoir simulation models improve the chance of success in developing marginal thin oil rim reservoirs using horizontal wells. In: Paper SPE 39548 Presented at SPE India Oil and Gas Conference and Exhibition, New Delhi, 7–9 April 1998
Kabir, C. S., Agamini, M., Holguin, R.A.: Production strategy for thin-oil columns in saturated reservoirs. SPE Reserv. Evalu. Eng. 11(1), 73–82 (2008)
Kasap, E., Lake, L.W.: Calculating the effective permeability tensor of a gridblock. SPE Form. Eval. 5(2), 192–200 (1990)
Lien, S.C., Seines, K., Havig, S.O., Kydland, T.: The first long-term horizontal-well test in the Troll thin oil zone. J. Pet. Technol. 43(8), 914–917, 970–973 (1991)
Mlacnik, J.L., Durlofsky, L.J., Heinemann, Z.E.: Sequentially adapted flow-based PEBI grids for reservoir simulation. SPE J. 11, 304–316 (2006)
Mundal, S.S., Keilegavlen, E., Aavatsmark, I.: Simulation of anisotropic heterogeneous near-well flow using MPFA methods on flexible grids. Comput. Geosci. 14, 509–525 (2010)
Schlumberger: ECLIPSE reference manual 2010. Houston, Schlumberger (2010)
Seines, K., Lien, S.C., Haug, B.T.: Troll horizontal well tests demonstrate large production potential from thin oil zones. SPE Reserv. Eval. Eng. 9(2), 133–130 (1994)
Thakur, S.C., Bally, K., Therry, D., Simon, L.: Performance of horizontal wells in a thin oil zone between a gas cap and an aquifer, immortelle field, trinidad. In: Paper SPE 36752 Presented at SPE Annual Technical Conference and Exhibition, Denver, 6–9 Oct 1996
Toronoyi, R.M., Farouq Ali, S.M.: Determining interblock transmissibility in reservoir simulators. J. Pet. Technol. 26(1), 77–78 (1974)
Vinje, J., Nybø, R., Grinestaff, G.: A new simulation grid type demonstrated for the giant Troll field. In: Presentation at SPE-Bergen One-Day Seminar, Bergen, Norway, 6 April 2011
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Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/2.0), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
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Pettersen, Ø. Horizontal simulation grids as alternative to structure-based grids for thin oil-zone problems: a comparison study on a Troll segment. Comput Geosci 16, 211–230 (2012). https://doi.org/10.1007/s10596-011-9240-8
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DOI: https://doi.org/10.1007/s10596-011-9240-8