Application of Neural Networks in Petroleum Reservoir Lithology and Saturation Prediction¸
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Abstract
The Kloštar oil field is situated in the northern part of the Sava Depression within the Croatian part of the Pannonian Basin. The major petroleum reserves are confi ned to Miocene sandstones that comprise two production units: the Lower Pontian I sandstone series and the Upper Pannonian II sandstone series. We used well logs from two wells through these sandstones as input data in the neural network analysis, and used spontaneous potential and resistivity logs (R16 and R64) as the input in network training. The fi rst analysis included prediction of lithology, which was defined as either sandstone or marl. These two rock types were assigned categorical values of 1 or 0 which were then used in numerical analysis. The neural network was also used to predict hydrocarbon saturation in selected wells. The input dataset was extended to depth and categorical lithology. The prediction results were excellent, because the training and prediction dataset showed little disagreement between the true and predicted values. At present, this study represents the best and most useful application of neural networks in the Croatian part of the Pannonian Basin.
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References
BALIĆ, D., VELIĆ, J. & MALVIĆ, T. (2008): Selection of the most ap-propriate method for sandstone reservoirs in the Kloštar oil and gas fi eld.– Geol. Croat., 61/1, 27–35.
BASSIOUNI, Z. (1994): Theory, Measurement, and Interpretation of Well Logs.– Society of Petroleum Engineers, Richardson, 372 p.
BHATT, A. (2002): Reservoir properties from-well logs using neural networks.– Unpubl. PhD Thesis, NTNU, Trondheim, 151 p.
BISHOP, C.M. (1995): Neural Networks for Pattern Recognition, 1st edi-tion.– Oxford University Press, New York, 504 p.
FAHLMAN, S.E. (1988): Faster Learning Variations on Back-propaga-tion: An Empirical Study.– Proceedings of the 1988 Connectionist Models Summer School, Los Altos, 38–51.
GORSE, D., SHEPHERD, A. & TAYLOR, J.G. (1997): The new ERA in supervised learning.– Neural Networks, 10/2, 343–352.
JACOBS, R.A. (1988): Increased rates of convergence through learning rate adaptation.– Neural Networks, 1, 295–307.
LEVENBERG, K. (1944): A method for the solution of certain problems in least squares.– Quardt. Appl. Math., 2, 164–168.
LUČIĆ, D., SAFTIĆ, B., KRIZMANIĆ, K., PRELOGOVIĆ, E., BRITVIĆ, V., MESIĆ, I. & TADEJ, J. (2001): The Neogene evolu-tion and hydrocarbon potential of the Pannonian Basin in Croatia.– Mar. Petrol. Geol. 18/1, 133–147.
LUTHI, S.M. & BRYANT, I.D. (1997): Well-log correlation using a back-propagation neural network.– Math. Geol. 29/3, 413–425.
MALVIĆ, T. (2006): Clastic facies prediction using neural network (case study from Okoli field).– Nafta, 57/10, 415–431.
MALVIĆ, T. & PRSKALO, S. (2007): Some benefits of the neural approach in porosity prediction (Case study from Beničanci fi eld).– Nafta 58/9, 455–467.
MALVIĆ, T., CVETKOVIĆ, M. & BALIĆ, D. (2008): Geomatematički rječnik [Geomathematical dictionary].– Hrvatsko geološko društvo (HGD), Zagreb, 74 p.
MARQUARDT, D.W. (1963): An algorithm for least-squares estimation of nonlinear parameters.– J. Soc. Indust. Appl. Math. 11/2, 431–441.
MCCULLOCH, W.S. & PITTS, W. (1943) A logical calculus of ideas immanent in nervous activity.– B. Math. Biol. 5/4, 115–133.
ROSENBLATT, F. (1958): The perceptron: A probabilistic model for in-formation storage and organization in the brain.– Psychol. Rev. 65/6, 386–408.
RUMELHART, D.E., HINTON, G.E. & WILLIAMS, R.J. (1986): Learn-ing internal representations by error propagation.– In: RUMEL-HART, D.E. & MCCLELLAND, J.L. (eds.): Parallel Distributed Processing, MIT Press, Cambridge, 1, 381–362.
VELIĆ, J. (1979): O razlikovanju neotektonskih, struktura u zapadnom dijelu Savske depresije [Distinguishing the neotectonic structures in western part of Sava Depression – in Croatian].– Geol. vjesnik, 31, 175–183.
VELIĆ, J. (1980): Geološka građa zapadnog dijela Savske depresije [Geological settings of the western part of Sava Depression – in Croatian].– Unpubl. PhD Thesis, Faculty of Mining, Geology and Petroleum Engineering, Zagreb, 139 p.
VELIĆ, J. (1983): Neotektonski odnosi i razvitak zapadnog dijela Savske potoline [Neotectonic relations and development of the Western part of Sava Depression – in Croatian].– Acta Geol. 13/2, 26–65.
VRAGOVIĆ, M. & MAJER, V. (1980): Prilozi za poznavanje metamor-fnih stijena Zagrebačke gore, Moslavačke gore i Papuka (Hrvatska) [Samples for recognition of metamorphic rocks of Zagrebačka gora, Moslavačka gora and Papuk mountain (Croatia) – in Croatian].– Geol. vjesnik, 31, 295–308.