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›› 2020, Vol. 37 ›› Issue (1): 103-112.DOI: 10.7523/j.issn.2095-6134.2020.01.012

• Research Articles • Previous Articles     Next Articles

TOC prediction model for muddy source rocks based on convolutional neural network (CNN): a case study of the Hangjinqi area of the Ordos Basin

WANG Huijun1, ZHAO Guiping1,2, LI Liang3, ZHANG Wei3, QI Rong3, LIU Jun4   

  1. 1 College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing 100049, China;
    2 Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences, Beijing 100049, China;
    3 Geoscience Research Institute of North China Company, SINOPEC, Zhengzhou 450006, China;
    4 Well Logging Company of North China Petroleum Engineering Company, SINOPEC, Zhengzhou 450006, China
  • Received:2018-07-23 Revised:2018-11-29 Online:2020-01-15

Abstract: Total organic carbon (TOC) is a significant factor for oil and gas exploration and development. For determining TOC, previous researchers mainly employed ΔlogR and back propagation artificial neural network (BP). However, ΔlogR has a low coefficient of the determination of the calculated TOC compared to the core measured data, while BP is easily trapped into a local optimum. To address these challenges, we propose a new method based on convolutional neural network (CNN) to calculate TOC. In this work, the argillaceous source rocks in the Hangjinqi area of the Ordos Basin were studied, and the effectiveness of the method was verified. The experimental verification showed that CNN could be used for TOC prediction of the source rocks and the prediction accuracy was higher than those of ΔlogR and BP neural network. CNN was used to predict the TOC values of the Shan 1 and Taiyuan mudstones of 108 wells. The TOC planar graphs were made in combination with the sedimentary microfacies. We found that the TOC values of the swamps in the southeast and central parts were higher and the TOC values of the distributary channels were generally lower. The TOC plane distribution well matched the sedimentary microfacies distribution, showing the feasibility of this prediction method.

Key words: muddy source rock, TOC content, well logging, convolutional neural network(CNN), BP neural network(BPNN)

CLC Number: