Research on Integrated Fractal Evaluation Method for Sweet Spot Intervals in Fractured Horizontal Wells of Yingxiongling Shale Oil Reservoir

doi:10.3969/j.issn.1672-7703.2025.02.013

Abstract

Abstract: The comprehensive evaluation of sweet spots requires consideration of both geological and engineering factors in shale oil reservoirs. This paper proposes a fractal characteristic-based method using conventional logging curves to assess integrated sweet spots in fractured horizontal wells within shale oil reservoirs. Taking the Chaiping 2 and Chaiping 4 fractured horizontal wells within the sweet spot zones of the Yingxiongling shale oil reservoir in Qinghai Oilfield as case studies, we extracted fractal characteristic parameters from conventional well-logging data. By integrating post-fracturing production profile monitoring and employing gray relational analysis, weighted multifractal spectrum width (Δα') and weighted fractal dimension (D') were introduced to establish a tripartite productivity evaluation criterion based on fractal characterization. The results show that the comprehensive fractal evaluation index of the high-yield well section after Class I layering is 0.75<Δ α '<1, 0

Key words: Logging curve, Multifractal spectrum, Fractal dimension, Gray relational analysis, Shale oil

CLC Number:

P631

Li Juhua, Lian Cuihao, Lei Zhengdong, Lin Hai, Liu Shiduo, Wan Youyu, Lei Fengyu. Research on Integrated Fractal Evaluation Method for Sweet Spot Intervals in Fractured Horizontal Wells of Yingxiongling Shale Oil Reservoir[J]. China Petroleum Exploration, 2025, 30(2): 174-184.

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