Classification and characterization of barrier-intercalation in sandy braided river reservoirs: Taking Hegli Oilfield of Muglad Basin in Sudan as an example

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• 作者：Tianjian SUN ; Longxin MU ; Guoliang ZHAO
• 关键词：sandy braided river ; barrier-intercalation ; channel ; braided river bar ; hierarchy analysis ; characterization method ; 3D modeling
• 刊名：Petroleum Exploration and Development
• 出版年：February, 2014
• 年：2014
• 卷：41
• 期：1
• 页码：125-134
• 全文大小：3386 K

文摘

Based on comprehensive analysis of core data, well logs and outcrops, the barrier-intercalations in the sandy braided river of Hegli Oilfield, Muglad Basin, Sudan were classified and analyzed. The barrier-intercalations in single wells were identified using grey theory, which, in combination of the modern braided river deposit measurements, was used to establish the quantitative calculation formulas for different barrier-intercalations in different scale. Three hierarchies of the barrier-intercalations are developed in the sandy braided river reservoirs in the study area, including barriers between the two single layers, intercalations between the two single sandbodies and intercalations in a single braided river bar. The barriers are 700-1 500 m wide and 1 000-2 000 m long, in continuous sheet shape. The intercalations of abandoned channel are 170-350 m wide; the intercalations of chute are 60-100 m wide and 900-1 500 m long; and the intercalations of braided river bars are 100-400 m wide and 300-800 m long. Based on the constraint of barrier- intercalation scale, 3-D geological models which accurately delineate different types of barrier-intercalations were built by facies-control and stochastic modeling.