| 摘要: |
| 基于东濮凹陷典型煤成气区成藏条件对比分析,厘定煤成气成藏关键控制因素,结合权重赋值法、模糊评价法,提出断层输导效率系数、保存条件系数等参数,对单一因素进行定量化表征,最终利用多元线性回归法等建立东濮凹陷煤成气藏形成规模的多因素预测模型,并优选勘探潜力区。研究表明:煤成气的宏观展布受源岩生烃能力控制,主要围绕生气强度大于20×108 m3/km2的区域分布;通源断层活动期与烃源岩生排烃期的时空配置关系决定煤成气有效运聚;煤成气藏保存条件受断-盖组合关系控制,泥岩盖层有效厚度封闭下限为40 m;充足的源-储剩余压差是煤成气高效成藏的必要条件;煤成气藏形成规模受“供烃-动力-输导-保存”多元耦合控制,其中生气供给、封盖保存为首要控制因素,成藏动力条件和断层输导条件次之;基于成藏条件分析及气藏规模定量预测评价结果,优选中央隆起带文中地区、西南洼方里集地区为重点潜力区。 |
| 关键词: 煤成气藏 成藏要素 富集规模 控制因素 定量评价 东濮凹陷 |
| DOI：10.3969/j.issn.1673-5005.2019.02.001 |
| 分类号::TE 122.2 |
| 文献标识码:A |
| 基金项目:国家科技重大专项(2016ZX05006-007) |
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| Quantitative analysis of the main controlling factors for coal-formed gas accumulation in Dongpu Depression |
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HU Hongjin1, JIANG Youlu1, LIU Jingdong1, ZHAO Kai1, XU Tianwu2
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(1.School of Geosciences in China University of Petroleum(East China), Qingdao 266580, China;2.Exploration ＆ Development Research Institute, Zhongyuan Oilfield Company, Puyang 457001, China)
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| Abstract: |
| Based on exploration results and previous studies, the differences in the coal-formed gas accumulation conditions among different coal-formed gas areas of Dongpu Depression were compared, and the main controlling factors of coal-formed gas accumulation were determined. The coefficients of fault transport efficiency and preservation condition coefficients were proposed quantitatively in this paper. The quantitative analysis of controlling factors for the scale of coal-formed gas reservoirs were carried out based on weights assignment method, fuzzy evaluation method and multiple linear regression method, and a quantitative prediction model for the enrichment scale of coal-formed gas reservoirs in Dongpu Depression was established based on multiple factors. Finally, the exploration potential areas were optimized. The results show that the macro distribution of coal-formed gas in the study area is controlled by the hydrocarbon generation capacity, and all the coal-formed gas reservoirs are distributed around the area where the gas generation intensity is greater than 20×108 m3/km2. The relationship between the fault activity and the hydrocarbon generation period of gas source rocks controls the effectivity of gas migration. The combination between fault and cap rocks controls the vertical enrichment of natural gas, and the coal-formed gas is distributed in the stratigraphic level which the faulted thickness of cap rock is more than 40 m. Sufficient residual pressure D-value between source and reservoir is a necessary condition for efficient coal-formed gas accumulation. The enrichment degree of coal-formed gas reservoirs is multi-controlled by "gas supply-dynamics-transportation-preservation" conditions, among which, the gas supply and preservation condition are the main controlling factors, while the dynamic and transportation conditions are less important. Combining results from quantitative forecasting model, it is concluded that the central uplift zone and the southwestern depression are the key potential areas. |
| Key words: coal-formed gas reservoir accumulation factors enrichment scale control factors quantitative evaluation Dongpu Depression |
