鄂尔多斯盆地华庆地区长8油层组成藏特征及控制因素
摘要: 通过对储层荧光、储层包裹体及原油和储层抽提物地球化学特征分析,结合储层、源岩分布特征及其接触关系,深入系统地研究了鄂尔多斯盆地华庆地区长8油层组成藏特征及其控制因素。长8段储层镜下存在两种不同颜色荧光,包裹体均一化温度频率分布存在两个峰值,流动原油的成熟度高于储层抽提物,且储层抽提物存在较严重的生物降解,说明长8油层组存在两期成藏。根据源岩演化史和储层包裹体均一化温度推断,第一期成藏发生在晚侏罗世,此时长7段源岩进入生烃门限,形成的低演化阶段产物遭生物降解形成沥青,目前油藏中的油主要是早白垩世聚集的成熟油。指出长8段油藏的分布受沉积相带、储层特征、烃源岩、储层与源岩接触关系、沥青堵塞孔隙等多种因素控制。华庆地区虽靠近长7期湖盆沉积中心,但源岩厚度及纯度存在差异,烃源岩厚度以及源岩与储层之间的输导层共同控制着该区长8段储层的含油性,烃源岩与储层之间的致密岩性段可阻碍油往下运移到长8段成藏。
Characteristics of Reservoir Formation and the Controlling Factors of Chang 8 Oilbearing Formation in Huaqing Area of Ordos Basin
Abstract: This paper applies reservoir fluorescence, reservoir inclusion and analysis of geochemical characteristics of crude oil and reservoir extracts, combined with distribution and contact relation of reservoir and source rock to study the characteristics of reservoir formation and the controlling factors of Chang 8 oilbearing reservoir in Huaqing area of Ordos basin thoroughly and systematically. Chang 8 reservoir has two different colors of fluorescence, the homogenization temperature of inclusion shows two peaks, the maturity of flow crude oil is higher than that of the reservoir extracts, and the reservoir extracts have serious biodegradation, it is shown that there are two stages of reservoirforming in Chang 8 oilbearing formation. According to the evolution history of source rock and homogenization temperature of reservoir inclusion, it can be implicated that the first stage of reservoirforming occurred in Late Jurassic, Chang 7 source rock reached the hydrocarbon generation threshold at the time, the generated oil with low maturity was biodegraded and formed asphalt. Now the oil in the reservoir is mainly mature which was gathered in Early Cretaceous. It is pointed out that the distribution of Chang 8 reservoir is controlled by multiple factors such as sedimentary facies belt, reservoir characteristics, hydrocarbon source rocks, the contact relationship of reservoir and source rock, pore blockage of asphalt etc. Huaqing area is near the depositional center of the Chang 7 source rock, but the thickness and purity of the source rock is different, source rock thickness and the carrier bed of the reservoir and source rock together control the oil potentials of Chang 8 reservoir, and the dense lithology segment between the reservoir and hydrocarbon source rock may block the migration of the oil to the Chang 8 reservoir.
鄂尔多斯盆地华庆地区长8油层组成藏特征及控制因素[J]. 沉积学报, 2012, 30(6): 1130-1139.
引用本文: |
鄂尔多斯盆地华庆地区长8油层组成藏特征及控制因素[J]. 沉积学报, 2012, 30(6): 1130-1139.
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Characteristics of Reservoir Formation and the Controlling Factors of Chang 8 Oilbearing Formation in Huaqing Area of Ordos Basin[J]. Acta Sedimentologica Sinica, 2012, 30(6): 1130-1139.
Citation: |
Characteristics of Reservoir Formation and the Controlling Factors of Chang 8 Oilbearing Formation in Huaqing Area of Ordos Basin[J]. Acta Sedimentologica Sinica, 2012, 30(6): 1130-1139.
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