鄂尔多斯盆地延长组长8油层组石油成藏机理及成藏模式
摘要: 鄂尔多斯盆地延长组长8油层组在不同地区其勘探成果和油藏规模存在明显的差异，为了分析其原因，对长8油层组油藏的油源、成藏期古物性特征、毛细管力、浮力和过剩压力等进行了研究，得出了过剩压力远大于毛细管力、源储压差能够克服相应储层的毛细管力从而运移成藏的认识。在此基础上，根据姬塬、陇东和陕北三个地区烃源岩和储层发育特征、物性及运移通道的特征，构建了三种不同的成藏模式。具体表现为，姬塬地区的双向排烃、复合成藏模式：即长7段优质烃源岩异常发育，生烃增压作用强烈，使得生成的烃类流体在过剩压力的驱动下向上覆的长6—长4+5地层和下伏的长8地层中双向排烃，在多层系富集成藏；陇东地区的上生下储、下部成藏模式：长7烃源岩发育，存在较高过剩压力，下伏的长8油层组储层物性明显的要优于上覆的长6油层组储层物性，利于烃类大规模向下运移，在长8聚集成藏；陕北地区的侧向运移、上部成藏模式：长7段烃源岩在该区不发育，且上覆长6储层物性远优于下伏长8储层物性，烃类优先在长6成藏，长8油藏规模有限。这三种成藏模式代表了以长7为主要烃源岩的油藏的主要成藏机理，三者在油气分布规律上存在明显的差异。
Accumulation Mechanisms and Modes of Yanchang Formation Chang 8 Interval Hydrocarbons in Ordos Basin
Abstract: The exploration and reservoir scale are of differences in different regions of Chang8 interval of Yanchang Formation in Ordos Basin Ordos, in order to clarify the difference reason, oil source, reservoir characteristics, the capillary force, buoyancy and the excess pressure are studied on Chang 8 reservoir. The excess pressure is much greater than the capillary force, source and reservoir pressure can overcome the corresponding reservoir capillary force and migration and accumulation. On this basis, according to the Jiyuan area, Longdong area and Shanbei area of hydrocarbon source rock and reservoir development characteristics, physical properties and migration channel characteristic, built three kinds of different reservoir forming pattern. Jiyuan area is two-way expulsion, composite reservoir model: Chang 7 source rocks of abnormal development, pressurization action of hydrocarbon generation is strong, which makes the generated hydrocarbon fluid in excess pressure driven to overlying the Chang 6 and Chang 4+5 formation and the underlying Chang 8 strata in bidirectional expulsion, in multi-layer accumulation; Longdong area is the upper source and below-storage reservoir，the lower reservoir model: Chang 7 source rocks, higher in the presence of excess pressure, underlying Chang 8 reservoir was superior to the overlying the Chang 6 reservoir, favorable hydrocarbon mass downward migration, accumulation in Chang 8; Shanbei area is the upper lateral migration, the upper reservoir model: Chang 7 hydrocarbon source rocks are not developed in this area, and overlying Chang 6 reservoir is far superior to that of the underlying Chang 8 reservoir, hydrocarbon priority in Chang 6 reservoir, due to the limited size of Chang 8 reservoir. The three accumulation models represented with Chang 7 as the main hydrocarbon source rock reservoir are the main reservoir forming mechanism; the three models have obvious difference in the distribution of oil and gas.
鄂尔多斯盆地延长组长8油层组石油成藏机理及成藏模式[J]. 沉积学报, 2013, 31(04): 683-692.
| 引用本文: |
鄂尔多斯盆地延长组长8油层组石油成藏机理及成藏模式[J]. 沉积学报, 2013, 31(04): 683-692.
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Accumulation Mechanisms and Modes of Yanchang Formation Chang 8 Interval Hydrocarbons in Ordos Basin[J]. Acta Sedimentologica Sinica, 2013, 31(04): 683-692.
| Citation: |
Accumulation Mechanisms and Modes of Yanchang Formation Chang 8 Interval Hydrocarbons in Ordos Basin[J]. Acta Sedimentologica Sinica, 2013, 31(04): 683-692.
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