鄂尔多斯盆地姬塬地区长6成藏主控因素分析

鄂尔多斯盆地姬塬地区长6油藏总体大规模发育,但油藏特征复杂、区块差异大、单个油藏内部变化大,为此重点研究了砂体结构、储层物性及其非均质性对油藏的影响:姬塬地区长6成藏受多因素控制,烃源岩分布范围、输导体系的配置和成藏动力控制了油藏平面上区域性的宏观分布,而砂体结构、储层物性及非均质性则控制了大型复合岩性油藏内油藏分布的不均匀性。姬塬地区延长组长6油层组油气成藏以近源充注、隐形输导、快速聚集的成藏模式为主。与优质储集空间等时发育的生烃高强度区、异常高压带及微裂缝发育带的叠置区域,应该是姬塬地区延长组长6油层组岩性油藏富集和勘探部署的有利区带,而在有利区带,储层物性、平面及垂向的非均质性又在微观上控制了油藏的分布范围。

Analysis on main control factors of Chang-6 reservoir in Jiyuan region,Ordos Basin

Chang-6 oil reservoirs in Jiyuan area of Ordos basin are generally developed in large scale,while the oil reservoir characteristics are complicated and oil reservoir scale is different in different regions.In light of the features,the influence of sand body structure,reservoir physical property and heterogeneity on the oil reservoir has been analyzed.As the hydrocarbon accumulation was controlled by multiple factors,the source rocks of Chang-6 oil reservoir group in Ji-yuan region are controlled by source rock distribution,passway system allocation and hydrocarbon accumulation dynamics.While the sand body structure,reservoir properties and heterogeneity have the control on the non-uniformity ofcompound lithology reservoir.The generated oil and gas enter into the Chang-6 high quality reservoir gather and accumulation and form large-scale lithologic traps cluster reservoir through the form of three-dimensional woven conducting channel by the drive of excess pressure.Chang-6quantitative division standard of sand body structure is set up for the first time.The oil and gas enrichment are controlled importantly by sand body structure and reservoir property and heterogeneity.Oil content of reservoir are better when develop Ⅰ,Ⅱ sand body structure and good reservoir property and large pore radius and less drive pressure in the same block and the same layer of a reservoir.Analysis of the main controlling factors of reservoir provide a geological basis for the found of oil of east and west region and guide the exploration and development of the same type of reservoir.