鄂尔多斯盆地下寺湾地区延长组长7油层组非常规储层特征研究
发布时间：2018-12-28 12:35
【摘要】：鄂尔多斯盆地具有丰富的低渗透油气资源,盆地中生界三叠系延长组泥页岩广泛发育,其中以长7油层组底部的“张家滩页岩”为代表的页岩层厚度大,分布广泛,有机碳含量高,热演化程度适中,具备良好的页岩气成藏条件。本次研究从分析下寺湾地区现有的测井、岩心、分析化验资料入手,结合储层地质学、沉积学、石油地质学理论,对4口井进行岩心观察及分析测试,开展研究区长7油层组非常规储层有机地化特征、成岩作用、储层物性等方面的研究,总结了研究区长7油层组非常规储层发育的影响因素及影响非常规储层物性的主要因素。长7油层组泥页岩脆性矿物中石英平均含量19.8%,长石平均含量15.9%。黏土矿物含量较高且变化大,主要为伊/蒙混层和伊利石,绿泥石及高岭石含量相对较少。有机质类型主要为Ⅱ型,有机显微组分以镜质组和惰性组为主,而壳质组含量相对较少。泥页岩有机碳含量(TOC)平均值4.79%,85%以上的样品属于好的烃源岩。泥页岩镜质体反射率(Ro)平均值0.92%,表明有机质热演化达到成熟阶段。根据扫描电镜观察的孔隙结构特征,将泥页样品孔隙分为粒间孔,粒内孔及有机组分孔3类,从孔隙成因来说主要为次生粒间孔,包括粘土矿物层间孔及少量黄铁矿晶间孔,也含少量粒内溶蚀孔。砂泥互层段孔隙较纯泥岩孔隙明显发育,且原生孔及次生孔均发育,一些长石颗粒被溶蚀形成粒内溶孔,是页岩气运移的重要通路。有机组分发育蜂窝状有机孔,主要是生烃有机显微组分原始生物细胞结构孔隙,以及后期热演化生烃过程中形成的次生孔隙,孔径分布于1-200nm。长7油层组泥页岩孔隙度很低,平均为2.1%,压汞曲线呈现出分选差、细歪度的特征,喉道属细微型,游离气储集条件较差。研究发现,脆性矿物中,长石含量越高,孔隙度越高。黏土矿物总体含量也呈现出与孔隙度的正相关性。泥页岩孔隙度与有机质含量呈负相关,说明有机质对孔隙度没有贡献反而有不利影响。研究认为鄂尔多斯盆地下寺湾地区延长组长7油层组非常规储层分布广,厚度大,生烃潜力较好,具有页岩气形成和勘探开发的潜力,泥页岩储层非均质性、粘土矿物与有机质之间关系等值得进一步研究。
[Abstract]:The Ordos Basin is rich in low permeability oil and gas resources, and shale is widely developed in the Mesozoic Triassic Yanchang formation, in which the "Zhangjiatan Shale" at the bottom of Chang 7 oil formation is characterized by large thickness and wide distribution. The organic carbon content is high, the thermal evolution is moderate, and there are good conditions for shale gas accumulation. This study begins with the analysis of existing logging, core and laboratory data in Xiusi Bay area, and combines the theories of reservoir geology, sedimentology and petroleum geology to conduct core observation and analysis and test on 4 wells. The organic geochemical characteristics, diagenesis and reservoir physical properties of unconventional reservoirs in Chang7 reservoir formation were studied. The influencing factors of unconventional reservoir development and the main factors affecting physical properties of unconventional reservoirs in Chang7 reservoir formation were summarized. The average content of quartz and feldspar are 19.8and 15.9in the shale brittle minerals of Chang 7 formation respectively. The clay mineral content is high and varied, mainly in the mixed layer and Illite, and the content of chlorite and kaolinite is relatively small. The type of organic matter is mainly type 鈪，
本文编号：2393945
[Abstract]:The Ordos Basin is rich in low permeability oil and gas resources, and shale is widely developed in the Mesozoic Triassic Yanchang formation, in which the "Zhangjiatan Shale" at the bottom of Chang 7 oil formation is characterized by large thickness and wide distribution. The organic carbon content is high, the thermal evolution is moderate, and there are good conditions for shale gas accumulation. This study begins with the analysis of existing logging, core and laboratory data in Xiusi Bay area, and combines the theories of reservoir geology, sedimentology and petroleum geology to conduct core observation and analysis and test on 4 wells. The organic geochemical characteristics, diagenesis and reservoir physical properties of unconventional reservoirs in Chang7 reservoir formation were studied. The influencing factors of unconventional reservoir development and the main factors affecting physical properties of unconventional reservoirs in Chang7 reservoir formation were summarized. The average content of quartz and feldspar are 19.8and 15.9in the shale brittle minerals of Chang 7 formation respectively. The clay mineral content is high and varied, mainly in the mixed layer and Illite, and the content of chlorite and kaolinite is relatively small. The type of organic matter is mainly type 鈪，
本文编号：2393945
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