鄂尔多斯盆地南部延长组泥页岩孔隙特征及其控制因素

发布时间：2018-07-17 00:40

【摘要】：泥页岩孔隙特征是页岩气藏储集能力及可开采性评价的关键参数。以鄂尔多斯盆地南部铜川地区瑶科一井延长组泥页岩样品为研究对象,通过扫描电镜、低温氮气吸附等实验手段,对延长组各段泥页岩孔隙特征及影响孔隙发育的控制因素进行了研究。研究表明:鄂尔多斯盆地南部延长组泥页岩孔隙类型主要有粒间孔、粒内孔、黄铁矿晶间孔、溶蚀孔、微裂缝,其中黏土矿物粒间孔最发育,有机孔基本不发育。延长组不同段的纳米孔隙发育特征有明显的差异性,长9段微孔含量相对较高,BET比表面积较大,长8段中孔比例较高,孔隙形态都以管状孔和平行壁的狭缝状孔为主;长7段有最大的宏孔比例和最小的微孔比例,比表面积最小,孔隙含有相对较多的封闭型孔,还有一端或两端开口的楔V型孔;长6段孔隙比例、比表面积大小介于其他各段之间,以平行板状的狭缝型孔隙为主。黏土矿物含量、石英含量是控制孔隙发育的主要因素,而孔隙总体积、比表面积与TOC含量基本呈负相关关系,这主要是由于孔隙中的残留烃对孔隙的堵塞作用,抽提后可以发现样品孔隙总体积、比表面积都有所增加。
[Abstract]:The pore characteristics of shale are the key parameters to evaluate the reservoir capacity and recoverability of shale gas reservoirs. The shale samples of Yanchang formation of Yaokeyi formation in Tongchuan area, southern Ordos Basin, were studied by scanning electron microscopy (SEM) and nitrogen adsorption at low temperature. The pore characteristics of shale in Yanchang formation and the controlling factors affecting pore development were studied. The results show that the pore types of shale in Yanchang formation in southern Ordos Basin are mainly intergranular pore, intragranular pore, pyrite intergranular pore, dissolution pore, microfracture, among which clay mineral intergranular pore is the most developed and organic pore is not. In Yanchang group, there were obvious differences in the development characteristics of nano-pores in different segments. The content of micropores in Chang 9 was relatively high, and the specific surface area of BET was relatively high, and the proportion of pores in the middle of Chang 8 was higher. The pore morphology was dominated by tubular pores and slit pores with parallel walls. Chang 7 has the largest macro pore ratio and the smallest micropore ratio, the smallest specific surface area, the pore contains relatively more closed pores, there are wedge V-shaped pores with one or both ends opening, and the long 6 segment pore ratio, The specific surface area is between the other sections and is dominated by parallel plate-like slit pores. Clay mineral content and quartz content are the main factors controlling pore development, while the total pore volume, specific surface area and TOC content are negatively correlated, which is mainly due to the plugging effect of residual hydrocarbon in pores. It was found that the total pore volume and specific surface area of the samples increased after extraction.
【作者单位】：甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室;中国科学院大学;
【基金】：国家重大专项项目(2016ZX05003002-004,2016B-0502) 中国科学院先导专项(XDB10010103) 国家自然科学基金项目(41072105)~~
【分类号】：P618.13;TE37

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