鄂西利川地区二叠系吴家坪组富有机质硅质页岩储层特征  

Reservoir characteristics of organic-rich siliceous shale of Permian Wujiaping Formation in Lichuan area, western Hubei Province

作　　者：曹涛涛 邓模[2] 刘光祥[2] 曹清古[2] 刘虎 黄俨然 CAO Taotao;DENG Mo;LIU Guangxiang;CAO Qinggu;LIU Hu;HUANG Yanran

机构地区：[1]湖南科技大学页岩气资源利用与开发湖南省重点实验室 [2]中国石化石油勘探开发研究院无锡石油地质研究所 [3]页岩气评价与开采四川省重点实验室

出　　处：《海相油气地质》2018年第3期32-42,共11页Marine Origin Petroleum Geology

基　　金：国家油气重大专项"生烃演化对常压页岩气富集的控制作用"(编号:2016ZX05061001-001);国家自然科学基金"页岩解析气碳同位素分馏特征及其指示意义"(编号:41503033);中国石化科技攻关项目"川东地区龙潭组页岩气成藏条件研究"(编号:P15103)联合资助

摘　　要：通过岩石薄片、X衍射、有机岩石学、氩离子抛光扫描电子显微镜、氮气吸附、气测孔隙度等手段,对鄂西利川地区上二叠统吴家坪组硅质页岩的矿物组成、有机地球化学特征、物性特征等进行了分析研究。结果表明:吴家坪组硅质页岩TOC含量高,为3.07%~11.29%,成熟度适中,干酪根为Ⅱ型,有机质主要由腐泥组分和固体沥青组成;矿物组成以石英为主,占57%~93%,其次为黏土矿物、长石,含少量的碳酸盐矿物和黄铁矿等。吴家坪组页岩微观孔隙类型以有机孔为主,其次为草莓体黄铁矿晶间孔和石英颗粒边缘孔,溶蚀孔和微裂缝发育较差。页岩的比表面积和孔体积分别为6.63~33.12 m2/g和0.015~0.047 m L/g,且与TOC之间具有很好的正相关性,而与长石和黏土矿物之间存在弱负相关性;孔隙度为2.81%~17.40%,整体与石英含量具有较好的正相关性。利川地区吴家坪组页岩的物性特征与涪陵地区下志留统龙马溪组页岩具有很好的可对比性,故推断具有较好的页岩气勘探潜力。The study on mineral composition,organic geochemistry,physical property of siliceous shale of Permian Wujiaping Formation were conducted by thin section,X-ray diffraction,organic petrology,low-pressure N2 adsorption,gas intrusion,and scanning electron microscopy combined with argon ion polishing.This shale has a high TOC content(3.07%-11.29%),and moderate maturity of organic matter(1.91%-1.96%),and kerogen typeⅡ,in which the carbon isotope of kerogen ranges from-27.4‰to-26.5‰.On organic petrology features the organic matter is mainly composed of sapropelinite and solid bitumen.It is mainly composed of quartz,ranging from 57%to 93%,followed by clay,feldspar,and few carbonate and pyrite.There are mainly organic pores,followed by the intergranular pores in framboidal pyrites,and the pores along the edge of quartz grains,and the poorly developed dissolution pores and microfractures.The specific surface area and pore volume are in the range of 6.63-33.12 m2/g and 0.015-0.047 mL/g respectively,which have a good positive correlation with TOC and have a weak negative correlation with the contents of feldspar and clay minerals.The porosity(2.81%-17.40%)has a good positive correlation with the content of quartz.Similar to Longmaxi shale in Fuling area(Jiaoshiba shale gas field)in Sichuan Basin,it is suggested that there has a very good condition of shale gas formation in Wujiaping siliceous shale.

关 键 词：二叠纪 吴家坪组 硅质页岩 储集空间 影响因素 利川地区 

分 类 号：TE122.2[石油与天然气工程—油气勘探]