【作者】 王金龙；

【导师】 陈孔全； 陈绵琨；

【作者基本信息】 长江大学 ， 地质工程（专业学位）， 2017， 硕士

【摘要】 我国拥有十分丰富的非常规油气资源,据初步估算,中国页岩气总资源量与美国相近,具有很好的勘探开发潜力。湘西北地区页岩气形成地质条件良好,是实现突破的有利地区。本论文在前人的基础上,以沉积地质学、储层地质学等多学科理论为指导,以湘西北下寒武统牛蹄塘组富有机质页岩层系为研究对象,以路线地质调查、野外剖面实测为主要手段,并开展系统的样品进行室内测试分析,同时结合研究区相关钻井、录井资料,在充分吸收邻区以及龙马溪组的勘探开发经验的基础上,来确定页岩的发育层段、页岩的埋藏深度、页岩厚度和分布情况,并通过地球化学测试分析获取了下寒武统牛蹄塘组的有机地化测试数据、岩石矿物学特征、储集性能和成藏地质条件。在此基础上,对湘西北地区下寒武统牛蹄塘组的形成规律进行研究,分析页岩气资源潜力,指出页岩气勘探有利区。研究区牛蹄塘组主要发育盆地-深水陆棚-浅水陆棚沉积体系。暗色页岩段主要发育于盆地-深水陆棚环境,以黑色硅质岩、硅质泥页岩、碳质页岩沉积为主。湘西北地区牛蹄塘组富有机质页岩的分布范围广,厚度在区域上基本稳定,其厚度的两个高值区分别为来凤-龙山地区和临澧-常德地区。牛蹄塘组页岩埋深在区域上变化较大,埋深一般为500-4500米,大部分地区超过2000米。湘西北牛蹄塘组页岩TOC平均含量为3.08%。纵向上牛蹄塘组优质页岩集中在中下段,平面上在咸丰和沅陵地区存在两个TOC高值区,TOC在6.0%以上。有机质类型方面,表现为I型有机质。有机质成熟度方面,有机质处于过成熟演化阶段,Ro都在2.5%以上。湘西北牛蹄塘组页岩具有低孔超低渗的特点。研究区页岩储集空间类型可划分为有机孔、无机孔和微裂缝3种,以顺层面分布的裂缝和孔隙居多。矿物组成主要为石英和黏土矿物,方解石次之,含少量的长石、白云石、黄铁矿等。石英含量平均为62%,较高的脆性矿物有利于后期的压裂改造。黏土矿物主要成分是伊利石、伊蒙混层,其次为绿泥石,最后为高岭石,不含蒙皂石。黏土矿物特征表明本区页岩演化程度高。根据国土资源部、和能源部公布的页岩气界定标准,并结合含气页岩面积、厚度、有机质成熟度、页岩埋深、含气量、地表及保存条件等因素,按照层位优选出多个页岩气有利区带。主要为慈利-永顺-张家界的狭长地区、龙山地区以及石门西北部。更多还原

【Abstract】 China has a large number of unconventional oil and gas resources,according to preliminary estimates,the total amount of shale gas resources in China is similar to the UnitedStates,which has a well potential of exploration and development.The geological forming conditions of shale gas in northwestern of Hunan Province is good.On the basis of predecessors,guided by sedimentology and reservoir geology,taking the organic shale layer of Niutitang Formation in the Lower Cambrian as the research object and the route geological survey and the profile measurements as the main means,a series of indoor test analysis were carried out.Combined with the drilling and logging data,fully absorb the experience of exploration and development to determine shale position,buried depth,thickness and distribution,and through geochemical test and analysis,the organic geochemical,rock mineralogical characteristics,reservoir properties and accumulation conditions in the Lower Cambrian Niutitang Formation can be available.On this basis,the reservoir distribution pattern in the study area is generalized,so as to analyze the potential of shale gasand find out the favorable exploration area.Basin-deep shelf shallow-continental shelf sedimentary system was developed in Niutitang Formation in the study area.The dark shale mainly developed in the basin-deep shelf environment and it is mainly composed of black siliceous rocks,siliceous shale and carbonaceous shale.The distribution for the black shale of Niutitang Formation in Northwest Hunan is wide,and it has stable thickness in the region.The thickness of the two high value area is respectively Laifeng-Longshan area and Linli-Changde area.Depth of shale in Niutitang Formation in the region varies greatly,which is generally 500 to 4500 meters,in most areas more than 2000 meters.The average content TOC for the black shale of NiutitangFormation in Northwestern Hunan is 3.08%.Vertical,high-quality shale concentrated in the middle and lower section.Xianfeng and Yuanling area has two TOC high value at plane,which is over 6.0%.The type of organic matter is I type organic matter.Organic matter is in the stage of over mature evolution of organic matter,Ro is over 2.5%.The black Shale of Niutitang Formation in Northwestern Hunan has the characteristics of low porosity and ultra low permeability.The types of shale reservoirs in the study area can be divided into 3 types: Organic pores,inorganic pores and micro fractures.The mineral composition is mainly composed of quartz and clay minerals,followed by calcite,Containing a small amount of feldspar,dolomite,pyrite,etc.The average content of quartz is 62%,and the higher brittle mineral is beneficial to later fracturing.The main component of clay minerals are illite,illite smectite mixed layers,chlorite,and kaolinite,not containing smectite.The characteristics of clay minerals indicate the high degree of shale evolution in this area.According to the shale gas definition standards released by the Ministry of land and resources,and the Department of energy,combined with the gas-bearing shale’s size,thickness,maturity,depth,content,surface and preservation conditions,a plurality of favorable zones of shale gas are selected according to the horizon.MainlyCili-Yongshun-Zhangjiajie panhandle region,Longshan area and northwestern Shimen.更多还原