基于四川盆地上奥陶统五峰组—下志留统龙马溪组富有机质页岩分布规律、优质页岩表观特征、页岩储集层微观特征、保存条件与页岩气富集、可压裂性等方面的分析,对中国页岩气勘探开发理论认识进行总结,并对未来中国页岩气勘探开发提出针对性建议。四川盆地五峰组—龙马溪组页岩气重要的地质认识可总结为以下几个方面：沉积环境和沉积过程控制了富有机质页岩分布;“甜点段”优质页岩具备高有机碳含量、高脆性、高孔隙度、高含气性的特征;有机质孔隙是页岩气富集的重要储集空间;保存条件是复杂构造区页岩气地质评价的关键因素;页岩气属“人工气藏”,可压裂性评价是获得高产的核心;纳米级储集空间与赋存状态决定了页岩气具有特殊的渗流特征。对中国页岩气产业的发展建议：①加大基础研究,实现页岩气地质理论体系的新突破;②强化勘探实践,形成多层系全方位新发现;③研究开发生产规律,建立页岩气开发新模式;④创新思维,攻关新技术;⑤探索管理创新,形成页岩气发展新机制。图6参72

Through detailed analyses of the distribution characteristics of organic-rich shale, appearance features of high-quality shale, microscopic characteristics of shale reservoir rocks, fracturabilities, and the relationship between preservation conditions and shale gas enrichment in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Sichuan Basin, theoretical understandings and specific suggestions with respect to the exploration and development of shale gas in China are summarized and proposed respectively. Successful experiences in the exploration and development of shale gas of the Wufeng Formation-Longmaxi Formation in the Sichuan Basin can be summarized into the following aspects: depositional environment and depositional process control the distribution of organic-rich shale; high quality shale in “sweet spot segments” are commonly characterized by high content of organic carbon, high brittleness, high porosity and gas content; organic pores are important storage space for the enrichment of shale gas; preservation conditions are the key factor for the geological evaluation of shale gas in structurally complex regions; shale gas can be considered as “artificial gas reservoirs” and the fracturability assessment is essential for high-production; nanoscale storage space and the mode of occurrence control the special seepage characteristics of shale gas. The following suggestions are proposed for the development of China’s shale gas industry: (1) focus more on fundamental research to achieve new breakthrough in the geological theory of shale gas; (2) emphasize exploration practices to have all-round discoveries in multiple strata; (3) study the regularities of development and production to establish new models of shale gas development; (4) think creatively to invent new technologies to tackle key problems; (5) explore the management innovation to create new mechanisms in shale gas development.

中美页岩气地质和地表条件的对比分析表明，中国南方海相页岩与北美典型页岩的主要评价指标相近，是页岩气勘探的主攻层系。其中，四川盆地及周缘地区是有利勘探地区。中国石油、化工股份有限公司2006年以来，经历6年的研究与勘探探索，2012年在四川盆地涪陵焦石坝地区龙马溪组页岩气获得重大突破，发现了涪陵页岩气田，取得了中国页岩气的首个商业发现。五峰组龙马溪组页岩气富集与高产的地质因素包括原始沉积条件和后期保存条件，台内坳陷控制优质页岩的形成分布，页岩厚度大、有机质含量高是页岩气选区的首要评价指标。保存条件影响页岩气的富集程度，四川盆地内部总体保存条件较好，有三叠系膏盐岩分布的地区保存条件好，页岩气层段压力系数高，页岩气富集程度高。在选区评价中，原始沉积条件和后期保存条件均有利的地区是页岩气勘探的有利区。通过对典型探井五峰组龙马溪组页岩气富集条件的分析表明，有机质提供了页岩气富集的物质基础，有机质孔是页岩气富集的主要储集空间，层理(缝)是页岩气水平渗流的高效通道，高硅质含量具有良好的可压性，高压力系数指示页岩气富集程度高。有机质、有机质孔、层理(缝)、硅质含量和压力系数等表征页岩气富集与高产的5种关键参数具有成因联系和统计相关的特征，纵向上又具有“五性一体”的分布特征，从而决定了五峰组龙马溪组下部富含有机质的优质页岩层段既可以富集页岩气，又有利于页岩气的开发，是开发页岩气的主要层段和水平井轨迹的关键目标层。

根据页岩气地质理论研究进展和勘探发现,基于"源-盖控烃"论分析了四川盆地及其周缘上奥陶统五峰组-下志留统龙马溪组页岩气富集的主控因素。①"源控"主要表现在优质页岩厚度、面积、有机碳含量等物质基础参数控制了页岩的生烃能力和储集能力,上奥陶统五峰组-下志留统龙马溪组一段下部页岩(WF2-LM4笔石页岩段)具有沉积速率低、有机质类型好、有机碳含量高和生烃能力强等特点,具备良好的页岩气发育生烃物质基础;浮游藻类来源的成烃生物有利于大量生烃和有机质孔大量发育,且高有机碳含量保证了发育大量有机质孔并形成三维连通的有机质孔孔隙网络,为天然气提供良好的赋存空间和渗流通道。②"盖控"的盖层包括直接盖层和间接盖层,直接盖层指龙马溪组一段中上部(LM5笔石页岩段及其以上)页岩对五峰组和龙马溪组一段下部页岩(WF2-LM4笔石页岩段)的封闭;中下三叠统膏盐岩、泥岩间接盖层(区域盖层)保证了一定的压力封闭,使得其下的五峰组和龙马溪组页岩气能有效富集,形成高压富集的页岩气藏(焦石坝、富顺-永川、长宁等地区);在中下三叠统缺失的地区,先存的高压封闭体系被破坏,页岩气保存失去有效性,形成低压-常压富集的页岩气藏(渝东南彭水、云南昭通等地区)。源-盖空间匹配关系的数量(静态匹配)和质量(动态匹配)控制着页岩气富集位置和富集程度。四川盆地及其周缘上奥陶统五峰组-下志留统龙马溪组一段下部页岩(WF2-LM4笔石页岩段)发育厚度大,中下三叠统膏盐岩、泥岩盖层发育,主成藏期在J₃-K₁以新的地区,是四川盆地及其周缘上奥陶统五峰组-下志留统龙马溪组页岩气富集的有利地区。

Based on the exploration discoveries of shale gas and research progresses of relevant geological theory as well as "source-cap controlling hydrocarbon" theory, the main controlling factors of shale gas enrichment in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation of Sichuan Basin and its periphery were analyzed:(1) "Source control" means that the shale hydrocarbon generation and reserving capacity can be controlled by the thickness, area, total organic carbon content of high-quality shale and other basic factors. The shale in Upper Ordovician Wufeng Formation-Lower Member 1 of Lower Silurian Longmaxi Formation (WF2-LM4 graptolite shale member) is characterized by slow sedimentary rate, good type of organic matter, high total organic carbon content and great hydrocarbon generation capacity, thus providing a favorable hydrocarbon-generation material basis for shale gas development; the hydrocarbon-generation materials such as planktonic algae are beneficial for massive hydrocarbon generation and organic matter development, and high organic carbon content is able to ensure the development of massive organic-matter pores, so as to form a three-dimensional connected network of organic-matter pores and provide favorable occurrence space and flow channel for natural gas. (2) In terms of "cap control" theory, the cap can be divided into direct cap and indirect cap. Direct cap refers to the confining bed between the shale in mid-upper Member 1 of Longmaxi Formation (LM5 graptolite shale member and above) and that in Wufeng Formation and the lower Member 1 of Longmaxi Formation (WF2-LM4 graptolite shale member). Indirect cap (regional cap) in the Mid-Lower Triassic gypsum rocks and mudstones can guarantee the pressure sealing to a certain degree. As a result, the shale in Wufeng Formation and Longmaxi Formation can be effectively enriched to form high-pressure enriched shale gas reservoirs (Jiaoshiba, Fushun-Yongchuan and Changning, etc.). In the regions with absent Mid-Lower Triassic, the pre-existing high-pressure closed system was destroyed and the shale gas preservation availability was lost, thus forming the shale gas reservoirs enriched under low-normal pressure (Pengshui in southeastern Chongqing, Zhaotong in Yunnan, etc.) The enrichment location and degree of shale gas is controlled by the quantity (static match) and quality (dynamic match) of source-cap spatial match relationship. Research results indicate that the shale in Upper Ordovician Wufeng Formation-lower Member 1 of Lower Silurian Longmaxi Formation of Sichuan Basin and its periphery (WF2-LM4 graptolite shale member) is developed with a large thickness, together with Mid-Lower Triassic gypsum rocks and mudstones. The regions with the main reservoir accumulation period of J₃-K₁ or after J₃-K₁ are favorable areas for shale gas enrichment in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation of Sichuan Basin and its periphery.

涪陵页岩气田焦石坝区块储层纵向上非均质性较强、各小层地质特征差异明显，尤其是③小层以上气层（上部气层）脆性指数降低、高导缝发育。在对比上下部气层地质条件的基础上，分析了上部气层压裂改造的技术难点并提出技术对策，通过应力干扰模拟、缝内净压力计算以及室内压裂模拟对施工参数进行优化，形成了一套以 “前置胶液增破裂、低黏减阻水促复杂、优化排量规模控缝高”为主体思路的压裂工艺技术，以充分动用上部气层并减小对下部气层的重复改造。上部气层井 ＪＹＣ１ＨＦ使用该工艺技术，压后采用 ８ｍｍ油嘴放喷排液，产气量最高达到 １６．３４×１０４ｍ３／ｄ，井口套管压力 １７．５８ＭＰａ，且该井下部气井流压稳定，为后期涪陵页岩气田上部气层的压裂工艺优化提供了技术借鉴。

涪陵页岩气田虽已取得巨大成功，但随着气田开发进入递减期，单井产量逐年递减，因此需寻找新的增产阵地。以四川盆地焦石坝地区龙马溪组一段上部为研究对象，在有机地球化学、全岩X?射线衍射、扫描电镜和岩心观察的基础上进行分析。结果表明，上部气层整体为Ⅱ类页岩储层，具有较优的地质条件。此外通过微地震监测等手段发现，下部气层井压裂形成的有效裂缝大部分未向上延伸至上部气层；上部气层井投产前地层压力比同期邻井的实测地层压力高21.03 MPa，也证实上、下部气层未沟通，上部气层可单独开发。对上部气层评价井进行生产动态分析，计算单井技术可采储量，均达到较高的技术可采储量，具有良好的开发潜力。

Fuling shale gas field has achieved great success, but with the development of the gas field entering the middle and late stages, the production of single well is decreasing year by year, so it is necessary to find new production increasing positions. Based on organic geochemistry, X-ray diffraction, scanning electron microscopy and core observation, the analysis results show that the upper shale gas reservoir belongs to class II shale reservoir, with good geological conditions. In addition, through micro seismic monitoring and other means, most of the effective fractures formed by fracturing of the lower gas reservoir well do not extend upward to the upper gas reservoir; the formation pressure of the upper gas reservoir well before production is 21.03 MPa higher than the measured formation pressure of the adjacent well in the same period, which also proves that the upper and lower gas reservoirs are not connected, and the upper gas reservoir can be developed independently. By analyzing the production performance of the upper gas reservoir evaluation wells and calculating the technical recoverable reserves of a single well, both of them have reached high technical recoverable reserves and have good development potential.

四川盆地威远页岩气田下志留统龙马溪组下部地层海相黑色页岩广泛发育,已实现了规模效益开发。但是随着气田投产年限增长,部分气井产量递减明显,给气田稳产带来较大压力,迫切需要开辟新的勘探开发层系和领域。以威远地区龙一¹亚段上部地层为研究对象,综合利用野外剖面、岩心、岩石薄片、古生物化石、测井、地球化学资料,以岩石地层学、化学地层学和生物地层学理论为指导对目的层进行层序界面的识别和层序的划分。建立了区内龙一¹亚段上部地层的层序格架,并探讨层序格架内有机质富集和储层品质的特征。结果表明：①龙一¹亚段上部地层经历了3次中小规模的海侵—海退旋回,划分出3个四级层序和6个体系域;②层序格架对有机质富集和储层品质的控制作用,主要体现在层序Pss7较层序Pss8水体更深,且海侵规模更大,尤其在上升半旋回内TOC和孔隙度值明显优于Pss8,层序Pss7之后海侵规模减小,Pss8-Pss9水体逐渐变浅,TOC 和孔隙度变差,③层序Pss7—Pss8海侵期—海退早期为上部地层优质页岩储层发育期,是有机质富集的优势层位,也是立体开发的重点开发单元。

There widely exists marine black shale in the Lower Silurian Longmaxi Formation, Weiyuan shale gas field, Sichuan Basin, which has been developed extensively and effectively. Shale gas production, however, is in decline as this field has put into production for many years, bringing tremendous pressure to its stable production. It is urgent to open up new exploration and development strata or domains. So, taken the upper Long1¹ submember in Weiyuan shale gas field as an example, its sequence boundary was identified to divide stratigraphic sequence through outcrop survey, core analysis, thin-section identification, and paleontological fossil, as well as well logging and geochemical data and according to some theories of lithostratigraphy, chemical stratigraphy, and biostratigraphy. Moreover, the sequence framework was established for this submember. Finally, enrichment characteristics were summed up for organic matter, and reservoir quality within this framework was discussed. Results show that (i) the upper Long1¹ submember experienced three transgressive to regressive cycles in small to medium scale, and can be divided into three fourth-order sequences and six system tracts; (ii) the sequence framework affecting organic-matter enrichment and reservoir quality mostly gives expression to deeper waterbody and larger transgressive scale in Pss7 sequence compared to Pss8 one, in particular significantly better TOC and porosity within the rising half-cycle for the former. After Pss7, this scale decreases, and waterbody from Pss8 to Pss9 gradually becomes shallower, creating TOC and porosity getting worse; and (iii) the period from transgression to early regression, also corresponding to Pss7-Pss8 sequences, represents the development of quality shale reservoirs of the upper submember, in which is prevalent for organic-matter enrichment and can be conducted as the key unit for 3D development.

根据四川盆地五峰组-龙马溪组主要页岩气井和典型剖面的资料，分析了不同笔石带页岩的沉积环境、厚度等特征，明确了五峰组下部WF2-WF3笔石页岩段（奥陶纪凯迪阶晚期447.62~445.16 Ma）、五峰组观音桥层WF4灰岩/泥质灰岩/灰质泥页岩段（奥陶纪赫南特阶早期445.16~444.43 Ma）和龙马溪组底部LM1-LM4笔石页岩段（奥陶纪赫南特阶晚期444.43~443.83 Ma和志留纪鲁丹阶早中期443.83~441.57 Ma）3个层段的沉积环境、岩性和厚度特征，分析了页岩平面展布特征。研究表明：①五峰组下部WF2-WF3笔石页岩段沉积期，研究区主体上受广西运动的影响较小，沉积环境为广海深水环境，主要沉积了黑色页岩，沉积中心发育在黔东北-川东北和川南2个区域，沉积中心最大厚度为4~6 m。②五峰组观音桥层WF4笔石页岩段沉积期，受全球海平面下降和广西运动增强的影响，研究区沉积环境发生重大变化，川中古隆起、黔中古隆起和江南-雪峰古隆起进一步扩大，沉积盆地面积减小，沉积环境变为以浅海碳酸盐生屑滩沉积为主，少量深水沉积环境为辅（仅分布在川东-川东北地区的石柱-涪陵-巫溪一带和川南地区的长宁-永川一带），浅水沉积物以富含赫南特贝的灰岩、泥质灰岩等沉积为主，深水沉积物主体为含赫南特贝的灰质泥岩、页岩沉积。③龙马溪组底部LM1-LM4笔石页岩段沉积期，受全球海平面上升和广西运动的控制沉积范围比观音桥层沉积期大，主体为滞留的深水沉积环境，沉积了厚度较大的LM1-LM4笔石页岩段黑色页岩，最大厚度超过20 m。进一步分析了川中古隆起、黔中古隆起及江南雪峰古隆起对黑色页岩的控制作用，探讨了自流井水下高地/隆起、华蓥山水下高地、丁山水下高地和湘鄂西水下高地/隆起对黑色页岩沉积与保存的控制作用。

According to the data of main shale gas wells and the type sections of Wufeng Formation-Longmaxi Formation in Sichuan Basin, this study analyzes the sedimentary environment, thickness and other characteristics of shale in various graptolite zones. determines the sedimentary environment, lithology and thickness characteristics of the graptolite shale interval WF2-WF3 in the lower part of Wufeng Formation (Late Ordovician Katian, 447.62-445.16 Ma), Guanyinqiao Member WF4 limestone/argillaceous limestone/calcareous shale interval in Wufeng Formation (Early Ordovician Hirnantian, 445.16-444.43 Ma) and the graptolite shale interval LM1-LM4 in the bottom of Longmaxi Formation (Late Ordovician Hirnantian, 444.43-443.83 Ma and Early-Middle Silurian Rhuddanian, 443.83-441.57 Ma), and also explores the plane distribution characteristics of shale. The study results shows:(1) During the deposition period of WF2-WF3 in the lower part of Wufeng Formation, the main study area was less affected by Guangxi movement. The sedimentary environment was characterized by open-sea deep water, where black shale was mainly deposited. The thickness center was developed in Northeast Guizhou-Northeast Sichuan and South Sichuan. The maximum center thickness is 4-6 m. (2) During the deposition period of WF4 in Guanyinqiao Member, Wufeng Formation, the sedimentary environment in the study area had significant changes as influenced by global sea level fall and enhanced Guangxi movement; palaeouplifts in central Sichuan and central Guizhou and Jiangnan-Xuefeng palaeouplift further expanded, and the area of the sedimentary basin decreased; the sedimentary environment changed to be dominated by neritic carbonate clastic shoal and shallow water sedimentary environment, with supplement of deepwater sedimentary environment (only distributed in Shizhu-Fuling-Wuxi area in East Sichuan-Northeast Sichuan and Changning-Yongchuan area in South Sichuan). Shallow water sediments were dominated by limestone abundant in Hirnantia, argillaceous limestone and other lithologic deposits. Deepwater sediments were dominated by Hirnantia-bearing calcareous mudstone and shale deposit. (3) During the deposition period of LM1-LM4 in the bottom of Longmaxi Formation, controlled by global sea level rise and Guangxi movement, the sedimentary range was larger than that in the deposition period of Guanyinqiao Member and the main body was hydropexic deepwater sedimentary environment with thick black shale from LM1-LM4. The maximum thickness is over 20 m. Moreover, the control effect of palaeouplifts in central Sichuan and central Guizhou and Jiangnan-Xuefeng palaeouplift on black shale was further analyzed, and that of underwater highland/uplift in Zhiliujing and western Hubei and Hunan as well as underwater highland in Huaying Mountain and Dingshan on shale deposition and preservation was also explored.

Ashgillian graptolites have been described and recorded globally from 15 different paleoplates. The most diverse graptolite faunas are from the Yangtze region, South China, including 28 genera and 96 species. Among them, 25 genera and 73 species belong to the DDO fauna (Dicranograptidae – Diplograptidae – Orthograptidae fauna), and only three genera but 23 species belong to the N fauna (Normalograptidae fauna). Among the Yangtze graptolite fauna there are six endemic genera and 51 endemic species, which represent 21% and 52%, respectively, of the Ashgillian fauna in the region. This is an unusually high level of endemism. Endemic species are present in both the endemic and the cosmopolitan genera.

Even range charts from the best graptoloid-bearing sections can be improved by adding information from nearby sections. Traditionally this is achieved on a scale of discrete biozones. Zonal composites improve upon the taxon richness of individual sections but lose resolving power; they artificially cluster range-end events at zone boundaries. Graphical and numerical methods allow composite sections to be constructed on continuous scales that match or exceed the resolving power of individual sections. Using a database of 582 graptoloid-bearing sections that together preserve 2214 distinct graptoloid taxa, we show that constrained optimization algorithms can construct objective, reproducible, global time-lines for the entire Ordovician to early Devonian graptoloid clade. The underlying database of locally observed ranges allows standardization for sampling unevenness. The quality and geographic origins of support for composite taxon ranges are explicitly revealed. A high precision, interval-free, standing species richness curve derived by this approach reveals the diversity trajectory of the graptoloid clade and of the families of which it is composed. Major reorganizations of the clade at the family level took place after diversity minima in the late Darriwilian and Hirnantian. Glacial events recognized on sedimentological evidence coincide with diversity minima.

上奥陶统五峰组-下志留统龙马溪组页岩生物地层研究中，笔石作为全球公认的主导门类，为五峰组-龙马溪组页岩的精细划分提供依据。在四川盆地及其周缘地区，五峰组-龙马溪组的WF2-LM4笔石带页岩是页岩气的富集高产层段，目前主要通过岩心鉴定来划分笔石带，但取心井数量少限制了这一技术的大规模推广应用。为了克服现有技术的不足，有必要开发一种基于笔石带特征的页岩等时地层测井划分方法及系统，以达到快速、精准评价页岩气高产层段的目的。技术上，可通过标准井的笔石鉴定确定研究区的笔石带类型与自然伽马（GR）测井曲线的对应关系；对于研究区的新井，可根据GR测井曲线的各个局部峰初步确定各个笔石带的位置；某个局部峰在向上（浅层）方向上邻近的局部极小值或极大值所对应的半幅值可确定为该局部峰值所对应笔石带的上边界，也即上覆笔石带的下边界。平面上可依据沉积环境和沉积相首先划分出不同的地层分区，再在每个分区分别建立标准井笔石带与GR测井曲线的对应关系。页岩笔石带的测井划分方案能够对五峰组-龙马溪组页岩气富集高产层段的纵向和平面分布进行快速划分，为预测和评价页岩气勘探开发的富集高产层段提供技术手段。

In the biostratigraphic research of the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation shale, graptolite is globally recognized as the dominant species, providing a basis for the fine division of shale in Wufeng-Longmaxi formations. In Sichuan Basin and its periphery, the WF2-LM4 graptolite zones in Wufeng-Longmaxi formations are the shale gas enrichment and high-yield intervals. Currently, graptolite zones are mainly divided by core identification. However, the large-scale application of this technology is limited by the sparse coring wells. In order to overcome the shortcomings of the existing technology, it is necessary to develop a logging division method and system for the isochronous shale strata based on the characteristics of graptolite zones, thus achieving the rapid and accurate evaluation of the shale gas high-yield interval. From the perspective of technology, the correspondence between the types of graptolite zones of the study area and the natural gamma-ray (GR) logging curve can be determined through the identification of graptolites in standard wells. For new wells in the study area, the position of each graptolite zone can be preliminarily determined according to the local peaks of GR curve. The half amplitude corresponding to the local minimum or maximum value adjacent to a local peak in the upward direction (to shallow layer) can be determined as the upper boundary of the graptolite zone corresponding to the local peak, namely the lower boundary of the overlying graptolite zone. On the plane, different stratigraphic zones can be divided according to sedimentary environments and facies, and then the correspondence between graptolite zones of standard wells and GR curves is established in each zone. The longitudinal and horizontal distribution of the shale gas enrichment and high-yield intervals in Wufeng-Longmaxi formations can be quickly determined by the logging division scheme of graptolite zone, providing technical means for predicting and evaluating the shale gas enrichment and high yield intervals in exploration and development.

通过X射线衍射分析、物性测试、薄片鉴定、地球化学分析以及测井资料，对川南泸州地区奥陶系五峰组—志留系龙马溪组深层页岩地层开展了沉积微相细分，明确了其测井响应特征及识别方法。研究结果表明：①泸州地区页岩沉积微相可细分为5个大类、8个小类，其中强还原富有机质富硅深水陆棚相物性好、含气量高、TOC含量高、脆性矿物含量高，是最优微相细分类型，主要分布于龙一段一亚段一小层； ②利用无铀伽马、自然伽马、钍含量、声波时差、中子、横波时差及钍铀比等7条敏感曲线，通过K-means的贝叶斯判别法划分的页岩地层微相细分类型，与取心结果的吻合率高于90.0%。

Based on the data of XRD，physical properties，thin section， geochemistry and well logging，the microfacies subdivision of Ordovician Wufeng-Silurian Longmaxi shale in Luzhou area of southern Sichuan Basin was carried out，and the logging response characteristics and identification methods were defined. The results show that： （1）The microfacies of shale in Luzhou area can be subdivided into five categories and eight sub categories. Among them，the strong reduction rich organic matter and silicon-rich deep-water shelf facies is the best microfacies subdivision type with the characteristics of good physical properties and high contents of gas，<i>TOC</i> and brittle minerals，which is mainly distributed in the lower sublayer of Long-11 submember.（2）Using seven sensitive curves such as <i>KTH</i>，<i>GR</i>，<i>Th</i>， <i>AC</i>，<i>CNL</i>，<i>DTS</i> and Th/U，the microfacies subdivision types divided by the Bayesian discrimination method based on K-means are consistent with coring results with a coincidence rate greater than 90.0%.

为深入研究渝东北巫溪地区五峰组-龙马溪组页岩气储层及含气性特征，以巫溪2井钻井资料为基础，以笔石生物地层作为黑色页岩地层划分对比的&quot;标尺&quot;，对富有机质页岩有机地球化学特征、岩石学特征、储集空间类型及特征等进行系统分层研究，并分析其含气性及影响因素。研究结果表明：巫溪2井五峰组-龙马溪组富有机质页岩厚度达89.8 m，笔石序列发育完整连续；有机质类型好、丰度高、热演化程度适中，生烃条件较好；有机质丰度受沉积速率的影响，缓慢的沉积速率有利于黑色笔石页岩有机质的富集；由顶至底硅质含量逐渐增加，黏土矿物含量逐渐减少，脆性逐渐增强；富有机质硅质页岩、黏土质硅质页岩具有&quot;既甜又脆&quot;的特性，为页岩储层发育的优势岩相；纳米孔隙形态多为四边开放平行板状孔，连通性较好；联合孔径分布曲线具有&quot;多峰&quot;特征，主孔位于0.42~0.62 nm、3~5 nm段；有机质孔、黏土矿物层间孔对总孔容贡献最大，脆性矿物间孔的贡献最小；由顶至底有机质孔隙逐渐增多，黏土矿物层间孔逐渐减少；现场实测岩心含气量最高超过8 m³/t，含气性受生烃、储集和保存条件的综合控制；凯迪阶沉积期-埃隆阶沉积早期（WF2-LM6带）对应Ⅰ类优质页岩气储层，赫南特阶LM1带为最佳层段，具有&quot;最甜、最脆&quot;的特性，可作为水平井最佳靶体位置&quot;甜点段&quot;。

To deeply study the reservoir characteristics and gas-bearing capacity of Wufeng-Longmaxi Formation shale in northeast Chongqing, based on the drilling data of Well WX-2, the graptolite biostratigraphy was taken as the standard ruler for stratigraphic division and comparison in black shale to systematically study the geochemical characteristics, petrography characteristics, reserving space types and features, and gas-bearing capacity of organic rich shale, as well as its controlling factors. The research results show that in Well WX-2, the graptolite biozonations are developed completely and continuously; the organic-rich shale in Wufeng-Longmaxi Formation has a thickness of 89.8 m, characterized by good organic matter type, high abundance of organic matter, moderate thermal evolution degree and favorable hydrocarbon-generation conditions. The abundance of organic matter is influenced by sedimentary rate, and low sedimentary rate is beneficial to the enrichment of organic matter in black graptolite shale. From top to bottom, the siliceous content is gradually increased, while the content of clay minerals is decreasing, leading to the enhanced brittleness. The organic-rich siliceous shale and clayey siliceous shale are characterized by the sweet spot with brittleness, and the dominant lithofacies favorable for the development of shale reservoirs. Nanometer pore morphology is dominated by parallel-plate pores with four sides open and good connectivity. The pore size distribution curve has "multimodal" characteristics, where the dominant pores are located in the sections of 0.42-0.62 nm and 3-5 nm. The organic pores and clay mineral pores make the greatest contribution to total pore volume, while the brittle mineral pores have the least contribution. From top to bottom, organic pores are gradually increased, while clay mineral pores are decreasing. The on-site measured core gas content can exceed 8 m³/t, and the gas-bearing capacity is jointly controlled by hydrocarbon generation, reserving and preservation conditions. The early period of Katian-Aeronian stage (WF2-LM6 biozone) corresponds to Type-I high-quality shale reservoirs, where Hirnantian LM1 biozone (Normalograptus persculptus) is the best "sweet spot" with the highest brittleness as the optimal target position in horizontal wells.