滇东曲靖地区下寒武统筇竹寺组泥页岩储层特征研究

下寒武统筇竹寺组页岩是南方页岩气勘查开发重点关注的层位之一,但滇东地区下寒武统筇竹寺组黑色页岩储层研究程度较低。样品采自2014年新钻的曲页1井,对下寒武统筇竹寺组黑色泥页岩进行全岩和粘土矿物X衍射分析、TOC、岩石物性、比表面积等测试和扫描电镜实验,综合分析了滇东曲靖地区筇竹寺组泥页岩储层特征及孔隙类型。结果表明:滇东曲靖地区下寒武统筇竹寺组泥页岩矿物组成主要是石英(44.75%)、粘土矿物(25.47%)、长石(16.44%);发育粒间孔、粒内孔和有机孔3种类型孔隙;有机质孔隙发育,以中孔为主,具有一定的页岩气勘探开发潜力;页岩储层自上而下孔隙体积有逐渐变小的趋势,但在井深400 m~500 m发育高孔隙体积;泥页岩储集性能的重要指标——孔隙度主要受有机质含量及发育程度的制约。     

川南筇竹寺组页岩储集空间类型及发育影响因素

川南地区下寒武统筇竹寺组是我国南方下古生界海相页岩气重要目的层系,由于时代较老、演化程度较高、埋深较大,勘探程度及成效均不及龙马溪组,对其储层特征的研究远不够深入,随着近期在井研-犍为地区取得重大突破,展示了筇竹寺组良好的勘探前景。为探明筇竹寺组页岩主要储集空间类型及对页岩气储集的不同贡献,以钻井资料为基础,依据多种分析测试方法,对川南地区筇竹寺组海相页岩孔隙类型与分布、孔隙定量表征进行研究,并探讨了页岩中微观储集空间的成因及发育影响因素。结果表明,川南下寒武统筇竹寺组页岩微观储集空间分为有机孔、无机孔和微裂缝3大类,主体以粘土矿物层间无机孔为主,富有机质页岩段有机孔发育比例明显增高,孔隙类型与分布特征的差异主要受TOC、Ro和成岩作用的控制。     

云南曲靖地区筇竹寺组泥页岩储层发育特征与影响因素

以云南曲靖地区筇竹寺组泥页岩为例,利用氩离子抛光-场发射扫描电镜、高压压汞、常规扫描电镜等实验技术手段,探究泥页岩储层微观储集空间的发育类型与特征。结果表明：筇竹寺组泥页岩储层孔隙成因复杂,类型多样,主要发育的微观储集空间类型包括有机质孔隙、粘土矿物孔隙、颗粒矿物孔隙、微裂隙等,以有机质孔隙最为发育,提供了主要的储集空间;孔隙度介于1.59%~11.33%之间,平均值达到了5.0%,小孔、微孔所占储集空间比例约56.5%,中孔和超大孔所占比例为34.0%,大孔相对较少。控制筇竹寺组页岩孔隙发育的因素主要有TOC、矿物组分和成岩作用,TOC是影响筇竹寺组页岩储层孔隙发育的主控因素,也是提供页岩气主要储存空间的重要物质。     

沁水盆地阳泉区块太原组煤系页岩孔隙结构特征

页岩孔隙结构是影响页岩气赋存与储集的基本因素之一。为研究高演化海陆过渡相煤系页岩的孔隙结构和评价页岩气储集能力,主要运用扫描电子显微镜、高压压汞、低温N₂和CO₂气体吸附实验方法,对沁水盆地阳泉区块太原组海陆过渡相煤系页岩孔隙微观特征与孔隙结构进行了研究,并分析了太原组煤系页岩孔隙发育的影响因素。研究结果表明:沁水盆地阳泉区块太原组海陆过渡相煤系页岩孔隙度介于2.54%~12.03%之间,平均为6.61%;发育多种类型的孔隙,常见粒间孔、粒内孔和微裂缝,有机质孔不发育;太原组煤系页岩孔隙总孔容介于0.025 5~0.054 7 mL/g之间(平均0.040 1 mL/g),总比表面积介于12.34~43.38 m²/g之间(平均28.74 m²/g),微孔(<2 nm)和介孔(2~50 nm)是页岩气储集的主要载体;有机碳含量、成熟度R_o和黏土矿物含量均对煤系页岩孔隙发育产生积极影响。     

沁水盆地武乡区块上古生界煤系页岩气储层孔隙特征和孔隙结构

储层孔隙特征和孔隙结构是影响页岩气赋存与储集的重要因素。为评价海陆过渡相高演化煤系页岩储层性质与页岩气储集性能,应用扫描电子显微镜、高压压汞、低温N₂和 CO₂气体吸附、微米CT扫描、核磁共振实验方法,对沁水盆地武乡区块上古生界煤系页岩气储层孔隙微观特征和孔隙结构进行了研究。结果表明,沁水盆地武乡区块上古生界煤系页岩样品中发育多种类型微观孔隙,常见粒间孔、粒内孔和微裂缝,有机质孔几乎不发育;武乡区块煤系页岩气储层样品孔隙总孔容分布在0.021 9~0.073 5 mL/g之间,平均值为0.039 9 mL/g,总比表面积主要分布在11.94~46.83 m²/g之间,平均为29.16 m²/g,其中介孔(2~50 nm)和微孔(<2 nm)是煤系页岩气储集的主要载体。煤系页岩中的高配位数孔隙数量越多,相应的孔容和孔比表面积越大,孔隙连通性越好;在孔隙数量和总孔容相差不大的前提下,山西组煤系页岩储层孔隙结构与连通性比太原组煤系页岩稍好。     

鄂尔多斯盆地延长探区延长组页岩气储层孔隙结构特征

为了评价陆相页岩气储层的储集空间和储气能力,以鄂尔多斯盆地延长探区上三叠统延长组长7段、长9段页岩为研究对象,运用电子扫描显微镜、高压压汞、低温CO2和N2气体吸附等实验方法,对陆相页岩气储层孔隙类型特征、孔隙结构及其影响因素进行研究。结果表明：(1)延长探区上三叠统延长组陆相页岩发育多种类型微观孔隙,以粒间孔和粒内孔为主,少量晶间孔和溶蚀孔,有机质孔发育较少,为陆相页岩气赋存提供了储集空间;(2)延长组页岩中介孔(2～50 nm)贡献了其主要的孔容和比表面积,占总孔容的7437%,占总比表面积的6440%,且长9段页岩的总孔容和总比表面积均大于长7段页岩;(3)延长组页岩孔隙结构以狭缝型孔和板状孔为主,孔径主要分布在04～09 nm、3～25 nm和5～200 μm区间段内,延长组页岩平均孔径为853 nm,且长7段页岩平均孔径大于长9段页岩;(4)页岩有机碳含量、有机质成熟度及矿物成分含量共同影响着延长组页岩孔隙的发育,其中矿物成分含量是以介孔孔隙为主的延长组页岩孔隙发育的主控因素,有机碳含量及成熟度的增加主要对页岩中微孔孔隙的发育起到积极作用。     

四川盆地南部早古生代海相页岩微观孔隙特征及发育控制因素

利用环境扫描电镜(ESEM)、原子力显微镜(AFM)、比表面积分析仪对四川盆地南部早寒武世筇竹寺组以及早志留世龙马溪组页岩气储层的微观孔隙类型、结构特征进行了系统研究。四川盆地南部筇竹寺组和龙马溪组页岩气储层微观储集空间类型多样,包括黏土矿物层间孔、有机质孔、晶间孔、矿物铸模孔、次生溶蚀孔等基质孔隙。ESEM和AFM两种方法结合,能客观地反映页岩气储层的微观孔隙结构特征,具有互补性。本区筇竹寺组和龙马溪组页岩气储层以极为发育的微孔为主,为页岩气储层提供了大量孔体积和表面积,但是筇竹寺组页岩比表面积和孔体积都较龙马溪组的小。笔者认为有机碳含量、黏土矿物类型及其含量、干酪根类型及其热演化程度是控制本区筇竹寺组和龙马溪组页岩气储层微观孔隙结构的主要因素,其中,热演化程度的影响最为明显。在一定范围内,热演化程度与比表面积、孔体积与黏土矿物中伊/蒙间层含量具有正相关性,随着热演化程度、有机碳含量、Ⅱ型干酪根含量的增加,表现为微观孔隙数量增加,比表面积和孔体积增大。     

扬子地台下寒武统页岩微观孔隙及吸附性能

扬子地台下寒武统发育一套富有机质泥页岩,是中国页岩气勘探开发的重点层位之一。通过扫描电镜、低温氮气吸附和高压CH4吸附实验对遵义牛蹄塘组、南京幕府山组和池州黄柏岭组3套同一层系的下寒武统页岩微观孔隙和CH4吸附特征进行分析,并结合有机质特征、矿物组成等研究页岩孔隙及含气性能的影响因素,结果表明:(1)下寒武统页岩微观孔隙类型众多,以有机孔、黏土矿物层间孔和微裂缝为主,亦含有一定量的矿物晶间孔、黄铁矿溶蚀脱落后形成的蜂窝状孔隙以及溶蚀印模等;(2)DFT孔径分布显示下寒武统页岩和干酪根以小于4nm孔隙为主,页岩中同时含有一定量的4nm以上的孔隙,可能是来自蒙脱石;(3)所研究的下寒武统页岩比表面积、孔体积和Langmuir CH4吸附容量分别为5.58~31.96m2/g、0.026~0.088m L/g和1.36~5.3m L/g,总体上受控于有机碳含量和蒙脱石含量,但TOC和蒙脱石对不同地区下寒武统页岩物性和含气性的影响具有明显分异的现象;(4)2个牛蹄塘组干酪根的比表面积是其页岩的7.08和7.92倍,CH4吸附容量是其页岩的5.81和7.09倍,显示出干酪根是CH4吸附气赋存的主要载体之一。     

四川盆地南部地区寒武系油气勘探前景

为明确四川盆地南部地区寒武系常规油气和页岩气的勘探前景,应用岩相学和地球化学分析手段相结合,对研究区中上寒武统娄山组和下寒武统清虚洞组的厚度、孔隙度、渗透率、孔隙类型和下寒武统筇竹寺组的厚度、总有机碳质量分数w(TOC)、镜质体反射率Ro、矿物组分等进行了深入剖析.结果表明:①川南地区烃源岩厚度大(80～100m),w...     

云南曲靖地区下寒武统筇竹寺组页岩气成藏地质条件及有利区预测

基于野外地质调查、岩心观测、地球化学分析、含气量现场解吸等技术手段,深入分析了云南曲靖地区下寒武统筇竹寺组页岩气形成与富集条件。研究认为该区筇竹寺组沉积期为浅水陆棚环境,黑色泥页岩厚度237~363 m,成熟度较高,平均R_o为3.06%,TOC多数大于2.0%;页岩中石英含量平均为53.18%,碳酸盐矿物含量平均为18.82%,储集空间以泥页岩微裂缝、粒间孔、粒内孔和有机孔为主;区域具有较好的页岩气勘探潜力。根据多口钻井现场解吸气量较低的特征,推断保存条件是曲靖地区页岩气富集的关键,马龙为页岩气勘探远景区。     

皖南地区古生界页岩孔隙特征及影响因素

为了评估下扬子皖南地区古生界页岩气储层性质,应用扫描电子显微镜、高压压汞法、N₂和CO₂气体吸附法,对皖南地区古生界页岩孔隙特征和孔隙结构进行研究,并探讨页岩孔隙发育的主要影响因素。结果表明,皖南地区古生界页岩孔隙度和渗透率低,页岩样品中常见粒间孔、凝絮孔、溶蚀孔、基质晶间孔和有机质孔,并且发育微米-纳米级孔隙。古生界页岩孔隙中50%以上为微孔和介孔;孔隙结构主要为圆柱孔、狭缝型孔和混合型孔,平均孔径范围为4.17~12.06 nm。页岩孔容和比表面积随着有机碳(TOC)含量的增大而增大;页岩孔隙度随着有机质成熟度(R_o)的增大而减小;页岩孔容随着黏土矿物含量的增加而增大,随着脆性矿物含量的增加而减小。     

Characterization of a Lacustrine Shale Reservoir and the Evolution of its Nanopores: A Case Study of the Upper Cretaceous Qingshankou Formation in the Songliao Basin,Northeastern China

The Songliao Basin is one of the most important petroliferous basins in northern China. With a recent gradual decline in conventional oil production in the basin, the exploration and development of unconventional resources are becoming increasingly urgent. The Qingshankou Formation consists of typical Upper Cretaceous continental strata, and represents a promising and practical replacement resource for shale oil in the Songliao Basin. Previous studies have shown that low-mature to mature Qingshankou shale mainly preserves type Ⅰ and type Ⅱ1 organic matter, with relatively high total organic carbon(TOC) content. It is estimated that there is a great potential to explore for shale oil resources in the Qingshankou Formation in this basin. However, not enough systematic research has been conducted on pore characteristics and their main controlling factors in this lacustrine shale reservoir. In this study, 19 Qingshankou shales from two wells drilled in the study area were tested and analyzed for mineral composition, pore distribution and feature evolution using Xray diffraction(XRD), scanning electron microscopy(SEM), low-pressure nitrogen gas adsorption(N2-GA), and thermal simulation experiments. The XRD results show that clay, quartz, and feldspar are the dominant mineral constituents of Qingshankou shale. The clay minerals are mostly illite/smectite mixed layers with a mean content of 83.5%, followed by illite, chlorite, and kaolinite. There are abundant deposits of clay-rich shale in the Qingshankou Formation in the study area, within which many mineral and organic matter pores were observed using SEM. Mineral pores contribute the most to shale porosity;specifically, clay mineral pores and carbonate pores comprise most of the mineral pores in the shale. Among the three types of organic matter pores, type B is more dominant the other two. Pores with diameters greater than 10 nm supply the main pore volume;most are half-open slits and wedge-shaped pores. The total pore volume had no obvious linear relationship with TOC content, but had some degree of positive correlation with the content of quartz + feldspar and clay minerals respectively. However, it was negatively correlated with carbonate mineral content. The specific surface area of the pores is negatively related to TOC content, average pore diameter, and carbonate mineral content. Moreover, it had a somewhat positive correlation with clay mineral content and no clear linear relationship with the content of quartz + feldspar. With increases in maturity, there was also an increase in the number of carbonate mineral dissolution pores and organic matter pores, average pore diameter, and pore volume, whereas there was a decrease in specific surface area of the pores. Generally, the Qingshankou shale is at a low-mature to mature stage with a TOC content of more than 1.0%, and could be as thick as 250 m in the study area. Pores with diameters of more than 10 nm are well-developed in the shale. This research illustrates that there are favorable conditions for shale oil occurrence and enrichment in the Qingshankou shale in the study area.     

渝东南渝页1井下志留统龙马溪组页岩孔隙特征及其主控因素

富有机质黑色页岩的孔隙结构控制了页岩气的赋存状态和储气量。中国南方地区下志留统是页岩气发育的最重要层位之一。为研究页岩的孔隙特征及其主控因素,对以下志留统龙马溪组页岩气为勘探目标的渝页1井的岩心进行系统的采样,并进行了比表面和孔径、有机质成熟度(Ro)、显微组分、总有机碳(TOC)含量、全岩X射线衍射和粘土矿物含量等一系列分析测试。结果显示,黑色页岩的孔径主要分布于2~5 nm,即以中孔隙为主;中孔体积占总体积的70%左右,微孔体积和宏孔体积分别占10%和20%左右。页岩孔隙结构(微孔体积、中孔体积和宏孔体积)和组成(碎屑矿物成分、粘土矿物成分、TOC和Ro)的相关关系分析表明：粘土矿物对微孔体积和中孔体积都具有控制作用,并且对中孔体积的控制作用更加显著;陆源碎屑含量的增加有利于宏孔体积的增加;有机质成熟度较高时和高成熟度有机碳含量都与宏孔隙体积呈正相关,这可能与高成熟有机质中nm级显微裂缝的发育导致宏孔体积增加有关。     

基于氮吸附法的页岩有机孔隙结构表征

页岩的微观孔隙结构对页岩气的赋存至关重要,气体吸附法可以较好对页岩的微观孔隙结构进行表征。通过测量丁页1井不同深度样品的矿物含量、RO值和TOC含量,结果表明丁页1井龙马溪组页岩样品的矿物含量比较稳定,有机质成熟度变化不大,均为过成熟。通过低温氮吸附法计算样品的比表面积和微、介孔容积和孔径分布,结果表明：（1）样品的平均孔径为2.8 ~ 4.9 nm,10 nm以下的孔隙提供了大部分的微、介孔容积。微、介孔容积为0.00136 ~ 0.0108 cm3/g,平均0.004 cm3/g,比表面积为2.54 ~ 13.69 m2/g,平均6.68 m2/g;（2）微、介孔容积、比表面积和TOC三者之间有很强的正相关性。通过计算TOC含量为0时的微、介孔容积和比表面积推算无机孔和有机孔之间的比例和其对比表面积的影响,发现有机孔提供了大部分的微、介孔容积,有机孔还是比表面积的主要贡献因素;（3）样品的吸附曲线符合IPUAC分类中的第IV型吸附曲线,样品的脱附曲线反映样品孔隙形态随TOC含量的增加,由楔形孔（不定型孔）变为连通的墨水瓶型孔（狭缝型孔）或墨水瓶型孔。     

滇东地区马龙区块筇竹寺组海相页岩储层特征及对比研究

利用最新钻探的马页1井的井下资料和大量岩心样品的测试分析数据,并结合野外地质调查资料,从富有机质页岩的有机地化、矿物组分、储集特性和裂缝特征等方面,系统地研究了滇东地区马龙区块下寒武统筇竹寺组黑色页岩的储层特征。研究区筇竹寺组黑色页岩有机碳丰度较高,TOC含量普遍大于2%;由于筇竹寺组地层较老,黑色页岩的有机质均处于高成熟过成熟阶段;黑色页岩的矿物组分主要为碎屑矿物、碳酸盐矿物和黏土矿物。脆性矿物含量较高,脆性指数平均值为0.62。黏土矿物主要以伊利石为主,其次为伊蒙混层和绿泥石,高岭石含量较低;该区筇竹寺组页岩的孔、渗较低,孔隙类型复杂多样,主要包括“墨水瓶”孔、板状孔和狭缝型孔。页岩主要发育纳米级中孔,且比表面积和总孔体积偏小,平均值分别为9.18 m2/g和10.38×10-3cm3/g;储层裂缝以高角度缝为主,上部碳质页岩裂缝发育,下部粉砂质页岩裂缝不发育。有机碳含量和脆性矿物含量促进了页岩裂缝的发育;与国内外典型海相页岩储层对比,滇东地区马龙区块筇竹寺组页岩以粉砂质页岩为主,碳质页岩层较薄,而Fort Worth盆地Barnett页岩、焦石坝地区龙马溪组页岩和岑巩区块牛蹄塘组页岩主要为硅质页岩和碳质页岩,筇竹寺组页岩的岩相与这3组海相页岩相比较差;筇竹寺组页岩有机碳含量低于其他3组海相页岩,有机质丰度中等;筇竹寺组页岩脆性矿物含量与龙马溪组页岩相当,稍低于牛蹄塘组页岩,脆性较好;Barnett页岩和龙马溪组页岩无论在储集物性上还是有机质孔隙发育程度上都要优于筇竹寺组页岩和牛蹄塘组页岩,筇竹寺组页岩有机质孔隙主要发育于有机质与黏土的混合物中;筇竹寺组页岩裂缝发育程度低于Barnett页岩、龙马溪组页岩和牛蹄塘组页岩。此外,筇竹寺组页岩含气量低于其他3组海相页岩,但吸附能力较强。     

Controlling Factors of Organic Nanopore Development: A Case Study on Marine Shale in the Middle and Upper Yangtze Region,South China

The Upper Ordovician Wufeng-Lower Silurian Longmaxi and the Lower Cambrian Qiongzhusi shales are the major targets for shale gas exploration and development in China. Although the two organic-rich shales share similar distribution ranges and thicknesses, they exhibit substantially different exploration and development results. This work analyzed the nanopore structures of the shale reservoirs in this region. Pore development of 51 shale samples collected from various formations and locations was compared using the petromineralogical, geochemical, structural geological and reservoir geological methods. The results indicate that the reservoir space in these shales is dominated by organic pores and the total pore volume of micropores, mesopores, macropores in different tectonic areas and formations show different trends with the increase of TOC. It is suggested that organic pores of shale can be well preserved in areas with simple structure and suitable preservation conditions, and the shale with smaller maximum ancient burial depth and later hydrocarbon-generation-end-time is also more conducive to pore preservation. Organic pore evolution models are established, and they are as follows: ① Organic matter pore development stage, ② Early stage of organic matter pore destruction, and ③ late stage of organic matter pore destruction. The areas conducive to pore development are favorable for shale gas development. Research results can effectively guide the optimization and evaluation of favorable areas of shale gas.