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正1研究目的(Objective)中国南方下寒武统牛蹄塘组广泛发育暗色页岩,有机质含量丰富,沉积厚度大,但普遍存在有机质成熟度过高导致页岩气赋存不利等因素。贵州黄平地区牛蹄塘组为一套深水陆棚相沉积,以炭质页岩为主,具有页岩厚度大、有机质含量高、成熟度适中且构造保存较好等有利条件,目前尚未获得页岩气调查突破。在前期研究的基础上,为摸清牛蹄塘组在该区地层发育,力争获得页岩气发现,在武陵山褶皱带南部贵州黄平地区上塘复背斜东翼南段部署实施了黄地1井,钻遇牛蹄塘组见良好油气 相似文献
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为查明柳州东部雒容有利区下石炭统鹿寨组的岩性、沉积相及富有机质有效泥（页）厚度、含气性,获取富有机质泥页岩段的页岩气相关参数,广西壮族自治区国土资源厅在桂中坳陷部署了一口小口径页岩气地质调查井——桂柳地1井。通过选用HXY-8B型岩心钻机、采用直井多开次钻探方法,分层钻进;利用前导向扩孔钻具分级扩孔,逐级下套管;配合PVA1788无固相冲洗液体系;同步开展录井、测井、固井及钻井评价等配套工作,解决了深孔泥岩中钻进取心困难、井壁稳定性差、钻孔弯曲度超标等施工难题。该井钻井技术可为该地区石炭系鹿寨组泥页岩钻探提供有益经验。 相似文献
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为研究旧司组页岩气聚集条件和含气性特征,以黔西地区下石炭统旧司组页岩为研究对象,采用薄片鉴定、X-射线衍射分析、覆压孔渗、扫描电镜、低温氮吸附、有机地球化学、含气量现场解析、等温吸附等测试方法开展研究。结果表明:黔西地区旧司组富有机质页岩广泛发育,厚度主体上介于30~100 m之间,有机碳含量高,有机质类型主要为Ⅱ型,处于过成熟生干气阶段;矿物成分主要为石英和黏土矿物,脆性指数均大于50%,为超低孔、超低渗,孔隙类型多样,孔径介于2~4 nm之间,以中孔为主,比表面积和总孔体积较大,具备良好的页岩气聚集条件;页岩微观孔隙的分形维数(D1、D2)较大,平均值分别为2.804 1、2.753 8,页岩孔隙结构较为复杂、非均质性较强;现场解析总含气量主体介于1.5~3.0 m3/t之间,等温吸附气量介于1.58~4.52 m3/t之间,含气性能较好,旧司组显示出具有良好的页岩气勘探潜力。 相似文献
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石炭系是柴达木盆地油气勘探的新层系,油气勘探程度低,但发育厚度大的高有机质丰度泥页岩,具有很好的页岩气资源潜力。通过对德令哈坳陷石炭系露头剖面进行实测和钻井岩心分析,明确石炭系泥页岩空间展布特征。测定样品有机地球化学参数、孔渗特征,并且进行等温吸附和渗流实验,分析其储集特征。结合德参1井盆地模拟分析,研究石炭系页岩气成藏事件,划分德令哈坳陷石炭系页岩气系统。研究表明：石炭系泥页岩广泛发育,埋深较大但未发生变质;泥页岩有机质丰度较高,有机质类型主要为Ⅱ2型和Ⅲ型,处于成熟-高成熟演化阶段;上石炭统泥页岩发育优于下石炭统;泥页岩表现为低孔低渗特征,孔隙度在1.89%~5.48%,渗透率为(0.115~2.7)×10-7 μm2;上覆地层发育厚层泥页岩可以提供良好的盖层条件;古近纪末-现今为页岩气系统形成的关键时期;上石炭统克鲁克组钻遇天然气显示,证实了德令哈坳陷石炭系页岩气系统的存在。在泥页岩厚度、埋深、TOC含量、成熟度等条件综合评价基础上,将德令哈坳陷划分为德令哈页岩气系统与埃北页岩气系统。 相似文献
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内蒙古自治区发育有三套富含有机碳的泥页岩地层,即中-上元古界渣尔泰山群和白云鄂博群的海相含炭页岩系:晚古生界上石炭统太原组和二叠系山西组的海陆交互相含炭页岩系;中新生界的陆相含炭页岩系,页岩气主要赋存在陆相含炭页岩系中.根据煤、油气勘查成果以及页岩气评价资料,认为鄂尔多斯盆地含页岩气地层厚度大,有机质碳含量高,为好的烃源岩;在阿拉善盆地、二连-海拉尔盆地、通辽地区中生界炭质页岩、煤层及油页岩发育且厚度大,河套盆地中渐新统临河组和中新统五原组形成于潟湖相,富含有机质,为生油气的有利层位,推断这些盆地页岩气资源前景良好.依据页岩气形成条件和含页岩气地层的相关分析,提出页岩气勘查工作首先在鄂尔多斯盆地和二连-海拉尔盆地群展开,在获得一定成果的基础上,再对阿拉善盆地和河套盆地进行勘查,对通辽盆地页岩气进行野外调查. 相似文献
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柴达木盆地北缘侏罗系页岩气地质特征及控制因素 总被引：3，自引：0，他引：3
柴达木盆地侏罗系赋存着丰富的煤炭和油气资源,已有钻井和近年施工的页岩气参数井多次证实有页岩气存在。文中在柴达木盆地北缘侏罗系共识别出9个富有机质泥页岩段,对这些泥页岩的岩性、厚度、分布、有机质组成和热演化程度等特征进行研究,分析了柴北缘侏罗系页岩气地质特征。富有机质泥页岩层发育5种岩相类型,包括油页岩、黑色页岩、碳质泥岩、灰黑色泥岩和黑灰色粉砂岩,主要形成于冲积扇辫状河、辫状河三角洲泥炭沼泽、扇三角洲和湖泊沉积体系,而最有利的富有机质泥页岩成因环境是湖泊、辫状河三角洲泥炭沼泽。柴北缘侏罗系富有机质泥页岩层厚度大(平均累计厚度10～916 m);TOC含量为1.24％～8.6％,总体大于4％;有机质类型较好（H1-H4段和H6-H8段为Ⅱ2 Ⅲ型,H5和H9段为Ⅰ Ⅱ1型）,热演化程度整体处于未成熟成熟阶段。从古气候、盆地构造演化和沉积古环境3个方面探讨了柴北缘侏罗系页岩气层的控制作用。研究表明,富有机质泥页岩主体形成于古气候潮湿温暖的早、中侏罗世,早侏罗世末和晚侏罗世气候干热化阻断富有机质泥页岩的发育;侏罗纪5个阶段的断陷盆地演化控制着泥页岩层的形成发育,湖西山组沉积期为形成于潜西-冷湖-南八仙地区的快速断陷盆地,沉积了H1-H3富有机质泥页岩段,有机质丰度高,厚度大,结构稳定性较好;小煤沟组沉积期主要为局限发育在潜西和大煤沟地区的断陷速率快慢周期变化盆地,形成了局限分布的H4-H6泥页岩;大煤沟组沉积期为以鱼卡和大煤沟地区为沉积中心的缓慢断陷盆地,形成了与煤层共生的H7泥页岩,有机碳含量高,厚度大,分布稳定;石门沟组沉积期为向东不断迁移的缓慢快速断陷盆地,沉积了分布不稳定厚度中等的H8泥岩和厚度大,有机质丰度高,区域连续分布的H9泥页岩;采石岭组和红水沟组沉积期为干旱气候条件下的前陆挠曲盆地,没有富有机质泥页岩形成。因此,下侏罗统H1-H3泥页岩,中侏罗统H7、H9泥页岩是柴达木盆地北缘侏罗系页岩气勘探开发的重点层位。 相似文献
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贵州发育多套黑色页岩层,其中最重要的页岩层为寒武系牛蹄塘组/渣拉沟组、奥陶系五峰组-志留系龙马溪组和石炭系打屋坝组/旧司组,前期实施了多口探井调查其页岩气资源条件,勘查结果显示不同的黑色页岩页岩气富集成藏特征有明显差异。牛蹄塘组/渣拉沟组页岩层在全省分布最广,有机质丰度最高,但热演化程度同样很高,页岩气含量偏低甚至局部地区以氮气为主,受构造破坏影响很大;五峰组—龙马溪组、打屋坝组/旧司组页岩层分布范围和有机质丰度不如牛蹄塘组/渣拉沟组,但生烃演化历程相对要短,热演化程度适中,受构造破坏影响相对较小,页岩气富集受有机质丰度、微观孔隙发育、矿物成分影响明显。三个主要页岩层中,五峰组—龙马溪组和打屋坝组/旧司组页岩气勘查显示较好,资源条件较佳,找矿潜力大,是下一步贵州页岩气勘查开发的重点层位。 相似文献
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《China Geology》2020,3(2):210-220
Shenhu Area is located in the Baiyun Sag of Pearl River Mouth Basin, which is on the northern continental slope of the South China Sea. Gas hydrates in this area have been intensively investigated, achieving a wide coverage of the three-dimensional seismic survey, a large number of boreholes, and detailed data of the seismic survey, logging, and core analysis. In the beginning of 2020, China has successfully conducted the second offshore production test of gas hydrates in this area. In this paper, studies were made on the structure of the hydrate system for the production test, based on detailed logging data and core analysis of this area. As to the results of nuclear magnetic resonance (NMR) logging and sonic logging of Well GMGS6-SH02 drilled during the GMGS6 Expedition, the hydrate system on which the production well located can be divided into three layers: (1) 207.8–253.4 mbsf, 45.6 m thick, gas hydrate layer, with gas hydrate saturation of 0–54.5% (31% av.); (2) 253.4–278 mbsf, 24.6 m thick, mixing layer consisting of gas hydrates, free gas, and water, with gas hydrate saturation of 0–22% (10% av.) and free gas saturation of 0–32% (13% av.); (3) 278–297 mbsf, 19 m thick, with free gas saturation of less than 7%. Moreover, the pore water freshening identified in the sediment cores, taken from the depth below the theoretically calculated base of methane hydrate stability zone, indicates the occurrence of gas hydrate. All these data reveal that gas hydrates, free gas, and water coexist in the mixing layer from different aspects. 相似文献
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正1研究目的(Objective)勘探实践证明,志留系是我国目前最为有利、最有前景的页岩气勘探开发层系,已在四川盆地的涪陵、长宁—威远等地区取得了页岩气重大突破,进入商业开发阶段。基础地质调查表明,四川盆地周缘地区志留系黑色页岩发育,尤其是鄂西—渝东北地区,志留系底部龙马溪组富含笔石黑色页岩发育,厚度大,页岩有机质丰度高,生烃潜力大。20世纪80年代以来,中石化、中石油实施的常规油气钻井,在志留系龙马溪组均见到了不同程度的页岩气显示,展示了其 相似文献
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《Russian Geology and Geophysics》2016,57(7):1064-1077
Because of the lack of gas supply from source rocks and gas loss, inefficient tight-gas fields represent a high share of all gas reservoirs in China. These gas fields are characterized by low abundance and large gas reserves. Here, the He 8 tight-gas reservoirs in the western region of the Sulige gas field are used as an example to characterize gas distribution under conditions of less efficient charging. Results show the following characteristics. First, the sandstone densification process has a relatively large impact on the charging of gas. Litharenite was already subjected to densification at the time of large-scale gas charging, and this was not conducive to gas charging. On the contrary, for sublitharenite, although strong compaction has already occurred during gas generation, quartz overgrowth that leads to further densification of the gas reservoirs occurs simultaneously with large-scale gas charging. This facilitates gas charging and is characterized by concomitant densification and reservoir formation. Second, structure traps can control the accumulation of gas to a certain extent. In particular, when physical properties of sandstones within the structure traps are appropriate, gas saturation during gas charging can be increased by approximately 7%. Third, less efficient charging is the main cause of the complex gas and water distribution in the He 8 gas reservoirs. The strong heterogeneity of the reservoirs and the decline in the gas reservoir pressure caused by tectonic uplift in the Yanshan period further exacerbate the complexity of gas and water distribution. These factors ultimately caused the He 8 gas reservoirs to become a multireservoir gas field with several gas–water interfaces. The He 8 gas reservoirs are neither conventional gas nor continuous gas reservoirs. Rather, they are quasi-continuous gas reservoirs, and the accumulation of gas is controlled by both the top surface of sandstone and the physical properties of the reservoirs. Traps and high-quality reservoirs within the regional traps are beneficial for the gas accumulation. 相似文献
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邓莉 《沉积与特提斯地质》2004,24(1):105-108
新都气田蓬莱镇组气藏是由多套含气砂体组合而成的工业性气藏，河口坝为其最有利沉积微相，储层岩性以细粒岩屑砂岩、细粒岩屑石英砂岩为主，岩性较为致密，以中一低孔渗为主。含气地震响应模式为“低频、强振幅、低阻抗”；测井信息反映储层具有“二高三低”特征。 相似文献
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鄂尔多斯盆地苏里格气区是中国最大的非常规连续型致密砂岩大气区,探讨其天然气分布与聚集机制可为非常规致密砂岩气的勘探提供理论依据。研究区地球化学方面的直接证据和储层、古构造背景等方面的间接证据包括:天然气主要分布在生气强度高值区,天然气组分未发生明显的混合效应,含气饱和度远离源岩明显减少,天然气碳同位素反映与原地烃源岩来源相同、成熟度一致的特征;储层经历了强烈的压实、硅质胶结和钙质胶结3种主要的致密化成岩作用,储层完成致密化过程、形成低孔渗、细孔喉致密储层的时间(Ro小于1.3%,早白垩世早期)要早于天然气大量生成的时间(Ro为1.5%~2.5%,早白垩世早期到晚白垩世初期);晚侏罗世到现今古构造坡降都较为平缓,缺乏形成较高垂直连续气柱的条件,综合多方面的证据,论证了现今苏里格大气区天然气分布聚集为近源短距离运聚的结果。 相似文献
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《Applied Geochemistry》2001,16(9-10):1033-1039
The CO2 gas pools of Jiyang sag are located along the Gaoqing–Pingnan fault within a region of alkaline basalts. The concentration of CO2 in the gas pools is in the range of 68.85–96.99%. All of the geochemical tracers for the CO2 gas pools support the suggestion that CO2 was mainly derived from mantle degassing. The δ13C values of CO2 in the gas pools are in the range of −5.67–−3.41‰, which are higher than those of organogenic CO2, and near to those of abiogenic CO2. Their 3He/4He ratios are 2.80–4.47×106, i.e. the R/Ra ratios are 2.00–3.19, showing that the Jiyang sag had undergone strong mantle degassing. CO2/3He ratios are 0.59–0.89×109, which are identical to those for N-MORB, indicating that CO2 in these CO2 gas pools was mainly derived from the mantle. Accompanying the intrusion of mantle-derived magma, the mantle-derived CO2 migrated upwards along deep faults and was trapped in advantageous structures forming gas pools. 相似文献
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洛带气田遂宁组主要为三角洲前缘斜坡亚相和浅湖亚相沉积,其物源区为龙门山隆起区。大多数产气层均处于浅湖砂坝、河口砂坝、水下分支河道及远砂坝等有利沉积微相较厚的砂体分布范围内。沉积微相的发育控制了砂体在平面上的展布,进而控制天然气富集区的分布区域与范围。产气层段砂体在纵向上的厚度与砂岩粒度受控于不同微相在纵向上的叠置关系,产能的高低与储层的孔、渗条件和孔隙结构特征有更直接的联系。自深层运移上来的天然气至上侏罗统遂宁组储层中占高点运移和聚集,形成构造-岩性复合型次生气藏,原生裂缝的发育对产量的增加起着至关重要的作用。因此,寻找构造适当部位有利沉积微相内的优质储集体和原生裂缝发育区,应为洛带气田今后的重点勘探方向。 相似文献
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L25气田位于琼东南盆地深水西区,由上中新统黄流组早、晚2期限制型重力流水道岩性圈闭相关气藏纵向叠置而成,早期的Ⅲ、Ⅳ气组为强超压气藏(压力系数1.806～1.840),晚期的Ⅰ、Ⅱ气组为常压气藏(压力系数1.170～1.188)。天然气组分、天然气碳同位素分析表明,L25气田天然气为有机成因煤型气。通过对天然气甲烷碳同位素与烃源岩镜质组反射率之间的关系、凝析油生物标志化合物特征、烃源岩埋藏史、热史等的综合分析,认为L25气田天然气来源于乐东凹陷下渐新统崖城组海相烃源岩生成的成熟—高成熟天然气。天然气成藏过程分析揭示,L25气田经历了早、晚2期天然气充注成藏:2.0Ma,成熟—高成熟天然气充注于晚期沉积的限制型重力流水道岩性圈闭,形成Ⅰ、Ⅱ气组常压气藏;近于现今,高成熟天然气充注于早期沉积的限制型重力流水道岩性圈闭,形成Ⅲ、Ⅳ气组强超压气藏。沉积与储层、压力演化及成藏特征的研究表明,早期天然气充注的规模化的储集体是琼东南盆地深水区新近系更有利的天然气勘探方向。 相似文献
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Natural gas in the Xujiahe Formation of the Sichuan Basin is dominated by hydrocarbon (HC) gas, with 78–79% methane and 2–19% C2+ HC. Its dryness coefficient (C1/C1–5) is mostly < 0.95. The gas in fluid inclusions, which has low contents of CH4 and heavy hydrocarbons (C2+) and higher contents of non-hydrocarbons (e.g. CO2), is a typical wet gas produced by thermal degradation of kerogen. Gas produced from the Upper Triassic Xujiahe Formation (here denoted field gas) has light carbon isotope values for methane (δ13C1: −45‰ to −36‰) and heavier values for ethane (δ13C2: −30‰ to −25‰). The case is similar for gas in fluid inclusions, but δ13C1 = −36‰ to −45‰ and δ13C2 = −24.8‰ to −28.1‰, suggesting that the gas experienced weak isotopic fractionation due to migration and water washing. The field gas has δ13CCO2 values of −15.6‰ to −5.6‰, while the gas in fluid inclusions has δ13CCO2 values of −16.6‰ to −9‰, indicating its organic origin. Geochemical comparison shows that CO2 captured in fluid inclusions mainly originated from source rock organic matter, with little contribution from abiogenic CO2. Fluid inclusions originate in a relatively closed system without fluid exchange with the outside following the gas capture process, so that there is no isotopic fractionation. They thus present the original state of gas generated from the source rocks. These research results can provide a theoretical basis for gas generation, evolution, migration and accumulation in the basin. 相似文献