Radiogenesis of Low Maturity Natural Gas in the Turpan-Hami Basin,NW China

The origin of the Jurassic low maturity natural gas in the Turpan-Hami Basin has attracted scientists’attention for some time,and it is known that radiogenesis may have played a role.However,little has been done on the uranium-rich background of the whole basin.Based on plentiful logging and geological data for the Jurassic strata in the Turpan-Hami Basin,this research examined the features and factors controlling the distribution of rocks with high gamma reading.The results show that 70%-100%of the rocks with high gamma readings correspond to mudstones in the prodelta subfacies rather than those in semideep-deep lacustrine subfacies rich in mudstones.Therefore,we propose that the distribution of rocks with high gamma readings is mainly controlled by sedimentary facies rather than by lithology.Further analysis of the gamma spectrometry logging data shows that high gamma values are more strongly correlated with U content than with Th or K content.By comparing the U and Th contents of felsic rocks in peripheral provenances,we find that the Jueluotage Mountain and Harlik Mountain were the dominant uranium sources for the Jurassic Turpan-Hami Basin.Radiolysis due to high-level uranium in the prodelta subfacies can make the low maturity source rocks generate H2 and CH4,thus contributing to the production of low maturity natural gas in the Turpan-Hami Basin.

Characteristic of homodrimane and maturity of organic matter in the low mature source rocks

Bicyclic sesquiterpenoids are mostly used to illustrate the origins of organic matter and genetic types of crude oil presently.In this paper,the relationship between distributions and compositions of C16 homodrimane in immature to mature source rocks and evolution of organic matter was studied,and the correlation between C16 homodrimane at immature to low mature stages and thermal evolution of organic matter was analyzed.The results show that in terrestrial facies depositional system,the ratio of 8α(H)-homodrimane to 8β(H)-homodrimane has a high sensitivity about the maturity’s minor changes at immature to low mature stages.It is found that when the vitrinite reflectance R0<0.7%,the ratio significantly decreases with increasing burial depth or maturity.This kind of phenomenon reveals that these parameters may be the useful maturity indicators for determining the relative maturation of organic matter at immature to low mature stages,and have certain practical value in biogeochemical and en- vironmental geochemical research on low mature oil and gas.

Distribution Patterns of Pentacyclic TriterpenoidHydrocarbons in Low-Mature Source Rocksfrom Eastern China

: Four typical distribution patterns of pentacyclic triterpenoid hydrocarbons (types A-D) are distinguished in the low-mature source rocks from eastern China. Type A has a relatively high content of pentacyclic triterpenes. It exists in immature sediments and the distribution and abundance of triterpenes vary with the maturity of the sediments. An unknown C30 triterpene (UCT2) has also been detected in very shallow sediments. This compound is very unstable and disappears rapidly with the increase of depth. Type B is characterized by a relatively high amount of 17α(H), 21β(H)-30-homohopane. This kind of distribution pattern is common in coals and terrestrial sediments of low maturity. Type C has a relatively high content of diahopane and neohopane series. The analysis shows that this distribution pattern may have an indirect relationship with the input of higher plants despite its microbial source. There are C30—unconfirmed triterpane (UCT2) and a relatively high content of C35 hopane in type D. The distribution patterns of pentacyclic triterpenoids are varied under influences of biological sources, diagentic and sedimentary environments, thermal maturity etc. Therefore, they can provide useful information about the source rocks. Based on geochemical characteristics of the source rocks, the authors postulated that the type B and type C patterns are mainly related to suboxic-anoxic environments. Type D indicates the reducing to anoxic environment, in which C30-UCT3 may be related to some specific biological source in saline environments. The precursors and thermal evolution of some triterpenoid hydrocarbons are also discussed herein.

Low-mature gases and their resource potentiality

In the 80’s of last century, based on the advances in natural gas exploration practice, the concepts of bio-thermocatalytic transitional-zone gas and early thermogenetic gas were proposed, and the lower limit Ro values for the formation and accumulation of thermogenetic natural gases of industrial importance have been extended to 0.3%–0.4%. In accordance with the two-stage model established on the basis of carbon isotope fractionation involved in the formation of coal-type natural gases, the upper limit Ro values of lowly evolved natural gases should be set at 0.8%–1.0%. This is the concept of low-mature gas which is commonly accepted at the present time. The Urengoy super-large gas field in western Siberian Basin is a typical example of low-mature gas field, where low-mature gas reserves account for 20% of the globally proven natural gas reserves, and this fully indicates the importance of this kind of resources. The proven reserves of natural gases in the Turpan-Hami Basin of China are approximate to 1000×108 m3, and the thermal evolution indices of source rocks are Ro=0.4%–0.8%. The δ13C1 values of methane are mainly within the range of -44‰– -39‰ (corresponding to Ro=0.6%–0.8%), and those of ethane are mainly within the range of -29‰– -26‰, indicating that these natural gases should be designated to the coal-type low-mature gases. The light hydrocarbon evolution indices of natural gases also provide strong evidence suggesting that they are the coal-type low-mature gases. If so, low-mature gas in the Turpan-Hami Basin has been accumulated to such an extent as to be equivalent to the total reserves of three large-sized gas fields, and their existence is of great significance in the study and exploration of China’s low-mature gases. If it is evidenced that the source rocks of low-mature gases are related mainly to coal measures, China’s abundant lowly evolved coal series resources will provide a huge resource potentiality for the generation of low-mature gases.

Kinetic Modeling the Formation of Low-mature Gases and Analysis of the Possibility to Be Accumulated

At present, shallow gases have received much attention due to low cost in exploration and production. Low-mature gases, as one significant origin to shallow gas, turns to be an important research topic. The present understanding of low-mature gases is confined within some geological cases, and few laboratory studies have been reported. Therefore, the potential and characters of low- mature gases are not clear up to now. Here, two premature samples （one coal and the other shale） were pyrolyzed in a gold confined system. The gaseous components including hydrocarbon gases and non-hydrocarbon gases were analyzed. Based on kinetic modeling, the formation of low-mature gases was modeled. The results showed that during low mature stage, about 178 mL/gTOC gas was generated from the shale and 100 mL/gTOC from the coal. Two third to three fourth of the generated gases are non-hydrocarbon gases such as H2S and CO2. The total yields of C1-5 for the two samples are almost the same, 30-40 mL/gTOC, but individual gaseous hydrocarbon is different. The shale has much lower C1 but higher C2-5, whereas the coal has higher C1 but lower C2-5. Hydrocarbon gases formed during low-mature stage are very wet. The stable carbon isotope ratios of methane range from -40‰ to -50‰ （PDB）, in good consistence with empiric criterion for low-mature gases summed up by the previous researchers. The generation characters suggest that the low-mature gases could be accumulated to form an economic gas reservoir, but most of them occur only as associated gases.

Study on Immature and Low Mature Oilin Huanghua Depression

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金坛盆地始新统阜宁组四段页岩油地质条件

为评价以金坛盆地为代表的苏南新生代残留盆地非常规油气勘探潜力,以金坛盆地J9井钻井、岩心、测井及分析测试资料为基础,开展阜宁组四段岩石沉积特征、有机地球化学特征、矿物组成特征、储层特征等地质条件分析。研究结果表明:金坛盆地阜四段形成于浅湖—半深湖为主的半封闭—封闭咸化沉积环境,具有泥页岩厚度大(深凹带大于250 m)、总有机碳(TOC)含量偏低(平均为1.02%)、热演化成熟度(R_(o))中低(介于0.81%~0.85%)的特征,具备一定的成烃物质基础。阜四段泥页岩发育裂缝、孔隙两类储集空间,具备良好的储集性能,同时脆性矿物含量较高,有利于后期的压裂改造。结合已有钻孔油气显示情况,认为苏南地区茅山构造推覆带前排的金坛盆地阜四段具备中低成熟度页岩油勘探潜力。

基于Swin Transformer与GRU的低温贮藏番茄成熟度识别与时序预测研究

面向绿熟番茄采后持续转熟特征,适时调温是满足不同成熟度番茄适宜贮运温度需求的关键,而果实成熟度自动识别与动态预测则是实现温度适时调控的基础条件。本文基于Swin Transformer与改进GRU提出了一种番茄成熟度识别与时序动态预测模型,首先通过融合番茄两侧图像获取番茄表观全局红色总占比,构建不同成熟番茄图像数据集,并基于迁移学习优化Swin Transformer模型初始权重配置,实现番茄成熟度分类识别;其次,周期性采集不同储藏温度(4、9、14℃)下番茄图像数据,结合番茄初始颜色特征与贮藏环境信息,构建基于Swin Transformer与GRU的番茄成熟度时序预测模型,并融合时间注意力模块优化模型预测精度;最后,对比分析不同模型预测结果,验证本研究所提模型的准确性与优越性。结果表明,番茄成熟度正确识别率为95.783%,相比VGG16、AlexNet、ResNet50模型,模型正确识别率分别提升2.83%、3.35%、12.34%。番茄成熟度时序预测均方误差(MSE)为0.225,相比原始GRU、LSTM、BiGRU模型MSE最高降低29.46%。本研究为兼顾番茄成熟度实现贮藏温度柔性适时调控提供了关键理论基础。

开鲁盆地陆东凹陷后河地区页岩层系原油地球化学特征

依据开鲁盆地陆东凹陷后河地区白垩系九上段Ⅱ、Ⅲ油组页岩油的分析化验测试资料,从多方面对其原油地球化学特征进行综合评价。研究结果表明:该油组页岩油为中质普通稠油;原油呈单峰偏后峰型分布,主峰碳以nC23为主,生物标志化合物具有五环萜烷、三环萜烷含量均较高的特征;原油的成烃母质形成于强还原—还原的微咸水—半咸水湖相沉积环境,原油具有低成熟度特征。此外,九上段原油不同油组的生物标志化合物参数存在差异,且页岩内形成的油藏运移距离有限,反映了其中各页岩油藏为独立生烃聚集系统,自生自储、内源成藏的特征。

微波辐射对泥页岩孔隙发育的影响——以松辽盆地青山口组一段为例

页岩油被认为是我国油气能源的革命者,其中中低熟页岩油资源潜力巨大。原位加热转化是中低熟页岩油有效开发的潜在技术。本文对松辽盆地青山口组一段富有机质泥页岩开展了常规加热和微波辐射加热实验,并结合场发射扫描电镜、低温氮气吸附实验,系统对比了微波辐射和常规加热页岩时孔隙结构与演化特征。结果表明:有机孔的演化主要经历了开孔→孔隙合并→形成复合孔隙及裂缝三个阶段,加热相同温度时微波辐射能够促进有机质裂解形成有机孔,对微裂缝的发育具有明显的促进作用;随温度增加,孔隙结构参数变化复杂,孔径先增后降,孔体积和比表面积呈增加→降低→增加的特征;随微波辐射加热时间的增加,小于50 nm的孔隙体积大幅减小,中大孔体积明显增加,表明小孔隙逐渐扩张、合并并演变成大孔。微波辐射对页岩孔隙空间改善效果更显著,裂缝更发育,利于油气渗流,但同时发现微波辐射加热的功率过高、时间过长时将会破坏孔隙,不利于改善页岩微观孔隙空间。本项研究对于中低熟页岩油原位加热方式选择及加热过程中微观孔裂隙演化认识有一定的帮助。

一种低风险投资方法的构建——基于可转债到期赎回条款的利用

扩容之后的可转债市场迎来持续几年的炒作,市场“股票化”的特征相当明显。炒作给转债投资既带来相当的超额收益,但也导致很多可转债价格及溢价率虚高,投资风险巨大。针对这种情况,理性的投资者可以利用转债相关条款的规则,通过合理安排投资,来规避相关的风险及获取合理的回报。

辽河西部凹陷低熟油的高分辨质谱特征及其成因机制

辽河西部凹陷低熟油资源丰富,不同类型稠油的成因机制差异尚不清楚,解决上述问题对辽河稠油的勘探工作具有指导意义。本文采用色谱/质谱(GC/MS)结合傅里叶变换离子回旋共振质谱(FT-ICR MS)技术对辽河西部凹陷北部高升和牛心坨油田低熟油的特征及其成因机制进行研究。高升原油形成于强还原咸水水体,有机质为菌藻类低等生物与陆源的双重贡献。牛心坨原油形成于还原性半咸水水体,有机质来源为低等微生物和陆源有机质双重输入,具有高蜡特征。成熟度参数表明二者均为低熟油。两种低熟油中均检测到N_(1)、N_(1)O_(1)、N_(1)O_(2)、O_(1)、O_(2)、O_(3)、O_(4)化合物,高升低熟油以N_(1)类为主,牛心坨低熟油以O_(2)类为主;前者富含脂肪酸和藿烷酸,后者富含脂肪酸,藿烷酸含量较低,反映两种原油成因机制的差异。高升低熟油中大量的藿烷酸表明其生烃母质在早期成岩作用阶段经历了细菌改造作用,低熟油为细菌改造有机质低温生烃和藻类类脂低温生烃混合成因机制。牛心坨低熟油富含脂肪酸和高等植物蜡质,成因机制为生物类脂物早期低温生烃。两种低熟油的成因机制,为低熟油成因理论提供了研究方法,有助于完善低熟油成因理论并指导类似盆地低熟油油气勘探。

财政金融支持绿色低碳技术创新研究--基于技术成熟度视角

绿色低碳技术是发展绿色低碳经济的基石,但由于投资期限错配、信息不对称、风险收益不匹配等问题,绿色低碳技术研发应用面临巨大的融资缺口。理论研究和国际实践表明,从技术成熟度角度对绿色低碳技术进行划分和界定,能够优化财政金融资金在绿色低碳领域的配置效率,有力缓解绿色低碳技术融资困难。据此,本文在梳理技术成熟度相关概念和国际经验的基础上,结合国内财政金融支持绿色低碳技术的现状与实践,从技术成熟度和预期碳减排效益两个维度提出财政金融支持绿色低碳技术的差异化路径设计,并从健全技术认定标准、构建财政金融支持体系、创新金融产品服务、完善融资服务平台等四个方面提出政策建议。

短期低温对大豆苗期生长和结瘤固氮的影响

采用早熟大豆品种“黑河43”、晚熟大豆品种“东农53”进行盆栽试验,出苗后进行连续7d的低温处理(LT),昼夜温度设定为13℃/3℃,以25℃/10℃为对照,从大豆出苗28d开始,每7d进行破坏性取样共4次,测定地上部和根干物质量、根瘤生物量、全氮含量及根瘤固氮量,研究苗期短期低温对大豆生长、结瘤和固氮能力的影响。结果表明:(1)大豆出苗后7d短期低温胁迫会延缓大豆生长发育。出苗后28~42d大豆生物量显著低于CK处理,出苗后49d低温胁迫对两个大豆品种生物量均无显著影响。(2)与CK相比,低温对“东农53”和“黑河43”根瘤形成的显著抑制作用分别出现在苗后42d和35d,根瘤数量分别降低了58.8%和72.0%。出苗后49d,低温使“东农53”和“黑河43”根瘤干重分别减少48.9%和48.5%。(3)低温刺激了两个品种大豆的生物固氮能力。在出苗后49d,低温处理“东农53”和“黑河43”的生物固氮量、单位根瘤生物量的固氮量和单个根瘤的固氮量分别增加了89.9%、118.9%,249.3%、172.6%,150.6%、114.2%。生物固氮百分率分别增加了26.4个和24.5个百分点。综合来看,大豆出苗后遭遇低温冷害会延缓生长发育,并抑制根瘤的形成与生长。低温胁迫解除后大豆生长逐步恢复。短期低温对大豆根瘤固氮量和根瘤固氮能力有刺激作用,对早熟品种“黑河43”刺激作用更明显。为了更好地适应东北大豆产区早春低温环境,推荐选用早熟品种大豆。

渤海湾盆地济阳坳陷陆相断陷湖盆中-低成熟度页岩“富烃-成储-富集-高产”的理论认识与开发实践

渤海湾盆地济阳坳陷页岩油资源丰富,初步估算资源量超100×10^(8) t,分析、研究、总结页岩油形成、富集和高产理论认识对指导页岩油勘探开发都具有重要意义。通过系统研究济阳坳陷古近系沙河街组四段(沙四)上亚段和沙河街组三段(沙三)下亚段2套主力页岩油层系有机质形成与演化特征以及页岩油富集与可动规律,提出了济阳陆相断陷湖盆中-低成熟度页岩“富烃-成储-富集-高产”的理论认识。研究表明:济阳陆相断陷湖盆页岩具有高有机质丰度和中-低成熟度特征,页岩为高生烃潜力和低成烃活化能的优质烃源岩。济阳坳陷沙河街组页岩沉积期,咸化水体中嗜盐菌藻等类脂类化合物发育,有机质古生产力高、富硫有机相成烃活化能低且生烃转化率高。生、排烃早,镜质体反射率(R_(o))值约0.65%时游离油量达到峰值。富有机质层与多孔纹层高频互层、有序分布,源-储配置好。洼陷带低级序断层未打破厚层页岩层系自封闭性,页岩层系普遍高压。页岩油层系多为纹层状富碳酸盐页岩和纹层状混积页岩2大类岩相。这2类岩相具有“纹层控油富集、缝网控油流动”的优质页岩油甜点特征,纹层组合控制了储集空间的发育和分布。多尺度、多类型基质微缝与压裂缝网的空间耦合,构成了页岩天然-人工多级缝网叠加的高效渗流系统,纹层框架下页岩具有“满层皆油”的富集特征。

低演化陆相页岩孔缝特征及对页岩油赋存的意义:以济阳坳陷外围青南洼陷沙河街组为例

济阳坳陷低演化页岩油资源潜力巨大,是继中高成熟页岩油成功突破后的重要领域之一。为了明确低演化陆相页岩孔缝特征及对页岩油赋存的意义,以济阳坳陷外围青南洼陷沙河街组沙三下-沙四上纯上亚段为例,综合运用薄片观察、有机碳测试、X射线衍射(XRD)分析、溶剂抽提、低温N 2吸附、高压压汞、扫描电镜、能谱元素等多种技术,在划分页岩岩相基础上,探讨了低演化页岩孔隙类型、大小、分形特征及影响因素,明确了裂缝发育特征,阐明了页岩孔缝对页岩油赋存的重要意义。结果表明:研究区页岩总有机碳质量分数w(TOC)多在1.0%~4.0%,矿物组分以长英质矿物为主,其次为黏土矿物和碳酸盐矿物。孔隙类型以墨水瓶孔、平板狭缝孔为主,包括石英粒间孔、黏土矿物片间孔、白云石晶间孔等,孔径多小于200 nm,呈多峰分布,主要集中在2~50,50~80,100~200 nm。页岩储层发育较多的水平层理缝、高角度缝和网状缝,多被沥青充填或浸染,裂缝有利于页岩油的赋存和运移。富长英质矿物岩相通常比富黏土矿物岩相具有更高的孔体积和比表面积,长英质矿物对孔隙有积极贡献,且随热演化程度的增加,孔体积和比表面积呈先降低后增加的趋势。当镜质体反射率R_(o)>0.6%时,页岩油含量显著增加,主要与有机质开始大量生烃有关。水平层理缝、石英颗粒粒间孔、白云石和方解石晶间孔是页岩油有利的储集和赋存空间。

不同施氮水平下低烟碱烟草品种烟碱累积和成熟落黄特性

为研究低烟碱烟草的烟碱累积和成熟落黄特性,解析烟碱含量与烟草成熟落黄特性的相关性,以NC95背景低烟碱烟草品种MAFC5、MLAFC34和LAFC53,K326背景低烟碱烟草品种CD01为材料,并以NC95和K326作对照,分析了不同施氮水平对供试烟草材料不同时期、不同叶位叶片烟碱含量的影响,并进行了成熟落黄特性比较。结果表明:随着烟株的生长,低烟碱烟草的烟碱含量逐渐增高;供试低烟碱烟草品种的烟碱含量均低于对照NC95和K326,表现为MAFC5>MLAFC34>LAFC53>CD01,分别较对照降低39%、43%、79%、96%;MAFC5、MLAFC34、LAFC53不同叶位叶片的烟碱含量由下至上逐渐升高,而CD01不同叶位叶片的烟碱含量则由下至上依次降低;施氮量增加,各品种烟草烟碱含量均增加,从低施氮量到高施氮量,MAFC5、MLAFC34和LAFC53的叶片的烟碱含量分别增加24.3%、26.1%、19.6%,而CD01仅增加9.9%左右,影响较小;MLAFC34和LAFC53的成熟落黄特性较差,CD01和MAFC5的成熟落黄特性和对照烟草接近。本研究发现低烟碱烟草品种叶片的烟碱含量均低于对照品种,施氮量增加对各品种烟碱含量有不同程度的提升作用,叶片烟碱含量与成熟落黄特性无必然关联。

陆东凹陷中低成熟度页岩油储层含油性特征及“甜点”评价

针对陆东凹陷交力格洼陷中低成熟度页岩油储层分布特征与富集控制因素不明等问题,通过开展二维核磁共振分析、纳米CT扫描、干酪根显微组分鉴定等方法,对页岩油储层含油性特征进行研究,综合页岩岩相、储集性、含油性及可动性等因素,基于储层及含油性分级参数建立了页岩油“甜点”综合评价标准。结果表明:页岩纹层与层理的发育程度、密度、岩性等结构特征是含油性特征及分布的主要影响因素。层状含粗粒岩屑粉砂岩与纹层状长英质页岩岩相微观孔隙结构及连通性较好,比表面积小于15 m 2/g,氮气吸附平均孔径大于8 nm,为优质储层。Ⅰ+Ⅱ类“甜点”TOC大于1%,储层发育中、大孔,占比大于25%,储集空间孔径大于8 nm,含油性和可动性为中等—好,油气相对富集。该成果可为研究区页岩油有利目标优选及试验区部署评价提供技术支撑。

Ce/HZSM-5和生物质原位改造油页岩:提高页岩油的收率和品质

为进一步提高油页岩的转化效率,缓解我国的原油对外依存度,将藻类水热液化与油页岩原位转化过程耦合,以Ce/HZSM-5为催化剂,利用藻类水热液化产物提升干酪根有机质的转化效率和页岩油的品质,借助SEM、TG、GC-MS和元素分析等对反应前后产物分析表征。实验结果表明,在催化剂和小球藻的共同参与下,水热裂解转化的页岩油产率为6.15%,页岩油品质也有了很大提升。与单纯油页岩水热裂解相比,提质后的页岩油轻组分提高了18.58%和4.04%,重组分含量降低了22.62%。

采收成熟度结合不同低温对番茄采后贮藏品质的影响

以番茄为试验试材,研究不同温度2~6℃、6~10℃、10~14℃对绿熟期、转色期和半红期番茄采后生理及品质的影响。分析番茄果实贮藏30 d期间失重率、硬度、可溶性固形物含量(soluble solids content,SSC)、可滴定酸(ti-tratable acid,TA)含量、维生素C含量、呼吸强度、色度及叶绿素含量的变化。结果表明,2~6℃贮藏温度下,绿熟期和转色期番茄贮藏结束时番茄都未能正常转红,表明此温度下不利于绿熟期和转色期番茄的贮藏;6~10℃贮藏温度下,绿熟期和转色期番茄在贮藏结束时可以正常转红,但SSC、TA含量和VC含量与半红期番茄存在明显差异,所以6~10℃贮藏也不利于绿熟期和转色期番茄的后熟软化;10~14℃贮藏温度下,绿熟期和转色期番茄可正常后熟软化,且成熟后SSC、TA含量与半红期番茄无明显差异。综上,10~14℃贮藏可以使绿熟期和转色期番茄正常后熟软化。