Influences of lithofacies on fluid mobility in mixed sedimentary rocks:Insights from NMR analysis of the middle Permian Lucaogou Formation,Junggar Basin

The multi-source mixed sedimentation resulted in a unique series of mixed fine-grained sedimentary rocks evolved within the Permian Lucaogou Formation in the Jimusar Sag,located in the southeastern Junggar Basin,China.The variety of lithofacies within this series resulted in pronounced heterogeneity of pore structures,complicating the analysis of fluid occurrence space and state within reservoirs.As a result,the impact of lithofacies on fluid mobility remains ambiguous.In this study,we employed qualitative methods,such as field emission scanning electron microscopy(FE-SEM)and thin section observation,and quantitative analyses,including X-ray diffraction(XRD),total organic carbon(TOC),vitrinite reflectance(Ro),high-pressure mercury intrusion(HPMI)porosimetry,and nuclear magnetic resonance(NMR),along with linear and grey correlation analyses.This approach helped delineate the effective pore characteristics and principal factors influencing movable fluids in the fine-grained mixed rocks of the Lucaogou Formation in the Jimusar Sag,Junggar Basin.The findings indicate the development of three fundamental lithologies within the Lucaogou Formation:fine sandstone,siltstone,and mudstone.Siltstones exhibit the highest movable fluid saturation(MFS),followed by fine sandstones and mudstones sequentially.Fluid mobility is predominantly governed by the content of brittle minerals,the sorting coefficient(Sc),effective pore connectivity(EPC),and the fractal dimension(D_(2)).High content of brittle minerals favors the preservation of intergranular pores and the generation of microcracks,thus offering more occurrence space for movable fluids.A moderate Sc indicates the presence of larger connecting throats between pores,enhancing fluid mobility.Elevated EPC suggests more interconnected pore throat spaces,facilitating fluid movement.A higher D_(2)implies a more intricate effective pore structure,increasing the surface area of the rough pores and thereby impeding fluid mobility.Ultimately,this study developed a conceptual model that illustrates fluid distribution patterns across different reservoirs in the Lucaogou Formation,incorporating sedimentary contexts.This model also serves as a theoretical framework for assessing fluid mobility and devising engineering strategies for hydrocarbon exploitation in mixed fine-grained sedimentary rocks.

On Word Formation According to the Phenomenon of Mixed Chinese and English

Nowadays, with the frequent use of English, many Chinese people tend to express with mixed Chinese and English. As to this phenomenon, the thesis mainly analyzes word formation of the mixed Chinese and English. Beginning with presenting the research background, status and significances, the thesis will employ three parts to clarify this topic.

Electro-oxidation of mixed reactants of ethanol and formate on Pd/C in alkaline fuel cells

Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol.In spite of the advantages,commercialization of direct ethanol fuel cells is hampered by the relatively low performance caused by its slow oxidation kinetics and difficulty of complete oxidation.In this study,formate,which has relatively faster oxidation kinetics,was mixed with ethanol to compensate the latter’s sluggish kinetics.Effects of p H,concentration,scan rate,and temperature on the mixed reactants oxidation on Pd were investigated by electrochemical experiments such as potential sweep and potentiostatic methods.Furthermore,the potential of the mixed reactants as fuel was evaluated by single cell experiments.As a result,we demonstrate that mixing formate with ethanol results in enhanced power performance in a single cell system.

CONVERGENCE OF SIMPLIFIED AND STABILIZED MIXED ELEMENT FORMATS BASED ON BUBBLE FUNCTION FOR THE STOKES PROBLEM

Two simplifled and stabilized mixed element formats for the Stokes problem are derived by bubble function, and their convergence, i.e., error analysis, are proved. These formats can save more freedom degrees than other usual formats.

Formation condition of solid solution type high-entropy alloy

Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors （the comprehensive atomic radius difference δ, the mixing enthalpy AH and the mixing entropy AS） of phase composition of the alloys were calculated, and the microstructure and phase compositions of alloys were analyzed by using SEM and XRD. The result shows that only the systems with δ≤2.77 and △H≥-8.8 kJ/mol will form high entropy alloy with simple solid solution. Otherwise, intermetallic compounds will exist in the alloys. So, selection of the type of element has important effects on microstructure and properties of high entropy alloys.

Mixing states and secondary formation processes of organic nitrogen-containing single particles in Guangzhou,China

Organic nitrogen(ON)compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols,however,the mixing state,secondary formation processes,and influencing factors of ON compounds are still unclear.This paper reports on the mixing state of ON-containing particles based on measurements obtained using a highperformance single particle aerosol mass spectrometer in January 2020 in Guangzhou.The ON-containing particles accounted for 21% of the total detected single particles,and the particle count and number fraction of the ON-containing particles were two times higher at night than during the day.The prominent increase in the content of ON-containing particles with the enhancement of NO_xmainly occurred at night,and accompanied by high relative humidity and nitrate,which were associated with heterogeneous reactions between organics and gaseous NO_(x)and/or NO_(3)radical.The synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the particles.In addition,the positive matrix factorization analysis found five factors dominated the formation processes of ON particles,and the nitrate factor(33%)mainly contributed to the production of ON particles at night.The results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles.

Pyrite Formation in Organic-rich Clay, Calcitic and Coal-Forming Environments

The early diagenetic characteristics of pyrite formation processes in a Miocene freshwater sequence of mixed sediments （coal fragments in clays, sandstones or shales） alternating with continuous brown coal layers was investigated. Based on abundant minerals, the following main sedimentary environments were distinguished： the illite-montmorillonitic （I-M）, calcitic （Ct） and coal-forming environment （CL）. For these hydrogeochemically differing environments the effects of limiting factors on the pyrite formation process （availability of sulphate and Fe, amount of organic matter and participation of organic sulphur） were assessed by correlation analysis. Significant differences in the effects of these limiting factors in the particular environments were observed. These differences were explained taking in account the different oxidative activity, Fe-complex and surface complex forming properties of humic substances in dependence of pH of environment and the abundance of sorptionally active clay minerals. In environments having a relatively low pH and containing clay minerals （I-M- and CL-environments） the oxidative activity of humic substances （Hs） on pyrite precursors was greatly prevented however pyrite formation depended on reactive Fe availability as the consequence of complex formation. On the contrary, in environments with a relatively high pH, as it was the calcitic, the oxidative activity of Hs was greatly enhanced, thus oxidizing the sulfur precursors of pyrite. The oxidation degree of organic matter was probably also a consequence of the differing activity of the humic electron-acceptors.

Facies Analysis and Sequence Stratigraphy of the Qal'eh Dokhtar Formation(Middle-Upper Jurassic) in the West of Boshrouyeh, East Central Iran

The study area is located in the east Tabas Block in Central Iran. Facies analysis of the Qal＇eh Dokhtar Formation（middle Callovian to late Oxfordian） was carried out on two stratigraphic sections and applied to depositional environment and sequence stratigraphy interpretation. This formation conformably overlies and underlies the marly-silty Baghamshah and the calcareous Esfandiar formations, respectively. Lateral and vertical facies changes documents low-to high energy environments, including tidal-flat, beach to intertidal, lagoon, barrier, and open-marine. According to these facies associations and absence of resedimentation deposits a depositional model of a mixed carbonate-siliciclastic ramp was proposed for the Qal＇eh Dokhtar Formation. Seven third-order depositional sequences were identified in each two measured stratigraphic sections. Transgressive systems tracts（TSTs） show deepening upward trends, i.e. shallow water beach to intertidal and lagoonal facies, while highstand systems tracts（HST） show shallowing upward trends in which deep water facies are overlain by shallow water facies. All sequence boundaries（except at the base of the stratigraphic column） are of the no erosional（SB2） types. We conclude eustatic rather than tectonic factors played a dominant role in controlling carbonate depositional environments in the study area.

Petrology,Mineralogy and Geochemisty of Antarctic Mesosiderite GRV 020175:Implications for Its Complex Formation History

GRV 020175 is an Antarctic mesosiderite,containing about 43 vol%silicates and 57 vol% metal.Metal occurs in a variety of textures from irregular large masses,to veins penetrating silicates, and to matrix fine grains.The metallic portion contains kamacite,troilite and minor taenite.Terrestrial weathering is evident as partial replacement of the metal and troilite veins by Fe oxides.Silicate phases exhibit a porphyritic texture with pyroxene,plagioclase,minor silica and rare olivine phenocrysts embedded in a fine-grained groundmass.The matrix is ophitic and consists mainly of pyroxene and plagioclase grains.Some orthopyroxene phenocrysts occur as euhedral crystals with chemical zoning from a magnesian core to a ferroan overgrowth;others are characterized by many fine inclusions of plagioclase composition.Pigeonite has almost inverted to its orthopyroxene host with augite lamellae, enclosed by more magnesian rims.Olivine occurs as subhedral crystals,surrounded by a necklace of tiny chromite grains（about 2-3μm）.Plagioclase has a heterogeneous composition without zoning. Pyroxene geothermometry of GRV 020175 gives a peak metamorphic temperature（～1000℃） and a closure temperature（～875℃）.Molar Fe/Mn ratios（19-32） of pyroxenes are consistent with mesosiderite pyroxenes（16-35） and most plagioclase compositions（An_（87.5_96.6）） are within the range of mesosiderite plagioclase grains（An_（88-95））.Olivine composition（Fo_（53.8）） is only slightly lower than the range of olivine compositions in mesosiderites（Fo_（55-90））.All petrographic characteristics and chemical compositions of GRV 020175 are consistent with those of mesosiderite and based on its matrix texture and relatively abundant plagioclase,it can be further classified as a type 3A mesosiderite.Mineralogical, penological,and geochemical studies of GRV 020175 imply a complex formation history starting as rapid crystallization from a magma in a lava flow on the surface or as a shallow intrusion.Following primary igneous crystallization,the silicate underwent varying degrees of reheating.It was reheated to 1000℃,followed by rapid cooling to 875℃.Subsequently,metal mixed with silicate,during or after which,reduction of silicates occurred;the reducing agent is likely to have been sulfur.After redox reaction,the sample underwent thermal metamorphism,which produced the corona on the olivine, rims on the inverted pigeonite phenocrysts and overgrowths on the orthopyroxene phenocrysts,and homogenized matrix pyroxenes.Nevertheless,metamorphism was not extensive enough to completely reequilibrate the GRV 020175 materials.

THERMODYNAMICAL CALCULATION OF FORMATION ENTHALPIES FOR ALKALINE METAL ALLOYS

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Depositional environments and sequence stratigraphy of the Bahram Formation(middleelate Devonian) in north of Kerman, south-central Iran

This study is focused on sedimentary environments, facies distribution, and sequence stratigraphy. The facies and sequence stratigraphic analyses of the Bahram Formation（middleelate Devonian） in southcentral Iran are based on two measured stratigraphic sections in the southern Tabas block. The Bahram Formation overlies red sandstones Padeha Formation in sections Hutk and Sardar and is overlain by Carboniferous carbonate deposits of Hutk Formation paraconformably, with a thickness of 354 and386 m respectively. Mixed siliciclastic and carbonate sediments are present in this succession. The field observations and laboratory studies were used to identify 14 micro/petrofacies, which can be grouped into 5 depositional environments： shore, tidal flat, lagoon, shoal and shallow open marine. A mixed carbonate-detrital shallow shelf is suggested for the depositional environment of the Bahram Formation which deepens to the east（Sardar section） and thins in southern locations（Hutk section）. Three 3rdorder cyclic siliciclastic and carbonate sequences in the Bahram Formation and one sequence shared with the overlying joint with Hutk Formation are identified, on the basis of shallowing upward patterns in the micro/pertofacies.

超大城市中心区三维空间业态混合特征研究——基于北上广深的实证

业态混合是现代城市商业体系的基本构成形式,是城市空间集约利用与集聚效应的共同产物。在此背景下,在以高密度为特征的城市中心区,业态在三维空间上复合拓展尤为突出,人流与功能结构的持续优化重组,产生了三维空间上的功能分异现象,这对于中心区楼宇经济的发展具有重大意义。该文基于POI业态数据,以北上广深的四个城市中心区为例,综合利用信息熵、均衡度、首位度为指标,构建业态混合度量化方法,以期充分揭示实际的业态三维混合规律。此外,共总结出三类业态混合布局模式,为中心区的经济与空间发展与途径提供新的启示。

普光地区千佛崖组致密砂岩-页岩气藏开发技术对策

普光地区侏罗系千佛崖组致密砂岩-页岩气藏为纵向叠合气藏,储层非均质性强,纵横向上储层特征和储集性能差异大,气藏开发潜力不明确,尚未形成开发井型、井网、井距等配套开发技术对策;且砂岩气藏与页岩气藏压力系统、气体运动方式不同,利用常规水平井压裂方式合层开采必定导致层间干扰和多余能耗,亟需采用最优开发方式。为此,文中参考鄂尔多斯盆地致密砂岩气藏水平井井位优选标准和四川盆地页岩气开发井型,根据储层展布特征,结合水平井与直井产能对比分析,优选水平井作为致密砂岩-页岩气藏的开发井型;采用类比法、经济评价法、单井产能法等,确定水平井水平段长度和合理井距;根据气藏特征,并借鉴同类气藏开发经验评价单井生产指标;在此基础上开展井位部署,评价气藏开发潜力。结果表明,采用2套井网分别开发千佛崖组致密砂岩气藏和页岩气藏,可建成年产能6.5×108 m3,这为普光地区千佛崖组致密砂岩-页岩气藏合理开发提供了有力支撑。

考虑编队意愿的CAV队列对混合交通流条件下交叉口通行能力的影响研究

为研究考虑编队意愿的网联自动驾驶车辆(CAV)队列对混合交通流条件下交叉口通行能力的影响,针对CAV、自动驾驶车辆(AV)、人工驾驶车辆(HDV)构成的混合交通流,考虑CAV的编队意愿,基于10种车辆跟随状态类型和4种车间时距类型,基于马尔可夫链理论,推导出车辆跟随状态类型的状态转移矩阵和状态概率分布,构建交叉口通行能力模型,分析队列时距、编队意愿、渗透率(P_(C))、最大队列规模对交叉口通行能力的影响并进行数值案例验证。研究结果表明:通行能力随CAV队列时距的减小而增加;在给定P_(C)时,通行能力随编队意愿的增强而增加;P_(C)小于0.2时,编队意愿对交叉口通行能力的提高很小,P_(C)大于0.4时,编队意愿对提高交叉口通行能力的影响变得显著;更高的P_(C)是否会带来更大的通行能力,取决于编队意愿和异质的车间时距;对于控制队列规模不超过一个最大值k_(m′),在给定P_(C)时,通行能力随最大队列规模的增大而增加,但增幅逐渐减小;P_(C)小于0.2时,提高最大队列规模对通行能力的提高较小,P_(C)大于0.6时,最大队列规模对提高通行能力的影响变得显著。

四川盆地及周缘地区晚奥陶世岩相古地理演化

综合利用野外露头、岩心、钻测井等资料,对四川盆地及周缘地区晚奥陶世岩相古地理演化过程进行了描述和对比,并探讨了其主控因素。研究结果表明:①加里东运动早期拉张—伸展作用导致四川盆地周缘坳陷加深,其后扬子板块和华夏地块碰撞挤压,形成了晚奥陶世以上扬子地区为中心,西北、西部、南部三面环隆的古地理格局。②四川盆地及周缘地区晚奥陶世可划分出(混积)滨岸、碳酸盐缓坡、(混积)陆棚相等沉积相类型。宝塔组—临湘组主要发育碳酸盐缓坡相;五峰组沉积期海侵达到高峰,碳酸盐缓坡被淹没,发育(混积)陆棚相深水黑色页岩;观音桥组沉积期发生的海退导致大部分地区由深水陆棚转为浅海陆棚亚相;各时期古隆起周缘均有(混积)滨岸相发育,受物源影响部分地区具有混合沉积特征。③研究区晚奥陶世岩相古地理格局受构造运动、海平面变化和古气候等因素综合控制,在沉积相平面展布和垂向演化上均有体现。

川东地区中寒武统高台组蒸发岩特征和沉积模式

为明确川东地区中寒武统高台组蒸发岩特征与发育模式,综合野外观察、岩心描述、薄片鉴定、测井及地震资料,在对高台组蒸发岩的岩性及成因类型进行分析的基础上,讨论其沉积模式以及与油气的关系。研究结果表明:1)蒸发岩主要为含膏白云岩类、石膏岩和膏盐岩,存在清水和浑水两种蒸发岩岩性组合序列,蒸发岩厚度具有由西向东逐渐增厚的特点,沉积中心分别位于建深1井区—巫溪一线和太和1井区—石柱一线,蒸发岩盖层以“宽广圆环状”覆盖川东大部分地区;2)蒸发岩在干旱炎热的古环境、障壁滩形成的封闭环境、海水的周期性波动以及物源补给的共同作用下形成清水潟湖和浑水潟湖,即源控多潟湖成因环境;3)高台组蒸发岩厚度与龙王庙组储层的分布存在一定的负相关关系,即厚层蒸发岩控低含气储层,薄层蒸发岩控高含气储层;4)蒸发岩为盖层的储盖组合包括浑水潟湖成因的岩下储层和清水潟湖成因的岩间储层,薄层蒸发岩岩下储层含气规模较大,岩间储层的非均质性较强,厚度较薄,总体上呈中—低孔低渗的特征,研究区发育3个天然气有利勘探区带,分别位于北部、中部以及南部地区,是川东地区潜在的后备勘探领域。

寒武系第二统浅水混合沉积发育特征及影响因素——以陕南朱家坝剖面仙女洞组为例

【目的】混积岩同时具有指示水体化学条件和生物活动的碳酸盐组分以及指示物源区性质和风化过程的碎屑组分,因而在古环境和古气候研究方面具有独特价值。【方法】寒武纪早期上扬子克拉通北部汉南—米仓山古陆周缘混合沉积非常发育,以陕西南郑朱家坝剖面仙女洞组为例,对研究区混积岩特征开展了系统的岩相学和沉积学研究。【结果与结论】混合沉积形成于海退背景下由中缓坡向内缓坡转变的过渡环境,且混积程度具有规律性,即在多个向上变浅序列的中部最为发育,在每个序列底部和顶部分别为碎屑组分主导和碳酸盐组分主导(或清水碳酸盐沉积)。中缓坡环境下以碎屑组分沉积为主,碳酸盐组分除小型原地生物礁外,主要来自浅水环境搬运的细粒沉积物;内缓坡潮下带相对低能环境仍以碎屑组分沉积为主,但原地生物礁以及礁角砾和内碎屑搬运沉积常见;内缓坡潮下高能带以鲕粒滩和生物礁等原地碳酸盐沉积为主,混入的陆源组分主要为砂级石英和岩屑颗粒;潟湖环境以白云石化颗粒和陆源细粒物质的混合为特征。研究区寒武纪早期混积体系的发育与当时浅水环境较高的碳酸盐产率以及沿岸流、波浪、风暴等搬运作用有关。本实例可为了解深时混合沉积成因提供一个思路,也可为上扬子地区寒武系混积岩油气勘探提供参考。

陆相断陷咸化湖盆细粒沉积岩特征及沉积环境——以泌阳凹陷核桃园组H3Ⅲ亚段为例

泌阳凹陷作为国内典型的陆相断陷咸化湖盆,在古近系核桃园组三段广泛发育细粒沉积岩。文中利用长井段连续取心资料以及薄片观察、二维XRF扫描、XRD分析、扫描电镜以及地球化学测试等手段,以矿物组分、沉积构造和粒度作为主要依据,把泌阳凹陷H3Ⅲ亚段细粒沉积岩划分为9种岩相类型,其中纹层状混合质页岩、纹层状长英质页岩是发育类型最多的细粒沉积岩;通过Mg/Ca、Al含量、Ti含量、(Fe+Al)/(Ca+Mg)、P/Ti、Sr/Ba和V/(V+Ni)等地球化学指标的垂向变化及岩相组合来分析沉积环境的演化特征。泌阳凹陷H3Ⅲ亚段沉积环境是半深湖—深湖环境,水体盐度为半咸水—咸水,陆源输入总体较强,气候变化相对较大,从下到上经历了干旱、干湿交替、湿润以及干旱的气候变化。岩相的垂向变化受气候、陆源输入、水深、水体盐度的影响,气候、陆源输入、水深决定了长英质矿物和黏土矿物的含量,而碳酸盐矿物的含量主要受到水体盐度和气候的影响。

混合沉积特征精细刻画:以江苏徐州寒武系馒头组为例

江苏徐州地区寒武系馒头组发育极具特色的陆源碎屑组分与碳酸盐组分混合沉积现象。本研究以寒武系馒头组一套典型的混合沉积序列为例,依据剖面实测与镜下特征,对该序列中的混合沉积组合类型开展了系统的岩石学研究;通过分析不同沉积环境中的混合沉积特征,建立了陆表海近岸背景下陆源碎屑组分与碳酸盐组分混合沉积模式,探讨了各种混合沉积组合类型的混积成因类型、混积过程及主控因素等。结果表明:徐州地区寒武系馒头组混合沉积序列中主要发育含砂鲕粒灰岩、含内碎屑砂质灰岩、灰质细砂岩、含灰粉砂岩等11种混合沉积组合类型;混合沉积序列整体为陆表海海侵背景下次级海平面频繁波动且伴随多期次风暴作用的产物,主要表现为海侵作用下由近岸的混积潮坪逐渐演化为混积局限台地;混合沉积主要为相混合与间断混合,局部发育原地混合与母源混合。气候、陆源输入程度、海平面变化、碳酸盐产率是形成相混合的主控因素,同时也受到生物活动、水动力条件的调控;多期次风暴作用在主导间断混合形成的同时,一定程度上会促进相混合与母源混合的发育;在各因素叠加影响下,研究区具有多种混积成因类型组合发育的特征。厘清各种混积成因类型的分布与混积过程可为华北板块寒武纪古环境恢复与沉积演化提供参考,并为“深时”陆表海台地混合沉积相关研究提供典型范例。

NH_(3)/Air混合层自点火直接数值模拟研究

采用直接数值模拟方法研究非预混状态的NH_(3)/Air混合层在层流和湍流条件下的自点火、火焰传播和生成NO过程.添加氢气、压力增加和湍流混合都会加快氨气的自点火过程.NH_(2)、HNO和OH 3个自由基可以分别表征点火的诱导和热释放阶段.层流和湍流条件下,释热率都会在火焰传播末期产生两个峰值,即分层现象:小峰值区主要与OH的基元反应有关,大峰值区主要与NH_(2)和HNO的基元反应有关.添加氢气和湍流都会提高NO的生成量.最大NO数值曲线随时间会先增大后减小,两个阶段由NO的反应项和扩散项分别主导.