高压水射流对白云鄂博矿单体解离度的影响

矿物的单体解离是其能被高效选别的关键因素之一，粉碎方法对矿物单体解离度有很大的影响。白云鄂博稀土矿含十几种稀土矿物，矿物共生密切，嵌布类型复杂，其中稀土主要富集在氟碳铈矿与独居石矿中。分析表明矿物因相互包裹穿插和交代而形成毗连、网脉、溶蚀和环状嵌布。为提高矿物的单体解离度，通过自主研发水射流矿物解离装置，探究了水射流速度对白云鄂博矿稀土单体解离度的影响。在同等粒度分布下，对高压水射流粉碎与常规球磨(铁介质)实验结果进行了对比，分析了两种粉碎方式对稀土矿物解离状态及颗粒界面的影响。激光共聚焦显微镜、矿物特征自动定量分析系统(AMICS)分析表明，高压水射流粉碎白云鄂博稀土矿物单体解离度优于球磨，具有解离度高、粒度相对均匀等特点；矿物颗粒天然界面保持较好、表面较光洁，稀土矿物集中在0.038 mm以下颗粒中，有益于稀土的浮选分离，对白云鄂博矿的矿石粉碎具有一定的指导意义。     

东海西湖凹陷A气田渐新统花港组三段厚层砂岩沉积环境

西湖凹陷A气田花港组三段巨厚碎屑岩储层为研究区主力产气层与优质储层，对其沉积微相的厘定争议较大。综合利用研究区岩心、测井、地震、分析化验等相关资料，研究了目的层相标志、微相类型、沉积环境与相分布。研究认为本区发育辫状河三角洲前缘亚相，主要发育水下分流河道微相与分流间湾微相，不发育反映海相及海侵的沉积物与相标志。垂向上多期水下分流河道砂体叠置、厚度较大，水平延伸好；平面上水下分流河道由东北逐渐向西南呈树枝状分叉、连片分布，物源来自东北部。明确研究区属于陆相背景下的湖泊-三角洲沉积体系，为典型的牵引流沉积，不见海侵层序，高能量牵引流的水下分流河道微相是本区高产气藏储层发育的有利因素。     

Mineral composition and organic geochemistry of the Lower Cretaceous Xiagou Formation source rock from the Qingxi Sag, Jiuquan Basin, Northwest China

The Lower Cretaceous Xiagou Formation contains the major source rocks for the crude oils discovered in the Qingxi Sag and the South Uplift in the Jiuquan Basin, northwestern China. The Xiagou Formation source rock was formed in a closed, anoxic, reducing, alkaline lacustrine environment with a high salinity. Its high content of brittle minerals is favorable for the fracturing of reservoirs in source rock formations in the Qingxi Sag. The Xiagou Formation contains a great number of fair to excellent source rocks, and their organic matter (OM) came chiefly from plankton/algae and high plants as well as possibly bacterial organisms. The Xiagou Formation source rocks mainly contain Type II OM and some Type III and Type I OM, with good oil-generating potential. The source rock maturity is mainly in the early-mature and mature stages, and its R_o value corresponding to oil peak is about 0.8%, which is lower than classic oil peak Ro value of 1.0%; therefore, a great deal of hydrocarbon was generated before the classic oil peak R_o = 1.0%. Mature source rock in the Xiagou Formation tends to be distributed in the older members and at a greater depth. There is a better exploration potential of tight oil in the deep Qingxi Sag.     

歧口凹陷断裂密集带形成演化特征及油气富集差异研究

断裂密集带作为斜向伸展作用的标志性产物,是断块油气藏形成与聚集的主要场所。针对歧口凹陷不同走向断裂密集带油气富集差异较大的问题,通过统计密集带几何学特征及构造组合样式,结合断裂带形成演化规律,分析不同走向断裂带油气富集差异。结果表明:歧口凹陷主要发育NEE、EW向及NNE向3种断裂带。其中,NNE向断裂带形成时期最早,断裂的垂向输导能力最弱,油气在深部富集;NEE向断裂带随后形成,断裂对盖层的破坏作用最强,油气在深、浅层均有分布;EW向断裂带形成时期最晚,断裂的垂向输导能力介于前两者之间。研究成果可为歧口凹陷及相似的多期裂陷盆地断裂密集带的油气勘探工作提供理论支撑。     

江汉盆地潜江凹陷古近系潜江组白云岩成因

潜江凹陷位于江汉盆地，其古近系潜江组以含有由富有机质白云岩和蒸发岩组成的193个韵律层为特征。然而，潜江凹陷古近系潜江组白云石的成因一直存在争议，限制了进一步对非常规油气的勘探工作。根据盐间层岩相与矿物特征研究潜江组盐间层富白云石岩相的沉积成因。根据沉积特征观测（岩心和薄片）和矿物组分数据，可识别出3种主要的岩相结合：薄层-纹层状泥晶白云岩、纹层状含云泥晶灰岩和夹钙芒硝层状泥晶白云岩。研究发现前两种岩相组合纹层特征明显，可见有机质纹层与无机纹层交互现象，说明形成于水体较深的还原环境。白云石与方解石晶体含有有机质降解孔，且白云石与黄铁矿和有机质薄膜共生，说明其成因与微生物诱导活动有关。浮游微生物和底栖藻分别控制了方解石和白云石的沉淀。这些岩相组合含有较高的有机质含量。最后一种岩相组合具有较高的蒸发矿物含量和陆源碎屑物质，说明其形成于相对浅水环境。高盐度和强烈陆源输入不利于有机质的保存。此次研究发现盐湖内白云石的形成受微生物活动和蒸发环境控制，不同的成因对岩相沉积特征和有机质富集产生重要影响。     

HIGHER LANDPLANT –DERIVED BIOMARKERS IN LIGHT OILS AND CONDENSATES FROM THE COAL-BEARING EOCENE PINGHU FORMATION,XIHU SAG,EAST CHINA SEA SHELF BASIN

The Cenozoic Xihu Sag in the East China Sea Shelf Basin contains large reserves of coals together with liquid petroleum derived from coal-associated sediments. However, the origin of the petroleum is not well understood. In this study, biomarker assemblages in a suite of recently discovered light oils and condensates from the Paleogene succession in the western margin of in the Xihu Sag were investigated using gas chromatography – mass spectrometry. The objectives were to investigate the samples' thermal maturity and the depositional environment of the precursor source rocks which generated the oils. The light oils are believed to have been derived from coaly source rocks in the Eocene Pinghu Formation. Assessment of thermal maturity based on CPI, pristane/n-C₁₇ ratio and isomerisation ratios of C₂₉ steranes and C₃₁ homohopanes suggest that the hydrocarbons have a relatively low maturity in the early to mid oil generation window. The distribution of isoprenoids relative to n-alkanes, the high pristane/phytane ratios (5.1–10.7), the almost complete absence of gammacerane and C₃₃₊ homohopanes, and the low dibenzothiophene/phenanthrene ratios indicate that the source rocks of the hydrocarbons were deposited in a relatively oxic and sulphate-poor fluvio-deltaic environment which was favourable for coal measure development. Abnormally abundant gymnosperm-derived diterpanes including labdane, 19-norisopimarane, fichtelite, rimuane, pimarane, isopimarane, 17-nortetracyclic diterpene, phyllocladanes and abietane were detected in the samples analysed. 16a(H)-Phyllocladane was identified unambiguously and kauranes were confirmed to be absent. In addition, three 19-norisopimarane isomers, 13β(H)-atisane, and 20-normethylatisane were tentatively identified in the studied samples. The distributions of n-alkanes, isoprenoids and regular steranes, the presence of 4β(H)-eudesmane and oleanane, high Pr/Ph ratios and the abundant diterpanes together suggest that the hydrocarbons were derived from a coaly source rock. Gymnosperms of the conifer families Cupressaceae (especially the former Taxodiaceae) and Pinaceae are interpreted to be the major source of the diterpanes and to have made a significant contribution to the coaly source rock. However, the low abundance of oleanane relative to diterpanes may underestimate the contribution from angiosperms relative to gymnosperms. This could be due to differential preservation and alteration of the di- and triterpenoid precursors during diagenesis and the occurrence of non-specific precursors in higher land plants.     

渤海海域莱州湾凹陷沙河街组硅化碎屑岩地质特征及其储层意义

渤海海域莱州湾凹陷硅化碎屑岩以粒间石英晶体孔隙式充填、强烈石英次生加大为特征，局部地区甚至发生低变质作用，表现为变余砂状结构，这在国内外含油气盆地中是极为少见的。运用地震、测井、岩石学和单颗粒锆石U-Pb测年等技术手段，揭示了硅质碎屑岩的地质特征，首次通过锆石测年证实了莱州湾凹陷沙河街组沉积时期存在火山活动。硅质热流体活动证据主要体现在硅质脉体发育，呈多期充注特征，石英颗粒次生加大强烈，岩石甚至出现变余砂状结构；粒间粘土几乎全部热蚀变为黑云母和白云母，并可见“帚状”正在生长的云母类矿物；岩石中发育大量集块状和集簇无序状黄铁矿，不同产状的黄铁矿为多期次热液成因；热场发射扫描电镜下识别出黄铁矿-重晶石-独居石-方铅矿-金红石-硬石膏热液矿物组合。深部硅质热流体进入储层，碎屑石英颗粒产生强烈次生加大，加大石英和硅质沉淀完全充填粒间孔隙，对储层起破坏性作用，但硅化作用大大增强了地层的脆性，在后期构造运动作用下产生大量断裂和微裂缝网络。另外，热液流体溶蚀了储层中的长石类矿物，产生大量长石粒内溶蚀孔和铸模孔，在裂缝沟通下形成了孔隙-裂缝型优质储层。     

黄河口凹陷北缘古近系物源及其对优质储层的控制

黄河口凹陷北部陡坡带古近系物源复杂，储层物性差异较大。利用岩心、薄片、录井、三维地震及物性等资料，对黄河口凹陷北缘古近系的物源面貌进行了恢复，并探讨了古物源对优质储层的控制作用。结果表明：①研究区古近系沟谷体系发育，沙河街组至东三段沉积期，母岩岩性和面积均发生了明显的变化，且物源区的范围经历了“大—小—大”的演化过程。②古物源演化对砂体具有明显的控制作用。纵向上，沙三段沉积期物源区范围大，有大量中生界碎屑岩参与供源，沉积区形成薄层砂砾岩；沙二段沉积期物源区范围大，物源以火山岩剥蚀为主，沉积区形成厚层砂砾岩；沙一段沉积期发生快速湖侵，物源区范围减小，在沉积区形成薄层砂砾岩；东三段沉积期发生湖退，物源区范围扩大，有大量沙一段泥岩参与供源，在沉积区形成薄层砂砾岩。平面上，同一沉积期，物源区西部和东部东段沟谷体系范围大，以火山岩、花岗岩剥蚀为主，在沉积区形成的砂砾岩厚度、规模均大；东部西段以碳酸盐岩剥蚀为主，在沉积区形成的砂砾岩厚度、规模均小。③母岩对储层物性具有明显的控制作用，沙三段至东三段，东部东段以火山岩剥蚀为主，且埋深较浅，储层中含有大量火山岩岩屑，后期易溶解，胶结作用弱，储层物性好；东部西段以碳酸盐岩剥蚀为主，埋深浅，但胶结作用强，物性差；西部埋深较深，压实作用和胶结作用均强，储层物性差。因此，在相近深度段内，碳酸盐岩母岩供源时，沉积区储层中含有大量的碳酸盐岩砾石和岩屑，填隙物以灰质胶结物为主，胶结作用强烈，储层物性差；火山岩和变质花岗岩供源时，沉积区储层中以火山岩或花岗岩砾石和岩屑为主，灰质胶结物含量较少，胶结作用相对较弱，储层物性整体较好。该项成果可为研究区下一步的勘探评价提供参考。     

渤海湾盆地黄河口凹陷新近系油气富集模式与成藏主控因素定量评价

长期以来油气成藏定量研究是油气勘探研究的难点。文章基于三维地震、测井以及录井等资料，对渤海湾盆地黄河口凹陷新近系油气成藏条件、富集模式和成藏主控因素进行了系统研究。指出黄河口凹陷新近系油气主要富集在走滑反转带和断隆带两类构造单元，具有两种不同的成藏模式。其中，走滑反转带新近系的油气运移能力受油源断层的活动强度和古近系区域盖层厚度共同控制；断隆带新近系油气运移的能力受仓储层的输导脊和切仓断裂共同控制。并建立了两类不同成藏模式下表征油气输导能力的定量模型和公式。进一步指出，新近系构造-岩性圈闭在具备供烃条件时，其成藏规模仍受到“断-砂”接触程度的控制。砂体与油源断层的总接触面积越大，其内部油气充满度一般越高。     

Sag in drying coatings: Prediction and real time measurement with particle tracking

Sag is a coating phenomenon characterized by gravity-driven flow after deposition; excessive amounts of sag can lead to coating defects. In this work, a new method for evaluating and quantifying sag is investigated. The motion of micron-sized Lycopodium spores on an inclined coating surface is tracked during drying, and the resulting surface velocity data is used to determine sag length. This in situ particle tracking method is minimally invasive and permits real time measurements. Measured sag lengths and real time surface velocities in aqueous polyvinyl alcohol solution coatings compare well with a theoretical model. The model is also used to develop a predictive sag regime map, which anticipates the extent of sag given coating properties and process-specific parameters. This map also identifies viable processing windows and aids in intelligent coating design given specific process constraints. The predictions of the sag regime map are compared against experimental sag results from polyvinyl alcohol solution coatings as well as four commercial latex paints, revealing good agreement for coatings with Newtonian or ‘Newtonian-like’ rheologies.