蒙皂石粘土矿物不正常转化的研究——以准噶尔盆地为例

利用岩石薄片和X射线衍射资料，分析了准噶尔盆地腹部地区蒙皂石粘土矿物的不正常转化。该区庄1井、成1井和董1井在超压段内粘土矿物转化出现异常现象，蒙皂石以及伊／蒙混层的相对含量随深度增加有所增加，而伊利石的相对含量随深度增加有所减少。结合前人的研究资料，讨论了超压对粘土矿物转化的影响。超压能增加蒙皂石层间水的稳定性，阻碍超压仓与外界流体和离子的交换，使伊利石含量有所减少。同时，火山岩屑物质的大量存在可能导致在晚成岩阶段伊／蒙混层含量较高，蒙皂石的含量也有所增加。     

天然粘土样品分析的伊利石/蒙皂石间层矿物的间层比计算方法

乙二醇(EG)处理定向样品的X射线衍射谱图上有无17?衍射峰,是区分伊利石/蒙皂石无序间层和伊利石/蒙皂石有序间层的重要标志.实验证明,对于纯样品,伊利石/蒙皂石无序间层矿物的17A衍射峰强度变化主要决定于间层比(S%)的大小;对于天然样品,尤其是含有分散伊利石的天然样品,伊利石/蒙皂石无序间层矿物的17?衍射峰强度除了受间层比的影响以外,还受样品中该间层矿物相对含量的影响,即受其它伴生矿物,尤其是分散伊利石相对含量的影响.本文根据具不同间层比的纯伊利石/蒙皂石无序间层矿物与分散伊利石以不同比例的混合样品的X射线衍射分析结果,提出一种适用于天然粘土样品分析的伊利石/蒙皂石无序间层矿物的间层比计算方法,同时还介绍天然粘土样品分析的伊利石/蒙皂石有序间层矿物的间层比计算方法.      

川东地区龙马溪组页岩黏土矿物组成与成因

为了分析页岩气储层中黏土矿物特征及其与有机质的关系,以川东地区下志留统龙马溪组页岩为研究对象,利用X-射线衍射分析和扫描电镜观察,并结合薄片、岩心和测井资料,深入分析了研究区龙马溪组黏土矿物成因、分布特征及其主控因素、对有机质的影响。结果表明:黏土矿物组合为伊利石+伊/蒙混层+绿泥石,具有陆源碎屑、自生和次生成岩3种类型,全区具有高伊利石、伊/蒙混层含量的特点;焦石坝地区龙马溪组下段地层具有封闭性,致使烃源岩生烃过程中产生异常高压,抑制伊利石化作用,在垂向上出现了随深度增加伊/蒙混层含量也增加的非正常转化序列,同时也可以用这种非正常转化序列反推地层中异常高压的存在;碎屑组分也间接影响黏土矿物的含量,尤其是钾长石的含量,在伊/蒙混层向伊利石的转化过程中,是否能提供足够多的K⁺,决定了两者之间是否能等量转化。     

我国含油盆地粘土矿物分布特征及控制因素

通过我国近20个含油盆地7000多块样品的粘土矿物分析研究发现,在不同类型沉积盆地中粘土矿物分布特征有很大不同,而且各自的主要控制因素也有明显差别。正常沉积盆地。随埋深增加蒙脱石向伊利石转化及高岭石向绿泥石转化的规律明显,控制因素以成岩作用为主。盐碱沉积盆地粘土矿物的特征是伊利石和绿泥石含最高,而缺乏高岭石。特征矿物主要受水介质条件制约。含煤沉积盆地普遍高岭石含量高,主要也是受水介质条件制约。火山碎屑岩沉积盆地的特征是普遍存在蒙脱石,主要受母质来源和水介质条件所制约。     

黏土矿物对不同类型烃源岩热解参数影响

选取高岭石、伊利石和绿泥石3种黏土矿物,以不同比例分别与Ⅰ型、Ⅱ型和Ⅲ型干酪根混合并进行热解实验,探讨黏土矿物种类及含量对不同类型烃源岩热解参数影响.实验结果表明,黏土矿物对干酪根热解生烃作用同时具有层间吸附作用和表面吸附作用,黏土矿物的表面吸附作用会增大矿物的催化能力,层间吸附会造成大分子烃类被吸附在层间沉淀,抑制热...     

三端元粘土矿物分析方法及应用

根据粘土矿物演化特征,首次提出了由蒙皂石 伊／蒙混层矿物 伊利石端元(S／I端元)、蒙皂石 绿／蒙混层矿物 绿泥石端元(S／C端元)、高岭石端元(K端元)这三个端元构成的粘土矿物三端元分析方法;应用粘土矿物三端元分析法查明了库车前陆盆地下侏罗统阳霞组和白垩系巴西盖组物源区粘土矿物组合特征,分析了下侏罗统阳霞组处于不同压力体系下的粘土矿物演化特征;发现静水压力体系下高岭石、绿泥石相对含量的增高、伊／蒙混层矿物 伊利石相对含量降低和异常高压体系下高岭石相对含量的降低、伊／蒙混层矿物 伊利石相对含量增高的粘土矿物演化特征。     

鄂尔多斯盆地西南部长6段粘土矿物特征

根据物性、粘土矿物X 衍射和扫描电镜等测试分析,鄂尔多斯盆地西南部延长组长6 段超低渗透砂岩粘土矿物类型为绿泥石、伊蒙混层和伊利石,粘土矿物相对含量分带性明显,研究区的东部绿泥石含量较高,而西部伊蒙混层含量较高。粘土矿物特征与储集层物性的相关性分析认为,伊蒙混层含量、伊利石含量均与储集层孔渗性能呈负相关;绿泥石含量与储集层孔渗性呈正相关;研究区东部储集层的质量优于西部。     

玛湖凹陷风城组黏土矿物组成特征及其成因

为明确准噶尔盆地玛湖凹陷下二叠统风城组烃源岩中黏土矿物的特征及其成因,利用X射线衍射和扫描电镜测试,分析了研究区风城组碱湖相烃源岩中黏土矿物组成。结果表明,风城组碱湖相烃源岩黏土矿物具有蒙皂石和伊蒙混层含量高及伊利石含量较低的特点,呈现蒙皂石伊利石化缓慢的现象;结合风城组的沉积背景,蒙皂石异常转化主要受物源区火山岩、气候和成岩流体的共同影响。中基性火山岩和干湿交替的气候,促进了蒙皂石的形成;而以CO2-3 为主要阴离子的碱性水体,抑制了蒙皂石的伊利石化。     

CLAY-MINERAL STUDIES OF THE SUBSURFACE NIGER DELTA

Mineralogical studies of Tertiary subsurface sediments in the Niger Delta have shown that smectite, kaolinite, mixed-layer illite/smectite and illite are the principal clay minerals, with subordinate quantities of chlorite. Clays from the Recent delta have similar mineralogical compositions.
Sediments in the eastern Niger Delta are contributed by rivers which drain the Oban and Bamenda Massifs, and the Tertiary volcanics and Cretaceous sediments of the Benue Trough. Sediments in the central and western delta are derived by weathering of the North, Central and SW Nigerian Basement, and also from Cretaceous sediments which are drained by the Niger/Benue river systems.
The clay-mineral assemblages of the western, central and eastern Niger Delta sequences differ. These differences are thought to be related to geothermal gradients, environments of deposition, source materials, pore-waters chemistry and basin tectonics.
Clay-mineral assemblages from nine wells in the Niger Delta are used in this study as a possible means of correlation. A relationship can be established between clay mineralogy and the occurrence of hydrocarbons in the wells investigated.     

MINERALOGICAL AND GEOCHEMICAL STUDIES OF TERTIARY SEDIMENTS FROM THE EASTERN NIGER DELTA AND THEIR RELATIONSHIP TO PETROLEUM OCCURRENCE

Mineralogical and chemical studies have been made of shale cuttings from the Akiri-1 well in Oligocene — Miocene sediments of the Niger Delta. The < 2μm fraction from the 2,183 to 3,720m stratigraphic interval was analyzed by X-ray diffraction. Kaolinite and chlorite are more abundant than other clay minerals. The illiteh mectite composition changes from a phase with 32% illite layers, to one with 82% illite layers over the 3,250 to 3,720m stratigraphic interval. Kaolinite decreased in shallow shales from 22 to 16% and increases to 29% in deep shales. Quartz increases in abundance with depth, while chlorite and plagioclase feldspar show no systematic trend with depth. Calcite is present in small amounts in all the samples.
Variations in the bulk chemical composition of true shale with depth only show significant changes in the K₂O and Fe₂O₃ content: other major chemical constituents show no systematic variations. The potassium appears to be derived from the pore water. The loss of smectite and abundance of Fe coincided with hydrocarbon occurrence. On the basis of the apparent systematic transformation of smectites to illites through mixed layers, the illite/smectite reference interval in the subsurface has been established: this interval coincided with hydrocarbon occurrence.
Mineralogical and chemical changes observed are dependent on the pore system chemistry, the temperature, and possibly compaction effects.     

干酪根及黏土单矿物对甲烷吸附能力的差异性

页岩气主要以游离气和吸附气的形式存在于富含有机质的泥页岩中。目前,国内外在干酪根和黏土矿物对甲烷吸附能力的差异性研究方面还比较薄弱。由此提出了将干酪根和黏土矿物进行分离的方法,对干酪根和不同黏土矿物分别进行等温吸附实验,研究单位质量的干酪根、伊蒙混层、高岭石、绿泥石和伊利石对甲烷吸附能力的差异性。结果表明:对甲烷吸附能力大小的次序为干酪根> 伊蒙混层> 高岭石> 绿泥石> 伊利石,有些样品干酪根吸附气量大于黏土矿物之和的吸附气量。随着温度的升高,干酪根和黏土单矿物对甲烷分子的吸附量有所下降。在同一温度下,干酪根吸附气量随镜质体反射率增大而增加,黏土矿物基本不受镜质体反射率的影响。      

伊蒙混层粘土I/S比加大方式及成分控制──以珠江口盆地两口井为例

对珠江口盆地两口井泥质岩中粘土矿物X衍射分析资料的分段定量研究证实,在渐进成岩过程中,伊-蒙混层粘土的伊利石层和蒙皂石层的含量之比(I/S)的加大,与钾长石的溶解有关。有三种形式:若沉积有机质和钾长石足够丰富,加大将优先以伊利石层净增加的方式进行,其出现的温度大致与生油门限温度相当或稍高;低于该温度,蒙皂石层将按溶解-沉淀机理伊利石化;若无K⁺供给,加大方式将是蒙皂石净溶解。一般情况下的渗透率均可保证离子的通畅输导而与加大方式无关;仅当渗透率低到只对较大的铝的有机络合离子具有过滤作用时,才可能使净增伊利石层被伊利石化反应所取代;更低渗透率或体系封闭将使所有加大行为趋于停止。     

四川盆地南部及其周缘龙马溪组黏土矿物研究

为了分析页岩气储层中黏土矿物特征及其对页岩气勘探、开发的影响,以四川盆地南部及其周缘下志留统龙马溪组黑色富有机质页岩发育层段为主要研究对象,利用X-射线衍射分析,并与大量的薄片和背散射分析资料相结合,较系统地揭示了研究区龙马溪组黏土矿物的发育及分布特征。研究表明：黏土矿物以绿泥石+伊/蒙混层+伊利石为主,具有陆源碎屑和次生成因2种类型,主要分布在盆地中心及其边缘地区,具有高伊利石、伊/蒙混层含量,较高绿泥石含量的特点|黏土矿物的类型和含量具有一定的指相意义,平均含量大于50%的地区,主要为深水陆棚沉积,在30%～50%之间的地区通常为浅水陆棚沉积,小于30%的地区为海陆过渡相沉积|龙马溪组沉积时为半干旱—干旱的气候,成岩过程中水介质具有盐度较高、偏碱性,富K⁺的特点|成岩演化已达到晚成岩阶段,烃类演化至干气阶段,具备形成页岩气的气源条件|根据黏土矿物对页岩气储集空间的影响,并与有机碳的展布特征相叠合,渝东南地区的綦江—武隆—彭水一带、黔西—滇北地区的雷波—筠连—兴文—仁怀—桐梓近EW向展布的一带,以及研究区西北部的峨边西河地区为页岩气的有利区,位于盆地中心的宜宾—江津—涪陵呈NE—SW向展布的区域,为次级有利区。     

辽东湾坳陷X油田黏土矿物对注水开发储层物性的影响

为摸清研究区储层物性变化规律,指导油田注水开发,以辽东湾坳陷X油田东二下段三角洲前缘储层中黏土矿物为研究对象,采用铸体薄片、扫描电镜、X—衍射等方法,通过对比不同位置、不同含水阶段密闭取心井黏土矿物体积分数、储层物性,结合古地貌与沉积环境,深入分析黏土矿物的分布规律及控制因素,探讨黏土矿物对注水开发储层的影响。研究结果表明:研究区储层中黏土矿物主要为伊/蒙混层和高岭石,含有少量的伊利石和绿泥石;受古地貌与沉积环境两大因素控制,黏土矿物含量呈现规律性变化,南西地区古地貌低洼,储层埋深较大,以石英砂岩为主的河口坝砂体发育,伊/蒙混层含量高,而北东地区古地貌略凸起,储层埋深小,以长石砂岩为主的水下分流河道砂体发育,高岭石含量高;黏土矿物总含量低的储层水淹较强,黏土矿物总含量高的储层水淹较弱;伊/蒙混层含量高的储层,水淹后储层物性明显降低,而高岭石含量高的储层,水淹后储层物性明显变好。研究成果为储层剩余油描述提供了新思路,也为同类油田的注水措施优化、开发方案调整提供了理论指导。     

华庆地区长6 油层组黏土矿物类型及其对储层物性的影响

在薄片、X 射线衍射和扫描电镜分析基础上,研究了鄂尔多斯盆地华庆地区长6 油层组砂岩中黏土 矿物的主要类型、赋存方式及其对储层物性的影响。结果表明：长6 油层组砂岩中的黏土矿物主要为绿 泥石、伊利石和混层伊利石/蒙皂石,黏土矿物总量平均为4.55%;自生绿泥石主要以孔隙衬里方式产出, 对深埋藏砂岩的储集空间具有显著的保护作用;伊利石和混层伊利石/蒙皂石主要以孔隙桥接或孔隙充填 方式产出,其大量存在会堵塞孔隙喉道、减小孔喉半径,从而对储层物性产生负面影响;高岭石在华庆地 区长6 油层组砂岩中不发育,是由于高含量杂基导致长6 油层组砂岩在酸性流体出现之前已基本完成压 实作用,且长7 烃源岩有机质演化过程中产生的酸性流体对其影响十分有限,使其缺乏足够的粒间孔隙 和活跃的酸性流体沉淀高岭石。     

新疆柯坪大湾沟剖面中-上奥陶统烃源岩高频海平面变化与有机质的关系

通过对柯坪大湾沟剖面中-上奥陶统萨尔干组与印干组页岩的自然伽马测量,建立了此两套页岩的高频海平面变化曲线。同时,对采自于大湾沟剖面的54块泥页岩样品进行了热解与有机碳含量、泥岩X衍射的矿物种类与含量、泥岩密度等分析,将泥页岩样品的分析结果与高频海平面升降变化对比后,认为：①萨尔干组页岩厚13.4 m,属于一个三级层序的海平面升降变化。在萨尔干组页岩的海侵体系域内,发育4次高频海平面升降变化,而在高位体系域内发育3次高频海平面升降变化。印干组页岩厚34 m,也同样属于一个三级层序的海平面升降变化。海侵体系域内发育2次高频海平面升降变化,在高位体系域内则发育6次高频海平面变化。②萨尔干组页岩与印干组页岩均在海平面上升期黏土矿物含量增加,且有机质丰度增高（有机碳含量值增大）。萨尔干组页岩黏土矿物含量高于印干组页岩,碳酸盐矿物低于印干组页岩,其有机质丰度亦高于印干组页岩。③萨尔干组页岩与印干组页岩的黏土矿物成分主要为伊-蒙混层,由于蒙皂石伊利石化是烃源岩催化活性的主要来源,因此富含伊-蒙混合层的这两套烃源岩是最有利的烃源岩。④萨尔干组页岩、印干组页岩均具有海平面上升,有机质丰度增高、泥页岩密度降低和海平面下降,有机质丰度降低、泥岩密度增高的特征。     

Evolution and significance of clay minerals in the Esna Shale Formation at Dababiya area,Luxor, Egypt

The Esna Shale Formation is broadly distributed in Egypt and one of the most of its important clay deposits. These deposits in the Dababiya area, Luxor region were subjected to intensive laboratory investigations (XRD, IR, and SEM analyses). The bulk and clay mineralogy of this formation varies from one layer to the next and comprises the phyllosilicates, calcite as principal minerals with remarkable amounts of quartz, feldspars dolomites, and anhydrite. Fluorapatite, pyrite, schaurteite, despujolsite, goethite, and halite are present in some beds but minor quantities. The clay mineralogy consists of smectite (41%), sepiolite-palygorskite (28%), illite (13%), smectite/illite mixed layers (13%), and kaolinite (6%). Smectite was differentiated into three species: nontronite (21%), Na-and Ca-montmorillonites (13%), and beidellite (8%). Smectites are dioctahedral with a typical fully turbostratic stacking mode and crystallite sizes varying from 2 to 3 nm. The detrital input is the dominant aspect responsible for distributing clay minerals in these marine sediments. The presence of shallow Paleogene constrained basins between arose land areas in Egypt, favorable to the neoformation of palygorskite and sepiolite, It indicates that most of the fibrous clay minerals present in this part of the Tethys could have formed in these coastal basins and that their presence is an indication of aridity. By transcending global sea level that occurred at the end of the Paleocene, the nonappearance of kaolinite at the Dababiya area (southern Egypt) and its richness at the Wadi Nukhul Section (Sinai, Egypt) no relationship is shown between differences in kaolinite abundance and sea level fluctuations during this period. Six units of clay mineral species were distinguished throughout this formation reflecting their evolution.     

Upper Cretaceous Duwi Formation shale’s oil potentiality Safaga-Quseir,Red Sea,Egypt

Duwi Formation shale deposits at Safaga – Quseir area were assessed by rock eval pyrolysis for its shale oil potentiality. The studied shale’s organic matter are mainly of type I, type II, mixed type I/II in addition to some of type III. The studied shale is described as very good source rock with total organic carbon (TOC?>?2?wt%). The kerogen maturation in the studied samples is immature according to PI and Tmax. Extracted shale oil from the studied samples as bitumen was fractionated by liquid chromatography (LG) into saturated hydrocarbon, aromatic hydrocarbon, resin and asphaltene. The saturated hydrocarbon was described by gas chromatography (GC), the pristane/phytane, isoprenoids/n-alkane and CPI ratios show that, samples were deposited in marine environment with some input of terrestrial environment and are characterized by immature level.The X-Ray Diffraction (XRD) analysis for the studied shale samples show their bulk minerals are mainly quartz, calcite, dolomite, gypsum, hematite and pyrite in addition to apatite and fluorapatite. While their clay minerals are mainly smectite and kaolinite. The chemical composition of the studied samples showed high concentration of trace elements such as Co, Cr, Cu, Ni, V and Zn which in turn through more lights on the depositional environment of the organic matter.     

鸡西盆地煤储层孔隙特征及主控因素

孔隙结构是煤层气等非常规储层研究的核心问题,既控制气藏储集性能,又影响开发评价效果。以鸡西盆地煤岩为研究对象,运用低温氮吸附方法、氩离子抛光电子扫描显微成像和核磁共振技术,对孔隙和裂隙结构进行定量表征。结合能谱分析、全岩分析测试、煤岩组分等实验数据,对有机质孔隙和矿物质孔隙发育的主控因素进行探讨。研究结果表明:有机质孔以气孔为主体,瓶型孔占主导地位,可见两端开口的圆筒孔、四边都开口的平行板状孔。T₂图谱既有双峰又有三峰,显示出较好的孔渗条件。成熟度和镜质组含量促进有机质孔的发育,而水分堵塞孔隙表面及喉道。矿物质孔主要包括黏土矿物晶间孔和溶蚀孔。高岭石、伊利石单体或集合体杂乱堆积,形成大量孔隙。黏土矿物面孔率随高岭石含量增加而增加,随伊蒙混层含量升高而减小。      

砂岩黏土矿物相对含量分析中存在的问题

中华人民共和国石油天然气行业标准 SY/T 5163—1995《沉积岩黏土矿物的相对含量 X射线衍射分析方法》存在着一个明显的缺陷：当砂岩分离黏土时,粉碎样品、浸泡至小于2 μm粒径的那些以伊利石、伊蒙混层、绿泥石和绿蒙混层组成的塑性岩屑,不可避免地会被分散进入黏土组分中。塑性岩屑中的黏土矿物成分便和砂岩填隙物中的黏土矿物混在一起,直接影响储集层填隙物黏土矿物的组成分析,使储集层填隙物中的各类黏土矿物相对含量失真。为此,提出一种求准碎屑岩填隙物中黏土矿物相对含量的新方法,此方法避免了无法将储集层中塑性岩屑分离出来,造成填隙物中黏土矿物相对含量失真的现象。