共查询到20条相似文献，搜索用时 15 毫秒
1.
Muhammad Umar Henrik Friis Abdul Salam Khan Akhtar Muhammad Kassi Aimal Khan Kasi 《Journal of Asian Earth Sciences》2011,40(2):622-635
The Maastrichtian Pab Formation in the southern part of Pakistan is composed of fine- to very coarse-grained texturally mature quartz arenite and subordinate sublitharenite varieties. The sandstones have undergone intense and complex diagenetic episodes due to burial and uplift. Diagenetic modifications were dependent mainly on the clastic composition of sandstone, burial depth and thrust tectonics. Diagenetic events identified include compaction, precipitation of calcite, quartz, clay minerals and iron oxide/hydroxide, dissolution and alteration of unstable clastic grains as feldspar and volcaniclithic fragments as well as tectonically induced grain fracturing. The unstable clastic grains like feldspar and lithic volcanic fragments suffered considerable alteration to kaolinite and chlorite. Dissolution and alteration of feldspar and volcanic lithic fragments and pressure solution were the main sources of quartz cements. Mechanical compaction and authigenic cements like calcite, quartz and iron oxide/hydroxide reduced the primary porosity, whereas dissolution of clastic grains and cements has produced secondary porosity. Chlorite coatings on clastic grains have prevented quartz cementation. Coarse-grained, thick bedded packages of fluviodeltaic, shelf delta lobe and submarine channels facies have higher average porosity than fine-grained, thin bedded and bioturbated sandstone of deeper shelf and abyssal plain environments and these facies are concluded to be possible future hydrocarbon prospects. 相似文献
2.
合川地区须二段砂岩储层成岩作用及其对储层的影响 总被引：1，自引：0，他引：1
依据普通薄片、铸体薄片、扫描电镜、X衍射等实验分析手段,对合川地区须家河组二段砂岩储层的岩石学特征、成岩作用及孔隙演化进行了研究。结果表明,该区须二段砂岩储层主要由长石岩屑砂岩和岩屑长石砂岩组成。主要成岩作用类型有压实作用、胶结作用、溶蚀作用和交代作用,成岩演化阶段已达到中成岩B期。早成岩A期—B期,压实作用强烈,原生孔隙迅速减少;中成岩A期,压实作用及硅质胶结作用是原生孔隙继续降低,有机质热演化过程中产生的有机酸及无机酸,使长石及富长石的岩屑颗粒发生强烈溶蚀,形成大量次生孔隙;中成岩B期,含铁方解石及铁白云石交代充填,使储层致密。压实作用及胶结作用是原生孔隙遭受破坏的主要成岩作用类型,而溶蚀作用是形成次生孔隙的主要成岩作用类型。受成岩作用及成岩演化阶段的控制,研究区须二段储集空间类型多样,粒内溶孔、粒间溶孔及残余粒间孔发育,特别是长石及富长石岩屑颗粒的溶蚀,使须二段储层出现孔隙度、渗透率异常发育带。 相似文献
3.
塔里木盆地西北地区苏盖特布拉克组发育一套潮坪相沉积,是该层系油气勘探的主要目标。基于什艾日克剖面、奇格布拉克剖面、肖尔布拉克剖面的地质测量,采用薄片鉴定、阴极发光、扫描电镜、流体包裹体测温及黏土矿物X衍射等分析手段开展海相碎屑岩成岩作用和成岩演化研究,为塔里木盆地苏盖特布拉克组进一步开展油气勘探部署和甜点储层预测提供地质依据。结果表明：（1）研究区苏盖特布拉克组发育潮坪沉积环境的砂体,砂岩类型以岩屑石英砂岩、岩屑砂岩为主,偶见长石岩屑砂岩,成分成熟度和结构成熟度中等;（2）苏盖特布拉克组砂岩经历了压实（溶）作用、胶结作用、溶蚀作用及交代作用等成岩作用,压实作用是造成储层致密的直接原因,钙质胶结和硅质胶结是储层致密化的根本因素;（3）苏盖特布拉克组砂岩的成岩演化阶段已达到中成岩B期,成岩演化序列为：压实作用/自生黏土矿物（绿泥石）环边—第一期长石、岩屑溶蚀作用—第一期硅质胶结—第一期泥微晶方解石胶结/压溶作用/黏土矿物的伊利化—第二次硅质胶结/第二期铁方解石胶结—钙质胶结物溶蚀。据此建立的成岩演化模式为塔里木盆地超深层致密砂岩中甜点储层预测提供可靠的地质依据。 相似文献
4.
Faiz Ahmad A. H. M. Ahmad M. A. Quasim 《Journal of the Geological Society of India》2017,90(3):273-282
Jaisalmer Formation consists of 360m thick succession of medium to coarse grained sandstones with interbeds of shale, claystone and occasional lignite that rest over Lathi Formation, is the basal part of the Jaisalmer basin. The rocks are exposed amidst desert, low mounds and shallow stone quarries. Sandstones were deposited in shallow marine to deltaic environments. The studied sandstones consist of abundant quartz followed by feldspar, mica, chert, rock fragments and heavy minerals. The study mainly deals with identification of various diagenetic features such as compaction, cementation and porosity evolution. During mechanical compaction rearrangement of grains took place and point, long and suture contacts were formed. The sandstones are cemented by iron oxide, silica overgrowth, carbonate and clay. Porosity has developed due to dissolution of iron, carbonate cement and feldspar grains. Dissolution and alteration of feldspar, lithic fragments and pressure solution were the main source of quartz cements. The sandstones show good amount of existing optical porosity with an average of 7.19%. Porosity reduction is mainly due to early stage of mechanical compaction and subsequent pervasive calcite and iron oxide cementation. Further, porosity reduced due to deposition of clay cement. 相似文献
5.
基于薄片鉴定分析、扫描电镜、物性分析、X射线衍射分析、碳酸盐碳氧同位素分析等实验手段, 研究文昌A凹陷珠海组低渗砂岩储层岩石学特征和成岩作用特征, 通过定量化分析, 评价压实、胶结、溶蚀作用对储层孔隙演化的影响, 实现成岩相预测及储层分类评价.结果表明:（1）研究区珠三南断裂带以岩屑砂岩和长石岩屑砂岩为主, 中、粗砂岩含量高; 6号断裂带以长石岩屑砂岩和岩屑石英砂岩为主, 细砂岩含量高.储集空间以次生溶孔为主, 物性变化大, 纵向及平面均表现出明显的分带性.（2）机械压实造成珠海组原生粒间孔隙大量丧失; 含铁碳酸盐、自生伊利石、硅质胶结等使粒间孔进一步减少, 早期绿泥石则能抑制石英次生加大; 溶蚀作用使深部储层物性得以改善, 研究区珠海组发育两个次生溶蚀带.成岩相预测结果表明, 发育厚层粗粒级砂岩的水下分流河道是研究区的有利储集相带.（3）通过孔隙演化定量分析, 认为成岩作用对粗粒砂岩和细-中粒砂岩的孔隙度演化的影响具有差异性. 相似文献
6.
准噶尔盆地陆1井砂岩成岩作用及其对储层的影响 总被引：1，自引：1，他引：0
本文探讨了陆1井岩屑砂岩的成岩作用及其对砂岩储层的影响.研究表明,压实作用使岩屑砂岩的孔隙度随埋深迅速减小,成岩早期的胶结物使大部分原生孔隙被充填。水化作用在成岩早期及有机质半成熟和成熟期成岩作用过程中,制约着各个阶段的成岩作用特点。在水化作用和有机质热演化作用的共同影响下,使得方解石胶结物发生选择性溶蚀形成了深部(上乌尔禾组)次生孔隙发育带。 相似文献
7.
准噶尔盆地西北缘克-百地区侏罗系成岩作用及其对储层质量的影响 总被引：1，自引：0，他引：1
准噶尔盆地西北缘克拉玛依—百口泉地区侏罗系砂岩、砂砾岩储层经历了压实、胶结、溶蚀等多种成岩作用,其中压实和溶蚀作用是控制储层物性的主要成岩作用,其次为胶结作用。压实作用以机械压实为主,是孔隙减少的主要原因。胶结作用主要为碳酸盐胶结,少量黄铁矿胶结,偶见方沸石胶结和硅质胶结。溶蚀作用导致碳酸盐胶结物、长石颗粒和少量岩屑溶解流失。储层孔隙经历了由原生到次生的演化过程。在成岩演化过程中,长石的溶蚀作用、碳酸盐矿物的沉淀与溶解作用是影响储层孔隙发育的关键因素,早期方解石的胶结有利于后期次生孔隙的形成。在克-乌断裂带上、下盘地层中,断裂带上盘埋深浅,一般小于1200m,原生孔隙非常发育;断裂带下盘埋深较深,压实作用强,原生孔隙所占比例明显减少,次生溶蚀孔隙相对发育。次生孔隙的形成受流体及断裂控制。 相似文献
8.
The Middle Jurassic Khatatba Formation acts as a hydrocarbon reservoir in the subsurface in the Western Desert, Egypt. This study, which is based on core samples from two exploration boreholes, describes the lithological and diagenetic characteristics of the Khatatba Formation sandstones. The sandstones are fine‐ to coarse‐grained, moderately to well‐sorted quartz arenites, deposited in fluvial channels and in a shallow‐marine setting. Diagenetic components include mechanical and chemical compaction, cementation (calcite, clay minerals, quartz overgrowths, and a minor amount of pyrite), and dissolution of calcite cements and feldspar grains. The widespread occurrence of an early calcite cement suggests that the Khatatba sandstones lost a significant amount of primary porosity at an early stage of its diagenetic history. In addition to calcite, several different cements including kaolinite and syntaxial quartz overgrowth occur as pore‐filling and pore‐lining cements. Kaolinite (largely vermicular) fills pore spaces and causes reduction in the permeability of the reservoir. Based on framework grain–cement relationships, precipitation of the early calcite cement was either accompanied by or followed the development of part of the pore‐lining and pore‐filling cements. Secondary porosity development occurred due to partial to complete dissolution of early calcite cements and feldspar. Late kaolinite clay cement occurs due to dissolved feldspar and has an impact on the reservoir quality of the Khatatba sandstones. Open hydraulic fractures also generated significant secondary porosity in sandstone reservoirs, where both fractures and dissolution took place in multiple phases during late diagenetic stages. The diagenesis and sedimentary facies help control the reservoir quality of the Khatatba sandstones. Fluvial channel sandstones have the highest porosities and permeabilities, in part because of calcite cementation, which inhibited authigenic clays or was later dissolved, creating intergranular secondary porosity. Fluvial crevasse‐splay and marine sandstones have the lowest reservoir quality because of an abundance of depositional kaolinite matrix and pervasive, shallow‐burial calcite and quartz overgrowth cements, respectively. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
陕甘宁盆地庆阳地区长8油层砂岩成岩作用及其对储层性质的影响 总被引：61，自引：7，他引：54
庆阳地区长8油层为湖泊三角洲前缘沉积。水下分流河道和河口砂坝组成的指状砂坝控制了水下三角洲沉积格局。砂岩主要由细砂和少量中砂组成,砂岩类型主要为细粒岩屑长石砂岩和长石岩屑砂岩。主要成岩矿物为绿泥石环边、方解石胶结物、石英和长石加大生长、伊利石、伊-蒙混层、钠长石和高岭石等。绿泥石环边的发育对原生粒间孔的保存起到有利的作用,对石英和长石加大起到抑制作用。烃类注入时储层埋深已较大,不利于孔隙保存。储层发育粒间孔隙、粒内溶孔、铸模孔隙、特大孔隙、裂缝孔隙和微孔隙等多种孔隙类型,其中以粒间孔隙最为发育。局部发育的特大孔隙和伸长状孔隙表明该区发生了一定规模的次生溶蚀作用。长8油层主要受埋藏作用的影响,成岩演化处于晚成岩A期。主要成岩相类型为绿泥石环边胶结成岩相、压实充填成岩相、压实压溶成岩相和碳酸盐胶结成岩相,不同成岩相类型决定了油气储层性质不同,绿泥石环边胶结成岩相构成了本区最好的储层类型。 相似文献
10.
松辽盆地深层储层砂岩中火山碎屑物质在成岩阶段的变化与孔隙发育 总被引：5，自引：0，他引：5
松辽盆地深层储层砂岩中岩屑成分主要为火山岩岩屑,体积分数最高可达60%。填隙物主要为凝灰质杂基和成岩期后的钙质及硅质胶结物,体积分数在11%～19%。其形成环境主要为陆相断陷盆地的河流、三角洲和扇三角洲。岩石的成分成熟度和结构成熟度普遍低,而储层物性通常却很好。孔隙铸体、岩石薄片和电镜分析结果表明,富火山岩岩屑储层岩石的物性受碎屑成分、填隙物和成岩流体3个因素影响,其中火山岩碎屑在埋藏成岩作用中易于形成的次生孔隙是改善储层物性的主要原因。岩屑砂岩与储层物性相关的主要成岩后生变化有：（1）埋藏压实作用使碎屑岩原生孔隙大量减少;（2）溶蚀、脱玻化、次生矿物的生成和重结晶等成岩作用的总效应导致孔隙增加;（3）成岩流体改造和蚀变作用使火山碎屑物质形成大量次生孔隙,从而改善了砂岩储层的物性。 相似文献
11.
为揭示深水重力流沉积致密砂岩储层发育特征及分布规律,笔者等以鄂尔多斯盆地合水地区三叠系延长组7段（简称长7段）为例,通过岩芯描述、铸体薄片以及扫描电镜观察,结合物性数据以及分析化验资料对研究区长7段沉积、储层岩石学、孔隙类型以及成岩作用特征进行了分析,在沉积和成岩作用特征研究基础上探讨了优质储层的形成机理,据此建立了湖相深水重力流致密砂岩储层质量的演化模式。结果表明：合水地区长7段储层岩性以长石岩屑砂岩为主,孔隙类型主要为溶蚀孔和残余粒间孔,属于特低孔—超低渗储层,主要成岩作用为压实、胶结和溶蚀作用。重力流致密砂岩储层质量受沉积相和成岩作用共同影响,限制性水道中沉积的砂体由于具有强的抗压实能力、少的伊利石和碳酸盐矿物含量以及较多长石、岩屑溶蚀孔隙,储层质量最好。不同沉积环境中的砂岩在颗粒粒度、分选、沉积厚度方面存在差异,通过影响成岩作用类型与强度综合控制储层质量。研究成果可为相同类型储层的预测和评价提供参考。 相似文献
12.
通过分析铸体薄片、物性、扫描电镜及压汞等资料,探讨了鄂尔多斯盆地东北缘临兴区块盒8段致密砂岩的储层特征及物性影响因素。结果表明：盒8段储层岩性以岩屑砂岩和长石岩屑砂岩为主,平均孔隙度为7.1%,平均渗透率为0.38 mD;主要孔隙类型为次生溶孔,孔喉半径的分布以双峰状为主,主峰值偏向于相对小的半径,砂岩以相对小孔隙为主;成岩作用主要包括压实作用、溶蚀作用、胶结作用及交代作用等,具有压实强而普遍、溶蚀普遍但不充分、胶结和交代作用强等特征;受贫石英、富岩屑和长石的碎屑组分特征影响,各组分含量对物性有影响但无明显控制作用;粒度是物性的主控因素,粒度越粗物性越好;此外,溶蚀作用对砂岩物性也有一定的积极作用,而封闭成岩体系下的强胶结作用是导致储层致密的主要因素。 相似文献
13.
塔中地区志留系沥青砂岩成岩作用及其对储层性质的影响 总被引：5，自引：0，他引：5
运用沉积学原理对塔中地区志留系经历复杂成岩演化的沥青砂岩进行研究分析,了解到该岩石主要经过压实作用、胶结作用和溶蚀作用等成岩作用。其胶结物的主要类型有绿泥石、伊利石、高岭石、伊-蒙混层等粘土矿物以及碳酸盐矿物、石英、长石、黄铁矿等。孔隙类型以粒间孔隙、粒内孔、铸模孔、特大孔、裂缝孔隙等为主,其中以粒间孔隙最为发育,低地温梯度有利于在深层形成次生孔隙。志留系沥青砂岩储层物性受沉积和成岩双重因素的影响,成岩演化阶段处于晚成岩A期。根据影响储层物性的储层成岩作用,可将成岩相类型划分为不稳定碎屑溶蚀成岩相、压实-弱溶蚀成岩相、压实充填成岩相、压实压溶成岩相、碳酸盐胶结成岩相等几种主要类型,成岩相类型决定了储层性质,不稳定碎屑溶蚀成岩相和压实-弱溶蚀成岩相是本区较好的油气储层。 相似文献
14.
龙虎泡地区高台子油层成岩作用及其对储集岩孔隙演化的影响 总被引：22，自引：3，他引：19
龙虚泡地区高台子油层储集岩基本上由岩屑长石粉砂岩组成。压实作用、胶结作用、溶蚀作用、粘土矿物的转化作用和交代作用对沉积岩 (物 )进行了改造。根据岩石的结构可以看出压实作用发育于早成岩阶段,方解石胶结物的结构和碳、氧稳定同位素组成说明方解石胶结作用发育于早成岩阶段。压实作用和方解石结作用对孔隙的减少起着决定性影响。长石和中基性火山岩岩屑的溶蚀作用使得孔隙有一定程度的增加。压实作用和胶结作用也阻止了自生石英的生长和次生孔隙带的形成。 相似文献
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黄骅坳陷三马地区中-深部储层成岩作用及主控因素分析 总被引：12，自引：2，他引：12
黄骅坳陷三马地区储集岩样品的显微特征及成岩矿物的组合关系分析结果表明，三马地区下第三系中深层储层主要处于晚成岩A期，成岩现象包括石英、长石的次生加大、碳酸盐矿物胶结作用、矿物交代作用、溶解作用和粘土矿物转化作用等。其中石英次生加大于2700m左右开始出现，随埋深增大，石英增生加强；长石次生加大现象不十分普遍；碳酸盐胶结作用包括早期自生泥晶方解石胶结作用、连晶方解石和晚期白云石(或铁方解石)的胶结作用。在扫描电镜下可见到方解石与含铁方解石集合体充填在粒间孔隙中或与石英、钠长石及粘土矿物共生，白云岩多呈菱形粒状分布于粒间；常见的交代现象主要有方解石交代长石、石英及粘土矿物，粘土矿物交代长石、石英等；溶解作用主要有长石的溶解、碳酸盐颗粒的溶解和方解石胶结物的溶解等，粘土矿物的转化主要为蒙脱石、高岭石向伊利石(或绿泥石)转化。还讨论了储层岩相、岩性特征、孔隙水中有机酸含量、早期方解石的充填、烃类早期注入等因素对储层成岩演化的控制作用。 相似文献
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川东建南地区须家河组储层非均质性极强,致密化程度极高,为了查明储层差异演化过程,剖析储层差异演化控制因素,运用岩石学和岩石地球化学的多种实验方法,在详细刻画储层岩石学特征的基础上,划分了储层成岩相类型,查明了不同类型砂岩的物性特征和孔隙结构特征,分析了储层的差异性演化过程.研究区砂岩可以划分为4种成岩相类型,即强压实相、溶蚀相、硅质胶结相和强钙质胶结相.溶蚀相砂岩物性最好,强压实相砂岩次之,硅质胶结相和钙质胶结相砂岩物性最差.碎屑组分的差异是造成储层非均质性强和差异性演化的重要原因.塑性岩屑含量的差异,导致早成岩时期压实减孔程度的不同;长石含量的差异,影响了砂岩中溶蚀强度和方解石胶结程度;石英含量的差异,控制了砂岩中硅质胶结作用的强弱;最终,使得储层演化有先有后,空间分布非均质. 相似文献
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综合利用岩心、铸体薄片、扫描电镜等多种资料,对鄂尔多斯盆地正宁地区三叠系延长组长9油层组储集层的岩石类型、成岩作用类型、成岩相分布特征及主控因素进行了系统研究。延长组长9油层组储集层的岩石类型为细—中粒岩屑质长石砂岩和长石质岩屑砂岩,成岩作用类型主要为压实作用,同时还有绿泥石、方解石、铁方解石及硅质胶结作用,方解石交代作用和少量的溶蚀作用,储集层目前处于中成岩A期。根据层理频率和塑性颗粒含量将岩石划分为高频层理富片状塑性颗粒粉—细砂岩岩石相和低频层理富刚性矿物细—中砂岩岩石相,前者分布于水下分流河道边部,发育压实致密成岩相;后者形成于水下分流河道主河道和河口坝。根据砂体结构可划分为厚层单砂体和厚层多砂体。厚层单砂体为单期形成的河道或河口坝砂体,上部以方解石充填胶结成岩相为特征,下部以绿泥石衬边胶结成岩相为特征;厚层多砂体为多期砂体冲刷叠置形成,发育方解石绿泥石充填胶结成岩相。塑性颗粒含量对压实作用强度影响最大,叠加碳酸盐胶结致使储集层质量变差,而早期绿泥石环边胶结抑制压实作用,是有利储集层发育的重要条件。综合评价表明,延长组长9油层组有利储集层发育于绿泥石衬边胶结相,其次为绿泥石和方解石充填胶结相,最差储集层为方解石充填胶结相和压实致密相。 相似文献
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Ezz El Din Abdel Hakim Khalaf 《Arabian Journal of Geosciences》2014,7(7):2603-2624
Wadi Queih basin hosts a ～2,500-m thick Neoproterozoic volcanoclastic successions that unconformably lie over the oldest Precambrian basement. These successions were deposited in alluvial fan, fluviatile, lacustrine, and aeolian depositional environments. Diagenetic minerals from these volcaniclastic successions were studied by X-ray diffractometry, scanning electron microscopy, and analytical electron microscopy. The diagenetic processes recognized include mechanical compaction, cementation, and dissolution. Based on the framework grain–cement relationships, precipitation of the early calcite cement was either accompanied or followed by the development of part of the pore-lining and pore-filling clay cements. Secondary porosity development occurred due to partial to complete dissolution of early calcite cement and feldspar grains. In addition to calcite, several different clay minerals including kaolinite, illite, and chlorite with minor smectite occur as pore-filling and pore-lining cements. Chlorite coating grains helps to retain primary porosity by retarding the envelopment of quartz overgrowths. Clay minerals and their diagenetic assemblages has been distinguished between primary volcaniclastics directly produced by pyroclastic eruptions and epiclastic volcaniclastics derived from erosion of the pre-existing volcanic rocks. Phyllosilicates of the epiclastic rocks display wider compositional variations owing to wide variations in the mineralogical and chemical compositions of the parent material. Most of the phyllosilicates (kaolinite, illite, chlorite, mica, and smectite) are inherited minerals derived from the erosion of the volcanic basement complex, which had undergone hydrothermal alteration. Smectites of the epiclastic rocks are beidellite–montmorillonite derived from the altered volcanic materials of the sedimentary environment. Conversely, phyllosilicate minerals of the pyroclastic rocks are dominated by kaolinite, illite, and mica, which were formed by pedogenetic processes through the hydrothermal influence. 相似文献