阿联酋阿布扎比地区早白垩世Lekhwair组滨外碳酸盐岩微相特征

阿联酋阿布扎比地区早白垩世Thamama群,包含Habshan、Lekhwair、Kharaib、Shu'aiba和Bab组。Lekhwair组由13个叠加的四级层序组成。根据化石组合、岩性、沉积结构确定了其四级层序海进体系域(TST)和高位体系域(HST)的微相类型,并根据有孔虫和藻类对深度的指示作用及微相的连续性,建立了Lekhwair组海进体系域和高位体系域的沉积模式,并对其沉积环境进行了分析。     

四川盆地二叠统海相碳酸盐岩储层测井评价

四川盆地下二叠统碳酸盐岩是目前重点勘探目标。与上二叠统礁滩相碳酸盐岩、下二叠统茅口组不整合面岩溶缝洞、热液白云岩不同,茅口组高能滩储层类型更加复杂化。对比分析几类储层特征基础上,针对礁滩相储层不同储集类型、不同孔隙区间以及不同储渗条件,建立了孔隙度和饱和度计算方法;针对茅口组高能滩相储层,剖析沉积微相变化、岩石矿物组分与灰泥储层构造对应关系,利用测井信息描述储集空间类型和分布特征,构建多元矿物体积模型逐点求取岩石混合骨架值,进而计算储层矿物组分和孔隙度,提高了灰泥储层参数计算精度。经岩心实验及试气验证,应用效果较好,具有良好的应用前景。     

鄂尔多斯盆地中央古隆起东侧非岩溶白云岩储层成因

近年来,鄂尔多斯盆地奥陶系马家沟组顶部除岩溶碳酸盐岩储层外,非岩溶白云岩储层也取得了天然气勘探突破。根据岩心观察、显微薄片鉴定、物性分析和测井录井等资料,研究了鄂尔多斯盆地中央古隆起东侧奥陶系马家沟组马五⁵―马五⁶亚段的沉积微相,分析了非岩溶白云岩储层特征及主控因素。结果表明：储集岩类型以砂砾屑白云岩和晶粒白云岩为主;储集空间类型主要为残余粒间孔、晶间孔和溶蚀孔,属非均质性较强的低孔隙度低渗透率储层;沉积环境为局限台地,包括潮缘滩、云坪、灰云质潟湖、灰质潟湖和膏质潟湖微相;储层分布明显受古隆起附近潮缘滩微相和选择性埋藏白云石化作用的控制;重结晶作用、胶结作用、压实压溶作用和充填作用等多种破坏性成岩作用导致了储层致密化;裂缝的存在改善了致密白云岩储层的物性,并且沟通了保存下来的孤立残余粒间孔和岩溶溶蚀孔。总之,潮缘滩微相中的埋藏白云石化、顺层岩溶作用和裂缝改造作用是储层发育的关键因素,有利于相对优质白云岩储层的形成。     

伊朗Zagros盆地西南部白垩系Sarvak组碳酸盐岩储层特征

为了阐明伊朗Zagros盆地西南部白垩系Sarvak组碳酸盐岩储层特征,利用岩心、薄片、录井、试油及测井资料,通过储层岩性类型、储集空间、物性、电性特征及孔隙发育的影响因素分析,指出Zagros盆地西南部白垩系Sarvak组碳酸盐岩储层岩性类型有白垩质灰岩、云质灰岩、颗粒灰岩,储集空间类型多,主要为次生溶孔、铸模孔,其中颗粒灰岩的物性最好,白垩质灰岩中白垩质主要为浮游有孔虫,孔隙较发育,一般随物性增加,含油性级别升高。成岩作用对储层物性影响也较大,起建设性的成岩作用有溶蚀作用、白云化作用、生物扰动及压溶产生缝合线、缝合面。泥粒灰岩、粒泥灰岩在这些成岩作用的影响下,物性有较大改善。储层孔隙发育微观上主要受控于岩相、成岩作用,平面上还和构造位置及沉积环境有关,位于构造高部位的台地浅滩微相往往物性较好。利用垂向上测井响应及平面上小层物性分布特征,明确了物性较好、含油丰度较高的层段,为寻找高产有利储层提供了依据。     

川西地区中三叠统雷口坡组储层特征及其形成条件

近年来,四川盆地川西地区雷口坡组的油气勘探取得了丰富的成果,但是对雷口坡组碳酸盐岩储层特征及其控制因素的综合研究还相对薄弱,严重制约了雷口坡组进一步的油气勘探步伐。基于野外露头、岩心、测井等资料,结合实验分析数据,系统总结了川西地区雷口坡组储层的发育特征及其形成条件。研究表明：① 川西地区雷口坡组储集岩主要以藻白云岩、颗粒白云岩和细粉晶云岩为主,粒间孔、晶间孔和生物格架孔是主要的孔隙空间,储层整体表现为低孔低渗特征;②沉积相和岩溶作用共同控制着川西地区雷口坡组储层的发育,其中沉积相是储层发育的物质基础,准同生期的白云石化和岩溶作用是孔隙规模保持和次生孔隙形成的主控因素,而中三叠世末期的表生岩溶作用起到加强和巩固的作用,埋藏期有机酸的溶蚀作用起到保护作用。     

川中地区磨溪气田嘉二段砂屑云岩储集层成因机制

对四川盆地磨溪气田嘉陵江组嘉二段二亚段C层(T<,1>j<,2><'2C>)砂屑云岩宏观与微观特征进行深入分析,建立滩相碳酸盐岩优质储集层的成因模式.原生粒间孔是滩相碳酸盐岩储集层的主要储集空间,其主要特征及判识标志包括:储集层发育严格受沉积微相控制、孔隙以残余粒澡孔和溶扩残余粒间孔为主、颗粒接触处仅有海底胶结物发育、初期压实使颗粒呈线一凹凸接触的格架支撑及部分孤立粒闻孔隙的埋藏胶结物不具溶蚀现象等.原生粒间孔的保存机制为:在海底胶结后,初期压实使具早期环边胶结物的颗粒呈格架支撑、喉道减小;压实流体胶结使滩体周缘致密化,并且粒间孔内有限的浅埋藏胶结物使喉道堵塞,成岩流体达到溶蚀-胶结平衡后胶结作用终止;后期埋藏溶蚀主要调整、优化改造先期孔隙层,其对单个储渗体储集空间的绝对增加值仅占次要地位,并不改变这类储集层的储渗体时空分布.     

冀中坳陷东北部石炭—二叠系储层特征及勘探方向

渤海湾盆地冀中坳陷石炭—二叠系残留分布区即坳陷东北部的文安斜坡、杨村斜坡、大城凸起等地区,受印支—燕山和喜马拉雅期强烈的后期构造运动改造,历经差异升降和拉张断陷两大构造发育阶段,致使东、西部剥蚀带的埋藏史表现为沉降—抬升—沉降、沉降—抬升两种类型。区内沉积体系发育较为齐全,自下而上可以识别出滨海潮坪—沼泽、三角洲和河流等三大沉积体系;其中,三角洲和河流体系发育的分流河道、辫状河道砂岩分布范围广、厚度大,形成了该区最主要的砂体类型。区内砂岩储层在其间断埋藏成岩过程中,受表生淋滤作用和深部淋滤作用的影响,形成了较为发育的次生孔隙,孔隙度一般为15%～25%,大气水的深部淋滤作用又进一步改善了断层发育区的储集性能,并由此形成了该区优质的储层。综合评价认为,西部剥蚀带附近是最有利的勘探区带。     

基于沉积微相-储集空间类型的储集层流动单元划分——以彭州气田雷口坡组碳酸盐岩储集层为例

沉积微相和储集空间类型分别从不同的角度反映了储集层的非均质性。四川盆地川西坳陷彭州气田中三叠统雷口坡组四段上亚段缝洞型碳酸盐岩储集层具有很强的非均质性,采用沉积微相-储集空间类型定性识别与流动层带指数定量划分相结合的方法,优选参数并利用聚类分析将彭州气田雷四上亚段缝洞型碳酸盐岩有效储集层划分为4类流动单元,不同类型流动单元与沉积微相、物性特征、储集空间类型具有很好的对应性。用典型岩心的压汞曲线对分类结果进行验证,揭示该方法对缝洞型碳酸盐岩储集层具有较好的分类效果。Ⅰ类和Ⅱ类流动单元具有相对优质的储渗条件和含气性,是彭州气田雷四上亚段缝洞型碳酸盐岩优质储集层评价的主要类型。     

长岭气田登娄库组储层沉积特征及沉积微相研究

松辽盆地南部长岭气田尚处于开发前期,储层沉积微相及砂体展布规律认识不清。为指导后续开发,结合岩心观察、薄片鉴定、测录井等资料进行了沉积特征和沉积微相研究,明确了沉积微相类型及其空间分布和演化规律。结果表明:下白垩统登娄库组储层为辫状河沉积,可细分为辫状河道、心滩、决口扇、泛滥平原等4种微相;沉积微相具有继承性,总体呈SE→NW向,辫状河道和心滩是沉积主体,决口扇分布局限且与泛滥平原共生。其中,d4-2→d3-2沉积期河道带不稳定、横向摆动和局部调整频繁。d3-1沉积期河流作用弱、泛滥平原发育,河道整体向西南部迁移;d2-3→d1-1沉积期河道稳定、横向摆动幅度小。辫状河道及心滩对油气富集有利,93.4%气层为河道及心滩砂体。     

四川盆地海相碳酸盐岩储层特征及控制因素

四川盆地海相碳酸盐岩储层发育层系多、累计厚度大,在川渝地区天然气储量和产量贡献中占有重要地位。从岩石类型、物性特征、储层类型等基本特征分析入手,研究和总结了盆地内碳酸盐岩储层发育的主控因素和分布预测思路。盆地主要储集岩类型是颗粒白云岩、藻（礁）格架白云岩、粉-细晶白云岩,石灰岩次之;物性总体上具低孔、低渗的特征,局部地区发育的优质储层是重要的勘探对象;储层类型可分为裂缝-孔隙型、孔隙型、裂缝-孔洞型和裂缝型4类;储层发育程度主要受有利沉积相带分布、白云石化作用、3期岩溶作用等因素控制。针对生物礁、颗粒滩等相控型储层,精细沉积微相刻画是储层分布预测的有效手段;对于风化岩溶型储层,区域性和重点目标区的岩溶古地貌恢复可为成藏区带评价和储层预测提供依据。     

古城地区碳酸盐岩岩性及微相测井识别方法

碳酸盐岩沉积相系统刻画及相关研究受到岩石样品有限的制约,为了充分发挥测井曲线高分辨率、信息量丰富的优势,开展了古城地区碳酸盐岩岩性及微相测井识别方法研究。在利用岩样确定的微相类型对测井曲线进行标定的基础上,依据常规测井参数与碳酸盐岩岩性、微相的响应关系,优选出DEN、DT、PE和U、Th、K等敏感测井曲线,进行新的参数组合,建立了岩性识别及微相识别图版,符合率分别为85.4%和81.4%。另外,建立函数关系将各微相类型按照沉积能量进行量化分类,并给出微相能量参数曲线。该方法识别出的微相及其能量参数曲线在相带及沉积旋回的空间划分对比的应用中,符合典型碳酸盐岩沉积模式中的相序组合及沉积能量分布特征,与岩石薄片典型相标志所确定的沉积相带一致。该识别方法的应用效果较好,可以作为沉积相精细研究的重要补充手段。      

喇嘛店油气田气顶流动单元及其对开发的影响

因气顶、油气界面的存在及严重的陆相储层非均质性，使气顶油气田与纯气田、纯油田的开发明显不同。针对井网较难控制的砂体窄小、微相、岩性、物性快变区，用离散井点的储层参数进行各种纯数学方法的平面内差成图方法，将很难客观、细致地揭示流动单元。为此提出使用大量成因信息与沉积模式进行平面微相精细研究以控制复杂的微相级单砂体，用微相内能量相单元精细研究以揭示单砂体内部变化规律，再结合渗流系数、存储系数、净毛比划分流动单元的能量相控流动单元的研究方法；并以喇嘛店气顶油气田为例，用此在SⅠ油层组的2小层识别出4种24处微相、5类47个流动单元，因差异显著、平面分布复杂的不同类型流动单元的气层油淹速度与程度不同，将造成严重的平面指进型油淹、低渗型残气区、气油界面呈多指形复杂曲面，且气油界面的快升，将造成严重的损能、损油、损气。     

礁滩型碳酸盐岩储层建模方法研究——以塔中62井区为例

礁滩型碳酸盐岩储层非均质性强,礁滩复合体储层井间预测难度大,难以建立精度较高的地质模型。针对礁滩型碳酸盐岩储层的特点,以塔中62井区为例,提出了"组合微相"的概念,利用地震相解释,采用确定性建模的方法,建立"组合微相"模型,以"组合微相"为约束条件,把能够反映储层变化的波阻抗作为次级变量,应用随机建模的方法建立孔隙度模型。由于裂缝对渗透率影响较大,应首先建立裂缝分布模型,以裂缝分布模型作为次级变量建立渗透率模型,从而提高渗透率模型的实用性。     

Sedimentological and petrophysical characteristics of Raha Formation at Wadi Tubia,Northern Gulf of Aqaba,Sinai, Egypt

The main aim of this study is to shed some light on the microfacies association, geochemistry and petrophysical properties of the rock types: dolomite, sandstone, shale and limestone forming the Raha Formation.The microfacies association includes: ferroan dolomite, sublithic arenite, ferruginous sublithic arenite, dolomitic lithic arenite, sandy bioclastic wackstone, bioclastic packstone, calcareous ferruginous lithic arenite and fossiliferous bioclastic grainstone.The depositional environments of these sediments are interpreted as restricted, shelf lagoon and open circulation.The dominant diagenetic processes presented in the studied samples are cementation, compaction, replacement, dissolution and dolomitization in sandstone rocks, while neomorphism, micritization, cementation, dolomitization, compaction and dissolution are present in carbonate facies. Geochemically, the ferruginous sublithic arenite microfacies are characterized by phosphate bands and high chemical weathering. Calcareous ferruginous lithic arenite microfacies are characterized by high concentration of iron oxides and fossiliferous bioclastic grainstone is characterized by high concentration of barium, as indicated from the chemical index of alteration (CIA).Statistical analysis of the measured petrophysical data shows that, the dolomitic lithic arenite and fossiliferous bioclastic grainstone microfacies have a good storage capacity in the Raha Formation of Wadi Tubia, Northern Gulf of Aqaba, Sinai, Egypt.     

FACIES HETEROGENEITIES AND 3D POROSITY MODELLING IN AN OLIGOCENE (UPPER CHATTIAN) CARBONATE RAMP,SALENTO PENINSULA,SOUTHERN ITALY

Appraisal of the volumes of fluid in a carbonate reservoir will typically require a reliable predictive model. This can be achieved by combining studies of well-exposed carbonate successions with 3D models in order to obtain reliable quantitative data. In this paper, we present a detailed outcrop study and a 3D porosity model of a well-exposed Oligocene carbonate ramp (Salento Peninsula, southern Italy) to investigate the nature of small-scale facies and porosity heterogeneities. Porosity and permeability in the ramp carbonates appear to be controlled by the original mineralogy of skeletal components and by depositional textures. The aims of the study were therefore to identify the factors controlling porosity development in an undeformed carbonate ramp; to model the scale-dependent heterogeneities characteristic of the facies associations; and finally to produce a 3D model of the porosity distribution. The upper Chattian Porto Badisco Calcarenite which crops out along the coast of the Salento Peninsula consists of six lithofacies ranging from inner ramp deposits to fine-grained outer ramp calcarenites. The lithofacies are: inner ramp small benthic foraminiferal wackestone-packstones associated with (i) sea grass meadows (SG) and (ii) coral mounds (CM) consisting of coral bioconstructions with a floatstone/packstone matrix; middle ramp (iii) large rotaliid packstones to wackestone-packstones (LR), (iv) rhodolith floatstone-rudstones (RF), and (v) large lepidocyclinid packstones (LL); and (vi) outer ramp fine-grained bioclastic calcarenites (FC). A total of 38 samples collected from six stratigraphic sections (A, B, D, J, E, LO), measured in the Porto Badisco ravine, were investigated to discriminate the types of porosity. Effective and total porosity was measured using a helium pycnometer. The 3D porosity modelling was performed using PETREL™ 2016 software (Schlumberger). Four main types of porosity were recognized in the carbonates: interparticle, intraparticle, vuggy and mouldic. Primary porosity (inter- and intraparticle) is limited to middle ramp lithofacies (LL and LR) and outer ramp lithofacies (FC), whereas secondary porosity (vuggy and mouldic) was present in both inner ramp lithofacies (CM and SG) and middle ramp red algal lithofacies (RF). In the Porto Badisco carbonates, stratigraphic complexity and the distribution of primary porosity are controlled by lateral and vertical variations in depositional facies. Significant secondary porosity was produced by the dissolution of aragonitic and high-magnesium calcite components, which are dominant in the sea-grass and coral mound facies of the inner ramp and in the rhodolith floatstone-rudstones of the middle ramp. 3D models were developed for both effective and total porosity distribution. The porosity models show a clear correlation with facies heterogeneities. However of the two models, the effective porosity model shows the best correlation with the 3D facies model, and shows a general increase in effective porosity basinwards in the middle ramp facies.     

川东云和寨石炭系气藏沉积微相研究

石炭系气藏是川东地区云和寨气田的主力气藏,该文充分利用地质、测井、薄片等资料,对黄龙组的岩相组合和沉积环境做了详细研究,利用咸化泻湖湖平面升降碳酸盐岩沉积模式,识别出两种亚相,五种微相,并研究了各微相的沉积和发育特征。     

磨溪气田嘉二段陆表海型台地内沉积微相研究

结合四川盆地下三叠统嘉陵江组区域地质背景资料,对磨溪嘉二段的岩石类型组合、沉积构造、沉积韵律、古气候及成岩演化等沉积相标志的详细分析表明,嘉二段并非普遍发育潮坪环境,而是属于陆表海型碳酸盐岩局限—蒸发海台地相沉积,并可进一步划分为台坪、粒屑滩、滩间海、局限泻湖、蒸发泻湖5种亚相及20余种微相,类潮坪相仅出现在嘉二~2B层沉积期。对重点层段沉积微相平面展布特征的研究表明,嘉二沉积期沉积微相演化受沉积古地貌特征、古气候及相对海平面变化共同控制,纵向上沉积微相展布具有一定的继承性。建立了适合本区嘉二段颗粒岩和粉晶云岩沉积时期的陆表海碳酸盐岩台地相的沉积演化模式。     

A Study of Microfacies and Petrophysical Analysis of Some Subsurface Cretaceous Rocks of Abu Gharadig-34 Well,Western Desert,Egypt

Abstract

The main aim of this study is to shed light on the microfacies association, petrophysical parameters, and depositional environment of different rocks such as sandstone, limestone, shale, siltstone, and dolomite of subsurface Cretaceous rock units (Abu Roash “C” member, Abu Roash “E” Member, and Bahariya Formation) from Abu Gharadig-34 well in the north western desert, Egypt. In this study, nine microfacies were identified. These microfacies include calcareous siltstone, bioclastic wackstone, ferruginous sublithic arenite, dolomitic lithic arenite, lithic arenite, fossiliferous bioclastic wackstone, glauconitic dolomitic sublithic arenite, ferroan dolomite, and ferruginous sandy siltstone. Generally, subsurface Cretaceous rock units are deposited in different depositional environments ranging from tidal flats to open circulation passes through restricted circulation shelves. Statistical analysis of the petrophysical data showed that the highest porosity was concentrated at Abu Roash “C” member, which had very good porosity and high permeability. The porosity increased when the bulk density decreased. The permeability of the studied samples was the same as the porosity, which increased when the bulk density decreased. It can be concluded that Abu Roash “C” member is a good reservoir in the Abu Gharadig-34 well.     

塔中地区碳酸盐岩储集层测井评价

采用井壁成像测井、方位电阻率测井和偶极声波测井等新技术，引进Ｅｌａｎｐｌｕｓ测井评价系统，对塔里木盆地塔中地区碳酸盐岩储集层进行评价。在岩心观察的基础上，对主要储集层类型及其有效性进行了测井分析，讨论了沉积相、微相对储集层的控制作用，确定了有效裂缝展布与区域断裂构造之间的关系。应用Ｅｌａｎｐｌｕｓ测井评价系统，利用试油井段测井数据，作出总孔隙度与裂缝孔隙度交会图、总孔隙度与深电阻率交会图、裂缝孔隙度与深电阻率交会图，确定各类产能储集层的总孔隙度、裂缝孔隙度及电阻率的下限值，并以此对储集层进行分类。研究成果运用于生产实践，效果良好     

Facies and sedimentary environments of the Abu Qada Formation at Gabal El-Gunna,Southeastern Sinai,Egypt

The biostratigraphy, microfacies association, mineralogical interferences, depositional environments and geochemical properties of the Abu Qada Formation, which exposed at Gabal El-Gunna Southeastern Sinai, Egypt were delineated. It belongs to the planktonic foraminiferal Whiteinella archaeocretacea Zone of the Late Cenomanian-Early Turonian and consists of calcareous shale and limestone. The calcareous shale facies is characterized by chlorite, smectite and illite with high concentration of P₂O₅, Zn, Ni, V, and Cr. The carbonate rocks are characterized by foraminiferal wakestone and bioclastic grainstone. These microfacies associations are characterized by barite with high content of Sr. The facies types with faunal contents, geochemical and mineralogical studies suggest a restricted to shelf lagoon open circulation environment.