潜江、沔阳凹陷新沟咀组下段砂岩储层成岩作用特征

本文用多种手段和方法首次系统地研究了江汉盐湖盆地的潜江和沔阳两凹陷下第三乐新沟咀组下段砂岩锗层的岩矿特征．成岩演化和孔隙演化特征，制定了新沟咀组下段砂岩成岩阶段划分方案，建立了成岩演化和孔隙演化模式，确定了储层的孔隙性质，油前孔隙度和砂岩成岩阶段划分的主要标志，恢复了沉积和成岩环境，从成岩作用的角度评价和预测了储层对新沟咀组下段砂岩中的次生孔隙成因和成岩作用机理进行了探讨．     

粘土矿物对砂岩储层损害的影响——回顾与展望

人们一开始就把地层损害与粘土矿物相联系,从20世纪30年代起,经历了发现水敏损害现象、确立分散／运移机制、探索分散／运移规律及防治技术三个阶段,80年代进入全面发展阶段,不断深化损害机理认识,损害诊断和控制技术取得实质性进展,在这一演变过程中分析技术的进步对揭示损害机理起到了重要的促进作用。指出应重视粘土矿物-水相互作用、结构粘土矿物学、粘土矿物-水-原油界面作用方向的研究工作。     

砂岩成岩作用的全球模式;在油气勘探中用于储层品质的预测

砂岩具有共同的碎放物，沉和环境和埋藏史，也具有共同的成岩史。据世界各地１００处砂岩的成岩史研究，已识别出５种共同的，可复原的和能预测的成岩类型，其中，能观察到相似的成岩矿物组合 。     

开鲁盆地陆西凹陷侏罗系火山岩屑砂岩的成岩作用特点

陆西凹陷侏罗系九佛堂组为一套成分、结构成熟度均低的火山岩岩屑砂岩，岩屑含量高达７５％以上。其成岩作用特点是：①机械压实的孔隙度损失约占原始孔隙度的５１．４％－７１．８％，且这种孔隙损失主要发生于油气聚集前；②岩屑的水化水解作用较强，产生对孔隙损失影响较大的粘土、沸石类和钠长石等蚀变矿物；③净砂岩中钙质胶结发育，并呈带关布，这可能与孔隙水溶液中振荡性钙离子释放有关；④受地层埋藏发育史影响，不同地区经     

成岩作用对致密砂岩储层物性的影响——以川中地区上三叠统须四段气藏为例

川中地区上三叠统须家河组四段砂岩是四川盆地内的天然气储层之一，该碎屑岩储层具有低孔隙度、低渗透率的特点。在对该区上三叠统须家河组气藏宏观沉积特征研究的基础上, 采用岩石薄片、铸体薄片、扫描电镜及X射线衍射等方法, 对该气藏储层的成岩作用及其对储集物性的影响进行了探讨，建立了该区致密砂岩成岩作用序列以及孔隙演化模式。研究结论如下：①随压实作用的不断增强，孔隙度呈持续下降的趋势；②成岩作用对致密砂岩储集层的影响具有双重性，压实作用、胶结作用使得砂岩孔隙度降低，而溶蚀作用则增加了孔隙度；③该区的孔隙构成主要是环边绿泥石剩余原生粒间孔以及溶蚀形成的长石、岩屑粒内溶孔，泥质杂基溶蚀粒间孔，伊利石黏土中微孔以及由压实压裂、压实滑动和构造动力所形成的微裂缝孔；④勘探中既要注意机械压实作用、压溶作用对储层的负面影响，同时也要重视成岩早期环边绿泥石胶结物形成、碎屑（主要是长石）及其填隙物溶蚀作用等有利因素。     

伦坡拉盆地罗玛迪库构造带牛三段砂岩成岩作用对储层储集性？…

伦坡拉盆地罗玛迪库构造带始新统牛三段砂岩储层岩屑砂砾岩和石英砂岩为主，岩屑成份以灰岩岩屑占优。这些储层在沉积成岩过程中，压实作用，胶结作用和充填作用极大地影响也孔隙发育，而溶蚀作用和强烈的破裂作用则有利于次生孔隙的形成。     

成岩场与砂岩孔隙度的关系研究

我国北方地区含油气盆地中的成岩场与砂岩孔隙度发育,保存之间有着良好的关系。盆地的地温场基本决定了砂岩孔度的发育程度,地温梯度每增加１℃／１００ｍ,相同埋藏深度的砂岩孔隙度平均减小约７％;     

苏里格南部地区盒8段致密砂岩储层成岩作用及成岩相划分

苏里格南部地区是苏里格气田新的资源接替区,目的层段为下二叠统石盒子组盒8段致密砂岩低渗透储层。为预测该区有利孔渗性成岩相,利用铸体薄片、扫描电镜等资料对盒8段储层的成岩作用及其演化规律进行了综合研究。结果发现：盒8段经过强烈的压实作用,原生孔隙基本消失殆尽,硅质胶结、黏土胶结、碳酸盐胶结现象在储层中都有发育,压实作用和胶结作用是造成储层致密和低孔低渗的主要因素,但是溶蚀作用又使得储层发育次生孔隙,从而为气藏形成提供了基础。通过判别自生矿物类型、镜下颗粒接触形态、孔隙类型、胶结物类型,以及对泥岩镜质体反射率的测定,认为该区盒8段已处于中成岩的B期和晚成岩期的过渡阶段。结合勘探现状及沉积相展布特征的研究成果,将该区储集层划分为4种成岩相,其中相对高渗粗粒弱压实-溶蚀相为最有利的储集相带;低孔渗中-粗粒溶蚀-胶结相次之;低孔渗中-细粒胶结相、特低孔渗细粒-泥质致密压实相为非有利储集相带,储集条件较差。     

轮南地区石炭系卡拉沙依组砂泥岩段砂岩储层特征及成岩作用影响

基于对岩石特征、孔隙特征及物性特征的分析认为,岩屑砂岩类是轮南地区石炭系卡拉沙依组(C1-2k)砂泥岩段砂岩储层的主要岩石类型,其次为长石岩屑砂岩类;粒间溶孔、粒间孔是主要的储集空间,其次为胶结物内溶孔、粒内溶孔,见少量高岭石和方解石晶间微孔、粒缘缝、微裂缝;储层的物性总体偏差,孔隙度多在10%以下,与渗透率呈指数正相关,相关系数为0.78;高效储层主要发育于残余原生粒间孔和粒间溶孔中。根据储层成岩作用特征分析,综合认为溶蚀作用是区内C1-2k砂泥岩段砂岩储层孔隙发育的建设性因素。     

低渗透砂岩储层成岩作用研究及有利储集区预测

做为砂岩储层建模重要方法之一的"相控建模"法的基础是有利储集相带的预测研究,应在沉积微相研究的基础上结合成岩作用研究来确定.低渗透砂岩储层经历复杂的成岩作用,对有利储集相带的分布有较强的控制作用.本文以渤南油田三区沙三段低渗透砂岩储层为例,介绍了低渗透砂岩储层成岩作用研究的思路与方法,并划分了三类成岩-储集相,指出有利储集相带,为相控建模奠定了基础.     

渤中地区第三系碎屑岩储层成岩作用研究

根据大量岩石薄片、X衍射、扫描电镜、压汞试验等资料,对渤中地区第三系馆陶组—沙河街组碎屑岩储层成岩作用及孔隙演化进行了研究．并在此基础上划分了成岩阶段,初步探讨了其成岩模式。研究结果表明,渤中地区第三系碎屑岩储层处于早成岩期B阶段一晚成岩期A阶段,局部达到晚成岩期B阶段初期;储层的岩石性质及成岩程度有利于次生孔隙的发育。由于长石溶蚀形成次生孔隙时伴随大量自生高岭石的生成,故自生高岭石高含量带可作为寻找次生孔隙发育带的标志,     

渤中地区第三系碎屑岩储层成岩作用研究

根据大量岩石薄片、X衍射、扫描电镜、压汞试验等资料 ,对渤中地区第三系馆陶组—沙河街组碎屑岩储层成岩作用及孔隙演化进行了研究 ,并在此基础上划分了成岩阶段 ,初步探讨了其成岩模式。研究结果表明 ,渤中地区第三系碎屑岩储层处于早成岩期 B阶段—晚成岩期 A阶段 ,局部达到晚成岩期 B阶段初期 ;储层的岩石性质及成岩程度有利于次生孔隙的发育。由于长石溶蚀形成次生孔隙时伴随大量自生高岭石的生成 ,故自生高岭石高含量带可作为寻找次生孔隙发育带的标志     

鄂尔多斯盆地白豹地区长6砂岩成岩作用及其对储层物性的影响

基于砂岩薄片、铸体薄片、扫描电镜和X-衍射分析,研究了鄂尔多斯盆地华庆油田白豹地区长6砂岩储层的成岩作用,认为长6储层处于中成岩B期阶段。压实作用和碳酸盐胶结作用对砂岩的原生孔隙结构破坏强烈,使物性变差;粘土矿物的胶结作用,使得渗透性变差,但由于绿泥石薄膜的发育,使得孔隙度有变好的趋势;溶蚀作用和破裂作用则有效地改善了砂岩的孔隙结构,对物性的改善起到建设性作用。     

THE INFLUENCE OF CEMENTATION ON THE RESERVOIR QUALITY OF THE RISHA SANDSTONE MEMBER (UPPER ORDOVICIAN), RISHA GASFIELD, NE JORDAN

Shallow-marine sandstones of the Upper Ordovician Risha Member of the Dubaydib Formation constitute important reservoir rocks for natural gas in the Risha area of NE Jordan. However, reservoir quality is frequently reduced by diagenetic effects including extensive cementation. This paper reports on the petrology of the Risha Sandstones and the nature of diagenetic alteration, based on standard petrographic analyses of 147 core samples collected from nine wells at Risha gasfield. In addition ten representative samples were investigated using scanning electron microscopy (SEM).
The sandstones comprise subarkoses and quartzarenites which are texturally submature to supermature. Petrographic analyses suggest a continental provenance, most probably from precursor plutonic rocks from the Arabian Shield. A generalized model of paragenesis includes early compaction and development of syntaxial feldspar overgrowths with quartz cementation of variable intensity. Carbonate cements occur as replacement and pore-filling phases. Dolomite and siderite cementation occurred during later-stage burial, together with pressure solution and the growth of authigenic clays. Most of the cements originated from meteoric or compaction-derived waters. Separate pathways of sandstone diagenesis were recognized for the texturally supermature and submature sandstones, both of which were facies-controlled.
Occlusion of most of the porosity preceded hydrocarbon accumulation, which is therefore restricted to areas where cementation was minimized or where cements were dissolved.     

CONTROLS ON RESERVOIR DIAGENESIS IN THE LOWER GORU SANDSTONE FORMATION,LOWER INDUS BASIN,PAKISTAN

Sandstones in the Lower Cretaceous Lower Goru Formation in the Lower Indus Basin, Pakistan, are important reservoir rocks for oil, gas and gas‐condensates. For this study, nine metres of core from depths of more than 3400m from well X‐1 in the north‐central part of the basin were analysed for major variations in porosity and permeability in two Lower Goru sandstone units referred to as the Basal and Massive Sands. The Lower Goru Basal Sand was deposited in lower shoreface to inner shelf settings at the well location, while the Massive Sand was deposited in a middle to lower shoreface setting. In both units, intervals with moderate to good (> 15%) porosities alternate with intervals with very low porosity (<5%), and similar variations in core permeability were observed. In this paper, the reasons for this reservoir quality variation at well X‐1 are investigated. Specifically, the study addresses the influence of different clay types on reservoir porosity and permeability within the Lower Goru sands and the distribution and impact of hard cements such as calcite and quartz. A range of petrographical data is integrated including thin sections, whole rock and clay XRD results and SEM images, which together provide some insights into the causes of reservoir quality variation and into the paragenetic relationships between the authigenic minerals. Chlorite grain coats are present in the higher‐porosity sandstones and are interpreted to have inhibited the formation of quartz overgrowths. Dissolution of feldspar and volcanic rock fragments in both the Basal and Massive Sands has contributed to an increase in overall porosity at well X‐1. Relatively low porosity intervals in the Massive Sand are associated with the absence of chlorite grain coats and the presence of abundant quartz overgrowths. By contrast, low porosity intervals in the Basal Sand have undergone early poikilotopic calcite cementation. The formation of authigenic illite resulted in a significant decrease in permeability in both the Basal and Massive Sands. Chlorite and kaolinite also reduced the permeability. The chlorite originated mainly from the dissolution of volcanic rock fragments or from precursor depositional berthierine clay. The transformation of K‐feldspar to illite is suggested to be the main reaction responsible for the formation of both authigenic illite and quartz overgrowths in the two reservoir units; the observed pressure solution will also have contributed to development of quartz overgrowths.     

INFLUENCE OF DEPOSITIONAL ENVIRONMENT ON DIAGENESIS AND RESERVOIR QUALITY: TIRRAWARRA SANDSTONE RESERVOIR, SOUTHERN COOPER BASIN, AUSTRALIA

Mechanical compaction and quartz cementation are the most important diagenetic controls on the reservoir quality of the Late Carboniferous - Early Permian fluvio-deltaic Tirrawarra Sandstone in the Cooper Basin of South Australia. The magnitude of these two diagenetic events is controlled by the mineralogical composition of the sandstones.
Assuming that the Tirrawarra Sandstones have a common provenance, the nature of the environments in which these sediments were deposited is the principal factor controlling the composition of the framework grains in the unit. Thus, the percentage of rock fragments decreases, and the relative quartz content increases, from the medial part of a braid-delta to point-bar and aeolian environments. The content of ductile rock fragments controls the degree of compaction and the development of quartz overgrowths.     

台3—北10井区侏罗系贫石英砂岩的成岩作用及储层特征研究

准噶尔盆地东部台3—北10井区侏罗系储层的储集性能为中等容量的储层。但在开发过程中往往表现出渗滤能力极差以及油层损害、井底出砂严重等现象。造成这一现象的原因除了地层异常高压外,贫石英砂岩粘土矿物的相互转化及蒙脱石受压释放出层间水等是其根本原因。贫石英砂岩的成岩作用使缩小了的原生孔隙得以再扩大。溶蚀孔(缝)的发育程度主要受控于储集岩体在地表或近地表地带接受风化淋滤的时间长短、范围大小等,埋藏深度的影响是次要的。次生孔隙发育带主要分布在不整合面以下的河道砂岩中。成岩作用对高含粘土矿物的贫石英砂岩既有有利的一面,也有不利的一面。     

流体pH值对致密砂岩储层渗透率的影响

地层流体pH值一般分布在4～9范围，一旦侵入储层的流体pH值过高或过低，将引发外来流体与储层流体、储层矿物不配伍的问题，必然造成储层损害。文章以川中香溪群致密砂岩气层为例，开展流体pH值逐级升高和pH值逐级降低对储层渗透率改变的综合评价实验。实验表明，储层具有强碱敏、强的HCl酸敏感性。研究指出，高pH值流体条件诱发粘土矿物微结构的破坏，导致伊利石、绿泥石等粘土矿物溶解、脱落、分散（运移），渗透率大幅度下降；低pH值流体破坏绿泥石的晶体结构，使结构中的Fe²⁺、Fe³⁺、Mg²⁺等离子析出，产生Fe(OH)₃以及Mg(OH)₂沉淀，堵塞喉道。     

陆西凹陷九佛堂组储层成岩作用

在沉积背景研究基础上,采用岩石学薄片、扫描电镜、x-衍射、电子探针和同位素等分析手段,对陆西凹陷九佛堂组储层成岩作用进行了研究.储层成岩矿物主要有蒙脱石、伊利石、伊/蒙混层、绿泥石、高岭石、石英、钠长石、沸石和碳酸盐等.以与地温有关的成岩变化为依据,将本区成岩作用带进行了划分.通过对储层储集空间的研究,提出储层以次生孔隙为主,且次生孔隙主要形成于成岩作用浅带.本区次生孔隙储集砂体的形成机制主要有两种:①与大气水下渗淋滤有关的次生孔隙砂体形成机制,可解释包日温都地区次生孔隙砂体的发育;②与粘土脱水和转化有关的次生孔隙形成机制,可解释马象铺地区次生孔隙储集砂体的形成.