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1.
黔南晚石炭世叶状藻礁灰岩的成岩作用 总被引：1，自引：1，他引：0
通过偏光显微镜研究和阴极发光技术, 对黔南晚石炭世叶状藻礁灰岩的成岩作用做了详细研究, 认为礁灰岩主要成岩作用类型有: 生物黏结障积作用、泥晶化作用、胶结作用、压实压溶作用、破裂作用、重结晶作用和溶解作用等。根据岩石薄片阴极发光测试结果的观察、分析, 将成岩过程划分为4个阶段: 准同生成岩阶段、早期成岩阶段、埋藏成岩阶段和后生成岩阶段。通过各种成岩作用的标志性特征及它们在阴极发光下的特征, 推测藻礁灰岩主要经历了海底成岩环境、大气淡水成岩环境和埋藏成岩环境。 相似文献
2.
南海珠江口盆地东沙隆起流花油田新近系灰岩储层为典型的台地边缘生物礁储层。岩石类型包括皮壳状珊瑚藻黏结灰岩、缠绕状珊瑚藻-珊瑚骨架灰岩、泥晶有孔虫-珊瑚藻颗粒灰岩、亮晶有孔虫-珊瑚藻颗粒灰岩、含红藻石灰岩、泥晶珊瑚颗粒灰岩、生屑泥晶灰岩7类。孔缝类型丰富,包括泥晶基质溶孔、粒间溶孔、藻架溶孔、粒内溶孔、铸模孔、体腔孔、晶间微孔7类孔隙及溶蚀缝、珊瑚藻皮壳间隙缝、似缝合线溶蚀缝、构造缝4类裂缝。划分了孔洞-网状裂缝型、孔隙型、裂缝-孔洞型、致密裂缝型4种储集类型。皮壳状珊瑚藻灰岩属于孔洞-网状裂缝型储层,泥晶颗粒灰岩、含红藻石灰岩和红藻石灰岩属于孔隙型,珊瑚骨架灰岩属于裂缝-孔洞型,亮晶生屑灰岩和胶结作用较强的皮壳状藻灰岩属于致密裂缝型。沉积微相和成岩作用控制了不同储集类型的分布,生物礁形成过程中的多期暴露对沉积微相和储集空间有重要影响。沉积-成岩演化过程划分为早期成礁与早期暴露、晚期成礁与次级暴露、埋藏压实与泥岩再造水改造阶段、两期成藏与地下水溶蚀4个阶段。根据沉积-成岩演化分析,预测了研究区储集类型空间分布。 相似文献
3.
南海早中新世珠江期东沙台地流花生物礁－ 滩组合中,具白垩状结构的灰岩属于广义的白垩状结构
灰岩。白垩状结构灰岩的主要鉴定特征是：在宏观上,岩石为白色或淡色松软、酥脆、多微孔的灰岩,其比重
较轻;在微观上,岩石组构具有低镁方解石微晶及微亮晶格架和晶间孔喉网络,其中含亮晶胶结物甚少。流花
生物礁－ 滩组合的白垩状结构化主要形成于成岩早期大气淡水成岩环境,在成岩中-晚期中埋-深埋环境中,通
过进一步溶蚀、淋滤,产生大量溶蚀孔洞,从而形成白垩状孔隙储集层。论述了流花生物礁－ 滩组合广泛发育白
垩状结构灰岩的证据、白垩状结构化产生于大气淡水成岩环境的证据及白垩状孔隙储集层的形成机理。 相似文献
4.
5.
三亚湾珊瑚可以分为５个微相：生物骨架岩、生物屑、礁岩屑、珊瑚碎块，强烈改造的生物质，成岩作用包括同生沉积作用、胶结、藻缠结、细粒物充填，机械和化学侵蚀。排浦更新世白云岩与掘穴生物的钻孔有关，粉至中晶结构为混合水成因，峨曼更新世灰岩为砂质灰岩、角砾状灰岩，豆状灰岩。生物屑经重结晶，Ｘ（ＭｇＣＯ３）小于２％，贫铁，三亚湾潮间带海滩岩胶结物为文石和高镁方解石，见悬挂式胶结和渗滤砂。 相似文献
6.
本文以阴极发光为主要研究手段，通过胶结物形态和结构以及接触关系的观察，对本溪市牛毛岭马家沟组顶部剖面成岩作用进行研究，重建成岩历史和孔隙演化过程。研究结果表明，该剖面成岩作用主要包括机械压实、胶结、白云岩化、溶蚀、早期破裂作用；同生成岩阶段的成岩作用多样：分层(1)、(2)和(5)经受较强压实作用，分层(3)—(5)白云岩化特征符合回流渗透模式，分层(4)由于溶蚀形成溶塌角砾；早成岩阶段主要为胶结作用，主要发生于浅埋藏环境：分层(1)的掘穴和破裂等大孔隙被铁方解石充填，分层(3)—(5)中晶间孔隙、小窗状孔隙、溶塌裂缝、硬石膏晶体铸模等孔隙被白云石充填；中、晚成岩阶段的成岩作用很少。该剖面的成岩作用主要发生在同生—早成岩阶段，这与鄂尔多斯盆地中部中奥陶统埋藏史相似。 相似文献
7.
四川盆地东部长兴组礁灰岩缺乏大规模白云石化作用的原因分析及启示 总被引：1，自引：0，他引：1
《海相油气地质》2015,(3)
位于四川盆地东部开江—梁平海槽西南侧台地边缘的长兴组礁灰岩,沉积时具有很高的原生孔隙度,但由于缺乏大规模白云石化作用,现今多数礁灰岩致密无孔。研究表明礁灰岩缺乏白云石化作用可能与早期白云石化流体供应不足有关,而并非如前人推测的是由于早期海水胶结作用将孔隙完全充填堵塞造成白云石化流体无法进入所致。早期海水胶结作用结束后,长兴组礁灰岩中仍存在大量孔隙及流体活动空间,但由于礁灰岩(礁核相)位于台地边缘靠近海槽的高能区,受早期沉积环境的控制,成岩流体为活跃循环的正常海水,不具备发生白云石化作用所需的轻度咸化海水渗透回流的条件。埋藏成岩环境下块状亮晶方解石的胶结作用是造成礁灰岩中孔隙完全丧失的原因。 相似文献
8.
为分析陆相页岩中方解石的成因及其对储层的影响,以四川盆地下侏罗统大安寨段的介壳泥岩与灰岩夹层为主要研究对象,利用X-射线衍射、普通薄片、岩芯观察、阴极发光及电子探针测试手段,识别出文石转化方解石、胶结物方解石和重结晶作用形成的方解石。在同生期和成岩早期,生物介壳中的文石转化为泥晶无铁方解石,阴极发光为橙黄色。成岩早期,生物介壳边缘可形成纤维状第一世代无铁方解石胶结物。在成岩晚期,岩石孔隙中形成颗粒状铁方解石胶结物,阴极发光为暗色。同时,部分介壳中的泥晶方解石新生变形为斑块状细晶方解石或柱状方解石。根据方解石的存在形式可知,方解石在成岩演化过程中,经历了转化、压实、溶解、胶结和重结晶作用。其中,溶解作用改善储层的物性。压实、胶结和重结晶作用破坏储集空间。统计裂缝密度发现,元坝地区大安寨段层理缝最为发育,涪陵地区大安寨段以层理缝和溶蚀缝为主。结果表明,方解石介壳有利于大安寨段内岩石层理缝和溶蚀缝的产生。 相似文献
9.
白垩状结构碳酸盐岩是一种白色或淡色疏松、酥脆、多微孔的灰岩。狭义白垩状结构灰岩是指深
水盆地、陆棚斜坡及内台地局限海相(如湖)中形成的白垩状微孔隙灰泥岩及粒泥岩基质。广义白垩状结构
灰岩指盆地相和陆棚相中包括生物礁、滩的各种沉积体内各种沉积组构产生的白垩状灰岩,也包括白垩状去白
云化灰岩及 (真)白垩。综合各国学者的有关研究资料,建议将白垩状结构化定义为：“ 碳酸盐沉积物和碳酸盐
岩中的镁方解石和文石在不同成岩阶段通过新生变形而转变成低镁方解石微晶和微亮晶格架,并在其中产生和
保存晶间孔喉网络的作用;强化白垩状结构化是指微晶和微亮晶格架受到进一步溶蚀和淋滤,从而形成次生溶
蚀孔隙网络的作用” 。论述了世界各地的地史中不同成岩阶段白垩状结构碳酸盐岩成岩环境的例证和白垩状结构
化成因。 相似文献
10.
天山东部晚灰炭世碳酸盐岩隆岩石学与成岩作用 总被引：2，自引：0，他引：2
新疆天山东部广泛发育晚石炭世碳酸盐岩隆。这些岩隆主要为生物丘,少数为生物滩及与岩隆有关的生物层,其中生物丘含大量灰泥和内碎屑,基本岩石类型为泥粒状灰岩、粒泥状灰岩、粒泥状－尼粒状灰岩、少量岩石类型包括颗粒岩、骨架岩和障积岩。成岩作用 岩隆发展演化的重要阶段和过程,在生物丘内,已经识别出四种重要的胶结物,即球粒泥晶、纤状主解石、放射轴状方解石和粒状方解石。尽管缺失典型的造礁生物,但通过岩石类型研究和 相似文献
11.
The Pennsylvanian phylloid algal mounds exposed in the Cervatina Limestone of the Cantabrian Zone (NW Spain) developed during the highstands of high-frequency shallowing-upward cycles and lack evidence of subaerial exposure at their tops. Mound core facies are composed of massive bafflestones with variable amounts of calcite cements and anchicodiacean phylloid algae with cyathiform thalli preserved in growth position. Through standard petrographic, isotopic (δ18O and δ13C), major and trace element (Ca, Mg, Fe, Mn, Sr) and cathodoluminescence analyses, five calcite cement phases (cement 1 (C1)–cement 5 (C5)) have been identified filling primary and secondary pores. Early marine diagenesis is represented by micritization and non-luminescent to mottled-dull luminescent high-Mg calcite fibrous marine cement (C1). A dissolution phase then occurred and created vuggy and moldic pores. Based on the absence of field or petrographical or geochemical evidence of exposure, it is inferred that dissolution occurred in near-surface undersaturated marine waters with respect to aragonite related to progressive organic matter oxidation. Secondary porosity was subsequently filled by dull-bright-dull bladed high-Mg calcite (C2), which precipitated in the early shallow burial from marine-derived pore waters. Remaining porosity was occluded by shallow-burial precipitates consisting of non-luminescent scalenohedral low-Mg calcite (C3) followed by non-ferroan dull luminescent calcite spar (C4). Latter phases of calcite spar exhibiting non- and dull luminescence (C5) are associated with burial calcite veins. Low δ18O values (around ?8‰), moderately depleted δ13C values (around 0.5‰) and the homogeneity of trace element contents of carbonate matrix, cements and vein-filling calcites suggest burial isotopic re-equilibration and recrystallization, probably in Early Permian times during post-thrusting orocline formation. 相似文献
12.
STEPHEN T. SOLOMON 《Sedimentology》1989,36(3):399-418
Dark mottles are a prominent and widespread feature of the regressive, cyclic, shallow marine limestones which form the late Asbian succession in many parts of Britain. The colour difference which defines mottles in outcrop is caused by distinct but often subtle petrographic differences in the limestone fabric. Specifically, mottles contain a light brown coloured opaque inclusion-rich calcite spar with characteristic dull brown luminescence; ‘mottle spar’. Outside mottle margins this calcite spar is absent, with clear inequant blocky cements forming the pore filling phase. ‘Mottle spar’ comprises a fabric of irregular crystals predominantly 5–40 μm in diameter, with more regular crystals up to 100 μm diameter often occurring in intraparticle and large interparticle pores. Under cathodoluminescence, ‘mottle spar’ displays crystal morphologies and growth patterns which indicate that both localized neomorphism and patchy cementation contributed to mottle formation. Cathodoluminescence cement stratigraphy shows that ‘mottle spar’ pre-dates all other major pore filling cements in the local Asbian succession, but post-dates marine micritization. ‘Mottle spar’ sharply defines the moulds of former aragonitic allochems which are now filled by the later clear, inequant spar cements. This shows that aragonite dissolution occurred after the formation of ‘mottle spar’. Mottles in calcretes contain unaltered allochems which have been protected from the effects of subaerial micritization by ‘mottle spar’, although mottles are often affected by subaerial brecciation. This evidence shows that mottles formed during early diagenesis; after marine micritization, but before dissolution of aragonite, subaerial exposure and meteoritic phreatic cementation. Mottles represented lithified patches of very low porosity which are interpreted to have formed in the marine/freshwater mixing zone, during the repeated phases of regression and emergence in the late Asbian. 相似文献
13.
Stromatactis is a spar network whose elements in cross section have flat to undulose lower surfaces and digitate upper surfaces. The network is composed principally of isopachous crusts of centripetal cement and commonly occurs embedded in finely crystalline limestone. It is the cement filling of interconnected cavities. Stromatactis of Upper Silurian red stromatactis limestone from Gaspé Peninsula, Québec Appalachians, exhibits two types of cements: (1) an isopachous cement that lined the walls of the conduits and is interpreted as early marine; and (2) a later blocky cement that occupies the centres of cavities. The first cement is composed exclusively of non-ferroan calcite, whereas the second cement is mixed non-ferroan and ferroan calcite. The early isopachous cement is white on polished slabs and has a turbid aspect under transmitted light. In a few samples, the relative homogeneity of this early cement is broken by the presence of distinctive grey clear calcite. Under cathodoluminscence, the grey clear calcite is non-luminescent and exhibits well defined bladed crystal shapes, whereas the white turbid cement has a dull orange luminescence and indistinct crystal shapes. The relationships between the two cements indicate that the dull luminescent cement is a secondary form of the non-luminescent cement, and it is concluded that the dull cement is the product of alteration of the non-luminescent cement by burial or meteoric fluids. The later blocky cement has the same dull luminescence as the white turbid cement and is thought to have been precipitated from the same fluids as those responsible for the alteration of the early marine cements. Oxygen isotopic values of the dull cement of the early isopachous crusts (mean δ18O= -6.8%o are intermediate between those of the non-luminescent early marine cement (mean δ18O= -5.3%o) and the dull luminescent blocky cement (mean δ18O= -11.8%o), while carbon isotopic values do not differ significantly (δ13C=+2.9, +2.4 and +2.6%o, respectively). The alteration also has affected the distribution of some trace elements, particularly Mg. Both unaltered and altered cements contain less than 1% microdolomite inclusions, but the Mg content of the background calcite of unaltered cement is three times that of altered cement (14171 vs. 5502 ppm). Precursor early marine cement is thought to have been low-Mg calcite. The mean δ18O value (− 5.3%o) of unaltered early marine cement is higher than values for the oxygen isotopic signature of Silurian oceans provided by brachiopod shells. 相似文献
14.
Contrasting diagenesis of two Carboniferous Oolites from South Wales: a tale of climatic influence 总被引：2，自引：0，他引：2
Two oolites in the Dinantian (Mississippian/Lower Carboniferous) of Glamorgan, SW Britain, were deposited in similar depositional environments but have contrasting diagenetic histories. The Brofiscin and Gully Oolites occur in the upper parts of shallowing-upward sequences, formed through strandplain progradation and sand shoal and barrier growth upon a southward-dipping carbonate ramp. The Brofiscin Oolite is characterized by a first-generation cement of equant calcite spar, preferentially located at grain-contacts and forming non-isopachous fringes around grains, interpreted as meteoric vadose and phreatic in origin. Isopachous fibrous calcite fringes of marine origin are rather rare and occur only at a few horizons. Burial compaction was not important and porosity was occluded by poikilotopic calcite spar. Fitted grain-grain contacts locally occur and could be the result of near-surface vadose dissolution-compaction. Syntaxial overgrowths on echinoderm debris are common. Pre-compaction overgrowths are cloudy (inclusion-rich) and probably of meteoric origin, and post-compaction overgrowths are inclusion-free. By contrast, the Gully Oolite has little first-generation cement. However, marine fibrous calcite is common in oolitic intraclasts, as isopachous fringes of acicular calcite crystals closely associated with peloidal internal sediment; and early equant, drusy calcite spar occurs in the uppermost part of the Gully, beneath a prominent palaeokarst where pedogenic cements also occur. The major feature of Gully diagenesis is burial compaction, resulting in extensive grain-grain dissolution and microstylolitic grain contacts, and post-compaction poikilotopic spar occluded remaining porosity. The Brofiscin Oolite is pervasively dolomitized up-dip but the Gully Oolite for the most part only contains scattered pre-compaction dolomite rhombs and late veins of baroque dolomite, with less pervasive dolomitization. The difference in diagenetic style of the two Dinantian oolites is attributed to prevailing climate. The paucity of early meteoric cements in the Gully is a result of an arid climate, and this is supported by the nature of the capping palaeokarst. The abundant meteoric cements in the Brofiscin reflect a more humid climate, and effective meteoric recharge also resulted in up-dip pervasive mixing-zone dolomitization. The style of early diagenesis in these two oolites exerted a major control on the later burial diagenesis: in the Brofiscin, the early cements inhibited grain-grain dissolution and pressure solution, while these processes operated extensively in the Gully Oolite. Thus, prevailing climate can influence a limestone's diagenetic history from near-surface through into deep burial. 相似文献
15.
The application of cathodoluminescence to interpreting the diagenesis of an ancient calcrete profile 总被引：1，自引：0，他引：1
A laterally extensive calcrete profile has been identified in the Late Asbian (Lower Carboniferous) shallow marine shelf limestones of the Llangollen area, North Wales. The upper surface of the profile is defined by a laterally discontinuous palaeokarstic surface and by laminated calcareous crusts which developed within the underlying limestone. The profile contains a unique series of early pore-filling vadose cements which only occur down to 1 m below the palaeokarstic surface. Cathodoluminescence reveals that these cements pre-date the late pore-filling meteoric phreatic cements which occur throughout local Asbian lithologies. A spar cement stratigraphy has been established for the calcrete profile. Subaerial vadose cements comprise two generations of non-luminescent cement, followed by a brightly luminescent generation which occasionally shows an acicular habit. This needle-fibre calcite represents the final stage of vadose cementation. Precipitation of vadose cements was contemporary with subaerial alteration and micritization of the limestone. Textures, visible only with cathodoluminescence, provide evidence of recurrent periods of fabric dissolution. The most extensive phase of dissolution occurred immediately after the precipitation of the non-luminescent subaerial vadose cements. Several different textures have been recorded, each reflecting the morphology of a partially dissolved substrate. Dissolution textures are generally confined to the walls of the larger pores and to early brecciation fractures. These probably acted as fluid pathways in the calcrete during early subaerial diagenesis. Much of the non-marine micrite in the calcrete profile appears as needle-fibre calcite under cathodoluminescence. This acicular calcite was probably formed in response to localized supersaturation of meteoric pore fluids caused by periods of near-surface evaporation. Since needle-fibre luminescence is strongly variable, these ambient conditions are not believed to have directly controlled the activator ion concentrations of cementing pore waters. Needle-fibre calcite is considered to be a cement precipitate which has almost completely recrystallized to micrite, probably during the late stages of subaerial diagenesis. Two generations of subaerial micrite which define a ‘micrite stratigraphy’, have been distinguished under cathodoluminescence. Reconstructing the diagenetic history of this ancient calcrete profile has revealed that subaerial alteration was multistaged, with many diagenetic processes acting simultaneously during a single phase of emergence. 相似文献
16.
Thomas Mann Andr Wizemann Marleen Stuhr Yannis Kappelmann Alexander Janßen Jamaluddin Jompa Hildegard Westphal 《Sedimentology》2022,69(1):282-300
Early-diagenetic cementation of tropical carbonates results from the combination of numerous physico-chemical and biological processes. In the marine phreatic environment it represents an essential mechanism for the development and stabilization of carbonate platforms. However, diagenetic cements that developed early in the marine phreatic environment are likely to become obliterated during later stages of meteoric or burial diagenesis. When lithified sediment samples are studied, this complicates the recognition of processes involved in early cementation, and their geological implications. In this contribution, a petrographic microfacies analysis of Holocene Halimeda segments collected on a coral island in the Spermonde Archipelago, Indonesia, is presented. Through electron microscopical analyses of polished samples, this study shows that segments are characterized by intragranular cementation of fibrous aragonite, equant High-Mg calcite (3.9 to 7.2 Mol% Mg), bladed Low-Mg calcite (0.4 to 1.0 Mol% Mg) and mini-micritic Low-Mg calcite (3.2 to 3.3 Mol% Mg). The co-existence and consecutive development of fibrous aragonite and equant High-Mg calcite results initially from the flow of oversaturated seawater along the aragonite template of the Halimeda skeleton, followed by an adjustment of cement mineralogy towards High-Mg calcite as a result of reduced permeability and fluid flow rates in the pores. Growth of bladed Low-Mg calcite cements on top of etched substrates of equant High-Mg calcite is explained by shifts in pore water pH and alkalinity through microbial sulphate reduction. Microbial activity appears to be the main trigger for the precipitation of mini-micritic Low-Mg calcite as well, based on the presumable detection of an extracellular polymeric matrix during an early stage of mini-micrite Low-Mg calcite cement precipitation. Radiocarbon analyses of five Halimeda segments furthermore indicate that virtually complete intragranular cementation in the marine phreatic environment with thermodynamically/kinetically controlled aragonite and High-Mg calcite takes place in about 100 years. Collectively, this study shows that early-diagenetic cements are highly diverse and provides new quantitative constraints on the rate of diagenetic cementation in tropical carbonate factories. 相似文献
17.
Johannes H. Schroeder 《Sedimentary Geology》1973,10(3):179-204
Well-rounded pebbles and cobbles of reef rock, which in bio- and lithofacies closely resembles the Recent algal cup reefs, occur in the basal conglomerate of the Pleistocene Devonshire Formation cropping out along Grape Bay on the south shore of Bermuda. The framebuilders of this rock include coralline red algae, vermetid gastropods, and barnacles. Study by petrographic microscope, electron microprobe, and SEM revealed aragonite-needle and spherulitic cements, high-Mg calcite micrite and palisade cements including calcified algal filaments. Two or three generations of these may occur in a given pore. By analogy with the Recent cup-reef material, on the basis of their composition (high strontium content of aragonite, high magnesium content of calcite) and of circumstantial evidence, these are considered submarine cements.In addition, a vadose blocky low-Mg calcite cement occurs, which never precedes any, but frequently succeedes one, two, or three of the above cements. Its fabrics vary: it may exhibit an increase in crystal size toward the center or not, it may or may not be bounded by the meniscus outline characteristic of the vadose diagenetic environment. The limitation of cement precipitation by a meniscus gives rise to a large diversity of forms determined by respective combinations of solution supply, permeability of the micro-environment, and substrate morphology. To illustrate the diversity, the meniscus cement is shown in relation to sediment particles, aragonite-needle cement, and calcified filaments.From the blocky low-Mg cement, selective neomorphism extends into some aragonitic gastropod shells; it is controlled, in part, by original shell structure. The resulting low-Mg calcite mosaic is characterized by relic structures and plane crystalline boundaries. Aragonite needles between blocky calcite cement and neomorphic calcite were not affected by the process of mineralogic alteration.This study shows that cements recognized earlier in Recent Bermuda cup reefs can be traced into the past and that additions to the diagenetic sequence can be distinguished. Knowledge of these features and their sequences should help decipher the diagenetic history of other fossil reefs. 相似文献
18.
为探讨成岩体系对致密砂岩储层质量的控制机理,综合岩心、铸体薄片、阴极发光、X衍射、扫描电镜、包裹体分析、孔渗和三维地震等资料,对四川盆地中台山地区须二段致密砂岩储层成因机制进行了分析。研究发现中台1井须二段主要发育长石石英砂岩、文探1井须二段主要发育岩屑石英砂岩,储集空间主要为长石和岩屑粒内溶孔,孔隙度多<8%,渗透率多<1×10-3 μm2;须二段砂岩经历压实、胶结、溶蚀和交代等成岩作用;中台1井须二段断裂发育,早期石英胶结物主要充填粒间及早期裂缝且成岩流体古盐度多<20%,晚期裂缝多被晚期硅质和方解石胶结物全充填且成岩流体古盐度多>20%;文探1井须二段断裂不发育,主要发育早期方解石和石英胶结且成岩流体古盐度多>20%;中台1井和文探1井均可见次生溶蚀产物,硅质与黏土胶结物多伴生出现,并普遍充填粒内溶孔或粒间孔,表现出次生溶蚀产物短距离迁移特征。研究表明中台1井早期为开放性成岩体系,晚期为封闭性成岩体系,而文探1井主要表现为封闭性成岩体系;开放体系下次生溶蚀产物能通过裂缝向外迁移产生孔隙度净增量,能有效改善储层质量,而封闭体系下次生溶蚀产物不能向外界迁移仍胶结充填于储层孔隙中,仅为储层孔隙空间再分配,储层孔隙度无净增量,质量无明显改善;中台山地区须二段致密砂岩储层受成岩体系演化控制,早期开放体系有利于储层质量改善,晚期封闭体系有利于早期形成储层的保存,裂缝的开启与封闭是影响成岩体系的关键因素。 相似文献
19.
《矿物学报》2013,(Z1)
Based on the analysis of the morphology, order, cathodoluminescence and microelement of the calcite crystals in the pores of Upper Ordovician limestone in Tazhong oilfield of Tarim Basin, this paper suggest that the calcite crystals can divided 11 kinds of cements into three stages, and confirms their cementation sequence characteristics and formation environment. First stage of the cementation occurred on the bottom of the diagenetic environment, the product of which mainly are microcrystalline, fine shape, radiation fibrous, fasciculation, radiation axis shape calcites and a ball-like aragonite, whose filling pore is 0%–30%; the second one occurred in the atmospheric fresh water environment, with main cement types of crescent or pendulous shape, vadose silt, hyperplasia of coaxial, the filling pore of which is 5%–100%; the third one occurred in a burial environment, the crystals of which are bright and thick, mainly coarse sparry and poikilitic calcite, with filling pore of 5%–5%. In this paper, influence from each stage of cementation on porosity is analyzed, and pore evolution is established. 相似文献