云南施甸铺门前组灰岩的微相特征及其环境意义

<正> 保山地块位于怒江和澜沧江断裂带之间,西为西缅地块及怒江—龙陵—瑞丽缝合带,东为昌宁—双江缝合带,海进自泥盆纪开始,早石炭世发生海退,下石炭统香山组及铺门前组碳酸盐沉积仅局限分布于由保山—施甸呈袋形向南延伸的区域内(图1)。沉积间断发生于早石炭世末、晚石炭世初之间。而后,海进扩大,上石炭统丁家寨组覆于铺门前组灰岩之上。     

Microfacies and environmental study of the lower cretaceous yamama formation in Ratawi field

The Yamama Formation is the main Lower Cretaceous (late Berriasian–Valangenian) carbonate reservoir in southern Iraq. Petrographic study from thin-section examination shows that the skeletal grains included calcareous algae from both red and green algae. Red algae is concentrated in the upper part of the Formation, and the most important of this algae species is Permocalculus ssp. Green algae is less common, and its concentration is in the middle part of the Formation. The most species found in the Yamama Formation is dasycladeans, and both small and large species of benthonic foraminifera such as Nautiloculina, Textularia, Trocholina, Pseudocyclammina, and Everticyclammina are also present. The non-skeleton grains included oolites, pellets, and micrite. Six cyclic type microfacies have been recognized for Yamama Formation in Ratawi-3 (Rt-3) and Ratawi-4 (Rt-4) Wells, namely peloidal packstone–grainstone, algal wackestone–packstone, oolitic–peloidal grainstone, bioclastic wackestone–packstone, foraminiferal wackestone, and mudstone microfacies. The latter has been divided into two submicrofacies: argillaceous lime mudstone and fossiliferous lime mudstone. The lateral extension of these microfacies has been identified by integrating the thin-section data and well logs’ character variations with similar characteristic for microfacies. The Yamama Formation was affected by five diagenetic processes, which are micritization, cementation, recrystallization, silicification, and stylolites. The Yamama Formation was deposited during a regressive period within the outer ramp, shoal, and inner ramp setting.     

Retraction Note to: Adaptive neuro-fuzzy selection of the optimal parameters of protective spur dike

Natural Hazards - The Editors-in-Chief have retracted this article [1] because validity of the content of this article cannot be verified.     

Retraction Note to: Adaptive neuro-fuzzy prediction of the optimum parameters of protective spur dike

Natural Hazards - The Editors-in-Chief have retracted this article because validity of the content of this article cannot be verified.     

生物碎屑灰岩差异成岩及储集层特征:以伊拉克HF油田白垩系Mishirif组为例*

中东地区白垩系Mishirif组以生物碎屑灰岩为主,其形成于温暖潮湿的环境中。综合利用岩心、铸体薄片、全岩分析、常规物性及高压压汞等资料,以伊拉克HF油田Mishrif组为例,开展生物碎屑类型、分布特征、差异成岩及储集层特征等研究。Mishrif组灰岩中生物碎屑以底栖有孔虫、非固着类双壳类、厚壳蛤和棘皮动物为主,含少量苔藓动物、藻类与海绵动物,其含量、类型及大小对沉积环境有重要指示意义。沉积环境决定岩石组分与结构的差异,在此基础上成岩作用控制岩石的孔隙结构与物性特征。生物碎屑主要经历了不同程度海水环境的泥晶化和生物钻孔、大气淡水环境的溶蚀和胶结、埋藏环境的压实压溶和颗粒破裂作用。以底栖有孔虫和非固着类双壳类碎屑为主的低能沉积环境具有“弱溶蚀、强胶结、强压实”的成岩特征,主要发育微孔、晶间孔及粒内孔,孔喉分布呈偏细态细微喉单峰型,物性较差;以厚壳蛤和棘皮动物碎屑为主的高能沉积环境具有“强溶蚀、弱胶结”的成岩特征,主要发育铸模孔、粒间孔及粒间溶孔,孔喉分布呈偏粗态中粗喉极宽峰型,是Mishrif组最有利储集层。以HF油田Mishrif组为代表的白垩系生物碎屑灰岩在中东地区发育广泛,故上述成果对于该地区生物碎屑灰岩油气开发具有重要意义。     

伊拉克M油田白垩系Mishrif组层序构型及储层展布

为明确伊拉克M油田白垩系Mishrif组碳酸盐岩储层展布规律及控制因素,基于岩芯、测井和铸体薄片资料,在三级层序地层格架的控制下,通过岩相分析识别碳酸盐岩地层暴露面、岩性转换面和最大海泛面,将Mishrif组划分为6个四级层序（SQ1~SQ6）。结果表明:研究区发育浅滩暴露型、局限环境暴露型、浅滩非暴露型和长期暴露风化型4种层序构型,每种层序的沉积环境,体系域类型、层序界面特征、暴露时间及对储层的控制等存在差异。浅滩暴露型层序高位体系域晚期发育厚壳蛤滩、生屑滩及滩前等高能沉积型储层;局限环境暴露型层序界面以薄层炭质泥岩为特征,主要发育台内滩储集层,高位体系域顶部致密胶结带可作为物性隔层;浅滩非暴露型层序界面为岩性转换面,高位体系域发育潮道和生屑滩等高能沉积储层;长期暴露风化型层序高位体系域发育生屑滩储层,低位体系域形成的风化角砾岩带可作为良好的物性隔挡层。在深水沉积环境和潟湖沉积环境中,与生物扰动作用相伴生的白云化作用有效地改善沉积物的结构组分,形成了多套薄层低能成岩型储集层。     

RETRACTED ARTICLE: Depositional environments and porosity distribution in regressive limestone reservoirs of the Mishrif Formation,Southern Iraq

Eight subsurface sections and a large number of thin sections of the Mishrif Limestone were studied to unravel the depositional facies and environments. The allochems in the Mishrif Formation are dominated by bioclasts, whereas peloids, ooids, and intraclasts are less abundant. The sedimentary microfacies of the Mishrif Formation includes mudstone, wackestone, packstone, grainstone, floatstone, and rudstone, which have been deposited in basinal, outer shelf, slop followed by shoal reef and lagoonal environments. The formation displays various extents of dolomitization and is cemented by calcite and dolomite. The formation has gradational contact with the underlying Rumaila Formation but is unconformably overlain by the Khasib Formation. The unconformity is recognized because the skeletal grains are dominated by Chaophyta (algae), which denotes the change of environment from fully marine to lacustrine environment. Thus, the vertical bioclast analysis indicates that the Mishrif Formation is characterized by two regressive cycles, which control the distribution of reservoir quality as well as the patterns of calcite and dolomite cement distribution. Mishrif Formation gradationally overlies Rumaila Formation. This was indicated by the presence of the green parts of Chaophyta (algae) as main skeletal grains at the uppermost part of well Zb-47, which refer to lacustrine or fresh water environment. Petrographical study shows that the fossils, peloids, oolitis, and intraclasts represent the main allochem. Calcite and dolomite (as diagenetic products) are the predominant mineral components of Mishrif Formation. Fossils were studied as an environmental age and facial boundaries indicators, which are located in a chart using personal computer programs depending on their distributions on the first appearance of species. Fifteen principal sedimentary microfacies have been identified in the Mishrif Formation, which includes lime mudstone, mudstone–wackestone, wackestone, wackestone–packstone, packstone, packstone–grainstone, grainstone–floatstone, packstone–floatstone, packstone–rudstone, and wackestone–floatstone. Markov chain analysis has been used to study the transitional pattern of different microfacies types vertically in each well and laterally in all wells as a composite section. The vertical analysis indicates that the Mishrif Formation characterized by two regressive cycles, the main one started with basinal or outer shelf environment, slop environment followed by shoal or reefal environment, and ended with a lagoonal environment. The lateral analysis shows the same regressive cycle, and by using the lithofacies association concepts, we built the depositional model of the Mishrif Formation environment.     

伊拉克M油田白垩系Mishrif组沉积特征及控储机理

为明确伊拉克M油田白垩系Mishrif组碳酸盐岩储层成因,基于岩芯观察、铸体薄片、物性分析及测井资料,通过沉积微相分析确定研究区沉积环境,系统分析不同沉积相储层特征。结果表明:M油田Mishrif组为带障壁的缓坡环境,包括潟湖边缘坪、潟湖、台内滩、滩后、潮道、浅滩、滩前及开阔浅海。中、高渗储层主要发育于浅滩和滩前等高能沉积环境,储集层以粒间孔和粒间溶孔为主,发育大孔喉,生屑滩储集层和滩前储集层物性分布区间较大。潟湖边缘坪、潟湖、台内滩及滩后等低能沉积环境以低渗和特低渗储集层为主,孔隙度跨度大,孔隙类型主要为基质微孔、颗粒微孔、铸模孔和粒间孔,以微喉和中喉为主,喉道分选较好。综合分析认为:沉积相通过控制沉积物的结构组分控制了岩石的成岩演化。高能沉积型储集层以溶蚀作用和胶结作用为主,储集层物性是胶结物对孔隙和喉道充填封堵程度的函数;低能沉积型储层是生物多样性和差异成岩作用的结果,选择性溶蚀作用、与生物扰动相伴生的白云化作用、泥晶化作用、胶结作用、非选择性溶蚀作用和混合白云化作用形成的复杂孔隙控制了储集层物性。     

伊拉克M油田白垩系Mishrif组潟湖环境碳酸盐岩储集层成因机理

为深化潟湖相碳酸盐岩储集层非均质性认识,以伊拉克M油田白垩系Mishrif组为例,基于岩心观察、物性分析数据、铸体薄片及压汞实验,对潟湖相储集层特征及成因机理开展研究.结果显示:研究区潟湖环境岩石类型复杂,生物碎屑具有多样性,储集层以低渗、特低渗为主,孔隙度分布范围宽,发育大量的基质微孔、铸模孔和晶间孔.储集层强非均质...     

伊拉克哈勒法耶油田Mishrif组滩相储层特征及其成因分析

伊拉克哈勒法耶油田Mishrif组滩相储层发育,是研究区内最主要的产油层位。利用岩心、薄片、测井资料对Mishrif组沉积相进行了研究,结果表明该组发育局限台地、开阔台地、台内洼地和台地边缘4种沉积相,滩相储层主要发育在开阔台地和台地边缘相带。并综合利用铸体薄片、物性实验数据及压汞曲线等资料对滩相储层特征和成因进行了分析。滩相储层岩石类型多样,发育生屑灰岩、生屑泥粒/粒泥灰岩、砂屑灰岩等多种岩石类型,岩石颗粒较粗。孔隙类型多样,主要以铸模孔、粒间孔、溶孔和体腔孔为主,其中以粒间孔和铸模孔发育最为广泛。各类滩相储层孔隙度较高,渗透率差异明显,平均渗透率为(2.35~139.17)×10~(-3)μm~2。整体孔隙结构较好,排驱压力较低,大喉道较为发育。滩相储层发育受沉积环境控制和成岩作用改造程度影响,有利的沉积条件是滩相储层原生孔隙发育的基础,同生期溶蚀作用的改造形成大量次生孔隙,从而提高了储层的储集性能。     

磨圆度定量表征在扇三角洲沉积微相判别中的应用

砾石颗粒的磨圆度对粗碎屑的沉积环境具有重要的指示意义。针对玛湖凹陷下三叠统百口泉组砾岩的地下钻井岩芯,运用去扁化De?flat磨圆度测量方法,通过定量获取砾石磨圆度参数对扇三角洲沉积中不同沉积微相的指示关系,分析黄羊泉扇的磨圆度及其方差的分布特征,讨论磨圆度定量表征指示扇三角洲沉积的科学性。研究结果表明,扇三角洲沉积的砾石磨圆度普遍较差,为次棱—次圆状和次棱角状。牵引流沉积的砾石磨圆度普遍好于重力流沉积的砾石磨圆度,且牵引流沉积的砾石磨圆度方差明显小于重力流沉积的方差,指示河道沉积中的砾石磨圆度更加集中。黄羊泉扇砾石磨圆度以棱角状和次棱角状为主。通过黄羊泉扇区砾岩砾石颗粒磨圆度及其方差的变化趋势,表明磨圆度对沉积相带具有指示意义。砾石磨圆度的定量表征可以为粗粒碎屑沉积相分析提供新的定量沉积学手段。     

哈南油田阿尔善组油藏储层沉积微相研究

以岩芯分析和大量的测井、录井资料为基础,通过对各种沉积相标志的分析,研究了哈南油田阿尔善组的沉积相类型、微相组成以及主要沉积微相的特征,认为该区阿尔善组早期为一套洪（冲）积扇沉积,晚期过渡为扇三角洲－滨浅湖滩坝沉积。储集层主要是扇三角洲前缘的水下分流河道砂体、水下分流河道边部砂体、河间薄层砂砂体、滨浅湖滩坝砂体及冲积扇辫状河道砂体。其次,在小层划分、对比的基础上,分析了４０个小层沉积微相的特点和平面展布状况,研究了沉积微相在纵向上的演化规律。     

波斯湾盆地中白垩统Mishrif组碳酸盐岩储层特征及其发育模式

Mishrif组碳酸盐岩储层是波斯湾盆地最主要的储集层之一,储层岩石类型主要为礁滩相生物礁灰岩、生屑灰岩和含生屑泥灰岩,储集空间主要为粒间(溶)孔、晶间(溶)孔、铸模孔、表生期组构选择性溶蚀孔洞和基质微孔。储层多呈层状展布,横向上连续,边界受沉积相带约束; 纵向上发育多套致密隔夹层,呈强非均质性。储层发育与保存主要受沉积作用、成岩作用和构造作用影响。碳酸盐岩缓坡背景下发育的生物礁和生屑滩空间分布受盆地基底古构造格局控制,是优质储层分布相带。相对海平面升降旋回控制相带迁移和成岩作用差异,导致优质孔渗层与致密隔夹层交互发育。构造圈闭发育与油气充注时间的耦合有效抑制压实作用和胶结作用对储层的破坏,是储层得以保存的有利因素。     

松辽盆地大老爷府油田泉四段三角洲前缘的沉积微相组合及特征

松辽盆地南部大老爷府地区早白垩世泉头组泉四段,三角洲前缘沉积体系中以水下分流河道和河口坝两种储油微相为主导的多种微相组合,提出将其划分为“水下分流河道区”、“水下分流河道与河口坝混合区”和“河口坝区”三段微相组合区。将水下分流河道进一步划分为废弃型、完整型和多期叠加型3种;识别出坝上河混合微相组合;将河口坝组合再划分为完整型河口坝和叠加型河口坝。讨论了在坳陷湖盆条件下三角洲前缘厚层储集砂体各微相组合的形成机制以及分布模式。