Sequence stratigraphic framework and sedimentary model of Shanxi Formation in northeast Zhoukou Depression of the North China Plate     

《China Geology》2020,3(4):575-590

The sequence stratigraphic framework of Shanxi Formation in the northeast Zhoukou Depression was established based on detailed sequence stratigraphical and sedimentological analysis by utilizing the logging and core data of six wells drilled in the eastern tectonic unit of Zhoukou Depression. It was divided into three third-order sequences, namely SQs1, SQs2, and SQs3 from bottom to top. Each sequence can be divided into a transgressive system tract (TST) and a highstand system tract (HST). Furthermore, four sequence boundaries and three maximum flooding surfaces were identified, and they are the bottom interface SBs and maximum flooding surface mfss1 of SQs1, the bottom interface SBs1 and maximum flooding surface mfss2 of SQs2, the bottom interface SBs3 and maximum flooding surface mfss3 of SQs3, and the top interface SBx from bottom to top. Carbonate tidal flat –clastic tidal flat sedimentary system developed in Shanxi Formation in the northeast Zhoukou Depression (also referred to as the study area) under the control of regression. Meanwhile, four sedimentary microfacies were identified in the sedimentary system, which are lime-mud flats, sand flats, mixed flats, and mud flats. The transgression in the study area occurred from the southeast to the northwest. Therefore, the northwestern part is the seaward side, and the southeastern part is the landward side. As revealed by relevant drilling data, SQs1 of the Shanxi Formation is characterized by the development of limestone and carbonaceous mudstone, with limestone, dark mudstone, and carbonaceous mudstone mainly developing. Meanwhile, lime-mud flats were mainly deposited in it. During the periods of SQs2 and SQs3, the sedimentary environment of the study area changed from the carbonate tidal flats to clastic tidal flats as the coastline migrated towards the sea. In these periods, sand flats mainly developed near the maximum flooding surfaces and were relatively continuous in the eastern and southern parts of the transgressive system tract; mixed flats were relatively continuous in the western and northern parts of the transgressive system tract as well as the eastern and southern parts of the highstand system tract; mud flats widely developed in the highstand system tract. Peat flats mainly developed in the period of HSTs2, with coal seams relatively developing in the southeastern part of the study area as revealed by drilling data. The peat flats in SQs2 are favorable hydrocarbon source layers, the lime-mud flats in SQs1 and sand flats formed in the transgression periods of SQs2 and SQs3 constitute favorable hydrocarbon reservoirs, and the mud flats form in the transgressions periods serve as favorable cap rocks. Therefore, the study area features a reservoir-cap assemblage for self-generating and self-storing of hydrocarbon, and the southeastern part of the study area can be taken as a favorable exploration area.  相似文献   

库车坳陷克深气田致密砂岩储层构造裂缝形成序列与分布规律     

王珂  杨海军  李勇  张荣虎  杨学君  王俊鹏 《大地构造与成矿学》2020,(1):30-46

综合采用岩心、薄片和成像测井等资料,对库车坳陷克深气田白垩系巴什基奇克组构造裂缝的形成序列、分布规律和影响因素进行了研究。结果表明:剪切裂缝和张性裂缝在克深气田均有发育,以直立缝和高角度缝为主,主要形成于近南北向的挤压作用、背斜弯曲拱张作用和异常流体高压作用,微观裂缝切穿胶结物和部分颗粒,早期充填构造裂缝可在后期构造应力和异常流体高压作用下重新裂开成为有效裂缝。克深气田发育3期构造裂缝,其中第3期构造裂缝的形成时间与天然气大量充注期吻合,是工业规模性气藏形成的关键因素。单个断背斜高部位的构造应力低于背斜翼部,因此背斜高部位的构造裂缝线密度相对较低,但背斜弯曲变形使裂缝开度较大,有效性好,单井的无阻流量较高;翼部和断层附近构造裂缝线密度较大,但开度较小,有效性差;构造应力、岩石强度和变形时间的不同造成了构造裂缝特征在各气藏之间具有差异性。储层中部第3砂层组的构造裂缝发育程度中等,充填程度相对较低,并且平面上分布连续,可形成连片分布的储层“甜点”区,应成为克深气田开发中的重点层位。对克深气田构造裂缝起主要贡献作用的为水下分流河道和河口坝微相的粉‒细砂岩。  相似文献   

应用核磁共振技术分析干盐湖地区地下卤水空间分布特征——以昆特依干盐湖为例   总被引：3，自引：1，他引：2  

杨修猛  刘文玉  韩凤清  韩继龙  HUSSAIN Syed Asim  年秀清  毛庆飞  严维德 《湖泊科学》2018,30(1):220-233

昆特依干盐湖位于柴达木盆地西北部,为特大型综合盐类矿床.大盐滩是昆特依干盐湖内最大的盐滩,地下赋存有一定量的卤水矿床,但该矿床的水文地质条件差,主要卤水矿层含水性弱,开采难度大.核磁共振找水方法作为当今世界上唯一的直接找水地球物理新方法,具有高分辨力、高效率、信息量丰富和解的唯一性等优点,本文运用该方法对昆特依干盐滩地区地下卤水空间分布特征进行研究,通过对核磁共振数据进行处理与反演,结合已有的地质与钻井资料,对测点进行综合地质-地球物理解释,获得以下认识:1)大盐滩0~130 m深度范围内,共存在3个卤水含水层,主要呈扁平状或漏斗状、近似层状展布,W1为晶间潜卤水层,渗透系数较大,颗粒较粗,单位体积含水量为0.4%~2.7%,W2和W3为晶间承压卤水层,渗透系数较小,颗粒较粗,单位体积含水量分别为0.2%~1.1%和0.1%~0.8%;2)大盐滩地区存在两个卤水富集区,分别为研究区西南部沉积盆地中心的Ⅰ号富卤区和盆地东北部的Ⅱ号富卤区;3)根据区域内卤水富集分布以及构造情况,划定大盐滩向斜沉积中心、大盐滩北侧F1~F8及遥F6断裂发育区和冷湖构造带为区域内主要的找矿找水远景区;4)GMR核磁共振系统在干盐滩地区理论探测深度为130 m,该系统不仅可以有效地探测自由水,而且可以依据束缚水的分布解译地下各类含水盐类矿物和含水黏土矿物的存在与分布.  相似文献   

东营凹陷波动古湖相烃源岩沉积特征   总被引：6，自引：2，他引：4  

陈中红  查明  金强 《湖泊科学》2006,18(1):29-35

以东营凹陷牛38井为例,研究显示,该井沙河街组沙三段烃源岩的沉积特征具有明显的波动性．宏观上体现为, 构造因素控制湖盆的整体升降和沉积构造旋回,但季节性气候及其它因素的影响使湖盆呈现次级旋回的复合性沉积．微观上表现为纹层的不连续性及生物扰动构造等事件性沉积.古湖面不同幅度的波动和变化导致相对稳定的泥岩沉积的不稳定性,有机质的分布也呈现较显著的非均质性．湖泊的沉积过程影响了微量元素、有机质以及烃源物质的分布,水体较深、盐度较高的沙三段下部多数微量元素含量较高以及B／Ca、Sr／Ba呈现高值;水体较浅、盐度较低的沙三段中部各元素的分布较为稳定,B／Ca、Sr／Ba比值及Sr的含量均显著降低.波动性沉积导致烃源岩呈现明显的优劣性分布,沙三段下部中的有机质富集,为优质烃源岩;沙三段中部的有机质分布较为分散,生排烃的资源潜力有限．  相似文献   

渤海湾盆地西部凹陷南段成岩相分析与优质储层预测   总被引：14，自引：0，他引：14  

孟元林  高建军  刘德来  牛嘉玉  孙洪斌  周玥  鞠俊成  王粤川 《沉积学报》2006,24(2):185-192

储层实测孔隙度、普通薄片、铸体薄片和扫描电镜的资料表明,渤海湾盆地辽河坳陷西部凹陷南段新生界储层在纵向上发育三个次生孔隙带。从而在一个普遍低孔渗背景下,形成了孔隙度相对较高的优质储层。优质储层的形成和分布主要受沉积微相和成岩作用的影响与控制。他们形成于河口坝、辫状分流河道以及心滩沉积微相,目前处于早成岩阶段B期—中成岩阶段A1亚期,发育溶蚀成岩相。该文通过模拟古地温、镜质组反射率、甾烷异构化率和自生石英含量随时间的变化规律,预测了西部凹陷南段成岩阶段和成岩相的横向展布。通过成岩相图和沉积相图的叠合,预测了沙三中亚段优质储层的分布。预测结果表明,优质储层主要发育于斜坡区的中部。  相似文献   

徐家围子断陷深层火石岭组致密火山岩储层地应力分布规律研究   总被引：4，自引：4，他引：0  

毛哲  曾联波  秦龙卜  祖克威  刘国平  田鹤 《地质力学学报》2018,24(3):321-331

徐家围子断陷位于松辽盆地北部,其深层中生代火石岭组为致密火山岩气藏,天然裂缝发育,地应力分布非均质性强。结合诱导裂缝法与井径崩落法进行单井现今地应力方向分析,利用声波测井法计算现今地应力大小的纵向分布。依据火石岭组构造顶底面图、火山岩相组及断层分布特征建立非均质三维地质模型;在动、静态岩石物理参数拟合校正的基础上,结合实验测试及已有研究成果,确定不同岩相组和断层岩石物理参数,建立三维力学模型;利用Ansys有限元数值模拟软件建立火石岭组三维数学模型并进行相关运算获得三维现今地应力分布模型。计算结果表明在火石岭组地层中,水平最大主应力方向主要为东西向,应力值范围在86~110 MPa;水平最小主应力方向主要为南北向,应力值范围在67~84 MPa。分析模拟结果可知火山岩相、断层和构造起伏三者对火石岭组现今地应力分布影响较大。其中水平主应力的方向主要受断层和近火山口相分布的影响,而水平主应力的大小则是受三者综合作用。在构造低部位,近火山口相组发育处,断层上盘及断层端部皆为主应力的集中区域。依据现今地应力研究成果可为徐家围子断陷下一步开发井网部署、压裂改造方案和水平井的设计以及注水管理提供重要指导。   相似文献   

库车坳陷依奇克里克地区下侏罗统阿合组致密砂岩储层的成岩差异性特征研究     

张立强  严一鸣  罗晓容  王振彪  张海祖 《地学前缘》2018,25(2):170-178

塔里木盆地库车坳陷依奇克里克地区深层致密砂岩储层的非均质性强,成岩成藏过程复杂。根据岩心观察、薄片鉴定、流体包裹体、荧光特征及碳氧同位素等分析,对下侏罗统阿合组致密砂岩的岩石类型、成岩演化及其差异性特征进行了研究。研究表明,阿合组致密砂岩分为强钙质胶结砂岩(C类)、富刚性颗粒岩屑砂岩(A类)、含塑性颗粒岩屑砂岩(D类)、富塑性颗粒岩屑砂岩(B类)4类,经历了两期油气充注,不同类型砂岩的成岩、致密化及成藏过程差异明显。A类砂岩的构造缝及溶蚀孔隙均较发育,渗透率较高、孔隙度分布范围广,代表第二期油气充注的蓝色荧光强。D类砂岩的长石及软岩屑含量稍高,晚期溶蚀作用发育,孔隙度较高、渗透率低,黄色和蓝色荧光共存。A、D两类为有效的致密气藏储层,成岩、成藏过程有差异,D类砂岩早期与晚期油气充注共存,早期油气充注减缓后期压实和碳酸盐胶结作用的发生,有利于晚期酸性溶蚀及油气充注。A类砂岩裂缝发育,对储集性能的影响大,渗透性好,晚期油气充注受早期油气充注的影响小。  相似文献   

Controls of hydrocarbon generation on the development of expulsion fractures in organic-rich shale: Based on the Paleogene Shahejie Formation in the Jiyang Depression,Bohai Bay Basin,East China     

《Marine and Petroleum Geology》2017

The development of expulsion fractures in organic-rich shale is closely related to hydrocarbon generation and expulsion from kerogen. Organic-rich shales from the upper part of the fourth member and the lower part of the third member of the Paleogene Shahejie Formation in the Jiyang Depression, Bohai Bay Basin, East China, are used as an example. Based on thin sections, SEM and thermal simulation experiments, the characteristics of hydrocarbon generation and the conditions supporting the development of expulsion fractures were explored. The key factors influencing these fractures include the presence of kerogens, their distribution along laminae and around particle boundaries, their exposure to heat and the build-up in pressure due to confinement by low permeability. The development of excess pore fluid pressures and intrinsic low rock fracture strength are the main influencing factors. Pressurization by rapid generation of hydrocarbon provides impetus for fracture initiation and cause bitumen to migrate quickly. The shale laminae results in distinctly lower fracture strength laminae-parallel than laminae-normal and this directs the formation of new fractures in the direction of weakness. When pore fluid pressure increases, maximum and minimum principal effective stresses decrease by different proportions with a larger reduction in the maximum principal effective stress. This increases the deviatoric stress and reduces the mean stress, thus driving the rock towards failure. Moreover, the tabular shape of the kerogen aids the generation of hydrocarbon and the initiation of expulsion fractures from the tip and edge. The resulting fractures extend along the laminae when the tensile strength is lower in the vertical direction than in the horizontal direction. Particle contact boundaries are weak and allow fractures to expand around particles and to curve as the stress/strength regime changes. When pore fluid pressure fields at different fracture tips overlap, fractures will propagate and interconnect, forming a network. This paper could provide us more detailed understanding of the forming processes of expulsion fractures and better comprehension about hydrocarbon expulsion (primary migration) in source rocks.  相似文献   

济阳坳陷特低渗透油藏地质多因素综合定量分类评价     

操应长  杨田  王艳忠  宋丙慧  郭迎春  孙渡 《现代地质》2015,29(1):119-130

在定量表征特低渗透油藏开发效果及地质特征的基础上,探讨特低渗透油藏开发效果主控地质因素。应用灰色关联分析法对济阳坳陷特低渗透油藏开展地质多因素综合定量分类评价,形成了一套以开发效果表征特低渗透油藏综合特征、从单井到区块基于灰色关联分析的特低渗透油藏地质多因素综合定量分类评价方法。研究结果表明,济阳坳陷特低渗透油藏主要为滩坝砂、浊积岩、砂砾岩沉积,具有埋藏深度大、粒度细、分选较好、孔喉微细、单层厚度薄、分布零散、比储量丰度低、流动性差的地质特点。定义累积产油差表征开发效果以反映特低渗透油藏综合特征,其主控地质因素为油层厚度层数比、砂岩厚度层数比、平均粒径、采油段中深、渗透率、孔隙度、比储量丰度。通过地质多因素综合定量分类评价,将济阳坳陷特低渗透油藏分为3类：Ⅰ类综合评价分数大于0.6,累积产油差大于4 500,开发效果最好;Ⅱ类综合评价分数0.4~0.6,累积产油差-2 500到4 500,开发效果中等;Ⅲ类综合评价分数小于0.4,累积产油差小于-2 500,开发效果差。利用不同区块已有开发数据检验,分类评价结果与实际生产情况一致性良好。Ⅰ类、Ⅱ类特低渗透油藏应该作为现阶段特低渗透油藏直井、水平井优先开发的对象。  相似文献   

Diagenetic fluid evolution and water-rock interaction model of carbonate cements in sandstone: An example from the reservoir sandstone of the Fourth Member of the Xujiahe Formation of the Xiaoquan-Fenggu area,Sichuan Province,China   总被引：1，自引：0，他引：1  

LIU SiBing  HUANG SiJing  SHEN ZhongMin  Lü ZhengXiang  SONG RongCai 《中国科学:地球科学(英文版)》2014,57(5):1077-1092

Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolution, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios(δ13C = 2.14‰, δ18O = -5.77‰), and was precipitated early. It was precipitated directly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid(δ18O = -3‰), which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios(δ13C = -2.36‰, δ18O = -15.68‰). This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2+, Fe3+ and Mg2+ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the burial process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite cements in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone(δ13C = 1.93‰, δ18O = -6.11‰), demonstrating that the two are from the same source that had a heavier oxygen isotope ratio(δ18O of about 2.2‰). The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different water-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles(lithic quartz sandstone) has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.  相似文献