用波形分析法预测滨浅湖滩坝砂岩储层:以东营凹陷西部地区沙-4上亚段为例

滩坝砂岩具有砂泥互层、单砂层厚度薄、并含有灰质白云质等高速夹层等特点,这些因素增大了滩坝砂岩储层的地震识别及预测难度.根据滩坝砂的实际岩性组合类型,用波形分析法对东营凹陷西部地区沙-4上亚段滩坝砂岩进行了储层预测.首先对滩坝砂岩常见的3类地震波形进行定义,建立了不同类型滩坝砂岩储层地震波形特征的实际正演模型;通过学习型地震波形预测技术,分析了不同岩性组合的地震波形特征,总结了波形模式与地层组合样式之间的关系;最后利用实际井资料作为约束对研究区地震波形进行了分类区划,明确了滩坝砂岩有利储层发育范围.     

歧北斜坡滩坝砂体地震预测技术

歧北斜坡沙二段滩坝砂体储层预测面临薄互层地层地震分辨率低,灰质砂岩与常规砂岩地震反射特征相似难以预测两个难点。通过试验优选,形成了两项针对性的地震储层预测方法。针对地震资料分辨率低,薄砂层预测困难的问题,采用谱分解和地震属性相结合方法,在分频体上提取地震属性,提高薄砂层识别能力。针对高灰质含量的滩坝砂体难以预测的问题,探索了利用地震属性降维和数据融合技术剔除灰质的方法。实际应用表明,谱分解技术和多地震属性降维技术,能够较好地预测歧北斜坡滩坝砂体的薄砂层,并在滩坝砂主砂体发育区的预测中,剔除了灰质的影响。     

东营凹陷始新世滩坝砂岩有效储层地震预测

滩坝砂岩是东营凹陷始新世晚期广泛发育的沉积类型,具有埋藏深、厚度薄、互层结构等特点,地震预测难度大。笔者针对滩坝砂岩在开发阶段如何区分滩砂与坝砂的关键问题,提出了应用"分频预测、多属性降维、反射系数反演"等多种地球物理方法解决有效储层描述的研究方案,实现了滩坝砂岩储层预测定性到定量的技术转变。该方法在具有同样的薄互层结构的沉积类型的描述中具有一定的推广意义。     

东营凹陷博兴油田沙四段滩坝砂岩储层特征研究

东营凹陷南斜坡发育滩坝、水下扇和重力流水道等多类型的储集体,为一个多油层、多油气藏类型的复式油气聚集带．沙四段储集层为滨浅湖相滩坝砂体,油藏类型以岩性和构造岩性油气藏为主。博兴油田沙四段滩坝砂岩储毯以长石粗粉砂岩、岩屑粉砂岩为主,砂体中发育有利余粒间孔、粒间溶孔和粒内溶孔等储集空间类型,孔隙结构以低渗小孔喉为主,为中低孔隙度、低渗透率的储层。沉积微相和成岩作用是控制本区滩坝砂体储层物性的主要因素。     

地震多属性分析在徐西地区营城组砂体识别中的应用

徐家围子断陷徐西地区营城组营四段砂砾岩储层发育、砂泥岩组合关系复杂、且横向变化快,单一属性描述该区砂岩发育状况比较困难。为了解决这一问题,首先对该区35口井的岩性、测井以及地震相特征综合分析,总结出了该区岩性发育的4种模式为厚砂(砂砾)岩、砂泥互层(砂岩厚度大)、砂泥互层(泥岩厚度大)及厚泥岩夹薄砂岩。在精细构造解释和属性提取的基础上,优选了频率带宽、均方根振幅及相对波阻抗等3种能对该区几种砂岩发育模式进行全面描述的敏感属性。并运用属性雕刻的方式,通过多属性分析对研究区营城组营四段砂岩发育区进行了预测。     

多属性反演技术在储层预测研究中的应用——以珠江口盆地陆丰A区中新统珠江组储层为例

珠江口盆地陆丰A区中新统珠江组中-下段2370层是该地区主力油层之一, 但储层厚度差异大、分布不清, 严重制约了区域勘探部署.本文综合地震、测井和地质资料, 分析得出纵波阻抗和V_P/V_S为研究区识别岩性的敏感参数, 并通过叠前同步反演技术刻画出研究区2370层砂岩分布特征, 整体呈北厚南薄的展布.以地震振幅、分频属性及叠前反演属性为基础, 利用多属性反演技术分析统计了各属性与孔隙度之间的关系, 优选出密度、V_P/V_S、地震导数、LR、V_P、25~30Hz地震分频6种属性为储层物性识别参数, 综合预测研究区2370层储层滨岸砂坝砂体孔隙度发育特征.多属性反演结果表明, 在研究区东北部、西部, 厚层的滩坝储集砂体的孔隙度发育, 普遍在18%以上; 而在中部和东部, 受滩间、坝间泥岩与滩坝砂的叠合区影响呈条带状分布, 孔隙度为10%~18%.预测结果与同期钻井的钻后结果基本一致, 预测成功率在75%以上.多属性反演技术在研究区的储层预测中表现出良好的有效性和实用性, 对类似地区的储层预测也具有借鉴意义.     

塔中地区卡塔克1区块东河砂岩地震储层预测研究

采用基于地震波形分类的地震相分析与沉积相解释、波阻抗约束稀疏脉冲反演、地震多属性储层预测及油气检测等针对岩性油气藏的储层地震预测技术，从塔中地区卡塔克1区块泥盆系东河砂岩储层的生储盖组合条件及相关的地震地质特点出发，利用卡1三维地震资料开展目的层系的目标精细解释，结合已有的钻探、测井和测试等资料，揭示了东河砂岩储层砂体的空间展布特征，圈定出砂岩发育带，并对有利储层段的潜在含油气性进行了综合预测和评价。     

薄储层的地震表征方法

正地震振幅属性常常被用来表征砂岩储层的分布特征,但在砂泥岩薄互层地区,由于薄层的调谐作用,且地震资料分辨率有限,一个反射同相轴通常是多个薄互层之间相互干涉的综合反映,地震资料的振幅属性既包含了薄互层间的干涉信息,又包含了岩性信息,加大了振幅属性的多解性,难以真实反映砂岩储层的分布(路鹏飞等,2010;黄捍东等,2012;徐伟慕等,2013)。而时频属性和波形属性受能量影响较小,且在一定时窗范围内较稳     

滩坝相砂岩油气分布特征及主控因素分析——以王家岗油田沙四上亚段为例

王家岗地区沙四上亚段发育大量滩坝砂岩储层,逐渐成为勘探人员关注的重点。在对地震、录井、测井、分析测试等资料综合分析的基础上,结合模拟实验对王家岗油田沙四上亚段滩坝砂岩油气分布特征及成藏主控因素进行了分析。结果表明:研究区滩坝相储层主要以砂泥薄互层状分布,油气分布具有较强的不均一性;研究区构造运动强烈,发育大量断层和裂缝,油气输导条件是控制该区滩坝砂岩油气成藏的重要因素;储层非均质性是造成油气不均一分布的另一个原因;模拟实验显示油气运移动力大小的变化会导致油气对非均质性砂体进行选择性充注,使得储层质量高的区域含油性好,储层质量差的区域含油性差或不含油,从而影响油气聚集分布规律。     

辽河盆地西部凹陷古近系沙四上亚段沉积相及演化

薄互层砂体研究是湖盆沉积学的研究难点。本文针对辽河西部凹陷沙四上亚段（Es^4上）薄互层砂体,以层序地层学、沉积学、测井地质学等理论为指导,综合岩心、测录井和地震等多种资料,对西部凹陷的薄互层砂体进行精细描述和深入剖析。结果表明,研究区主要发育辫状河三角洲和湖泊沉积相,其中,滩坝砂体是湖泊相的主力砂体。通过考虑不同沉积背景下滩坝在岩相组合、发育位置和成因机理的差异性,将滩坝划分成侧缘改造型滩坝、前缘改造型滩坝、基岩改造型滩坝、淹没改造型滩坝和风暴改造型滩坝5种沉积模式;对薄层滩坝砂体的控制因素进行分析,认为其受到"风场-物源-盆地"三端元的控制。     

川西新场气田蓬莱镇组有利储集砂体展布研究

川西新场气田蓬莱镇组次生气藏为岩性气藏，在蓬莱镇组砂、泥岩中，砂岩为最主要储层。通过对该气藏进行沉积相、储层及气层地震响应等特征的详细研究后，认为控制储层储集性好坏的主要因素是沉积微相。气藏内有利储集砂岩多属三角洲前缘河口砂坝、三角洲平原分流河道砂坝及河流相河道砂坝微相。有利储集砂体展布即与这三种微相展布一致     

Sedimentary characteristics of large‐scale lacustrine beach‐bars and their formation in the Eocene Boxing Sag of Bohai Bay Basin,East China

The beach‐bar reservoir play has become an important exploration target within the Bohai Bay Basin, especially in the Boxing Sag within the Dongying Depression, where a large‐scale lacustrine beach‐bar oil pool has been discovered recently. The sedimentary characteristics, distribution patterns and formation mechanisms of beach‐bar sand bodies in the upper fourth member of the Eocene Shahejie Formation (Es4s) in the Boxing Sag were studied in detail based on seismic, well log data and core data. The Es4s in the Boxing Sag is composed of a third‐order sequence consisting of three systems tracts, i.e. a lowstand systems tract, a transgressive systems tract and a highstand systems tract. Beach‐bar sand bodies were deposited widely in the basin during the lowstand systems tract period. The sandy beach‐bars are characterized by siltstones, fine‐grained silty sandstones interbedded with thin mudstone units. The presence of well‐developed sedimentary structures, such as swash bedding, parting lineation, parallel bedding, ellipsoidal mud clasts, ripples, terrestrial plant debris and vertical burrows, suggests that beach‐bars were deposited in a relatively shallow water environment under the influence of strong hydrodynamics. Laterally, the sandy beach facies occurred as a more continuous sheet‐like body around the sandy bar in most parts of the sag. Stratigraphically, beach‐bars were distributed mainly in the lowstand systems tract and they were less well‐developed in the transgressive systems tract and highstand systems tract. Several factors were probably responsible for the occurrence of the large‐scale beach‐bars during the lowstand systems tract period, including: (i) a gentle palaeoslope and relatively weak structural activities; (ii) a shallow‐water condition with a strong hydrodynamic environment; (iii) high‐frequency oscillations of the lake level; and (iv) an abundant terrigenous clastic feeding system with multiple‐point and linear sediment sources.     

东营凹陷博兴洼陷沙四上亚段滩坝优质储层形成机理与分布特征

综合运用岩心观察、铸体薄片鉴定、扫描电镜分析、岩石物性测试以及试油结果等分析方法,对东营凹陷博兴洼陷沙四上亚段滩坝中深部储层基本特征进行了研究。结果表明：滩坝中深部储层主要为低孔低渗储层,储集空间表现为原生孔隙和次生孔隙并存发育;研究区优质储层的形成机理主要有沉积作用、地层超压、油气充注、酸性溶蚀和绿泥石颗粒包壳;坝主体和滩脊距泥岩层较远部位储层分选好,抗压实能力强,由于酸性溶解对储层的改造以及油气充注对胶结作用的抑制,中深层仍发育大量原生孔隙和次生孔隙,储层物性较好,并在异常超压和绿泥石颗粒包壳的保护下保存至今并成为有效优质储层;坝主体和滩脊距泥岩层较近部位储层,由于早期强烈的碳酸盐胶结作用并形成致密胶结壳,导致现今储层物性极差,主要发育无效储层;坝侧缘以及滩席储层原始沉积条件差,杂基含量高,在埋藏过程中以压实作用和泥质碳酸盐胶结作用为主,溶解作用微弱,现今物性差,从浅层到深层基本全为无效储层。博兴洼陷沙四上亚段滩坝优质储层主要分布在厚层坝主体和滩脊砂体的中部位置。     

平湖油气田H63砂体成藏模式和剩余油分析

在对H63砂层组展布、区域构造和沉积背景研究的基础上,阐述了砂体展布和构造作用、沉积作用之间的关系。认为H63砂层组顶部的滩坝砂体是剩余油分布的主要区域。     

川中、川南过渡带须家河组储集砂体成因类型及特征

川中、川南过渡带地区在晚三叠世须家河期湖盆演化的各阶段沉积了不同成因类型的碎屑岩储积砂体,以须家河组二段、四段和六段最为发育,其成因类型主要有三角洲平原分流河道砂体、三角洲前缘水下分流河道砂体、河口坝砂体、滨湖砂滩和浅湖砂坝砂体。通过野外剖面、岩芯、测井曲线以及样品的薄片鉴定和扫描电镜分析,对各成因类型砂体的分布特征进行了研究,进而对各类砂体的结构构造、物性特征进行了对比研究。     

Geologic-seismic models,prediction of shallow-water lacustrine delta sandbody and hydrocarbon potential in the Late Miocene,Huanghekou Sag,Bohai Bay Basin,northern China

The Huanghekou Sag is located at the southeast part of the Bohai Bay Basin, northern China. Large-scale shallow lake delta developed in the Neogene provided suitable geological conditions for the formation of a subtle oil-gas reservoir in this area. The key for analyzing sandstone reservoir and sedimentary facies is by using seismic attributes(amplitude) to establish the relationship between lithology combination and seismic attributes. The lower unit of Late Miocene Minghuazhen Formation at the BZ34 block in the Huanghekou Sag was subdivided into 10 parasequence sets(PSS). Thicker sandstones mainly occurred in PSS1 and PSS10, whereas thin sandstones are mostly observed within other parasequence sets. This study presents statistics and analyses of lithology, i.e., statistics of root-meansquare(RMS) amplitude and lithology of well locations in different parasequence sets of the study area,as well as 1-D forward seismic models of 7 types of lithology combinations, the establishment of a spatial distribution of 2-D sandbody, forward seismic models etc. Our study indicates that high amplitude peaks correspond to thicker sandbodies, while low amplitude indicates non-development of sandbodies(generally less than 2 m), and medium amplitude agrees well with large sets of mudstones interbedded with medium and thinner sandstones. Different sand-mudstone combinations genetically reflect a combination of multiple micro-facies, therefore, amplitude features can predict sandbodies as well as facies characteristics.     

四川盆地威东—安岳地区上三叠统须二段湖泊滩坝砂体特征

文章系统研究了四川盆地威东—安岳地区上三叠统须家河组须二段湖泊滩坝砂体的岩性、沉积构造和结构特征,电性和地震反射特征,物性、含油性特征及其展布特征,讨论了该地区须二段滩坝砂体的石油地质意义,认为须二段滩坝砂体属于优质储层,近油源且具生储盖组合,含油性良好,应进一步勘探开发.     

东濮凹陷濮城地区沙三中亚段古地貌与沉积相关系

在富油气凹陷“满凹含油论”的指导下,近洼带岩性油气藏勘探是当前和今后一段时间渤海湾盆地东濮凹陷和其他凹陷油气勘探的重点,而古地貌分析是准确预测深部储层的基础,具有构造背景的有利沉积相带是勘探成功的关键?采用盆地模拟技术对东濮凹陷濮城地区沙三中亚段进行了古地貌恢复,通过岩心观察?薄片鉴定?粒度分析?砂地比和地震属性研究,确立了沉积相类型,系统研究了古地貌与沉积相之间的关系?结果表明:研究区沙三中沉积时期主要发育扇三角洲-湖相泥-滩坝沉积体系,古地貌控制沉积相类型及展布,在兰聊断层上升盘发育两大冲沟,在其下降盘发育两个扇三角洲,具有沟扇对应关系;濮城背斜带沙三中沉积时期发育两个古低凸起,砂体厚值区围绕古低凸起分布,具有滩坝砂体的发育特征?在濮城背斜带与濮城次洼之间的斜坡地区,发育的扇三角洲前缘砂体以及两个扇三角洲之间的滩坝砂体具备形成岩性上倾尖灭?砂岩透镜体油气藏的条件,为岩性油气藏勘探的有利目标?     

Genetic type,distribution patterns and controlling factors of beach and bars in the second member of the Shahejie formation in the Dawangbei Sag,Bohai Bay,China

As an important reservoir type in the Bohai Bay Basin, China, lacustrine beach and bar sands which refer to the shallow water complex deposited mainly by nearshore, delta‐rim and buried hill‐related beaches as well as longshore bars were developed in a particular stage in the evolution of those faulted Cenozoic continental depressions. In the Chezhen Depression, for example, the Second Member of the Oligocene Shehejie Formation (abbr. as Es2 hereafter) formed during the rifting‐to‐thermal subsidence transitional stage. Although well developed in Es2, beach and bar sands are difficult to recognize owing to their relative thinness. The paper summarizes sedimentary characteristics of lacustrine beach and bar sands on cores and logs. Low‐angle cross‐stratification, swash stratification, as well as occasional small‐scale hummocky cross‐stratification resulted from storms can be observed in beach and bar sands. The paper distinguishes bars and beaches from each other in Es2 mainly based on the grain‐size, bed thickness, facies succession and log responses. In order to predict the distribution of beach and bars, a chrono‐stratigraphic correlation framework of Es2 in the study strata is established using a high‐resolution sequence stratigraphic approach. Es2 strata are sub‐divided into six medium‐scale cycles and the mapping of the high‐frequency cycles allows the geographic and stratigraphic distribution of both beach and bar sands to be predicted. The study shows that beach and bars are better developed in times of base‐level fall than in base‐level rise. Factors such as lake‐level fluctuation, sediment supply, palaeogeomorphology and palaeowind direction have exerted control on the formation and distribution of beach and bar sands. Finally, the genetic pattern of beach and bar sands in the Es2 unit has been constructed, which provides a foundation for the prediction of beach and bars reservoir in continental basins in general. Copyright © 2011 John Wiley & Sons, Ltd.