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地层划分与对比是开展盆地分析,进行油气等能源矿产勘探与开发的基础工作。常用方法包括：岩石地层、古生物地层、层序地层、磁性地层及同位素定年等[1⁃4]。各种地层划分与对比方法均有一定的适用性和局限性,因而在现实工作中,仍然面临着诸多困难与挑战。与海相沉积盆地相比,陆相盆地具有物源多、相带变化快、沉积中心易迁移等特点。按照沉积旋回划分与对比、标志层约束,参考厚度的原则,开展陆相地层的划分与对比,在沉积古地形相对平坦的区域可靠性较高,然而在湖盆边缘存在明显地形起伏的坡折带或前积斜坡沉积区,往往会引起地层划分与对比的“穿时”问题[5⁃12]。
近年来,随着高分辨率三维地震勘探技术的发展和应用,在国内外诸多盆地识别出前积斜坡,这为重新认识盆地地层格架和沉积充填过程提供了重要的启示。如Magyar[12]通过对地震剖面上前积斜坡的追踪与对比,结合不同水深软体动物、藻类等化石组合特征,建立了匈牙利Pannonian盆地中新世晚期至上新世的高精度年代地层格架。Fongngern et al.[13]根据三维地震资料揭示的前积反射特征,将罗马尼亚Dacian盆地中新统Meotian阶中上部划分为7个期次的前积体,并结合测井响应和微体古生物学研究等,重新厘定了该套地层的划分与对比关系。周华等[14]基于地震剖面前积体分析,结合钻井资料,将松辽盆地古龙凹陷上白垩统嫩江组三、四段底界分别上移了2个砂组。
三叠系延长组是鄂尔多斯盆地主力含油层系,发育一套厚200~1 400 m的陆相碎屑岩沉积建造[15⁃19]。以往主要依据钻井、测井及野外露头等资料,采用沉积旋回控制,辅以凝灰质泥岩、油页岩等标志层（K0~K9）约束,参考厚度的方法,将延长组自下而上划分为长10—长1共10个油层组[20⁃22],研究认为延长期湖盆演化具有“整体升降、平起平落”的“千层饼”式特征[23⁃24]。近年在盆地西南部的环县、庆城及合水三维地震剖面上,普遍可见前积反射现象,主要发育于长7—长1油层组,这些前积现象已被部分学者关注。前人从前积体的形态特征、前积体对湖盆古水深的指示及开发区砂体对比关系等方面,开展了相关研究[25⁃28]。但对于发育前积反射的地层如何进行等时划分与对比,其与传统延长组地层划分方案如何合理衔接等问题,前人研究尚未涉及。
本文以鄂尔多斯盆地西南部延长组为研究对象,基于最新三维地震资料解释,结合测井和岩心资料,尝试建立前积模式指导下延长组中上部（长7及以上地层）的等时划分与对比方案,探索等时地层划分与传统分层的衔接关系。在此基础上,重新解释了延长组湖盆沉积充填过程,以及三角洲—深水区砂体的连通关系与分布规律等。研究结果为深化延长期湖盆的形成演化研究和石油资源的高效勘探开发提供了重要启示。
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中生代鄂尔多斯盆地是在晚古生代华北克拉通盆地基础上形成的大型内陆坳陷湖盆[23]。中—上三叠统延长组沉积期,湖盆呈西南陡、东北缓的不对称碟状,发育东北、西北、西南三大物源沉积体系,其中东北沉积体系以曲流河三角洲沉积为主,西北、西南主要发育辫状河三角洲沉积体系（图1a）[23⁃25,29⁃30]。延长组沉积期湖盆经历多期湖侵—湖退,形成多套砂泥岩沉积组合。长7段沉积期是湖盆发育的鼎盛期,沉积一套分布约4×104 km2、厚度20～60 m的黑色油页岩,是盆地中生界主力烃源岩（图1c）,多期砂岩储集体广泛分布,构成良好的源储配置关系。
图 1 （a）鄂尔多斯盆地延长组沉积期古地理略图；（b）研究区三维地震工区分布及庆城工区井位分布；（c）延长组综合柱状图
Figure 1. (a) Paleogeographical sketch map of the Ordos Basin during deposition of the Yanchang Formation; (b) 3D seismic survey areas and wells location in the study area; (c) stratigraphical column of the Yanchang Formation
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基于沉积学、地震地层学理论,首先对盆地西南部环县、庆城及合水三维地震资料进行精细解释,取得前积体形态类型、迁移叠加关系及内部结构等认识,进而在前积模式指导下,结合岩心沉积相标志的识别,通过井—震相互约束和标定,实现延长组中上部（对应传统分层的长7—长1）地层的等时划分与对比。对庆城三维工区进行了600 m×300 m间隔的地震层位追踪与闭合检验,刻画出前积模式下等时地层单元的平面分布样式。资料基础包括盆地内环县、庆城与合水地区约5 000 km2的三维地震资料,146口井的测井资料和35口井的岩心观察资料。
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依据地震地层学和地震沉积学原理,区域性标志层的地震反射同相轴大多数是等时的[31]。盆地西南部延长组长7底部发育一套分布稳定的20~60 m油页岩（俗称“张家滩页岩”）,在地震剖面上表现为明显的强振幅连续反射,地震反射同相轴连续性好,区域可追踪,可作为等时地层划分的依据。此外,分析前积体的形态和结构,应将地层恢复至沉积结束时的水平状态。但由于印支运动影响,延长组沉积后,盆地发生整体抬升和差异剥蚀改造,难以在延长组中上部找到理想的拉平基准面。侏罗系富县组（J1 f）、延安组延10（J2y10）是延长组顶部不整合面之上的填平补齐式沉积[32⁃33],延10沉积结束后,盆地又进入一个类似于延长组的大型坳陷湖盆演化阶段。基于此,且利用延安组煤层广覆分布、地震反射特征明显的特点,本文将延安组延9（J2y9）煤层作为拉平基准面,来近似反映延长组沉积结束后的古地貌特征。以下分别对盆地西南部3个工区顺物源方向的典型前积现象进行分析。
对环县工区顺物源的南西—北东向多条地震剖面分析发现,顶积段为中、强振幅强连续地震反射,前积段多为中强振幅中连续反射,底积段多为中强、强振幅强连续反射。以A—A’地震剖面为例,延长组中上部可识别出5期前积体,自下而上依次命名为F1~F5（图2a）。各期前积体顶积段同相轴近水平且连续性好,向西南方向可延伸追踪,反映滨湖区沉积物垂向加积特征。F1~F4前积斜坡体以进积为主,内部地震反射结构主要为“S”形态,局部可见斜交型。其中F1仅可见底积段沉积,厚度较薄且相对稳定；F2、F3顶积段厚度小于前积段,F2为不对称“S”形态,F3为中间厚、两端薄的对称“S”形态；F4仅可见顶积段、前积段,顶积段厚度明显小于前积段。F5期以垂向加积为主,外部形态为板状,F5底部为一上超面,其顶部遭受印支运动抬升后的剥蚀改造。
图 2 鄂尔多斯盆地西南部延长组中上部典型地震剖面前积反射特征（剖面位置见图1b）
Figure 2. Interpreted clinoforms on typical seismic profiles in the middle and upper parts of the Yanchang Formation, southwestern Ordos Basin (location of profiles in Fig.1b)
庆城工区北东—南西方向地震剖面上前积斜坡现象最为典型,也反映了西南部为物源供给方向（图2b）。前积段多为中强振幅的中连续反射,底积段多为中强或强振幅强连续反射。以B—B’地震剖面为例,可识别出F1~F6共6期前积体。顶积段同相轴连续性好,可向物源方向追踪延伸。由于工区范围较小,剖面上F1仅可见前积段和底积段,形态为不对称“S”型,F2~F4顶积段厚度明显小于前积段,外部形态呈透镜状,内部结构为S型或斜交型前积反射。F2顶积段较前积段和底积段厚,F3、F4具有前积段厚、顶积、底积段薄的特点。F5、F6以垂向加积沉积为主,且顶部均遭受印支运动的剥蚀改造,地层保存不完整。
合水工区顺物源方向的剖面也显示出典型的前积斜坡结构（图2c）。以C—C’地震剖面为例,延长组中上部也可识别出F1~F6共6期前积体。顶积段同相轴水平段连续性较好,可向西南物源方向追踪。F1、F2顶积段厚度略小于前积段和底积段,为不对称“S”形态。F3、F4顶积段厚度明显小于前积段,外部形态呈透镜状,内部结构为S型和斜交型。F5与前期斜坡顶面呈上超接触,内部为中—强振幅的中—弱连续反射层。F6呈板状,是在F5基础上近水平叠加的中—弱振幅中连续反射层。
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通过对环县、庆城、合水工区典型三维地震剖面分析,发现研究区延长组中上部前积反射现象普遍发育,各工区前积形态存在差异,但共性特征明显。结合测井、岩心资料,大致以长7底为界,可识别出6期前积体。F1~F6的顶积段分别与传统分层长7—长1对应,F1~F4以进积为主,F5、F6以垂向加积为主。F1~F4的顶积段均可向物源方向延伸追踪,在顶积段与传统分层方案形成较好的衔接对应关系,而前积段、底积段与传统“千层饼”式的分层方案差异较大（图3）。
图 3 鄂尔多斯盆地西南部延长组前积生长模式及等时地层划分示意图
Figure 3. Schematic of clinoform growth pattern and isochronous stratigraphic division of the Yanchang Formation, southwestern Ordos Basin
依据延长组中上部前积地层发育特征,探索建立了前积模式指导的延长组中上部等时地层划分与对比新方法,即：“顶积段自然延伸追踪,前积反射及标志层约束,三维空间闭合检验”。具体方法为：（1）根据盆地区域性标志层确定目的层顶、底界线。长7油页岩、延长组顶部不整合面及延安组延9煤层,在测井和地震响应上特征明显,均为区域性标志层。据此确定延长组中上部地层的顶、底界面（图4）。（2）利用钻井、测井资料合成地震记录,标定地震剖面顶积段的分层,结合地震剖面上的前积反射和包络特征,由顶积段向前积斜坡区、深水区自然延伸,对前积斜坡沉积进行识别和叠加关系划分,完成顺物源地震剖面的前积体解释。（3）将地震剖面的解释方案应用到钻井剖面。通过时深转换,进行钻井层位标定,完成前积模式指导下顺物源方向钻井剖面的等时地层划分与对比。（4）通过同相轴追踪,实现对垂直物源方向（地震和钻井）剖面的等时地层划分与对比,进而实现等时地层划分与对比的三维空间闭合,刻画出各等时地层单元的平面分布特征。
图 4 鄂尔多斯盆地Z67井延长组合成地震记录
Figure 4. Synthetic seismic records of the Yanchang Formation from well Z67 in the Ordos Basin
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分析表明,前积模式下的等时划分方案与传统分层方案的差异主要体现在前积体的前积段和底积段。按照传统分层方案,研究区长7厚度介于100~120 m,长6厚度介于110~130 m,长4+5厚度介于80~90 m,长3厚度介于90~110 m,长2—长1由于遭受印支运动抬升剥蚀,地层厚度变化较大。总体上,长7—长3地层厚度相近,呈近等厚的“千层饼”状叠加分布[32⁃33]。
在前积模式指导下的等时地层划分对比方案中,各期前积体斜坡段逐期向湖盆中心迁移,剖面上呈“顶积段薄,前积段厚,底积段薄”的透镜状形态。两种分层方案在前积段与底积段厚度差异明显（图5）。F2~F4沉积期,物源供应充足,碎屑沉积物向湖盆中心进积,斜坡部位堆积量大,各期前积段地层普遍增厚,而深水区地形平缓,底积段厚度比传统分层明显减薄。F5、F6期沉积物以垂向加积为主,地层厚度增加。对单井地层厚度计算表明,在前积段,F1厚度介于80~100 m,F2厚度介于60~250 m,F3厚度介于80~170 m,F4厚度介于80~210 m；在底积段,F1、F2逐渐减薄至10~40 m凝缩段,F3、F4厚度介于60~80 m,F5、F6厚度介于200~250 m。
图 5 鄂尔多斯盆地西南部延长组传统等岩性分层方案与等时分层方案对比（剖面位置见图1b中D—D’）
Figure 5. Comparison between traditional isolithologic division scheme and isochronous division scheme in the southwestern Ordos Basin (location of D⁃D’ section in Fig.1b)
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为揭示前积模式下地层厚度平面分布特征,选择庆城三维地震工区,开展了600 m×300 m间隔的地震层位追踪,采用层位内插功能的线性插值算法加密三维地震解释,得到工区长7以上各期前积体的时间域厚度,并通过时深转换,生成F1~F4前积期次的深度域地层厚度分布图（图6）。与传统分层近等厚的“千层饼”状分布模式相比,在前积模式指导下建立的等时地层格架中,地层平面展布具有明显的分带性。工区内各期前积体在平面上均呈北西—南东向的带状展布,由西南向东北依次表现为薄—厚—薄的地层分布样式。各期次前积斜坡在西南部与东北部地层厚度较薄,分别对应前积斜坡的顶积段和底积段,而中部地层厚度较大,为前积体的前积段。F1沉积期,前积段斜坡带位于工区西南角,底积段厚度变化较小,主要在20 m左右；F2沉积期,斜坡带向工区东北迁移,沉积范围变大,可占工区面积的1/3~1/2；F3沉积期,斜坡体顶积段厚度较F2减薄,斜坡带持续向东北迁移,底积段厚度与F2期底积段厚度相近；F4沉积期,前积段持续向东北迁移,斜坡带分布面积较F3斜坡带减小。综上可知,从F1到F4,斜坡带逐渐向北东迁移,指示庆城地区前积斜坡体由西南向东北持续进积,形成大规模进积型三角洲,湖盆逐渐收缩充填的过程。
图 6 庆城地区延长组中上部F1~F4期前积斜坡地层厚度图
Figure 6. Isopach maps of clinothems in the middle and upper part of the Yanchang Formation in Qingcheng area
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以往在缺乏高精度三维地震资料的情况下,基于钻井资料解释建立的地层划分方案,未考虑到三角洲—深水区存在前积现象,造成延长组中上部砂体划分的“穿时”问题及砂体横向连通对比关系的判断偏差。在近年来油田开发过程中,上述问题已有所显现。如曹江骏等[34]、屈雪峰等[35]指出合水地区长6油层组砂体连通出现错位情况,导致注采关系匹配性欠佳等。王西强等[22]对姬塬油田罗38区、罗211区的研究发现,传统分层所依据的K2~K5标志层是穿时的,不能作为区域对比的标志层,指出按照前积模式进行延长组地层划分与对比的合理性。
按照等时地层划分对比方法,结合区内典型钻井、取心资料,重新进行砂体解释和对比。研究发现,F1~F4期具有斜坡下半部富砂的特点。前积体顶积段发育三角洲平原和前缘亚相的水下分流河道、河口坝砂体等,如庆城工区Z518、Z389井均钻遇F2、F4顶积段。岩心观察表明,顶积段主要为灰白色、灰色细砂岩,发育平行层理、交错层理等牵引流成因沉积构造（图7a）,见植物碎屑（图7b）,指示沉积水体较浅。前积段砂体主要富集于前积段顶底部位,如Z130、X260、Y49等大量钻井钻遇到前积段,其顶部常见灰绿色细砂岩,发育逆粒序构造,火焰状构造（图7c）、冲刷面等沉积构造,砂泥岩薄互层较为常见,反映三角洲前缘的沉积特征。前积段底部可见深灰色块状细砂岩（图7d）,发育包卷变形构造、槽痕和沟痕（图7e）、泥质撕裂屑（图7f）和阶梯状断层（图7g）等,指示深水重力流沉积相标志。底积段主要发育灰黑色泥岩,偶见鱼鳞化石（图7h）,具包卷变形构造的深灰色砂岩等,指示深水沉积环境。
图 7 研究区延长组中上部前积斜坡岩心典型沉积特征
Figure 7. Typical sedimentary characteristics of cores from the clinothem in the middle and upper part of the Yanchang Formation in the study area
与传统等厚方案不同,前积模式下的地层划分和砂体对比更强调同期性和等时性,主张按照前积体生长形态进行砂体连通,区别于以往的“等岩性”连通方式。为检验前积模式下的砂体连通关系,对庆城工区典型钻井剖面进行了砂体对比解释（图8）。由图8可知,依据前积模式,F2期砂体连通性由西南逐渐向东北方向稳定可追踪,F3晚期由西南部位的顶积段向东北方向的斜坡延伸,砂体连通关系持续可对比,F4期砂体的连通性在顶积段、前积段上部和底积段亦较好。前积模式下砂体连通关系更趋合理,更能客观地反映地下砂体横向展布及其连通的真实情况,有利于油田开发井网的合理布置和注水开发层位的选择（图8）。
图 8 鄂尔多斯盆地西南部X303井—B285井延长组中上部砂体分布图（剖面位置见图1b中D—D’）
Figure 8. Distribution of sand bodies in the middle and upper part of the Yanchang Formation, crossing well X303⁃well B285 in the southwestern Ordos Basin (location of D⁃D’ section in Fig.1b)
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以往认为,鄂尔多斯盆地延长期湖盆中心以细粒沉积为主,由湖水表层细粒悬浮物的垂向加积以及深水重力流异地搬运形成,湖盆沉积表现为“千层饼”式的垂向叠加充填。在前积模式指导下,认为湖盆的充填主要是由多物源方向的前积体向湖盆中心持续进积作用形成。在同一沉积期,前积斜坡的不同部位可形成厚度差异显著的等时沉积体（图9）。
图 9 鄂尔多斯盆地西南部延长组中上部前积斜坡生长过程模式图
Figure 9. Clinoform growth pattern in the Yanchang Formation, southwestern Ordos Basin
湖平面在F1沉积期上升至最大,此时湖盆可容纳空间最大,沉积物供给速率小于可容纳空间增长速率。此后湖平面持续下降且伴随短暂湖进（F2~F4沉积期）,沉积物供给充足,供给速率大于可容纳空间增长速率,且沉积物供给速率与可容纳空间增长速率的比值总体上不断增大。F2~F4沉积期,在早期形成的沉积斜坡基础上,后期前积体不断进积,虽存在湖盆范围短期扩张的情况,但湖盆范围总体收缩,形成多方向进积型斜坡体。在湖盆演化末期（F5~F6沉积期）,多方向物源推进合围,湖盆范围显著缩小,物源供给速率远大于可容纳空间的增长速率,湖盆充填以垂向加积为主,湖盆萎缩消亡（图9）。
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（1） 鄂尔多斯盆地西南部庆城、合水地区延长组长7及以上地层可划分为6期前积斜坡体,环县地区可识别出5期前积体。根据对前积发育区地震反射样式的分析,探索建立了“顶积段自然延伸追踪,前积反射及标志层约束,三维空间闭合检验”的等时地层划分与对比方法,提出盆地西南延长组中上部等时地层划分与对比方案。
（2） 等时划分与对比结果表明,在各期斜坡体顶积段,新方案与传统分层方案的划分结果一致；在前积段,新方案普遍较传统分层增厚；而在底积段,新方案的F1~F3期地层厚度较传统分层显著变小,F5~F6期地层厚度则显著增大。平面上,F1~F4期前积斜坡体地层等厚线呈北西—南东向展布,地层厚度由西南向东北呈薄—厚—薄的分布样式。
（3） 前积模式指导下,地层划分和砂体的追踪具有等时性,砂体连通关系更符合客观实际,更有利于油田开发井网的合理布置和注水开发层位的确定。延长组湖盆的沉积充填主要是由多物源方向的前积体向湖盆中心持续进积作用实现,直到沉积晚期（F5~F6沉积期）才转变为垂向加积作用为主,而不是传统认为的始终以“千层饼”式垂向加积作用为主。上述认识更能客观地反映湖盆的充填和萎缩过程,为深化延长期湖盆的形成演化和石油资源的高效勘探开发提供了重要启示。
鄂尔多斯盆地西南部三叠系延长组划分与对比关系再认识
doi: 10.14027/j.issn.1000-0550.2023.018
cstr: 32268.14.cjxb.62-1038.2023.018Reconsideration of Division and Correlation of the Yanchang Formation in the Southwestern Ordos Basin
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摘要:
目的 最新三维地震资料显示,鄂尔多斯盆地西南部三叠系延长组三角洲—深水沉积过渡带存在大量的前积反射现象,指示以往“千层饼”式的近等厚地层划分方案在前积发育区存在“穿时”问题。研究旨在探索建立前积模式下延长组的等时划分与对比方案,并探讨其与传统地层划分方案的衔接对比关系。 方法 以三维地震资料为基础,通过井—震相互约束和标定,结合岩心沉积相标志的识别,明确盆地西南部延长组中上部（长7及以上地层）的等时划分与对比关系。 结果 将庆城、合水地区延长组中上部划分出6期前积斜坡体（F1~F6）,环县地区划分出5期前积体（F1~F5）。 结论 各期前积体在顶积段与传统分层可较好地衔接对比,但在前积段和底积段,新、旧方案差异较大。各期前积体在前积段普遍较厚,在深水区,F1~F3厚度明显减薄,F5、F6厚度大幅增加。研究区从西南向东北,各期前积体平面分布呈薄—厚—薄的带状样式；北西向展布的地层较厚带指示前积体向湖盆中心的持续推进,指示了湖盆的收缩和充填过程。研究结果为深入理解延长组三角洲—深水区砂体连通关系、空间分布规律以及湖盆沉积充填过程等提供了重要启示。
Abstract:Objective The Yanchang Formation comprises the most important source rock and reservoirs in the Ordos Basin. Recent 3D seismic exploration shows that progradational reflection is widely developed in the delta-deepwater transition zone of the Yanchang Formation, which means that the previous “thousand-layer pie-like” and near equal-thickness stratigraphic division and correlation scheme would cause stratigraphic diachronistic correlation in clinoform development area. The aims of this study are to explore the establishment of isochronal division and correlation of the clinoform pattern for the Yanchang Formation, and to explore its connection and correlation with the traditional stratigraphic division scheme. Methods Based on the 3D seismic data, seismic profiles in the study area are carefully interpreted to obtain the shape type, migration superposition relationship and internal structure of the clinothem, guided by the theories of sequence stratigraphy and sedimentology. Well-seismic mutual calibration （i.e., drilling calibration of seismic horizon, seismic calibration of horizontal correlation of drilling profile strata）, and constrained by core facies marks, a new isochronous stratigraphic division and correlation scheme is established for the mid-upper Yanchang Formation： divided into six stages of clinothems （F1-F6） in Qingcheng, Heshui area, and five stages of clinothems （F1-F5） in the Huanxian area. In the topsets, these correspond to the traditionally stratified Chang 7 - Chang 1 oil layers. Results and Discussions The different stratigraphic divisions are mainly reflected in the foreset and bottomset areas. In the foresets, the strata in each clinothem are generally thicker than suggested by the traditional schemes. In the deep-water area, the newly determined F2 and F3 strata are significantly thinner than the traditional values, while the thicknesses of F5 and F6 are dramatically increased. In plan view, the isochronous stratigraphic units of each clinothem show a NW⁃SE zonation. In the study area from SW to NE there is an alternating thin-thick-thin NW-SE zonal distribution pattern. Within the clinoform pattern there are isochronous and intrinsic genetic relationships of the tracking and correlation relationships between stratigraphic division and sandstone bodies. The connectivity relationship of the sandstone bodies approximates more closely to the actual situation of underground reservoirs, which is conducive to a reasonable well pattern of oilfield development layout, and the determination of water injection horizon. The foresets indicated by the thicker strata continue to advance towards the basin depocenter, indicating the contraction and filling process of the lacustrine basin. Conclusions The “natural extension tracking of the topsets, marker bed constraint, and 3-D space closure test” establishes an isochronous correlation in mid-upper Yanchang Formation in the progradational development area in the SW Ordos Basin. It provides significant implication for re-understanding the stratigraphic division and correlation in the delta- deepwater areas of the Yanchang Formation, and also provides new insights for a greater understanding of the connectivity and spatial distribution of sandstone bodies, as well as the sedimentary filling process of the basin.
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Key words:
- isochronous stratigraphic division /
- clinoform /
- depression basin /
- Yanchang Formation /
- Ordos Basin
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图 1 （a）鄂尔多斯盆地延长组沉积期古地理略图；（b）研究区三维地震工区分布及庆城工区井位分布；（c）延长组综合柱状图
Figure 1. (a) Paleogeographical sketch map of the Ordos Basin during deposition of the Yanchang Formation; (b) 3D seismic survey areas and wells location in the study area; (c) stratigraphical column of the Yanchang Formation
图 2 鄂尔多斯盆地西南部延长组中上部典型地震剖面前积反射特征（剖面位置见图1b）
(a) Huanxian area interpreted clinoforms; (b) Qingcheng area interpreted clinoforms; (a) Heshui area interpreted clinoforms
Figure 2. Interpreted clinoforms on typical seismic profiles in the middle and upper parts of the Yanchang Formation, southwestern Ordos Basin (location of profiles in Fig.1b)
Fig.2
图 3 鄂尔多斯盆地西南部延长组前积生长模式及等时地层划分示意图
(a) clinoform growth pattern of the Yanchang Formation based on seismic profile analysis; and (b) isochronous stratigraphic division of the D⁃D’ seismic profile in the study area
Figure 3. Schematic of clinoform growth pattern and isochronous stratigraphic division of the Yanchang Formation, southwestern Ordos Basin
Fig.3
图 4 鄂尔多斯盆地Z67井延长组合成地震记录
90°⁃phase Ricker⁃like wavelet synthetic seismogram was used for AC curve
Figure 4. Synthetic seismic records of the Yanchang Formation from well Z67 in the Ordos Basin
Fig.4
图 5 鄂尔多斯盆地西南部延长组传统等岩性分层方案与等时分层方案对比（剖面位置见图1b中D—D’）
Figure 5. Comparison between traditional isolithologic division scheme and isochronous division scheme in the southwestern Ordos Basin (location of D⁃D’ section in Fig.1b)
图 6 庆城地区延长组中上部F1~F4期前积斜坡地层厚度图
(a) F1 depositional period; (b) F2 depositional period; (c) F3 depositional period; (d) F4 depositional period
Figure 6. Isopach maps of clinothems in the middle and upper part of the Yanchang Formation in Qingcheng area
Fig.6
图 7 研究区延长组中上部前积斜坡岩心典型沉积特征
(a) gray⁃white sandstone with parallel bedding, topsets of F4, well Z389, 1 872.60 m; (b) gray⁃black mudstone with carbonized plant debris, topsets of F2, well Z518, 2 096.90 m; (c) gray sandstone with flame structure and ripple bedding, foresets of F2, well Z130, 2 026.10 m; (d) gray sandstone with argillaceous tear fragments, foresets of F2, well Z130, 2 111.60 m; (e) flute, foresets of F3, well Y49, 2 071.48 m; (f) gray massive sandstone, foresets of F3, well Y49, 2 066.68 m; (g) stepped fault, foresets of F2, well X260, 1 998.77 m; (h) grayish black mudstone containing fish scale fossils, bottomsets of F1, well X270, 2 075.44 m
Figure 7. Typical sedimentary characteristics of cores from the clinothem in the middle and upper part of the Yanchang Formation in the study area
Fig.7
图 8 鄂尔多斯盆地西南部X303井—B285井延长组中上部砂体分布图（剖面位置见图1b中D—D’）
Figure 8. Distribution of sand bodies in the middle and upper part of the Yanchang Formation, crossing well X303⁃well B285 in the southwestern Ordos Basin (location of D⁃D’ section in Fig.1b)
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[1] Dunay R E, Hailwood E A. Non-biostratigraphical methods of dating and correlation: An introduction[J]. Geological Society, London, Special Publications, 1995, 89: 1-2. [2] 赵俊峰,刘池洋. 定年的非生物地层学方法[J]. 新疆石油地质,2006,27（6）：757-762. Zhao Junfeng, Liu Chiyang. Non-Biostratigraphical methods for dating[J]. Xinjiang Petroleum Geology, 2006, 27(6): 757-762. [3] 王思恩,季强. 冀北张家口组、大北沟组的岩石地层学、生物地层学特征及其在东北亚地层划分对比中的意义[J]. 地质通报,2009,28（7）：821-828. Wang Sien, Ji Qiang. Lithostratigraphy and biostratigraphy features of Zhangjiakou Formation and Dabeigou Formation and its significance for stratigraphic subdivision and correlation in the Northeast Asia[J]. Geological Bulletin of China, 2009, 28(7): 821-828. [4] 陈丕基. 中国陆相侏罗、白垩系划分对比述评[J]. 地层学杂志,2000,24（2）：114-119. Chen Peiji. Comments on the classification and correlation of non-marine Jurassic and Cretaceous of China[J]. Journal of Stratigraphy, 2000, 24(2): 114-119. [5] Patruno S, Helland-Hansen W. Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins[J]. Earth-Science Reviews, 2018, 185: 202-233. [6] 蒲仁海. 前积反射的地质解释[J]. 石油地球物理勘探,1994,29（4）：490-497. Pu Renhai. Geological interpretation of progradational reflections[J]. Oil Geophysical Prospecting, 1994, 29(4): 490-497. [7] Rich J L. Three Critical environments of deposition, and criteria for recognition of rocks deposited in each of them[J]. GSA Bulletin, 1951, 62(1): 1-20. [8] Hampson G J, Sixsmith P J, Kieft R L, et al. Quantitative analysis of net-transgressive shoreline trajectories and stratigraphic architectures: Mid-to-Late Jurassic of the north sea rift basin[J]. Basin Research, 2009, 21(5): 528-558. [9] Gilbert G K. The topographic features of lake shores[R]. U.S. Geological Survey, Annual Report, 1885. [10] Steel R, Olsen T. Clinoforms, clinoform trajectories and deepwater sands[M]//Armentrout J. Sequence-stratigraphic models for exploration and production: Evolving methodology, emerging models and application histories. Tulsa: GCSSEPM Proceedings 22nd Annual Conference, 2002: 367-381. [11] Helland-Hansen W, Hampson G J. Trajectory analysis: Concepts and applications[J]. Basin Research, 2009, 21(5): 454-483. [12] Magyar I. Chronostratigraphy of clinothem-filled non-marine basins: Dating the Pannonian Stage[J]. Global and Planetary Change, 2021, 205: 103609. [13] Fongngern R, Olariu C, Steel R J, et al. Clinoform growth in a Miocene, Para-tethyan deep lake basin: Thin topsets, irregular foresets and thick bottomsets[J]. Basin Research, 2016, 28(6): 770-795. [14] 周华,黄清华,陈泽亚. 古龙凹陷嫩江组地震前积反射特征与岩石地层厘定[J]. 大庆石油地质与开发,2014,33（3）：35-38. Zhou Hua, Huang Qinghua, Chen Zeya. Characteristics of the seismic progradational reflection and lithostratigraphic calibration for Nenjiang Formation in Gulong Sag[J]. Petroleum Geology and Oilfield Development in Daqing, 2014, 33(3): 35-38. [15] 付金华,郭正权,邓秀芹. 鄂尔多斯盆地西南地区上三叠统延长组沉积相及石油地质意义[J]. 古地理学报,2005,7（1）：34-44. Fu Jinhua, Guo Zhengquan, Deng Xiuqin. Sedimentary facies of the Yanchang Formation of Upper Triassic and petroleum geological implication in southwestern Ordos Basin[J]. Journal of Palaeogeography, 2005, 7(1): 34-44. [16] 李文厚,刘溪,张倩,等. 鄂尔多斯盆地中晚三叠世延长期沉积演化[J]. 西北大学学报（自然科学版）,2019,49（4）：605-621. Li Wenhou, Liu Xi, Zhang Qian, et al. Deposition evolution of Middle-Late Triassic Yanchang Formation in Ordos Basin[J]. Journal of Northwest University (Natural Science Edition), 2019, 49(4): 605-621. [17] 谭聪,于炳松,阮壮,等. 鄂尔多斯盆地西南部延长组高分辨率层序地层划分[J]. 吉林大学学报（地球科学版）,2016,46（2）：336-347. Tan Cong, Yu Bingsong, Ruan Zhuang, et al. High-resolution sequence stratigraphy division of Yanchang Formation in southwestern Ordos Basin[J]. Journal of Jilin University (Earth Science Edition), 2016, 46(2): 336-347. [18] 付锁堂,金之钧,付金华,等. 鄂尔多斯盆地延长组7段从致密油到页岩油认识的转变及勘探开发意义[J]. 石油学报,2021,42（5）：561-569. Fu Suotang, Jin Zhijun, Fu Jinhua, et al. Transformation of understanding from tight oil to shale oil in the member 7 of Yanchang Formation in Ordos Basin and its significance of exploration and development[J]. Acta Petrolei Sinica, 2021, 42(5): 561-569. [19] 倪新锋,陈洪德,韦东晓. 鄂尔多斯盆地三叠系延长组层序地层格架与油气勘探[J]. 中国地质,2007,34（1）：73-80. Ni Xinfeng, Chen Hongde, Wei Dongxiao. Sequence stratigraphic framework of the Triassic Yanchang Formation in the Ordos Basin and petroleum exploration[J]. Geology in China, 2007, 34(1): 73-80. [20] 刘化清,廖建波,房乃珍,等. 鄂尔多斯盆地环县地区长6沉积体系展布特征[J]. 沉积学报,2005,23（4）：584-588. Liu Huaqing, Liao Jianbo, Fang Naizhen, et al. Distribution characteristics of the Chang 6 sedimentary system (Triassic) in Huanxian area, Ordos Basin[J]. Acta Sedimentologica Sinica, 2005, 23(4): 584-588. [21] 刘池洋,赵红格,桂小军,等. 鄂尔多斯盆地演化—改造的时空坐标及其成藏（矿）响应[J]. 地质学报,2006,80（5）：617-638. Liu Chiyang, Zhao Hongge, Gui Xiaojun, et al. Space-time coordinate of the evolution and reformation and mineralization response in Ordos Basin[J]. Acta Geologica Sinica, 2006, 80(5): 617-638. [22] 王西强,舒成龙,高雪,等. 对鄂尔多斯盆地三叠系延长组传统地层划分方案的反思：以姬塬油田罗38区、罗211区为例[J]. 大庆石油地质与开发,2020,39（6）：21-30. Wang Xiqiang, Shu Chenglong, Gao Xue, et al. Reflection on the traditional stratigraphic dividion program for Triassic Yanchang Formation in Ordos Basin: A case of block Luo-38 and Luo-211 of Jiyuan oilfield[J]. Petroleum Geology & Oilfield Development in Daqing, 2020, 39(6): 21-30. [23] 杨俊杰. 鄂尔多斯盆地构造演化与油气分布规律[M]. 北京：石油工业出版社,2002：104-213. Yang Junjie. Tectonic evolution and oil-gas reservoirs distribution in Ordos Basin[J]. Beijing: Petroleum Industry Press, 2002: 104-213. [24] 何自新,杨华,费安琪,等. 鄂尔多斯盆地演化与油气[M]. 北京：石油工业出版社,2003：88-108. He Zixin, Yang Hua, Fei Anqi, et al. The evolution history and oil-gas of Ordos Basin [M]. Beijing: Petroleum Industry Press, 2003: 88-108. [25] 惠潇,侯云超,喻建,等. 大型陆相坳陷湖盆深湖区前积型地震地层特征及砂体分布规律：以鄂尔多斯盆地陇东地区延长组中段为例[J]. 沉积学报,2022,40（3）：787-800. Hui Xiao, Hou Yunchao, Yu Jian, et al. Progradational seismic strata features and distribution of sandstone in the deep-water area of a large-scale lacustrine depression basin: A case study of the middle Yanchang Formation in Longdong, Ordos Basin[J]. Acta Sedimentologica Sinica, 2022, 40(3): 787-800. [26] 冯雪,高胜利,刘永涛,等. 鄂尔多斯盆地陇东地区延长组三角洲前缘前积结构特征[J]. 岩性油气藏,2021,33（6）：48-58. Feng Xue, Gao Shengli, Liu Yongtao, et al. Characteristics of delta front progradation structure of Yanchang Formation in Longdong area, Ordos Basin[J]. Lithologic Reservoirs, 2021, 33(6): 48-58. [27] 李相博,朱如凯,惠潇,等. 晚三叠世卡尼期梅雨事件（CPE）在陆相盆地中的沉积学响应：以鄂尔多斯盆地延长组为例[J]. 沉积学报,2023,41（2）：511-526. Li Xiangbo, Zhu Rukai, Hui Xiao, et al. Sedimentological response of a lacustrine basin to the Upper Triassic Carnian Pluvial Episode (CPE): Case study from the Yanchang Formation, Ordos Basin[J]. Acta Sedimentologica Sinica, 2023, 41(2):511-526. [28] 李慧琼,蒲仁海,王大兴,等. 鄂尔多斯盆地延长组地震前积反射的地质意义[J]. 石油地球物理勘探,2014,49（5）：985-996. Li Huiqiong, Pu Renhai, Wang Daxing, et al. Progradational reflection from lacustrine Yanchang Formation in Ordos Basin[J]. Oil Geophysical Prospecting, 2014, 49(5): 985-996. [29] 邓秀芹,付金华,姚泾利,等. 鄂尔多斯盆地中及上三叠统延长组沉积相与油气勘探的突破[J]. 古地理学报,2011,13（4）：443-455. Deng Xiuqin, Fu Jinhua, Yao Jingli, et al. Sedimentary facies of the Middle-Upper Triassic Yanchang Formation in Ordos Basin and breakthrough in petroleum exploration[J]. Journal of Palaeogeography, 2011, 13(4): 443-455. [30] Zhao J F, Mountney N P, Liu C Y, et al. Outcrop architecture of a fluvio-lacustrine succession: Upper Triassic Yanchang Formation, Ordos Basin, China[J]. Marine and Petroleum Geology, 2015, 68: 394-413. [31] 林承焰,张宪国,董春梅. 地震沉积学及其初步应用[J]. 石油学报,2007,28（2）：69-72. Lin Chengyan, Zhang Xianguo, Dong Chunmei. Concept of seismic sedimentology and its preliminary application[J]. Acta Petrolei Sinica, 2007, 28(2): 69-72. [32] 杨俊杰,张伯荣. 陕甘宁盆地油气区及油气藏序列[J]. 石油学报,1988,9（1）：1-8. Yang Junjie, Zhang Borong. Region Shan-Gan-Ning petroliferous basin and its reservoir sequence[J]. Acta Petrolei Sinica, 1988, 9(1): 1-8. [33] 邓秀芹,罗安湘,张忠义,等. 秦岭造山带与鄂尔多斯盆地印支期构造事件年代学对比[J]. 沉积学报,2013,31（6）：939-953. Deng Xiuqin, Luo Anxiang, Zhang Zhongyi, et al. Geochronological comparison on Indosinian tectonic events between Qinling Orogeny and Ordos Basin[J]. Acta Sedimentologica Sinica, 2013, 31(6): 939-953. [34] 曹江骏,杨友运,陈朝兵,等. 致密砂岩储层骨架砂体构型特征：以鄂尔多斯盆地合水地区延长组长6段砂体为例[J]. 沉积学报,2019,37（6）：1103-1116. Cao Jiangjun, Yang Youyun, Chen Chaobing, et al. Analysis of configuration characteristics for skeleton sand body with tight sandstone reservoir: A case study of Triassic Chang 6 members in Heshui area, Ordos Basin, NW China[J]. Acta Sedimentologica Sinica, 2019, 37(6): 1103-1116. [35] 屈雪峰,王武荣,谢启超,等. 坳陷湖盆湖底扇储层单砂体构型：以鄂尔多斯盆地合水地区三叠系长6油层组为例[J]. 地球科学与环境学报,2021,43（5）：850-867. Qu Xuefeng, Wang Wurong, Xie Qichao, et al. Single sandbody architecture of sublacustrine fan in a depression lacustrine basin: Insights from Triassic Chang-6 oil-bearing interval in Heshui area of Ordos Basin, China[J]. Journal of Earth Sciences and Environment, 2021, 43(5): 850-867. -
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