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海陆过渡背景下混积碳酸盐岩层序地层结构及其控沉控储作用——以塔中东部石炭系巴楚组生屑灰岩段为例
崔仕提, 张少伟, 程钊, 朱茂, 郑剑锋, 段军茂, 邵冠铭
海相油气地质 ›› 2025, Vol. 30 ›› Issue (4) : 313-325.
PDF(16360 KB)
PDF(16360 KB)
海陆过渡背景下混积碳酸盐岩层序地层结构及其控沉控储作用——以塔中东部石炭系巴楚组生屑灰岩段为例
Sequence stratigraphic framework and its control on sedimentation and reservoir formation of mixed siliciclastic-carbonate rocks under marine-terrestrial transitional setting: a case study of the Carboniferous Bachu bioclastic limestone member in eastern Tazhong area, Tarim Basin
针对塔里木盆地塔中东部巴楚组生屑灰岩段层序架构不明确、沉积演化规律不清晰的核心问题，基于丰富的岩心、薄片、测井及地球化学等数据资料，深入分析了生屑灰岩段的岩石学特征，构建了生屑灰岩段的层序地层结构，并探讨了其控沉控储作用。研究结果显示：①塔中东部生屑灰岩段为海陆过渡背景下的混积碳酸盐岩，主要由泥晶—粉晶灰（白云）岩、砂屑—砾屑灰（白云）岩、混积岩及过渡岩性组成，陆源碎屑含量相对较高。岩性分布呈现出明显的垂向分段和平面分带特征。②生屑灰岩段与下伏东河砂岩段、下泥岩段及上覆中泥岩段共同构成了一个完整的三级层序；生屑灰岩段本身为一个完整的海进-海退序列，中亚段沉积时期水体相对最深。③海平面升降旋回对沉积微相的演化和成岩作用类型具有决定性影响。下亚段和上亚段沉积水体较浅，以蒸发潮坪相潮上带的云坪、灰云坪等沉积微相为主；中亚段随着相对海平面升高，发育潮间带高能碳酸盐岩颗粒滩微相，叠加高频旋回暴露的大气淡水溶蚀作用和准同生白云石化作用，可形成优质的储集体。这种白云石化的颗粒滩与发育针孔状结构的云坪构成了塔中东部生屑灰岩段最有利的储集相带，是未来勘探开发的主要目标。
This study addresses the core issues of unclear sequence architecture and sedimentary evolution patterns of the bioclastic limestone member of the Carboniferous Bachu Formation in eastern Tazhong area, Tarim Basin. Based on a wealth of data, including core, thin section, logging, and geochemical data, we conduct an in-depth analysis of the petrological characteristics of the bioclastic limestone member, construct the sequence stratigraphic framework for this member, and explore its control on sedimentation and reservoir formation. The research findings demonstrate that: (1) The bioclastic limestone member in the eastern Tazhong area represents a mixed siliciclastic-carbonate sedimentation within a marine-terrestrial transitional setting, mainly composed of micritic to peloidal limestone/dolomite, calcarenite/doloarenite to calcirudite/doloyunrudite, mixed rocks, and transitional lithologies, with a relatively high content of terrigenous clastics. The distribution of lithologies exhibits distinct vertical segmentation and lateral zonation patterns. (2) Based on variations in lithology and sedimentary facies, the bioclastic limestone member, along with the underlying Donghe sandstone member, the lower mudstone member, and the overlying middle mudstone member, forms a complete three-order sequence. The bioclastic limestone member itself represents a complete transgressive-regressive sequence, with the middle submember recording the relatively deepest marine flooding conditions during deposition. (3) The eustatic cycles exert a decisive influence on the evolution of sedimentary microfacies and diagenetic processes. The lower and upper submembers, deposited in shallow waters, are dominated by supratidal dolomicrite (dolomudstone) facies within evaporitic tidal flats. During relative sea-level rise in the middle submember, high-energy grain shoal complexes developed within intertidal settings, where superimposed high-frequency exposure events drove meteoric dissolution and penecontemporaneous dolomitization, thereby generating high-quality reservoirs with superior storage capacity. These dolomitized grain shoal and dolomicrite flats with pinprick vugs together constitute the most favorable reservoir facies of the bioclastic limestone member in the eastern Tazhong area, Tarim Basin, and represent the primary targets for future exploration and development.
海陆过渡背景 / 混积碳酸盐岩 / 生屑灰岩段 / 层序 / 巴楚组 / 塔中东部
marine-terrestrial transitional setting / mixed siliciclastic-carbonate rock / bioclastic limestone member / sequence / Bachu Formation / eastern Tazhong area
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以海相层序地层学理论为基础,通过研究塔里木盆地BT4井及地震剖面,识别层序界面、分析层序内部组合、体系域特征,在层序内部分析BT4井区沉积相特征.以层序和沉积相为基础,通过薄片特征分析有利储层与层序界面、体系域和沉积相的关系.将本区石炭系分为四个三级层序,三种类型的层序界面.本区共有三种层序模式:海相碎屑岩缓坡层序模式、碳酸盐岩缓坡层序模式和碳酸盐岩镶边层序模式.重点分析小海子组的铸体薄片可知,高位体系域的礁滩相灰岩受同生期淡水淋滤和混合水白云岩化作用,形成溶蚀缝、粒间溶孔、粒内溶孔等储集空间.因此预测BT4井区东北部层序界面控制的碳酸盐岩上倾尖灭的异常体是可能的有利目标.
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通过岩心、薄片观察，从岩石学特征入手，结合测井资料，对塔里木盆地巴楚—麦盖提地区石炭系的陆源碎屑—碳酸盐混积岩和混积层系进行了研究。根据混积强度将混积岩划分为混积型碎屑岩、混积型碳酸盐岩和高度混积岩。巴楚组下泥岩段和中泥岩段发育混积型碎屑岩，巴楚组生屑灰岩段、中泥岩段和小海子组发育混积型碳酸盐岩，卡拉沙依组上泥岩段、巴楚组下泥岩段及巴什托局部地区的中泥岩段发育高度混积岩。高度混积岩出现在海退期沉积的碎屑岩段，代表了陆源碎屑—碳酸盐强烈混合的过渡性沉积环境。研究区石炭系可识别出4个三级层序，混积层系主要发育在海侵体系域早期和高位体系域晚期，以间断混合和相缘混合为主。研究认为混积强度是评价混合沉积环境性质的主要参数，并将其划分为4级。下泥岩段存在混积强度达3级以上的混积界面，能用于地层对比。最后，结合混合沉积特征讨论了构造运动和海平面变化对研究区石炭系层序组以上的混合沉积的控制作用。
The characteristics of clastic-carbonate mixed rocks and mixed bed series of the Carboniferous in Bachu-Makit area in the Tarim Basin were reported，through analyses of petrology，observation of cores，thin sections and well-log data.According to the intensity of mixed sedimentation，the clastic-carbonate mixed rocks are divided into mixed clastic，mixed carbonate rocks and high-mixed rocks.The Lower Mudstone and Middle Mudstone of the Bachu Formation were mixed clastic，while the bioclastic limestone of the Bachu Formation，Xiaohaizi Formation and Middle Mudstone of the Bachu Formation were mixed carbonate rocks，while high-mixed rocks distributed in the Upper Mudstone of the Karashayi Formation and Lower Mudstone of the Bachu Formation，as well as in the Middle Mudstone of the Bachu Formation partly in Bashituo area.The occurrence of high-mixed rocks in clastic of regression corresponded to the transition environment with intense clastic-carbonate mixing.There were four sequences identified in the Carboniferous in this area.The mixed bed series almost formed in the early stage of TST and later period of HST，with punctuated mixing and facies mixing domination.It is concluded that the intensity of mixed sedimentation can be used as a main indicator of evaluating the nature of mixed sedimentation environment，which can be divided into four orders.There was a mixed sedimentary surface in the Lower Mudstone of the Bachu Formation，where the intensity of mixed sedimentation reached the third order，and can be used in stratigraphic correlation.In conclusion，based on the characteristic of clastic-carbonate mixed sedimentation，the main controlling factors of mixed sedimentation were discussed，mainly including tectonic movement and eustatic change.
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通过研究确定塔里木盆地哈得逊地区巴楚组地层序列类型及其成因机理，解决地层演化和沉积历史的相关争议。通过岩心、测井资料的分析及区域地层对比，确定哈得逊地区巴楚组东河砂岩段之上存在下泥岩段和生屑灰岩段。哈得逊地区东河砂岩段、下泥岩段、生屑灰岩段在石炭系早期依次沉积，此沉积序列为该区巴楚组标准沉积序列，该标准序列与塔里木盆地其他地区的东河砂岩段_下泥岩段_生屑灰岩段沉积序列一致。由于在沉积之后即受构造抬升、不均匀剥蚀及混积作用影响，该区大部分巴楚组标准地层序列不再完整，并形成角砾岩段，形成5种地层序列类型（自下而上）：Ⅰ东河砂岩—下泥岩—生屑灰岩；Ⅱ东河砂岩—下泥岩—角砾岩；Ⅲ东河砂岩—下泥岩；Ⅳ东河砂岩—角砾岩；Ⅴ东河砂岩，此种地层序列在东河砂岩油藏区具有明显的分区性。对哈得逊地区巴楚组地层序列的正确认识对该区沉积环境和沉积层序、东河砂岩钙质来源和成岩作用、地震资料应用以及油气勘探等研究具有重要意义。
<p>The aim of this article is to confirm the strata sequence and the mechanisms of the Bachu Formation of the Hudson area，Tarim Basin and to settle the related debates of the stratigraphic evolution and sedimentary history.Based on the specific analysis on cores，well-logging and regional stratigraphic correlation，it has been proved that the lower mudstone member and bioclastic limestone member exist above the Donghe sandstone member of the Bachu Formation in Hudson.Donghe sandstone member，lower mudstone member，bioclastic limestone member in Hudson were deposited successively during the Early Carboniferous，which constituted the standard sedimentary sequence of the Bachu Formation in the area.This standard sedimentary sequence is identical with those in other areas in the Trim Basin.Because of the later tectonic uplift，differential denudation and mixed deposition，the strata sequence of the Bachu Formation was no longer intact.The Breccia member was generated and five types of strata sequence were formed (from bottom to top)：Ⅰ Donghe sandstone member-lower mudstone member-bioclastic limestone member，Ⅱ Donghe sandstone member-bioclastic limestone member-breccia member，Ⅲ Donghe sandstone member-lower mudstone member，Ⅳ Donghe sandstone member-breccia member and Ⅴ Donghe sandstone member.Each type of strata sequence lies in its own unique area within the Donghe sandstone reservoir area.The recognition of the Bachu Formation in Hudson influences the study of sedimentary environment and sequence，the source of the calcium of the calcareous interlayers and diagenesis in the Donghe sandstone，the application of the seismic data and the petroleum exploration of the area.</p>
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塔中地区西北部石炭系已开发TZ10、TZ40等多个海相碎屑岩油藏，CⅢ油组（石炭系III油组）含砾砂岩段为其主要的产油层段。通过岩心观察、分析化验资料、测井及地震资料等对含砾砂岩段的沉积相类型进行了研究。分析结果表明，研究区石炭系含砾砂岩段主要为细砂岩、含砾细砂岩，形成多期相互叠置的正韵律砂体，砂岩岩石类型以岩屑质石英砂岩、岩屑砂岩为主，成熟度中等；发育冲刷面、滞留沉积、平行层理、交错层理等层理构造；砂岩粒度概率曲线以2段式为主，悬浮总体含量较高；含砾砂岩段灰色泥岩、褐色泥岩均有发育；泥岩微量元素反映出淡水、咸水古盐度特征；测井形态组合、三维地震属性均显示河道沉积特征。结合区域地质背景，认为研究区CⅢ油组含砾砂岩段为辫状河三角洲沉积，发育三角洲平原的分支河道、越岸沉积以及三角洲前缘的水下分支河道、支流间湾、河口砂坝及席状砂等多种微相类型。辫状河三角洲河道的频繁侧向迁移垂向上形成了砂体的多期叠置，平面上形成了砂体的大面积分布，成为良好的油气储集体，寻找以河道砂体为主的岩性地层油藏是滚动勘探开发的主要目标.
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从沉积环境入手，依据岩心、铸体薄片、扫描电镜等资料，并结合区域地质背景对塔里木盆地西部麦盖提斜坡西段下石炭统巴楚组生屑灰岩段进行了研究，指出该区生屑灰岩段优质储层的岩性为粉晶白云岩、泥粉晶白云岩及灰质白云岩；储集空间以孔(晶间孔、晶间溶孔、鸟眼孔)+构造溶扩缝组合为主；孔隙结构具有粗歪度，分选好的特点，排驱压力一般小于0.5 MPa，最大孔喉半径一般为1.5~20 μm，平均孔喉半径大于0.5 μm，最大可达7 μm；孔隙度为8%~29.6%(均值104％)，渗透率一般为(0.1~68.4)×10\+\{-3\} μm\+2(均值2.6×10\+\{-3\} μm\+2)，属中孔中渗—高孔中渗(Ⅰ—Ⅱ类)储层。认为蒸发台地潮上含膏云坪及潮间带上部灰云坪环境是优质储层发育的先决条件，白云岩化、准同生大气淡水溶蚀作用、海西期构造裂缝—油气注入对储层的储集空间发育、连通、保存起到主要的建设作用；优质储层的分布纵向上受控于沉积环境，集中发育在生屑灰岩段的上部—顶部的蒸发台地相带，厚度1~5 m，横向上受控于早石炭世晚期群苦恰克古隆起，沿古隆起既是优质储层发育的有利成岩相带(准同生白云岩化、大气淡水溶蚀)，也是油气勘探的重点目标区。
<div style="line-height: 150%">Commencing from sedimentation, according to core, cast liquid photo, scan electron microscope etc., combining the geology setting in the area, this study thinks</div><div style="line-height: 150%"> that the high quality reservoirs of Carboniferous bioclastic limestone member in the western Maigaiti slope is silt crystal dolomite and clay\|silt crystal dol</div><div style="line-height: 150%">omite; and the pore space is mostly pores (intercrystalline pore, intercrystalline emposieu, and birdeye pore) and tectonic dissolution fractures; the pore stru</div><div style="line-height: 150%">cture is chick flexure and wellsorted, with drainage pressure less than 0.5 MPa, and most pore throats of 1.5~20 μm, and with average pore throats more than</div><div style="line-height: 150%">0.5 μm, most pore throats 7 μm; and the porosity is 8~29.6% with the average of 10.4%, permeability is (0.1~68.4)×10\+\{-3\} μm\+2 with the average of 2.6×</div><div style="line-height: 150%">10\+\{-3\} μm\+2, the reservoirs are of medium porosity and medium permeability to high porosity and medium permeability. Epilittoral zone dolomite of evapora</div><div style="line-height: 150%">tion tableland and eulittoral zone limy dolomite are the primary factors controlling the development of the high quality reservoirs, and dolomitization, air fre</div><div style="line-height: 150%">sh water dissolution, and tectonic fractures and hydrocarbon infusion of late Hercynian play the most important constructive roles in the development, connectio</div><div style="line-height: 150%">n and preservation of pores. Vertically, the high quality reservoirs are controlled by depositional setting and mostly developed in evaporation tableland on the</div><div style="line-height: 150%"> upper and top of the bioclastic limestone member, with the thickness of 1~5 m; horizontally, they are controlled by the Qunkuqiake palaeohigh of late Early Car</div><div style="line-height: 150%">boniferous, and along the palaeohigh are not only favorable diagenetic facies (syngenetic dolomitization, air fresh water dissolution) of good quality reservoir, but also important target areas for exploration.</div>
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玛湖大油气区的重大发现掀起砂砾岩储层勘探新热潮，塔里木盆地东河砂岩“石英质砾”储层已获多个油气发现，其油气藏特征及分布规律已基本明朗，而“灰质砾”的成因以及对储层的影响目前还是研究空白区域。以塔里木盆地TZ2井区含砾砂岩段为例，探索从滨岸体系控制下的高精度层序地层学角度来展开研究。综合薄片、岩心、测井、地震等资料，对TZ2井区石炭系含砾砂岩段沉积环境及储层特征进行研究，进而探索灰质砾对储层的影响及储层在地层层序和沉积相序中的划分，总结层序沉积对有效储层展布的控制作用。研究表明：东河砂岩段底至生屑灰岩段顶构成一个具有海侵体系域—高位体系域旋回的Ⅲ级层序，并可进一步划分为4个Ⅳ级层序，在Ⅳ级层序里含砾砂岩段为高位体系域，主要为海侵作用以及奥陶系潜山剥蚀作用下形成的一套滨岸相沉积体，发育前滨亚相和临滨亚相，具有纵向上厚度变化大，横向上非均质性强的特点，其中前滨亚相是储层发育的有利相带。灰质砾在前滨亚相普遍分布，其母岩为奥陶系灰岩，来自于具有多期隆升特征的奥陶系潜山，灰质砾石含量越高，储层物性越差，是影响有效储层发育与否的关键因素。
Great discoveries of oil and gas in Mahu area have set off a new wave of exploration for glutenite reservoir. Several oil and gas discoveries have been made in the “quartz gravel” reservoir of Donghe sandstone， Tarim Basin. The characteristics and distribution of the reservoir are basically clear. But the origin of gray gravel and its influence on the reservoir is still a study blank area. This paper， taking the pebbled sandstone section in Tazhong 2 well block， Tarim Basin as an example， explores this issue by employing high precision sequence stratigraphy controlled by coastal system. Based on thin section， core， well logging， and seismic data， the sedimentary environment and reservoir characteristics of the Carboniferous pebbled sandstone section in Tazhong 2 well block were studied， and then the influence of gray gravel on the reservoir and the division of reservoir in stratigraphic sequence and sedimentary facies sequence are explored， and the controlling effect of sequence deposition on effective reservoir distribution is summarized. The results indicate that it is a third-order sequence from the bottom of Donghe sandstone section to the top of Crumbs limestone section， which contains a transgression system tract and a highstand system tract cycle assemblage. The third-order sequence concludes four four-order sequence， and the pebbled sandstone section belongs to highstand system tract， which is a set of shore facies deposits controlled by transgression and denudation of Ordovician buried hill. The pebbled sandstone section develops foreshore subfacies and shoreface subfacies with the characteristic of large thickness variation and strong transverse heterogeneity， in which the foreshore subfacies is the favorable facies zone for reservoir development. Gray gravel is widely distributed in foreshore subfacies， and its parent rock is Ordovician limestone， which comes from the Ordovician buried hill with multi-stage uplift characteristics. The higher the content of gray gravel， the worse the physical property of the reservoir， which is the key factor affecting the development of effective reservoir. |
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田军, 王清华, 杨海军, 等. 塔里木盆地油气勘探历程与启示[J]. 新疆石油地质, 2021, 42(3): 272-282.
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何治亮, 苟华伟, 李孝容, 等. 塔里木板块石炭—二叠纪原型盆地与沉积模式[J]. 石油与天然气地质, 1992, 13(1): 1-14, 125-126.
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赵宗举, 周新源, 范国章. 塔里木盆地塔中地区主要构造圈闭形成期分布及成藏意义[J]. 海相油气地质, 2006, 11(2): 1-8.
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周新源, 李本亮, 陈竹新, 等. 塔中大油气田的构造成因与勘探方向[J]. 新疆石油地质, 2011, 32(3): 211-217.
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朱茂, 黄世伟, 宋叙, 等. 四川盆地潼南—合川区块中二叠统白云岩储层形成主控因素与勘探区带预测[J]. 中国石油勘探, 2022, 27(4): 149-161.
近年来，除川西地区和川南地区外，川中地区潼南—合川区块中二叠统栖霞组—茅口组多口钻井也钻遇白云岩储层并获得高产，展现了川中地区栖霞组—茅口组巨大的勘探潜力。但是前期针对川中地区栖霞组—茅口组研究认识较少，白云岩储层的成因与分布也存在较大争议。为弄清潼南—合川区块地层分布、沉积与储层特征，特别是优质白云岩储层形成的主控因素，充分利用最新的油气勘探成果和丰富的基础资料开展研究。结果表明：（1）潼南—合川区块栖霞组—茅口组划分为2个三级层序和6个四级层序，优质白云岩储层发育在层序的高位体系域。（2）栖霞组—茅口组均具有发育台内滩的沉积背景，大量发育台内生屑滩，白云岩储层主要发育在台内中高能滩相带内。（3）栖霞组白云岩储层单层厚度薄，垂向叠置发育；茅口组白云岩储层单层厚度较大，横向较连续；栖霞组—茅口组储集空间均以原生孔和准同生期溶蚀孔为主，台内中高能滩、受层序控制的岩溶作用和早期白云石化作用控制了白云岩储层的发育。（4）栖霞组白云岩储层环洼分布，有利勘探区带分布在潼南—合川区块中西部；茅口组白云岩储层主要发育在微古地貌高地的边缘斜坡部位，合深4 井东北侧地区是最有利的勘探区带。
In recent years, in addition to the western and southern Sichuan Basin, dolomite reservoirs of the Middle Permian Qixia Formation-Maokou Formation have been penetrated in multiple wells in Tongnan-Hechuan block in the central Sichuan Basin and high production has been achieved, showing promising exploration potential in the central Sichuan Basin. However, there is little understanding on Qixia Formation-Maokou Formation in the central Sichuan Basin from previous study, and great disputes appear on the genesis and distribution of dolomite reservoirs. The latest petroleum exploration results and a large number of basic data are analyzed to identify the stratigraphic distribution, sedimentary and reservoir characteristics, especially the main controlling factors of the high-quality dolomite reservoir. The results show that: (1) Qixia Formation-Maokou Formation in Tongnan-Hechuan block is divided into two third-order sequences and six fourth-order sequences, and the high-quality dolomite reservoir is developed in the highstand system tract. (2) The sedimentary facies of Qixia Formation-Maokou Formation in Tongnan-Hechuan block was conducive to the deposition of granular beach, with a large number of bioclastic beach developed. The dolomite reservoir was mainly developed in high-energy beach facies zone. (3) The single layer of dolomite reservoir of Qixia Formation is thin and vertically superimposed, while that of Maokou Formation is greater and continuous in lateral. The reservoir space is dominated by primary pores and quasi syngenetic dissolution pores. The development of dolomite reservoir is mainly controlled by highenergy granular beach, sequence related karstification and early dolomitization. (4) The dolomite reservoir of Qixia Formation is mainly distributed in the circum subsag and the western part of Tongnan-Hechuan block is a favorable exploration zone. The dolomite reservoir of Maokou Formation is mainly developed in the edge slope of micro paleogeomorphologic high area and the northeast side of Well Heshen 4 is the most favorable exploration zone.
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