【作者】 高航；

【导师】 王璞珺； 陈树民；

【作者基本信息】 吉林大学 ， 工程硕士（专业学位）， 2023， 硕士

【摘要】 松辽盆地是我国著名的白垩系陆相盆地,不仅蕴藏着丰富的油气资源,而且在研究白垩纪时期陆地温室气候环境特征及演化规律方面也具有独特的地质优势。为获取白垩纪连续地层资料,国际大陆科学钻探计划在松辽盆地开展了松辽盆地白垩纪大陆科学钻探松科1井(南孔、北孔)、松科2井、松科3井钻探工程。松科3井钻取了登娄库组-泉头组的连续岩心,为探索白垩纪中期古温室气候烃源岩生烃演化模式、明确断坳转换期盆地演化机制和评价松辽盆地及周围地区油气资源潜力提供了地质依据。本文基于松科3井岩心资料开展了登娄库组和泉头组地层序列和储层研究,在松辽盆地上下白垩统界线划分和德惠断陷登娄库组-泉头组有利储层预测方面具有重要意义。本文通过对松科3井全取心资料进行岩心精细描述,厘定了登娄库组-泉头组岩性序列,并结合岩心岩性、颜色、沉积构造和含有物以及测井曲线特征等相关识别标志,对登娄库组-泉头组沉积相进行划分。岩性序列和沉积相划分结果表明松科3井登娄库组-泉头组主要发育10种不同粒度的碎屑岩类型,四种主要沉积相(辫状河、曲流河、三角洲、湖泊,包括9种沉积亚相、23种沉积微相)。根据松科3井岩性序列及沉积相划分结果,泉头组二段上部发育沉凝灰岩薄夹层,对其进行碎屑锆石U-Pb测年分析,其中四颗年轻锆石加权平均年龄为96.8±2.9Ma,属于晚白垩世塞诺曼中期。结合前人对登娄库组和泉头组年龄约束及沉积速率相关研究,可推算出松科3井潜在的上、下白垩统界线可能位于泉一段中下部;考虑测年误差的推算结果则表明该界线也可能位于泉二段中部至登四段上部。登娄库组-泉头组在全盆地范围内广泛发育的连续沉积记录,指示着在松辽盆地其他地区同层位中同样存在该界线的连续沉积的地质记录。松科3井岩性序列揭示登娄库组-泉头组发育碎屑岩储层,具有以下主要特征:(1)登娄库组储层岩性以中-粗粒砂岩为主,泉头组储层岩性主要为细砂岩。(2)储层主要发育原生孔隙、次生孔隙和裂缝三种储集空间类型,并包含六种亚孔隙类型。(3)储层平均孔隙度和渗透率分别为7.09%、2.479m D。(4)根据高压压汞毛管压力曲线形态及孔喉大小差异,可将登娄库组-泉头组储层按储集能力依次分为Ⅰ、Ⅱ、Ⅲ三种类型。其中Ⅰ型储层粒间孔和次生孔隙发育,Ⅱ型储层的胶结作用会留存部分粒间孔且碳酸盐胶结物易被溶蚀,Ⅲ型储层胶结物封堵了绝大部分孔隙,说明成岩作用类型和强度是影响登娄库组-泉头组储层孔喉大小及物性的主要因素。(5)根据恒速压汞毛管压力曲线特征将登娄库组-泉头组储层孔喉配置关系分为孔喉均等型和喉道主导型。孔喉均等型储层胶结物及碎屑颗粒溶蚀孔普遍发育,物性相对更好;喉道主导型储层原生和次生孔多被胶结物堵塞,细小缝隙相对发育,物性较差。这表明溶蚀作用和胶结作用的次序是影响孔喉配置的主要因素。(6)岩心CT扫描表明,基于高压压汞及恒速压汞曲线分类的Ⅰ型-孔喉均等型储层孔隙极为发育,渗透性好;Ⅱ型-喉道主导型储层孔隙空间发育较差,孔隙度和渗透率较差。利用松科3井岩性序列和沉积相划分和铸体薄片观察结果,对登娄库组-泉头组储层控制因素进行分析,可得到如下认识:(1)登娄库组-泉头组储层物性与石英含量呈正相关、与岩屑和填隙物含量呈负相关、与长石含量相关性较差。(2)登娄库组-泉头组储层主要通过溶解作用增加孔隙空间;压实作用、胶结作用会破坏储层孔隙性和渗透性。(3)储层主要为辫状河和曲流河河道砂体,登二段上部-登三段下部辫状河河道心滩微相和泉一段中下部曲流河河道河床滞留沉积-边滩微相发育残余粒间孔和次生孔隙,物性较好,为有利储层发育相带。更多还原

【Abstract】 The Songliao Basin is a famous Cretaceous continental basin in China,which not only contains rich oil and gas resources,but also has unique geological advantages in studying the characteristics and evolution of the terrestrial greenhouse climate environment during the Cretaceous period.In order to obtain the continuous stratigraphic data of the Cretaceous period,the International Continental Scientific Drilling Project(ICDP)carried out the drilling project of the Cretaceous Continental Scientific Drilling borehole SK1(South and North boreholes),SK2,and SK3 in the Songliao Basin.The continuous cores from Denglouku Formation to Quantou Formation drilled from borehole SK3,which provides a geological basis for exploring the hydrocarbon generation evolution model of paleogreenhouse climate source rocks in the middle Cretaceous,clarifying the basin evolution mechanism during the fault depression transition period,and evaluating the potential of oil and gas resources in Songliao Basin and its surrounding areas.This paper conducts a study on the stratigraphic sequence and reservoirs of the Denglouku Formation and Quantou Formation based on the core data of the borehole SK3.It is of great significance in the division of the upper and lower Cretaceous boundary in the Songliao Basin and the prediction of favorable reservoirs of the Denglouku Formation Quantou Formation in the Dehui Fault Depression.This paper defines the lithological sequence of Denglouku-Quantou Formation through detailed core description of the complete coring data of borehole SK3,and classifies the sedimentary facies of Denglouku-Quantou Formation based on relevant identification indicators such as core lithology,color,sedimentary structure,inclusions,and logging curve characteristics.The results of lithological sequence and sedimentary facies division indicate that the Denglouku-Quantou Formation of borehole SK3 mainly develops 10 types of clastic rocks with different grain sizes,and four main sedimentary facies(braided river,meandering river,delta,and lake,including 9 sedimentary subfacies and 23 sedimentary microfacies).According to the lithological sequence and sedimentary facies division results of borehole SK3,a thin intercalation of sedimentary tuff is developed in the upper part of the second member of the Quantou Formation,and the U-Pb dating analysis of clastic zircons is conducted.The weighted average age of four young zircons is 96.8 ± 2.9 Ma,belonging to the Middle Cenomanian Period of the Late Cretaceous.Based on previous studies on age constraints and sedimentation rates of the Denglouku and Quantou Formations,it can be inferred that the potential Upper and Lower Cretaceous boundary of the borehole SK3 may be located in the middle and lower part of the first member of Quantou Formation.The calculation results considering the dating error indicate that the boundary may also be located in the middle of the second member of Quantou Formation to the upper part of the fourth member of Denglouku Formation.The continuous sedimentary records of the Denglouku-Quantou Formation,which are widely developed throughout the basin,indicate that there are also geological records of continuous sedimentation of this boundary in the same horizon in other areas of the Songliao Basin.The lithological sequence of borehole SK3 reveals that clastic rock reservoirs are developed in the Denglouku Formation and Quantou Formation,with the following main characteristics:(1)The reservoir lithology of Denglouku Formation is mainly medium to coarse grained sandstone,while the reservoir lithology of Quantou Formation is mainly fine sandstone.(2)The reservoir mainly develops three types of reservoir space: primary pores,secondary pores,and fractures,which can be further divided into six sub pore types.(3)The average porosity and permeability of the reservoir are 7.09% and 2.479 m D respectively,with a moderate overall correlation deviation.(4)According to the difference in capillary pressure curve shape and pore throat size of high-pressure mercury injection,the reservoir of Denglouku Formation-Quantou Formation can be divided into three types: I,II,and III.The reservoir capacity is reflected in: I>II>III.Among them,intergranular pores and secondary pores are well developed in Type A reservoirs,some intergranular pores are retained by cementation in Type Ⅱ reservoirs,and carbonate cements are prone to dissolution.Type Ⅲ reservoir cements block most of the pores,indicating that the type and intensity of diagenesis are the main factors affecting the pore throat size and physical properties of the Denglouku-Quantou Formation reservoir.(5)According to the constant velocity mercury injection capillary pressure curve,the pore throat configuration relationship of the Denglouku-Quantou Formation reservoir is divided into pore throat equalization type and throat dominant type.Cements and clastic particle corrosion pores are commonly developed in reservoirs with equal pore throat,and their physical properties are relatively better;Primary and secondary pores of throat dominated reservoirs are mostly blocked by cement,and throat channels dominated by small cracks are relatively developed with poor physical properties.This indicates that the order of dissolution and cementation is the main factor affecting the pore throat configuration.(6)The core CT scan results show that the Ⅰ-type pore throat equalization type coarse sandstone reservoir based on the classification of high-pressure mercury injection and constant velocity mercury injection curves in borehole SK3 has extremely developed pores and good permeability;Type Ⅱ-throat dominated gravelly coarse sandstone reservoirs have poor pore throat space development,porosity,and permeability.This indicates that the combination of high-pressure mercury injection and constant velocity mercury injection curve features can better characterize the pore throat space of the reservoir,thereby making a more accurate determination of the reservoir’s reservoir and permeability.By using the lithological sequence and sedimentary facies division of borehole SK3,as well as the observation results of cast thin sections,the control factors of the Denglouku Formation Quantou Formation reservoir are analyzed,and the following understanding can be obtained:(1)The reservoir properties of the Denglouku-Quantou Formation are positively correlated with quartz content,negatively correlated with rock debris and interstitial material content,and poorly correlated with feldspar content.(2)DengloukuQuantou Formation reservoirs mainly improve reservoir performance through dissolution;Mechanical compaction,pressure solution,and cementation will destroy the porosity and permeability of the reservoir.(3)The clastic rock reservoirs in the Denglouku-Quantou Formation are mainly braided and meandering river channel sand bodies,The braided river channel core beach microfacies in the upper part of the second member of Denglouku Formation to the lower part of the third member of Denglouku Formation and the meandering river channel bed retention sedimentation in the middle and lower part of the first member of Quantou Formation develop residual intergranular pores and secondary pores with good physical properties,which are favorable facies zones for reservoir development.更多还原