独山子背斜沙湾组油源对比分析及油气成藏模式探讨

独山子背斜位于准噶尔盆地北天山山前冲断带四棵树凹陷。四棵树凹陷不同程度地发育二叠系、侏罗系、白垩系和古近系等多套烃源岩,具多个生烃期及多期成藏特征。不同时期生成的原油相互混合,导致成藏油源判识困难。据碳同位素、正构烷烃、生物标志化合物等地球化学分析资料,对独山子背斜沙湾组原油进行油源对比研究。结果表明:独山子背斜沙湾组原油与古近系安集海河组烃源岩具很好的亲缘关系。来自渐—始新统安集海河组油气通过独山子断裂向上运移至沙湾组,被上部新近系塔西河组巨厚泥岩封盖而聚集成藏。     

准噶尔盆地四棵树凹陷烃源岩地球化学特征及其对车排子凸起油气聚集的贡献

准噶尔盆地西南缘四棵树凹陷主要分布侏罗系、白垩系和古近系3套潜在烃源岩,其中侏罗系八道湾组烃源岩有机质丰度较高,有机质类型以Ⅲ型为主,部分为Ⅱ2型,生烃潜力较高;三工河组烃源岩有机质丰度、类型明显偏差,生烃潜力较低;西山窑组泥岩有机质丰度较高,但由于受西山窑组沉积末期构造抬升导致地层剥蚀的影响,烃源岩厚度较小,总体上生烃条件较差;白垩系烃源岩在四棵树凹陷最大厚度可达300 m,处于低熟阶段,生烃潜力较小;古近系烃源岩有机质丰度较高、类型好,但成熟度偏低,生烃条件较差。侏罗系八道湾组烃源岩处于主要生油阶段;白垩系烃源岩已达到生烃门限,处于低熟—中等成熟阶段;古近系烃源岩成熟度偏低,目前仍处于未熟到低熟阶段。油源对比表明,四棵树凹陷北部斜坡及车排子凸起带原油主要来源于四棵树凹陷及沙湾凹陷侏罗系烃源灶,后期受到白垩系低熟油源灶的侵染,古近系烃源岩的油源贡献有限。     

车排子凸起井下高GR砂岩分布特征与铀矿勘探前景

车排子凸起位于准噶尔盆地西缘,为一海西期继承性古隆起,总体呈向东南倾斜的斜坡.石炭系火山岩上超覆于侏罗系、下白垩统吐谷鲁群、古近系安集海河组、新近系沙湾组、塔西河组、独山子组和第四系.至少发育2个大的区域不整合面,一个为石炭系顶面与中新生界间的不整合面,一个为白垩系顶面与新近系间的不整合面.笔者通过对该区石油钻井测井、录井资料分析发现,在石炭系、白垩系和新近系发育多层高GR（自然伽马）异常段,且主要分布在新近系沙湾组和塔西河组砂岩、砂砾岩和下白垩统吐谷鲁群砂岩及石炭系顶面风化堆积物中,具有高异常GR（自然伽马）和GRSL（总伽马）值、低KTH（去铀伽马）值特征,预示该区具良好的铀资源勘探前景.     

准噶尔盆地南缘四棵树凹陷及周缘油源关系研究

准噶盆地南缘四棵树凹陷地质条件复杂,勘探历程曲折,现为新疆油田第5阶段的重要战略接替区块。为了查清该凹陷油气成藏规律、确定未来勘探方向,本文应用有机岩石学、有机地球化学和同位素地球化学的原理和方法,对区内烃源岩的分布及地化特征、油气地化特征、油源特征及与周缘的油源关系进行了系统的研究。结果表明,下侏罗统三工河组与古近系安集海河组暗色泥岩为区内主力烃源岩;目前所见原油可分为三类,分别主要来源于两套主力烃源岩及二者混源,且侏罗系烃源岩生成的油气主要在古近系下部及以下地层聚集;该凹陷与周缘构造不具油源关系,应为凹陷级独立含油气系统。     

准噶尔盆地西北缘车排子凸起原油类型与油源

准噶尔盆地西北缘南部红车断裂带- 车排子凸起油气藏众多,原油物理化学性质和地球化学特征十分复杂,原油类型及其来源长期存在很大争议。本文在准噶尔盆地不同时代烃源岩生成原油典型地球化学特征与主要油源判识指标归纳总结的基础上,对红车断裂带- 车排子凸起原油地球化学特征和来源进行系统分析研究,将该区域原油分为五类,其中三类原油分别来源于二叠系湖相烃源岩、中—下侏罗统煤系烃源岩、古近系安集海河组湖相烃源岩,另外两类为混合原油,分别为来源于二叠系湖相烃源岩的生物降解稠油与中—下侏罗统煤系烃源岩生成的正常原油和古近系湖相烃源岩生成的正常原油的混合原油。红车断裂带石炭系—白垩系油藏原油主要来源于沙湾凹陷二叠系湖相烃源岩,车排子凸起东北部春风油田稠油来源于沙湾凹陷二叠系湖相烃源岩;车排子凸起东侧- 红车断裂带西侧新近系沙湾组油藏轻质原油来源于四棵树凹陷古近系湖相烃源岩;车排子凸起中部春光油田白垩系—古近系油藏稠油为二叠系来源稠油和侏罗系正常原油的混合原油,新近系沙湾组油藏稠油为二叠系来源稠油与新近系正常原油的混合原油;车排子凸起西部石炭系—古近系油藏轻质原油来源于四棵树凹陷中—下侏罗统煤系烃源岩,而新近系沙湾组油藏轻质原油来源于四棵树凹陷古近系湖相烃源岩。本文对准噶尔盆地西北缘南部地区油气藏成藏研究及区域油气勘探决策具有重要参考作用。     

准噶尔盆地南缘安集海河组烃源特征及成藏条件

通过应用地球化学分析、油源对比及盆地模拟等手段对准噶尔盆地南缘古近系安集海河组烃源岩进行了评价,认为该区为一套以Ⅱ型干酪根为主的中等丰度烃源岩,生烃的门限深度为3500 m,时间是8 Ma±。第三系的油藏与其具有密切关系,同时侏罗系煤系烃源岩也为第三系的生油做出了贡献。造成该套烃源岩评价较低的主要原因是地层内发育的异常高压降低了烃源岩的成熟度指标,但由于长期构造挤压的"力化学"作用还是促进了烃源岩的生排烃,并且位于向斜部位的烃源岩其埋深大多超过生烃门限深度,也可以生成大量油气,因此认为还是有效的烃源岩。其生排烃时间与该区构造大规模形成时间相匹配,在背斜形成过程中,伴随着异常压力的产生、平衡,最终促进了油气在背斜核部聚集成藏。有利的勘探区是南缘中段的第二排、第三排构造古近系的安集海河组以及新近系的沙湾组储层。     

准西车排子地区中新生界层序格架及砂体预测模式

前陆盆地由于其独特的构造和沉积背景形成不同的层序地层格架样式.以准噶尔盆地车排子地区为例,详细分析了造山带前缘隆起斜坡带层序样式.在准西车排子地区中新生界主要目的层段(下白垩统吐谷鲁群、古近系安集海河组、新近系沙湾组和塔西河组)充填沉积中识别出5条主要等时界面,据界面的性质和级别划分出一级层序2个,二级层序组3个,三级层序4个.受前陆盆地造山带前缘隆起斜坡带独特的沉积背景及多幕逆冲构造活动作用过程的控制,准西车排子地区中新界各三级层序具有二元沉积结构特征,仅发育低位和湖扩体系域.逆冲挤压期发育低位粗碎屑沉积,应力松弛期发育湖扩细碎屑沉积.低位下切谷、大型扇三角洲和湖扩滩坝砂是准西车排子地区的有利储集砂体及勘探目标.      

准噶尔盆地南缘安集海河组烃源特征及成藏条件

通过应用地球化学分析、油源对比及盆地模拟等手段对准噶尔盆地南缘古近系安集海河组烃源岩进行了评价,认为该区为一套以Ⅱ型干酪根为主的中等丰度烃源岩,生烃的门限深度为3〖CS％0,0,0,0〗 500 m,时间是8 Ma±。第三系的油藏与其具有密切关系,同时侏罗系煤系烃源岩也为第三系的生油做出了贡献。造成该套烃源岩评价较低的主要原因是地层内发育的异常高压降低了烃源岩的成熟度指标,但由于长期构造挤压的“力化学”作用还是促进了烃源岩的生排烃,并且位于向斜部位的烃源岩其埋深大多超过生烃门限深度,也可以生成大量油气,因此认为还是有效的烃源岩。其生排烃时间与该区构造大规模形成时间相匹配,在背斜形成过程中,伴随着异常压力的产生、平衡,最终促进了油气在背斜核部聚集成藏。有利的勘探区是南缘中段的第二排、第三排构造古近系的安集海河组以及新近系的沙湾组储层。     

准噶尔盆地南缘白垩系原油成藏特征

准噶尔盆地南缘地区的油气勘探与石油地质研究长期以来以二叠系和侏罗系含油气系统为主。本文在前人工作基础之上,从烃源岩、油源和油气运聚三方面,首次比较系统地剖析了本区的白垩系原油成藏特征。研究结果表明,白垩系烃源岩的生烃和油气聚集中心位于玛纳斯—呼图壁一带,烃源层系最大厚度可超过250 m,有机质类型以Ⅰ—Ⅱ1型为主,在古近纪末进入成熟排烃阶段,是本区不可忽视的一套重要烃源岩。白垩系原油纵向上主要聚集于古近系安集海河组到白垩系吐谷鲁群储层流体系统,可能存在三期油气运聚,第一期在早更新世晚期,以流体系统内部的白垩系原油运聚成藏为主,第二期是在中更新世晚期至晚更新世早期,白垩系原油,以及成熟度相对较低的古近系原油在此流体系统内部发生混合,第三期在晚更新世末期,以油气(并以侏罗系天然气为主)在垂向上沿断层的调整为特征,最终形成了复杂的多源、多层系油气分布态势。综合认为,需要充分重视白垩系原油在本区的勘探和研究。     

准噶尔盆地腹部车莫古隆起南北两侧含油构造油源及烃源灶转移

车莫古隆起位于准噶尔盆地腹部,在其主要发育期,古隆起南北两侧分别存在昌吉和盆1井西两个沉积凹陷,分布有白垩系、侏罗系和古近系等多套烃源岩。目前已在古隆起所在区域的南部发现了永进油田,在其北部发现了征沙村、沙窝地和莫西庄等油田或含油气构造,油层主要分布在侏罗系和白垩系,其中沙窝地、莫西庄和征沙村3个构造主要目的层为侏罗系三工河组,永进构造目的层为侏罗系头屯河组、三工河组、西山窑组和白垩系吐谷鲁群。为了揭示研究区原油的油源特征以及车莫古隆起对油源及成藏过程的影响,比较系统地分析了研究区原油及相关层位烃源岩的地球化学特征,进行了油源对比;根据流体包裹体和烃源岩演化等方面的研究成果,分析了油气成藏特征,并结合构造地质资料讨论了车莫古隆起形成与演化对研究区油气源特征、油气藏形成过程及分布的控制作用。结果表明:研究区不同构造或同一构造不同层位的原油地球化学特征均存在一定的差异,根据饱和烃和芳烃生物标志物组成特征将研究区原油划分为五类,这五类原油在区域分布特征、油气来源及烃源灶位置等方面均存在差别。车莫古隆起的形成与演化、生油凹陷的展布特征及主要烃源岩的成熟演化历史共同决定了研究区不同油田或含油气构造烃源灶位置的分布及其转...     

准南前陆冲断带烃源岩地质地球化学特征

准南前陆冲断带具有丰富的油气资源,但与资源评价关系密切的烃源岩研究不足。本文应用地球化学分析方法,对准南前陆冲断带的上二叠统、中下侏罗统、下白垩统和古近系等4套烃源岩的有机质丰度、有机质类型、热演化程度进行了系统分析和综合对比。结果表明,上二叠统烃源岩和中下侏罗统烃源岩为良好的烃源岩,古近系安集海河组其次,下白垩统烃源岩相对较差。     

Characteristics and evaluation of Mesozoic source rocks in the southeastern East China Sea continental shelf

Source rocks are the material basis of oil and gas generation and determine the potential resources of exploration blocks and have important research value. This paper studies the lithology, thickness, and geochemistry of Mesozoic source rocks in the southeastern East China Sea continental shelf. The results show that the Mesozoic source rocks are mainly dark mudstone and coal-bearing strata. The total thickness of Lower–Middle Jurassic source rocks ranges from 100 m to 700 m, and that of Lower Cretaceous source rocks ranges from 50 m to 350 m. The overall thickness of Mesozoic source rocks is distributed in the NE direction and their thickness center is located in the Jilong Depression. The Lower–Middle Jurassic source rocks are mainly developed shallow marine dark mudstone and transitional coal measure strata. Those of the Lower Cretaceous are mainly mudstone of a fan delta front. Lower–Middle Jurassic and Lower Cretaceous hydrocarbon source rocks are dominated by type III kerogen, with Lower–Middle Jurassic hydrocarbon source rocks having high organic matter abundance and being medium–good hydrocarbon source rocks, while Lower Cretaceous hydrocarbon source rocks have relatively poor quality. From northwest to southeast, the vitrinite reflectance Ro of Mesozoic source rocks increases gradually. Source rocks in the study area are divided into three types. The first hydrocarbon-generating area is mainly located in the southeastern region of the study area, and the Jilong Depression is the hydrocarbon-generating center. The results of this study can provide a basis for exploration of Mesozoic oil and gas resources in the southeastern East China Sea continental shelf.© 2019 China Geology Editorial Office.     

叶城凹陷柯东1井凝析油及柯克亚原油的油源分析

塔里木盆地叶城凹陷拥有多套烃源岩层,主要为石炭系卡拉乌依组、二叠系棋盘组与普司格组2-3段、侏罗系煤系地层与叶尔羌群等,这些烃源岩都可能是柯东1井凝析油和柯克亚第三系原油的母源。在这一地区,油源一直是一个很具争议性的问题。选取了叶城凹陷克里阳构造带柯东1井2个凝析油、柯克亚构造带7个第三系原油,以及叶城凹陷各烃源岩层具有代表性的17个烃源岩样品,对其生物标志物及正构烷烃单体烃稳定碳同位素比值等参数进行了详细的测试分析。油油对比揭示,柯东1井原油与柯克亚第三系原油在正构烷烃组分、成熟度与稳定碳同位素组成等特征上具有明显的相似性,显示同源的特征。油源对比显示,普司格组2-3段下部是这些原油的源岩。这一烃源岩层具有与柯克亚地区原油一致的成熟度和相似的特征性生物标志物,即高含量的重排藿烷、Ts和 C27-C29重排甾烷等,而其他烃源岩层则不具备这类特征。较高成熟阶段形成的原油,解释了普司格组2-3段烃源岩可溶有机质与柯东1井等原油在单体烃稳定碳同位素比值上具有2‰~3‰的差别。     

1D PetroMod software modeling of the Basrah oil fields, Southern Iraq

1D (Petromod) hydrocarbon charge modeling and source rock characterization of the Lower Cretaceous and Upper Jurassic underlying the prolific Cretaceous and Tertiary reservoirs in the Basra oilfields in southern Iraq. The study is based on well data of the Majnoon, West Qurna, Nahr Umr, Zubair, and Rumaila oil fields. Burial histories indicate complete maturation of Upper Jurassic source rocks during the Late Cretaceous to Paleogene followed by very recent (Neogene) maturation of the Low/Mid Cretaceous succession from early to mid-oil window conditions, consistent with the regional Iraq study of Pitman et al. (Geo Arab 9(4):41–72, 2004). These two main phases of hydrocarbon generation are synchronous with the main tectonic events and trap formation associated with Late Cretaceous closure of the neo-Tethys; the onset of continent–continent collision associated with the Zagros orogeny and Neogene opening of the Gulf of Suez/Red Sea. Palynofacies of the Lower Cretaceous Sulaiy and Lower Yamama Formations and of the Upper Jurassic Najmah/Naokelekan confirm their source rock potential, supported by pyrolysis data. To what extent the Upper Jurassic source rocks contributed to charge of the overlying Cretaceous reservoirs remains uncertain because of the Upper Jurassic Gotnia evaporite seal in between. The younger Cretaceous rocks do not contain source rocks nor were they buried deep enough for significant hydrocarbon generation.     

Petroleum geology and exploration direction of gas province in deepwater area of North Carnarvon Basin,Australia

North Carnarvon Basin is a gas province with minor oily sweet spots in deepwater area with water depth more than 500 m, which is one of the hot spots of global petroleum exploration for its series of giant hydrocarbon discoveries in recent years. However, the degree of oil and gas exploration in deepwater area is still low, and the conditions for oil and gas accumulation are not clear. Based on the current exploration situation and latest database of fields, applying multidisciplinary analysis of hydrocarbon geology, hydrocarbon accumulation elements and its exploration direction of North Carnarvon Basin in deepwater area are analyzed. The results show that there are three sets of main source rocks in deepwater area of North Carnarvon Basin, which are Triassic marine shale in Locker Formation and delta coal-bearing mudstone with thin carbonaceous mudstone in Mungaroo Formation, Lower –Middle Jurassic paralic carbargilite and coal measure strata in Athol Formation and Murat Formation, Cretaceous delta mudstone in Barrow Group and marine shale in Muderong Formation. Most source rock samples show gas-prone capability. The coarse sandstone of delta facies in Middle–Upper Triassic Mungaroo Formation is the most important reservoir in deepwater area, Lower Cretaceous Barrow Group deep-water gravity flow or underwater fan turbidite sandstone is the secondly main reservoir. Lower Cretaceous marine shale in Muderong Formation is most important regional caprock. Triassic mudstone in Mungaroo Formation is an important interlayer caprock in deepwater area. There are two main reservoir accumulation assemblages in deepwater area, one is Triassic structural-unconformity plane reservoir accumulation assemblage of Locker Formation to Mungaroo Formation, and the other is Lower–Middle Jurassic Athol Formation and Murat Formation–Lower Cretaceous stratigraphic lithology-structural reservoir accumulation assemblage of Barrow Group to Muderong Formation. There are three main control factors of hydrocarbon Accumulation: One is coupling of source and seal control hydrocarbon distribution area, the second is multi-stage large wave dominated deltas dominate accumulation zone, the third is direction of hydrocarbon migration and accumulation in hydrocarbon-rich generation depression was controlled by overpressure. The south of Exmouth platform in deepwater area is adjacent to hydrocarbon rich depression zone, reservoir assemblage is characterized by “near source rocks, excellent reservoir facies, high position and excellent caprocks ”, which is the main battlefield of deepwater oil and gas exploration in North Carnarvon Basin at present. There are a lot of fault block traps in the northern structural belt of Exmouth platform, and the favorable sedimentary facies belt at the far end of delta plain in Mungaroo Formation is widely distributed, which is the next favorable exploration zone. The Lower Cretaceous, which is located at the concave edge uplift adjacent to the investigator depression and the Exmouth platform, also has a certain exploration prospect in northwest of deepwater area.     

吐鲁番-哈密盆地陆源碎屑沉积环境及物源分析

吐鲁番-哈密盆地从晚二叠世到晚第三纪经历了复杂的,多旋回的沉积构造演化历史,造成主要地层间均以不整合为界。盆地内沉积相类型丰富,沉积环境随时间的推移而发生改变。在晚石炭世,盆地北部为浅海环境;到晚二叠世,沉积环境由海相转变为陆相,并在上二叠统下部形成大量冲积相或河流相粗碎屑沉积;在三叠纪,沉积物主要形成于冲积相或河流-湖泊环境中,古气候则由干旱转为温暖湿润。早、中侏罗世,沉积环境以湖泊-沼泽相为主;到晚侏罗世,则以辫状河流相为主及干旱气候为特征。在白垩纪,盆地的沉积范围大为缩小,以湖泊环境为主;第三纪,沉积范围则扩大到整个盆地,沉积相以辫状河流及冲积相为特征,沉积气候干旱,局部地区接受了盐类沉积。古流向分析显示,吐-哈盆地具有复杂的沉积搬运体系。在盆地南侧,沉积物搬运方向总是由南向北,表明觉罗塔格山是盆地的主要物源区;而在盆地北侧,博格达山自晚侏罗世开始隆起,构成盆地的另一新的物源区,沉积物搬运方向由北向南。在白垩及第三纪,博格达山成为盆地的主要物源区。     

新疆萨热克砂砾岩型铜矿床富烃类还原性盆地流体特征

新疆萨热克大型砂砾岩型铜矿床含矿地层为上侏罗统库孜贡苏组,与下伏下-中侏罗统煤矿形成"同盆共存"现象。在萨热克铜矿床的铜矿体内,构造裂隙中含较多沥青(有机碳含量达0.11%~2.55%),并与辉铜矿等铜硫化物共生。铜矿石中次生石英、方解石和白云石等胶结矿物包裹体含烃盐水类、含烃盐水-液烃共生类、含烃盐水-气烃共生类、轻质油类等四类富烃类盆地流体的包裹体。研究认为铜矿石中的有机质主要来源于下伏烃源岩煤层,当盆地深部富含有机质的还原性流体沿NE向构造裂隙上侵到渗透率较高的上侏罗统库孜贡苏组上段(J3kz2)砂砾岩层时,该层上部的下白垩统克孜勒苏群下段(K1kz1)褐红色粉砂质泥岩,与下部的上侏罗统库孜贡苏组下段(J3kz1)灰绿色粉砂质泥岩形成封闭的隔水层,还原性流体沿砂砾岩层发生水平渗滤扩散,与盆地中封存的地层水淋滤含铜赤铁矿质砾岩类后形成的含铜氧化相流体混合时,造成了辉铜矿的大量沉淀和碳酸盐等矿物的结晶析出,并沿砾石间隙充填分布。     

合肥盆地中生代地层时代与源区的碎屑锆石证据

合肥盆地位于大别造山带北侧、郯庐断裂带西侧,其发育过程与这两大构造带演化密切相关。本次工作对合肥盆地南部与东部出露的中生代砂岩与火山岩进行了锆石年代学研究,从而限定了各组地层的沉积时代,确定了火山岩喷发时间,指示了沉积物的源区。这些年代学数据表明,合肥盆地南部的中生代碎屑岩自下而上分别为下侏罗统防虎山组、中侏罗统圆筒山组或三尖铺组、下白垩统凤凰台组与周公山组(或黑石渡组)与上白垩统戚家桥组,其间缺失上侏罗统。盆地东部白垩系自下而上为下白垩统朱巷组与响导铺组和上白垩统张桥组。该盆地出露的毛坦厂组或白大畈组火山岩喷发时代皆为早白垩世(130～120 Ma)。盆地南部的下——中侏罗统及白垩系源区皆为大别造山带,分别对应该造山带的后造山隆升与造山后伸展隆升。而盆地东部白垩系的源区始终为东侧的张八岭隆起带,后者属于郯庐断裂带伸展活动中的上升盘。