洛阳-伊川盆地构造演化特征及含油气远景评价

洛阳-伊川盆地是南阳油田近期油气勘探的新地区和新领域之一,主要勘探目的层系为中生界三叠系.研究认为,该区三叠系埋藏较浅,残存厚度大,分布面积广,其中暗色泥岩发育,具有一定的生油潜力.并且盆地的构造演化对地层的保存、构造发育、油气分布以及油气藏的形成有明显的控制作用.因此明确了该区下步油气勘探的方向和目标.     

西藏羌塘盆地中生代构造岩相演化及油气远景

西藏羌塘盆地中生代构造岩相组合分带及特征明显 ,可以反映羌塘盆地的演化史。早中三叠世北羌塘构造岩相组合表现为前陆盆地沉积 ,而南羌塘盆地为剥蚀环境 ;至晚三叠世除中央隆起剥蚀外 ,北羌塘仍为前陆盆地沉积 ,而此时南羌塘坳陷演化成陆缘海沉积。早侏罗世早期盆地开始坳陷 ,造成相对较窄沉积相的构造岩相组合特点 ,初步形成“两坳一隆”的构造格局 ;中侏罗世南北羌塘坳陷继续下降 ,“两坳一隆”的构造格局更加明显 ;晚侏罗世羌塘盆地发育到晚期 ,并萎缩、封闭成型。从构造岩相组合特征看 ,中侏罗统北羌塘坳陷龙尾湖—雀莫错凹陷区与南羌塘坳陷蒂让碧错凹陷区都是有利于储、聚油气的远景区。     

新西兰Great South盆地构造演化对油气的控制作用

为研究Great South盆地的油气分布规律,分析了该盆地构造演化与油气成藏之间的关系。结果显示:该盆地划分为前裂谷期、裂谷期、漂移期与新的板块边界形成期4个构造演化阶段。该盆地构造演化对油气藏的形成起到了重要的控制作用,主力烃源岩的形成与分布受当时盆地构造位置与控凹断层的控制,主要分布于早期断陷湖盆的控凹断层下降盘,而断陷湖盆白垩系发育的储层是盆地最主要的储层。同时,构造演化也控制了与断垒、古基底凸起相关的圈闭发育及油气的运聚成藏,圈闭多具有继承性,可分为西部斜坡、中央凹陷与东部凸起三个构造带。垂向上,油气主要在断层比较发育的白垩系地层聚集成藏。平面上,油气以近源成藏为主,中央凹陷圈闭带为最有利的油气聚集带。     

十万大山地区构造演化和含油气评价

十万大山盆地地构造演化过程为：在华夏被动大陆边缘发育的弧间洋盆基础上,经东吴、印支和燕山期碰撞造山运动,形成晚古生代－中生代前陆盆地,又经过短暂的弧后陆内裂谷阶段,形成了喜马拉雅期右列张扭性盆地。共原型盆地经历了镀嵌、交错、披盖、再镶、交错、披盖、再镶嵌等四个叠置过程。其构造发展由正反转向负反转变化,以多次构造运动叠加后保留的基底部分卷入的冲断－推覆构造形成占主导,并发育典型的楔状前陆盆地、斜坡带     

西北非构造演化与油气成藏组合特征

西北非油气资源丰富,是我国石油公司海外油气勘探的重要区块。受泛非、加里东、海西、阿尔卑斯运动的影响,西北非构造演化经历了泛非期基底形成、古生代稳定陆块演化、中生代裂陷、新生代反转隆升的复杂过程,发育三叠、伊利兹、锡尔特等多个超大型含油气盆地。主要有两套成藏组合:撒哈拉地台为主的古生代成藏组合、北部大陆边缘为主的中新生代成藏组合。     

三塘湖盆地构造演化与油气聚集

三塘湖盆地处于西伯利亚板块南缘,早石炭世晚期,盆地褶皱基底形成; 晚石炭世早期,总体处于碰撞期后伸展构造环境; 晚石炭世晚期,洋壳消亡,断陷收缩与整体抬升,形成剥蚀不整合。早二叠世,进入陆内前陆盆地演化阶段; 中二叠世,盆地进入推覆体前缘前陆盆地发育期; 晚二叠世,构造褶皱回返,前陆盆地消失; 三叠纪晚期至侏罗纪中期,进入统一坳陷期; 中晚侏罗世—早白垩世,盆地坳隆格局基本定型。平面上构造分带清晰：东北逆冲推覆隆起带、中央坳陷带和西南逆冲推覆带; 发育基底卷入型和盖层滑脱型两大类构造样式。盆地主体条湖—马朗凹陷发育上石炭统、中二叠统、侏罗系水西沟群3套有效烃源岩,且多表现为两期生烃、两期成藏; 形成相对独立3套成藏组合; 呈现“晚期近源自生自储成藏”特点; 多围绕各自含油气系统形成各具代表性3种成藏模式： 1）北东向凹中隆起及古隆起油气聚集成藏; 2）北西向冲断带油气聚集成藏; 3）不整合油气聚集成藏。三塘湖盆地油气资源量达7×108～9×108 t（油气当量）,盆地总体勘探程度较低,主要勘探方向有：围绕马朗—条湖继承性凹陷浅层侏罗系地层—岩性油气藏领域、北缘凸起带石炭系火山岩风化壳与内幕油气藏领域、南缘构造推覆带断层遮挡二叠系白云岩与石炭系火山岩油气藏领域。     

新疆北部石炭纪盆地构造演化与油气成藏

根据油田近期勘探资料及前人研究成果,在新疆北部地区石炭系沉积前构造背景分析的基础上,对石炭纪盆地沉积构造演化进行了研究,该区具有微地块、多拼合、弱固结、构造活跃等盆地形成背景,经历了早石炭世、晚石炭世两期盆地的形成、发展与消亡过程,二叠纪—新生代是石炭纪盆地的改造演化期。石炭纪火山岩广泛发育,结合前人研究成果,通过盆地覆盖区钻井样品的地球化学综合分析,认为该区石炭纪整体处于拉张的构造环境。通过石炭系的沉积与分布特征,认为早石炭世和晚石炭世盆地演化受早期构造的控制,具有继承性、方向性和新生性的特点。石炭纪末期的构造事件基本结束了该区的海相盆地的演化,进入陆内盆地演化期,石炭纪盆地遭受埋藏或隆升改造,经历了海西晚期、印支期、燕山期以及喜马拉雅期的构造改造作用,存在埋藏、隆升剥蚀、岩浆热改造、断裂、褶皱变形等多类型的改造作用,各地区的改造特点存在差异。油气勘探成果证实,石炭系是新疆北部重要的勘探层系,在早石炭世和晚石炭世盆地演化期都形成了优质的烃源岩,火山岩系既是油气的储集层,也是重要的盖层,盆地的多期改造事件不仅有利于火山岩储层物性改善,也形成了石炭系有利的油气圈闭,目前已经发现了石炭系自生自储和上生下储的油气藏类型,油气的分布特征显示了石炭系自生自储油气藏具有近源分布特征。因此,加强盆地形成演化研究,圈定沉降中心和烃源岩的分布对于油气勘探具有重要意义。     

中亚及邻区沉积盆地形成演化与含油气远景

中亚及邻区位于亚洲大陆古老地块之间的巨型构造活动带,在这个地区发育众多类型的沉积盆地。在形成演化机制上,发育有裂谷盆地、前陆盆地、克拉通盆地等单型盆地和这些单型盆地组成的叠合盆地。在形成时代上,发育前寒武纪沉积盆地、古生代沉积盆地和中新生代沉积盆地。这些不同时代不同类型的沉积盆地发育在不同的大地构造背景上,基底性质、成盆机制、沉降特征、构造特征及含油气性等具有较大的差别。沉积盆地类型和形成时代与油气分布规律和含油气远景密切相关,拉张裂谷型沉积盆地油气资源潜力较大,克拉通裂谷-坳陷型盆地具有一定的油气资源潜力。     

宁蒗盆地油气勘探远景分析

宁蒗盆地为一个中亲生代断陷盆地，面积约３３００ｋｍ＾２。由于其面积有限，至今尚未开展过任何石油勘探工作，但其周缘的泥盆系地层油苗、沥青众多却被各方所瞩目。主要从１／２０万区测资料及楚雄盆地石油地质等资料入手，通过构造－沉积演化研究、勘探有利条件分析，结合与四川盆地、楚雄盆地对比分析，认为该盆地是一个含油气远景极好的盆地，是油气兼探的有利地区。     

“源热共控”新西兰南大盆地生烃潜力

新西兰南大盆地(Great South Basin)经历了裂谷期、拗陷期及大陆边缘期三个构造演化阶段,并发育了三套烃源岩,分别为裂谷期的上白垩统Hoiho群煤系烃源岩(为主要烃源岩)、拗陷期的上白垩统—古新统Taratu组海岸平原相煤系烃源岩和Wickliffe组海相泥岩烃源岩。源热耦合分析发现,裂谷期Hoiho群湖沼相煤系烃源岩埋藏深,有机质丰度高,热演化程度高,有效烃源岩体积大,生气潜力也大;Taratu组海岸平原相煤系烃源岩也是有效烃源岩。认为中央坳陷烃源岩发育,油气潜力大。     

四川盆地震旦纪-早寒武世构造-沉积演化过程

前人对四川盆地震旦纪-早寒武世构造-沉积演化的认识存在较大分歧.利用最新的地震、钻井及露头资料,系统论述了四川盆地震旦纪-早寒武世构造-沉积演化特征.四川盆地在陡山沱组沉积前呈现隆坳相间地貌格局,汉南古陆构造高点从陡山沱期到早寒武世持续向北东方向迁移;开江-宣汉古隆起灯一、灯二段沉积期为主要发育时期,古隆起核部出露水面,灯三、灯四段沉积期古隆起规模减小,转为水下隆起,到早寒武世与川中古隆起合并.通过连井剖面、典型井元素测井、野外露头特征综合分析认为德阳-安岳古裂陷槽内发育灯三、灯四段深水沉积.在此基础上总结古裂陷发育模式:古裂陷具有明显的多期发育特征,东侧台地边缘不断向北东方向迁移,灯二段沉积期台缘位于双探地区,灯四段沉积期台缘位于元坝西地区;同时古裂陷具有"北早南晚、先断陷后坳陷"的发育特征,灯影组沉积期在川中-川北发育,具有断陷发育特征,早寒武世裂陷槽转为坳陷发育特征,川南地区开始大规模发育,川中-川北地区持续向北东方向迁移,川北元坝-仁和场-马路背地区转化为深水沉积,发育厚层筇竹寺组烃源岩层系,至早寒武世晚期,古裂陷消亡、被填平补齐.      

试论渤海湾盆地油气富集规律与勘探

渤海湾盆地至今已发现油气田226个,探明油气地质储量114.4×108t,油气资源量为285×108t。盆地内的油气富集规律与盆地东界的郯庐深大断裂带紧密相关。靠近郯庐断裂带的东部坳陷区,其探明油气地质储量和油气资源量是远离断裂带的西部坳陷区的3.6倍和3.3倍;根据探明油气地质储量进行划分,东部坳陷区以大油气田为主,而西部坳陷区则以中、小油气田为主;东部坳陷区发现的浅层油气藏、稠油油藏、火成岩油藏及非烃CO2气藏比西部坳陷区多得多,但两者的潜山油气藏的数量和储量却很相近。研究表明,郯庐深大断裂不仅控制了盆地的发育和形成,而且还控制了油气的生成、运移和聚集。渤海湾盆地既是中国大盆地中油气富集程度最高的盆地,也是具有独特油气富集规律的盆地。尽管该盆地油气探明率已达40.1%,但仍有170.7×108t的油气剩余资源量可供再勘探,勘探潜力仍十分巨大。     

The characteristics, classification and origin of late Pleistocene fan deposits in the Cass Basin, Canterbury, New Zealand

The deposits comprising 'valley-side fans' in a small intermontane basin of the Southern Alps are classified as debris flow, water-laid, intermediate and mixed deposits on the basis of particle size and clast orientation characteristics. Five varieties of debris flow deposit are identified including unimodal and bimodal 'mudflow gravels'. The fans comprise mainly unimodal mudflow gravels which although apparently similar to the mudflow gravels described from montane and periglacial environments are coarser, have less silt and clay and are better sorted than the mudflow deposits described from semiarid alluvial fans. Additions of airborne silt and fine sand to the fan catchments during later stages of fan building gave rise to bimodal debris flow deposits which appear similar to gravels described from cold-climate fans in Tasmania and classed as water-laid deposits. Braided stream deposits were added to the depositional sequence towards the closing stages of fan building indicating that the fan had become 'wetter'. In many places, however, the youngest Pleistocene fan deposits are silt-rich mixtons reflecting a peak in loess deposition.     

Structural Evolution and Hydrocarbon Potential of the Upper Paleozoic Northern Ordos Basin, North China

The hydrocarbon potential of the Hangjinqi area in the northern Ordos Basin is not well known, compared to the other areas of the basin, despite its substantial petroleum system.Restoration of a depth-converted seismic profile across the Hangjinqi Fault Zone(HFZ) in the eastern Hangjinqi area shows one compression that created anticlinal structures in the Late Triassic, and two extensions in ~Middle Jurassic and Late Early Cretaceous, which were interrupted by inversions in the Late Jurassic–Early Early Cretaceous and Late Cretaceous, respectively.Hydrocarbon generation at the well locations in the Central Ordos Basin(COB) began in the Late Triassic.Basin modeling of Well Zhao-4 suggests that hydrocarbon generation from the Late Carboniferous–Early Permian coal measures of the northern Shanbei Slope peaked in the Early Cretaceous, predating the inversion in the Late Cretaceous.Most source rocks in the Shanbei Slope passed the main gas-migration phase except for the Hangjinqi area source rocks(Well Jin-48).Hydrocarbons generated from the COB are likely to have migrated northward toward the anticlinal structures and traps along the HFZ because the basin-fill strata are dipping south.Faulting that continued during the extensional phase(Late Early Cretaceous) of the Hangjinqi area probably acted as conduits for the migration of hydrocarbons.Thus, the anticlinal structures and associated traps to the north of the HFZ might have trapped hydrocarbons that were charged from the Late Carboniferous–Early Permian coal measures in the COB since the Middle Jurassic.     

东非鲁伍马盆地深水区构造-沉积演化过程及油气地质特征

利用深水区的二维、三维地震资料开展构造-沉积演化研究,鲁伍马盆地二叠纪—早侏罗世为冈瓦纳陆内—陆间裂谷活动期,发育河流—湖泊沉积;中侏罗世—早白垩世为马达加斯加漂移期,位于剪切型大陆边缘,发育海陆过渡相沉积;晚白垩世—渐新世为被动大陆边缘期,深水沉积广泛发育,重力流沉积延伸至戴维隆起带;中新世—第四纪为东非裂谷海域分支活动期,陆坡和凯瑞巴斯地堑发育深水重力流沉积。盆地垂向上形成"断—坳—断"结构,二叠纪—早侏罗世及中新世—现今发育两期明显的裂谷活动。马达加斯加漂移期的海相泥岩为深水区的主力烃源岩,古近纪的陆坡深水浊积砂体为主要储层。东非裂谷海域分支的断层活动沟通了下伏烃源岩,晚期断层不发育的西部陆坡成为主要的油气聚集区。     

The Acheron rock avalanche, Canterbury, New Zealand—morphology and dynamics

The 1100-year-old Acheron rock avalanche deposit lies in an active tectonic setting in Canterbury, New Zealand, and has a volume of ten million cubic metres and a runout distance 3.5 km. The deposit comprises intensely fragmented greywacke rock, and the processes of intense rock fragmentation during runout are postulated to have generated an isotropic dispersive stress. Dynamic simulation shows that the runout can be explained as a flow of dry granular material with a normal coefficient of friction, if the presence of an isotropic dispersive stress within the moving rock debris throughout the runout is assumed. The dispersive stress distribution required to model the rock avalanche runout and match velocities calculated from run-up traces is closely similar to that used to simulate the runout of the much larger Falling Mountain rock avalanche in a similar lithologic and tectonic setting. Both events thus behaved in a fundamentally similar fashion.     

Successive Holocene rock avalanches at Lake Coleridge, Canterbury, New Zealand

At Lake Coleridge, Canterbury, New Zealand, at least three rock avalanches have been released from a single source area during the Holocene. The first of these was of 10⁷ m³ volume and dates to about 9,750 BP, and two with volumes 5 × 10⁵ and 4 × 10⁴ m³ occurred about 700 BP. All three crossed the course of the Ryton River; the latter two were emplaced within the part of the first that had subsequently been eroded by the Ryton River. All three were most likely triggered by, or related to, seismicity. The first rock avalanche formed a long-lived landslide dam, and no evidence remains to indicate whether its eventual failure was catastrophic. The second formed a correspondingly smaller dam, but there is no evidence that its lake was long-lived; however, a set of anomalously steep outwash terraces downstream of the landslide deposits show that it failed catastrophically. A camping ground is sited about 1 km downstream of the landslide deposits, and proposals to develop it further risk potentially severe hazards from future rock avalanche activity at the site.     

Radiocarbon dating of quaternary loess deposits,Banks Peninsula,Canterbury, New Zealand

Quaternary loess deposits containing charcoal and in situ organic matter constituents from Banks Peninsula, New Zealand, were subjected to various physical and chemical treatments before radiocarbon assay. A stepwide procedure was used in which each component was radiocarbon dated before and after the treatments were applied. The criterion adopted for judging the effectiveness of a treatment is an increase in the radiocarbon age of loess layer. On this basis the oldest and therefore the most reliable date was obtained from the intra-loess charcoal and its humic acid extract. By comparison, the radiocarbon ages of organic matter constituents of the whole or partitioned loess were much younger, and are considered to represent only average ages for the particular layers concerned. No advantage was gained by dating the carbon-enriched clay-humus fraction as opposed to whole loess samples. There is an apparent conflict between our dates and current interpretation of loess stratigraphy and chronology in the South Island of New Zealand, which requires further investigation. This uncertainty apart, the upper layers of multiple loess deposits are clearly much older than earlier reports indicate, and it follows that the correlation of these deposits with late-glacial events both within and beyond New Zealand is even more tenuous and unreliable than previously thought to be the case.     

河套盆地临河坳陷油气成藏过程解剖及勘探潜力分析

河套盆地属于我国中西部地区中小型陆相含油气盆地,近期于临河坳陷西南部吉兰泰构造带发现亿吨级大油田。工区地质条件复杂且勘探程度低,油藏动态演化过程研究有待深化。针对吉西凸起带和中央断垒带已发现油藏,应用地质、地震和分析化验等资料,在石油地质综合分析的基础上,采用“九史”分析方法对油藏进行动态解剖,取得了以下三点认识:(1)油气晚期成藏并表现出“三晚”,即烃源岩晚期生烃、断裂晚期活动及油气晚期充注;(2)第四纪走滑活动影响油气富集,负花状构造不发育且晚期强烈反转地区有利于成藏;(3)优选出西南部凸起带和中央断垒带两大油气有利勘探区带。