Formation and evolution of petroliferous basins in African continent and their hydrocarbon distribution

There are eighty sedimentary basins in five different types in African continent,i.e.craton sag basin,foreland basin,intermountain basin,passive margin basin and rift basin,which underwent the stress environment of stable depression-compression-extension.The first three types of basins had been intensely influenced by Hercynian and Alpine tectonic movement,while the later two types of basins always exist in a stable extension environment.Different basin evolution caused the obviously hydrocarbon distributio...     

东非大陆边缘构造演化与油气成藏模式探析

近年来,东非海上不断有大型天然气田发现,已成为国际能源勘探的新兴热点。东非地区蕴藏着巨大的油气资源潜力,但其勘探和研究程度很低。在调研大量区域地质和油气地质资料的基础上,通过对东非大陆边缘构造演化特征的分析,从油气成藏要素(烃源岩、储盖组合以及圈闭类型)入手,探讨了油气成藏模式,并对其勘探前景和方向进行了分析。研究结果表明,东非大陆边缘经历了4期构造演化,形成了裂谷叠加被动大陆边缘的双层系盆地结构;主力烃源岩形成于卡鲁裂谷期,主力储层形成于被动陆缘期,在大型三角洲发育区,油气保存条件最好,以构造和构造-地层圈闭为主;油气成藏模式受到构造演化的阶段性、构造变形的横向分带性以及成藏要素的配置关系所控制。      

缅甸安达曼海弧后坳陷天然气成藏要素及成藏模式

缅甸安达曼海已成为中国石油企业的重要海外探区之一。受印度板块向欧亚板块和西缅甸微地块多期斜向俯冲的影响,该区先后经历了被动陆缘、过渡型陆缘及主动陆缘的演化阶段,盆地属性与油气成藏特征极为复杂。通过系统梳理安达曼海弧后坳陷的烃源岩、储盖层、圈闭、输导体系与油气生-运-聚匹配史等成藏要素,总结出该区油气成藏主控因素。结果表明:本区发育渐新统—下中新统、中中新统与上新统3套泥质烃源岩,前二者为成熟烃源岩,后者为生物气源岩;岛弧带上碳酸盐岩礁体与斜坡带上砂体的储集条件良好;斜坡带继承性古隆起之上的断背斜圈闭容积大;高角度张性断裂与连通性砂体分别构成以垂向、侧向为主的输导体系。结合油气成因、运移方式与圈闭类型的主要特征,建立了2种成藏模式:①中央凹陷带浅层生物气或混源气垂向运移断块圈闭成藏模式;②东部斜坡带、西部斜坡和岛弧带热解气侧向运移断背斜-岩性圈闭成藏模式。西部斜坡及岛弧带上的碳酸盐岩礁体和东部斜坡带继承性古隆起之上的大型断背斜是有利勘探目标。     

A study on accumulation and distribution of gas in southern Songliao Basin

A number of isolated fault sags in Late Jurassic--Early Cretaceous were developed in the early stage of southern Songliao Basin,and unified to a depression basin in the late stage.Therefore,multiple isolated lower petroliferous systems were formed with fault sags as source rocks.The source rocks of fault sags in Late Jurassic--Early Cretaceous were mainly described with gas generation as favorable source rocks,leading to the southern Songliao Basin rich in natural gas resources combined with organic gas resources in Nenjiang Formation.A number of tectonic movements in southern Songliao Basin led to the formation of abundant structural traps and complex fault systems,and controlled the distribution strata and positions of sources rocks in Late Jurassic--Early Cretaceous fault sags.The oil-gas reservoirs can be divided into two types,i.e.,primary and secondary ones.The primary oil-gas reservoirs were distributed in the fault sag strata and the bottom of overlying depression strata(lower Quan-1 Member).The oil-gas reservoir accumulation depended on the trap development situation and the distance from source rocks.The preservation conditions of oil-gas reservoirs depended on the degree of reconstruction in the late tectonism.The secondary oil-gas reservoirs were distribution in the Quantou Formation of depression strata,where oil and gas reservoir accumulation depended on three conditions,i.e.,trap development situation,deep gas sources and the fault to connect the shallow traps and deep gas sources.The southern Songliao Basin is rich in lower coal type gas,upper oil-gas and biogas resources,which are important resources in the future.     

中国及境外天山铅锌成矿作用与找矿方向

中国及境外天山铅锌矿床多有发现,如哈萨克斯坦Tekeli、Shalkiya和Achisai,乌兹别克斯坦Kurgashinkan和Uchkulach,塔吉克斯坦Altyntopkan,中国新疆乌拉根、彩霞山、阿齐山、阿尔恰勒等大型—超大型铅锌矿床,构成了天山巨型铅锌成矿带.这些铅锌矿床形成于怎样的地球动力学背景?铅锌成...     

东非Lake Albert盆地构造调节带特征及其对油气成藏的控制作用

构造调节带是裂谷盆地中的一类重要构造形变,而东非裂谷带是研究这一构造现象的理想区域。以东非Lake Albert盆地为研究对象,在对盆地构造、沉积及油气成藏精细研究的基础上,对该区构造调节带的特征及其对油气成藏的控制作用进行了深入分析。研究表明,Lake Albert盆地构造调节带作为张性应变调节构造系,圈闭相对发育,以断块圈闭为主;同时因其在古地貌上一般表现为斜坡,对砂体注入有强烈的控制作用,在Lake Albert盆地构造调节带附近发育优质的三角洲砂体;加之其侧翼往往与油气潜在生成场所相接,因此构造调节带对油气成藏具有明显的控制作用。      

海塔盆地中部断陷带反转构造特征及其对油气的控制

为研究海塔盆地中部断陷带反转构造的类型、分布、形成机制、与油气藏的关系及成藏模式和控藏特征,分析地震、油气藏开发及地球化学等资料.结果表明:伊敏组晚期,海塔盆地中部断陷带在近东西向压扭应力场作用下发生大规模反转,形成断层型、褶皱型和混合型3类5个亚类反转构造,并与上部含油气系统的大二段次生油气藏具有良好耦合关系.大二段次生油气藏为反转期原生油气藏沿主干反转断裂向上调整形成,以南一中段及下段烃源岩形成的原生油气藏为源,以大二段砂岩为储层,以伊敏组泥岩为盖层,以主反转断层为疏导为成藏模式;该次生油气藏的形成与反转程度密切相关,主要形成于反转程度较弱的塔南凹陷隐伏断展型反转构造发育的区域,北北东向的隐伏断展型反转构造圈闭是寻找该类次生油气藏的首选目标.     

Meso-Cenozo ic basin evolution in northern Korean Peninsula

In the Korean Peninsula the Meso-Cenozoic basins were mainly formed due to fault block and block movement. The Mesozoic fracture structures correspond basically to modern large rivers in direction. Such faults were usually developed to rift and formed lake-type tectonic basin, such as the Amrokgang-, Taedonggang-, Ryesonggang-, Hochongang-, Jangphari-, Susongchon-, Pujon-, and Nampho basins. The Mesozoic strata are considered to be divided into the Lower Jurassic Taedong System, Upper Jurassic Jasong System, Upper Jurassic－early Lower Cretaceous Taebo System, and the Upper Cretaceous－Paleocene (Chonjaebong, Hongwon, Jaedok Series) . The Cenozoic block movement succeeded the Mesozoic fault block movement. The Kilju-Myonchon Graben and Tumangang Basin, etc, are the basins related to the fault zones developed from the Oligocene to Miocene. In addition, the Tertiary basins were formed in many areas in the Miocene ( e. g. Sinhung, Oro, Hamhung, Yonghung, Anbyon, Cholwon, etc) . The Cenozoic sedimentation occurred mainly from the late Oligocene to Miocene. The Kilju-Myongchon Graben was the fore deep connected to the sea and the basins inclined in the Chugaryong Fault Zone are intramountain basins. Therefore, coal-bearing beds and clastic rocks in the intramountain basins and rare marine strata and terrigenous clastic rocks are main sedimentary sequences in the Cenozoic.     

Structural characteristics and hydrocarbon accumulation in Bashituo area,Tarim Basin

According to well logs, core, seismic and other geological data, the authors studied the tectonic evolution stages, trap formation stages, fault and fracture development in the Bashituo area, and furthermore, analyzed the time of hydrocarbon accumulation, hydrocarbon migration pathways and related controversial issues in the study area. It is believed that the tectonic evolution in the study area can be divided into three stages, namely Late Hercynian, the Early Himalayan and the Late Himalayan. In the Late Hercynian, tectonic movement led to folding and faulting, resulting in the embryonic form of anticlinal traps. In the Early Himalayan, affected by both tectonic movement and transformation, deep faults reactivated and cut through the Lower Tertiary strata. After the Early Himalayan tectonic movement, faulting stopped and no vertical migration pathway was available. Then hydrocarbon migrated laterally along the sand bodies in the Bachu Formation and accumulated in the Carboniferous reservoirs. However, the Carboniferous accumulation was formed late, and the tectonic movement was weak at the Late Himalayan, and faults were underdeveloped, so the reservoirs in the deep Bachu Formation were not disturbed.     

Melut盆地北部远源油藏类型、特征及勘探启示

Melut盆地为非洲内陆一个重要含油气盆地,其北部具有下白垩统生油、古近系聚集成藏的远源成藏特征,明确盆地远源油藏形成条件与控制因素是提高远源油藏勘探成功率、寻找新的勘探领域的关键。基于区域石油地质条件与油藏解剖,开展了Melut盆地北部远源油藏形成条件、类型及特征研究,在此基础上提出了源内Yabus组远源断层-岩性复合油藏及源外Yabus组远源断块油藏两大潜力勘探领域。研究表明:Melut盆地北部古近系Yabus组发育源内和源外2种类型的远源油藏,二者具有不同的油气充注方式与成藏模式。源内Yabus组远源油藏的形成取决于3个地质条件的耦合,即"两强一弱"的3期裂陷作用为古近纪Yabus组-Adar组远源储盖组合的形成创造了条件;富油凹陷的发育为Yabus组远源油藏的形成提供了必要的油源基础;多期裂陷作用为Yabus组远源圈闭的油气充注提供了垂向通道条件。源内远源油藏主要通过油源断裂的垂向充注成藏,油源断裂是其成藏的主要控制因素,油源断裂的识别及控圈断层的侧向封堵性评价是源内远源断块圈闭评价的重点。源外远源油藏主要通过富油凹陷的侧向运移充注成藏,由富砂地层与断块、古隆起形成的输导脊控制源外远源圈闭的成藏,输导脊的识别与圈闭充注油气程度研究是源外远源圈闭评价的重点。研究成果指导了Melut盆地远源油藏的勘探部署与深化勘探,对其他含油气盆地成熟探区远源油藏的勘探具有指导和借鉴意义。      

Meso-Cenozoic basin evolution in northern Korean Peninsula

In the Korean Peninsula the Meso-Cenozoic basins were mainly formed due to fault block and block movement. The Mesozoic fracture structures correspond basically to modem large rivers in direction. Such faults were usually developed to rift and formed lake-type tectonic basin, such as the Amrokgang-, Taedonggang-, Ryesonggang-, Hochongang-, Jangphari-, Susongchon-, Pujon-, and Nampho basins. The Mesozoic strata are considered to be divided into the Lower Jurassic Taedong System, Upper Jurassic Jasong System, Upper Jurassic-early Lower Cretaceous Taebo System, and the Upper Cretaceous-Paleocene （ Chonjaebong, Hongwon, Jaedok Series）. The Cenozoic block movement succeeded the Mesozoic fault block movement. The Kilju-Myongchon Graben and Tumangang Basin, etc, are the basins related to the fault zones developed from the Oligocene to Miocene. In addition, the Tertiary basins were formed in many areas in the Miocene （e. g. Sinhung, Oro, Hamhung, Yonghung, Anbyon, Cholwon, etc）. The Cenozoic sedimentation occurred mainly from the late Oligocene to Miocene. The Kilju-Myongchon Graben was the fore deep connected to the sea and the basins inclined in the Chugaryong Fault Zone are intramountain basins. Therefore, coal-beating beds and clastic rocks in the intramountain basins and rare marine strata and terrigenous clastic rocks are main sedimentary sequences in the Cenozoic.     

Tectonic Evolution and Geological Characteristics of Hydrocarbon Reservoirs in Marine Mesozoic–Paleozoic Strata in the South Yellow Sea Basin

The South Yellow Sea Basin is the main body of the lower Yangtze area in which marine Mesozoic–Paleozoic strata are widely distributed.The latest geophysical data were used to overcome the limitation of previous poor-quality deep data.Meanwhile,the geological characteristics of hydrocarbon reservoirs in the marine Mesozoic–Paleozoic strata in the South Yellow Sea Basin were analyzed by comparing the source rocks and the reservoir and utilizing drilling and outcrop data.It is believed that the South Yellow Sea Basin roughly underwent six evolutionary stages:plate spreading,plate convergence,stable platform development,foreland basin development,faulted basin development,and depression basin development.The South Yellow Sea Basin has characteristics of a composite platform-fault depression geological structure,with a half-graben geological structure and with a ‘sandwich structure' in the vertical direction.Four sets of hydrocarbon source rocks developed – the upper Permian Longtan–Dalong formation,the lower Permian Qixia formation,the lower Silurian Gaojiabian formation,and the lower Cambrian Hetang formation/Mufushan formation,giving the South Yellow Sea Basin relatively good hydrocarbon potential.The carbonate is the main reservoir rock type in the South Yellow Sea area,and there are four carbonate reservoir types:porous dolomitic,reef-bank,weathered crust,and fractured.There are reservoir-forming horizons similar to the typical hydrocarbon reservoirs in the Yangtze land area developed in the South Yellow Sea,and there are three sets of complete source-reservoir-cap rock assemblages developed in the marine strata,with very good hydrocarbon potential.     

中元古代鄂尔多斯盆地南缘裂谷沉积相与震积岩序列

鄂尔多斯盆地南缘中元古代处于拉张期,发育多裂谷系.分析鄂尔多斯盆地野外地质调查、物探和钻井等资料,划分沉积相剖面,研究沉积演化及相类型.结果表明:盆地南缘中元古代沉积陆相三角洲至海陆过渡相的长城系与滨浅海至深海盆地相的蓟县系,并于蓟县系中发现液化底劈构造、震褶岩、震裂岩、震浊积岩、津浪丘状层和风暴岩等震积岩序列单元;沉积水体逐渐加深,为裂谷非补偿型沉积,蓟县系中存在震积岩序列,反映该区中元古代盆地南缘处于裂谷带内,受裂陷作用持续影响.通过沉积相及震积岩序列划分耦合裂谷说,为区域构造研究提供佐证.     

琼东南盆地北部中生代凹陷特征及油气成藏条件初探

琼东南盆地的中生代凹陷群是扩大油气勘探发现的远景区。为了实现琼东南盆地中生界的勘探突破,急需落实中生代凹陷的油气成藏条件和有利勘探领域。基于地球物理、地球化学、钻井资料及古生物资料,首次对琼东南盆地中生代凹陷开展了深入系统的分析研究。研究表明,在琼东南盆地北部崖北凹陷、崖城凸起、崖南低凸起和西南部陵南低凸起及南部隆起均存在中生代沉积地层。根据盆地构造演化分析,中生代沉积形成于燕山期太平洋板块向欧亚板块俯冲期以及其后的弧后伸展期,存在烃源岩、储层及圈闭等油气地质基本条件。琼东南盆地北部坳陷带崖城-崖北地区相比盆地其他地区中生代沉积凹陷规模大,因此本研究重点对琼东南盆地北部坳陷带崖城-崖北地区进行了系统的油气地质综合分析研究,落实了崖城-崖北地区中生界沉积地层分布,并初步评价预测了有利油气勘探区带及重点目标。研究表明,琼东南盆地崖城-崖北地区中生代凹陷发育湖相烃源岩、三角洲等储集体以及构造与地层圈闭,存在西洼南坡带和中部隆起带2个有利油气勘探区带。在这些区带加大勘探,有望获得中生界油气突破。      

辽河断陷中元古代构造演化

辽河断陷的中元古代构造演化与华北北缘和郯庐断裂带的构造演化密切相关。大红峪期,华北北缘在大陆裂谷的基础上进一步发展成被动大陆边缘,郯庐断裂带随之响应发生张裂接受沉积。之后海平面升降,辽宁境内表现为杨庄上升和凌源上升,其不整合面均为沉积属性,在这期间,郯庐断裂带与华北北缘一致保持着裂解趋势。由兴城上升至芹峪上升,辽河断陷沉积了大红峪组、高于庄组、杨庄组和雾迷山组,洪水庄组和铁岭组尚待确定。芹峪上升表示华北北缘开始由被动大陆边缘转换成主动大陆边缘,洋壳低角度俯冲使华北北缘挤压抬升并迫使华北克拉通向南挤压,NE向郯庐断裂由张裂转换成挤压滑动,辽河断陷抬升遭受剥蚀。辽河断陷内的杨庄组和雾迷山组可能就在这一时期剥蚀殆尽。随后洋壳高角度俯冲,华北北缘形成弧后盆地,辽河断陷与燕山地区一样沉积下马岭组。蔚县上升为华北北缘陆陆碰撞造成,陆陆碰撞使华北北缘再次抬升,郯庐断裂挤压走滑增强,辽河断陷褶皱抬升,下马岭组遭受剥蚀。直到罗迪尼亚大陆开始裂解,郯庐断裂带再次张裂,辽河断陷沉积长龙山组和景儿峪组。     

Petroleum geological framework and hydrocarbon potential in the Yellow Sea

Sedimentary basins in the Yellow Sea can be grouped tectonically into the North Yellow Sea Basin (NYSB), the northern basin of the South Yellow Sea (SYSNB) and the southern basin of the South Yellow Sea (SYSSB). The NYSB is connected to Anju Basin to the east. The SYSSB extends to Subei Basin to the west. The acoustic basement of basins in the North Yellow Sea and South Yellow Sea is disparate, having different stratigraphic evolution and oil accumulation features, even though they have been under the same stress regime since the Late Triassic. The acoustic basement of the NYSB features China-Korea Platform crystalline rocks, whereas those in the SYSNB and SYSSB are of the Paleozoic Yangtze Platform sedimentary layers or metamorphic rocks. Since the Late Mesozoic terrestrial strata in the eastern of the NYSB (West Korea Bay Basin) were discovered having industrial hydrocarbon accumulation, the oil potential in the Mesozoic strata in the west depression of the basin could be promising, although the petroleum exploration in the South Yellow Sea has made no break-through yet. New deep reflection data and several drilling wells have indicated the source rock of the Mesozoic in the basins of South Yellow Sea, and the Paleozoic platform marine facies in the SYSSB and Central Rise could be the other hosts of oil or natural gas. The Mesozoic hydrocarbon could be found in the Mesozoic of the foredeep basin in the SYSNB that bears potential hydrocarbon in thick Cretaceous strata, and so does the SYSSB where the same petroleum system exists to that of oil-bearing Subei Basin.     

转换型边缘盆地转换边缘类型识别与特征分析: 以非洲科特迪瓦盆地为例

转换型边缘盆地是一类特殊的大陆边缘盆地,前人对其研究较少,随着近十几年在转换型边缘盆地的一系列重大油气发现,该类型盆地越来越受到重视。但在盆地边缘转换断层的识别解释、转换断层对盆地构造格局的影响以及转换断层相关的火山活动对盆地的影响方面等研究仍相对较少。以典型的转换型边缘盆地——科特迪瓦盆地为研究对象,从盆地的转换边缘入手,利用多种数据综合分析,识别出转换型边缘盆地的两类转换边缘——转换型边缘和过渡离散型边缘,并分别总结了其各自特征;对比了两类转换型边缘在地层发育、断裂体系、火山活动以及应力场等方面存在的差异及其对盆地造成的影响。研究结果表明,典型的转换型边缘盆地具有转换型边缘和过渡离散型边缘两种不同类型的洋陆过渡边缘;两类边缘在接触关系、火山活动强度、对早期地层的改造作用等方面具有显著差异;转换型边缘盆地结构受早期断裂和转换断裂的双重控制,受多期构造运动改造,拉张与走滑应力叠加,使早期断裂具有走滑和拉张双重性质,多期的改造作用对油气运聚及保存具有显著影响。转换断层附近早期断裂可能会发生反转作用,断裂性质发生改变,形成挤压构造或地层反转。      

内蒙古赛罕塔拉煤田地质特征及其聚煤规律研究

二连盆地群是内蒙古自治区最大的一个晚中生代盆地群,都呼木盆地是其中之一富煤盆地,含煤层位于白垩纪彦花组第五段,煤层的煤质为中灰、中高硫、高发热量、低磷—中磷低氯的褐煤,受好来-锡林呼都格断裂控制形成的赛罕塔拉煤田,自然分割成了若干个规模不等的聚煤盆地。盆地边缘地区岩浆岩发育,以华力西中晚期、燕山早期侵入岩为主,岩性从超基性—酸性,一般呈岩基产出。煤层形成于漫流为主的沉积组合类型和浅水重力流和泥炭沼泽沉积物为主的沉积相。沉积环境对富煤带展布起控制作用,该区主要聚煤作用发生在盆地发育的晚期,富煤带在控盆断裂的西北一侧2～4km附近。     

Comparison of Kuqa foreland basin with Persian Gulf Basin in salt tectonics

Compared Kuqa foreland basin with Persian Gulf Basin in development of salt layers, salt tectonics, and the relation between salt tectonics and hydrocarbon, it is concluded that the salt diapirs are relative to hydrocarbon. Searching salt diapirs and related traps in Kuqa foreland basin is important. The forming mechanism of salt tectonic in Kuqa foreland basin is different from that of Hormuz Series, but similar to that of Lower Fars Series/Gachsaran Formation. Inspired by the role of salt tectonics of Lower Fars Series/Gachsaran Formation in hydrocarbon accumulation, the authors considered that the exploration below salt layer should be enforced, and the traps below salt layer in the southern part of the Kuqa foreland basin would be found where salt layer is thicker. On the contrary, the traps should be found both above and below the salt layer in front of the northern mountain where salt layer is thin. The Triassic and Jurassic source rocks are rich in this area with great exploration prospective.     

Comparison of Kuqa foreland basin with Persian Gulf Basin in salt tectonics

Compared Kuqa foreland basin with Persian Gulf Basin in development of salt layers, salt tectonics, and the relation between salt tectonics and hydrocarbon, it is concluded that the salt diapirs are relative to hydrocarbon. Searching salt diapirs and related traps in Kuqa foreland basin is important. The forming mechanism of salt tectonic in Kuqa foreland basin is different from that of Hormuz Series, but similar to that of Lower Fars Series/Gachsaran Formation. Inspired by the role of salt tectonics of Lower Fars Series/Gachsaran Formation in hydrocarbon accumulation, the authors considered that the exploration below salt layer should be enforced, and the traps below salt layer in the southern part of the Kuqa foreland basin would be found where salt layer is thicker. On the contrary, the traps should be found both above and below the salt layer in front of the northern mountain where salt layer is thin. The Triassic and Jurassic source rocks are rich in this area with great exploration prospective.