构造坡折带隐蔽圈闭发育模式浅析

构造坡折带是由同沉积构造长期活动引起的沉积斜坡明显突变的地带,对盆地充填的可容纳空间和沉积作用可产生重要的影响,构造坡折带和油气资源分布有着较为密切的关系。隐蔽圈闭是沉积盆地油气勘探中后期重点勘探领域。构造坡折带是沉积盆地中隐蔽圈闭最发育的部位之一,多级构造坡折带组合对盆地隐蔽圈闭的发育有一定的影响,多级构造坡折带隐蔽圈闭发育更受到沉积环境和湖平面变化的影响;构造坡折带地区隐蔽圈闭油气成藏良好,高位域和三角洲前缘泥岩是良好的烃源岩,连片砂体和不整合界面及生长断裂是良好的输导条件,生长断裂和高位域泥岩具有良好的封盖作用。     

伊通盆地莫里青断陷双一段油气成藏模式

莫里青断陷为伊通盆地最南端的一个二级构造单元,古近纪以来经历了张扭、热沉降、压扭和挤压构造演化阶段。通过对莫里青断陷双一段油气特征及分布的分析,厘清了高凝油、天然气的来源,分析了油气的输导体系和成藏过程,建立成藏模式,以指导油气勘探。双一段高凝油主要分布在凹陷的东西斜坡带,其成因与烃源岩的有机质类型和环境有关,分布与有机质低成熟及运移特征有一定关系;天然气主要分布在东南高部位,具有低熟特征。双一段油气主要来源于双阳组,凹陷斜坡带的扇三角洲、湖底扇砂岩体、断层及不整合面为油气侧向运移的良好通道。凹陷的远端则可能由于运移动力的不足或者输导体系不连通而难以到达。烃源岩分布、砂体展布、断层发育和不整合面结构分布是油气成藏主控因素。伊6区块晚期基底拱张,低熟气以断层和低渗储层为通道于高部位聚集成藏。     

超压盆地油气地质条件与成藏模式——以莺歌海盆地为例

超压沉积盆地分布广泛,对油气勘探具有重要意义。超压盆地具备良好的油气成藏条件:超压地层不仅是有利的生油层,亦是有效的封盖层;异常高压流体活动改善储层物性,控制圈闭形成与分布;超压流体活动形成断层、裂缝,改善油气运移输导网络,为油气运移提供了动力。通过研究提出了超压盆地漏斗状网毯式油气成藏模式,指出高压底辟体是超压盆地油气成藏之核心,油气在高压驱动下沿漏斗状输导体系运移到底辟体上覆低势区成藏。     

通王断裂带沙河街组油气成藏主控因素研究

通王断裂带地区位于济阳坳陷东营凹陷南斜坡东部,沙河街组是本区的主要含油层系。通过烃源岩分析、储集层类型划分、孔隙流体动力场的描述、优质输导体系类型及断裂构造特征的研究,认为牛庄洼陷烃源岩主要为沙四上和沙三段深湖相一半深湖相暗色泥岩、油页岩,油气以生油洼陷为中心,呈环状或半环状分布;沙三段大型三角洲相储集砂体、沙四段中上部的滨浅湖近岸砂坝、远岸砂坝和席状砂岩储层是主要储集层类型;砂体一断层类输导体系是本区优质输导体系,牛庄洼陷北部发育的高压型复式温压系统,使油气顺着断层、砂体向南部通王断裂带常压常温和常压高温区运移。通王断裂带的油气藏主要是受断裂控制的构造油气藏,王家岗油田往西的中浅层是断层类油藏的有利地区,王家岗地区北部和陈官庄地区的西北部,是沙三段隐蔽油气藏以及断层-岩性复合型油气藏勘探的有利勘探地区。     

印尼加里曼丹岛东部主要含油气盆地油气富集差异

为加强印尼加里曼丹岛东部地区战略选区研究,指明选区方向,从分析已发现油气分布规律入手,重点探讨了油气分布的控制因素,分析了低勘探程度区勘探潜力。研究表明:(1)陆上和海上分别受控于始新统和中新统三角洲煤系烃源岩,烃源岩类型、成熟度和规模共同控制油气发现"海多陆少、中部为气、南北为油"格局;(2)烃源岩和输导体系是控制油气成藏和分布的两个关键因素,海上和陆上输导体系的差异控制了海陆油气发现,表现为"陆老海新"特征;(3)海上北部达拉根盆地"近源逆冲断裂带"与陆上南部巴里托盆地南部"基底潜山带",石油地质条件优越,勘探潜力较大。     

歧口凹陷张东地区沙河街组油气成藏条件与主控因素研究

歧口凹陷张东地区油气勘探工作开展较晚,通过基础地质研究认为张东地区油气成藏条件优越。砂岩输导层、断层和不整合面三大输导体在研究区不同的构造位置相互交叉、叠置、连通构成了复杂多变的输导体系,进而控制了研究区油气聚集部位与油气藏的分布,而不同的沉积相带直接影响到储层物性的好坏,对油气富集高产具有决定作用。     

西湖凹陷孔雀亭地区复合圈闭发育模式与油气富集差异控制因素

随着勘探程度不断加深,东海西湖凹陷保俶斜坡带全面进入了断层-岩性复合油气藏勘探阶段,位于保俶斜坡中北部的孔雀亭地区是复合油气藏有利发育区。通过对孔雀亭地区复合圈闭发育的构造沉积背景、断裂-古地貌的控砂作用以及分带、分层系油气成藏富集规律研究,明确了孔雀亭地区复合圈闭形成条件、发育模式及油气富集差异控制因素。认为孔雀亭地区西高东低的地貌背景、西部古隆起上发育的多条“U”型及“V”型沟谷,NE向断裂坡折及NW挠曲坡折共同控制了多条水系的平面发育特征及砂体展布,与NE向断层匹配形成了典型的断层-岩性复合圈闭,成为孔雀亭地区重要的勘探领域,取得了断层-岩性圈闭勘探突破。孔雀亭地区不同区带油气富集程度不同,圈闭与有效烃源岩距离、砂体规模、储层物性、断层封堵性等要素的匹配程度控制各带油气富集程度。中低带相对近源,断层未断至浅层,保存条件好,受断坡及挠曲坡折共控,为规模砂体卸载区,物性较好,油气相对最为富集,具有良好的勘探潜力。     

阿联酋地区古生界碳酸盐岩油气成藏与勘探潜力

古生界是波斯湾盆地天然气的主要产出层位,阿联酋地区古生界天然气主要富集于上二叠统胡夫组碳酸盐岩储层。在构造、沉积演化研究的基础上,分析了阿联酋地区古生界碳酸盐岩油气藏的成藏主控因素,优选了2类有利勘探区带,指明了该区古生界下一步勘探方向。结果显示:阿联酋古生代可划分为4个构造演化阶段,构造演化对油气成藏具有重要影响,古生界已发现油气主要分布于被动大陆边缘。该区古生界古赛巴段热页岩烃源灶分布及规模控制着油气分布范围与资源规模;胡夫组层内膏盐层为古生界油气藏的主要盖层,控制油气纵向与平面分布;同时油气在平面上的富集带明显受胡夫组岩相分布控制,已发现油气主要位于碳酸盐岩陆架颗粒灰岩—泥粒灰岩相带内;热页岩生烃灶周围的古构造高是古生界油气运聚的有利指向区。阿联酋古生界胡夫组仍有较大的勘探潜力,膏盐盖层发育区与优质储层岩相带的叠合部位,且邻近热页岩生烃灶的地区,油气成藏条件最好,该区域内的背斜构造和岩性—地层型构造是古生界油气勘探的重点。     

南海北部陆坡深水区天然气水合物成藏系统及其控制因素

天然气水合物成藏系统目前已越来越受到油气地质专家们的重视与关注。天然气水合物运聚成藏亦遵循从烃源供给到圈闭(高压低温稳定带)中运聚成藏的含油气系统理论。天然气水合物成藏系统的构成及形成,主要取决于充足的气源供给、较好的运聚输导系统和高压低温稳定带三大要素的时空耦合配置。为了深入剖析我国南海北部深水区天然气水合物成藏系统基本特征,在近年来所获南海北部天然气水合物勘探成果的基础上,根据天然气水合物成藏系统理论,重点从天然气水合物的烃源供给、流体输导系统和高压低温稳定带及其储集系统3方面,系统分析总结了我国南海北部陆坡神狐海域、东沙海域和西沙海槽天然气水合物成藏的基本地质条件与控制因素,建立了各区域不同类型天然气水合物成藏分布模式,尤其是提出了生物成因的"渗漏型"水合物成矿类型,以期能够为加快和促进南海天然气水合物勘查提供指导和参考借鉴。     

松南气田登娄库—泉头组天然气成藏特征分析

松南气田位于松辽盆地南部长岭断陷中央隆起带达尔罕断凸带腰英台深层构造高部位.通过分析解剖烃源岩、输导等,认为松南气田登娄库—泉头组天然气藏具有双向供烃的特征;达尔罕断裂是控制气藏规模的主断裂,它的开启与封闭直接决定天然气藏的形成保存及破坏散失.在典型气藏解剖的基础上,综合油气成藏条件,总结了成藏规律：多期生烃,北、西次凹供烃、近距离运移,长期运移指向、聚集,深层储盖组合匹配.     

松辽盆地登娄库—永安地区油气成藏模式研究

在已了解的松辽盆地登娄库—永安地区构造和沉积演化特点的基础上,利用现有钻井的岩心资料、测井资料和地震资料,对该地区的成藏模式特征从运移方式和生储盖空间组合两个方面上进行了研究和分类,分析了各自形成的主控因素.研究表明,该区域地层具有断坳双层结构,按油气运移类型划分,在断陷期主要发育两种油气成藏模式,分别为原生油气成藏模式和次生油气成藏模式;在坳陷期主要发育次生油气成藏模式和混生油气藏.从储层与烃源岩的空间组合上来看,区域内主要发育有上生下储、下生上储和自生自储这三种油气成藏模式.形成这些不同成藏模式的主要因素是该区深至基底的大型断裂构造和继承性断裂、反转构造以及固有沉积环境等.     

Geological control factors of micro oil distribution in tight reservoirs

Understanding the oil distribution characteristics in unconventional tight reservoirs is crucial for hydrocarbon evaluation and oil/gas extraction from such reservoirs. Previous studies on tight oil distribution characteristics are mostly concerned with the basin scale. Based on Lucaogou core samples, geochemical approaches including Soxhlet extraction, total organic carbon (TOC), and Rock-Eval are combined with reservoir physical approaches including mercury injection capillary pressure (MICP) and porosity-permeability analysis, to quantitatively evaluate oil distribution of tight reservoirs on micro scale. The emphasis is to identify the key geological control factors of micro oil distribution in such tight reservoirs. Dolomicrites and non-detrital mudstones have excellent hydrocarbon generation capacity while detritus-containing dolomites, siltstones, and silty mudstones have higher porosity and oil content, and coarser pore throat radius. Oil content is mainly controlled by porosity, pore throat radius, and hydrocarbon generation capacity. Porosity is positively correlated with oil content in almost all samples including various lithologies, indicating that it is a primary constraint for providing storage space. Pore throat radius is also an important factor, as oil migration is inhibited by the capillary pressure which must be overcome. If the reservoir rock with suitable porosity has no hydrocarbon generation capacity, pore throat radius will be decisive. As tight reservoirs are generally characterized by widely distributed nanoscale pore throats and high capillary pressure, hydrocarbon generation capacity plays an important role in reservoir rocks with suitable porosity and fine pore throats. Because such reservoir rocks cannot be charged completely. The positive correlation between hydrocarbon generation capacity and oil content in three types of high porosity lithologies (detritus-containing dolomites, siltstones, and silty mudstones) supports this assertion.     

东海盆地X凹陷Y气田的天然气成因、成藏模式及勘探意义

本文旨在厘清东海盆地X凹陷Y气田天然气成因,建立成藏模式,以指导下步勘探部署。本文从天然气组分、烷烃气碳同位素、轻烃、凝析油生物标志化合物等分析入手,系统研究了油气成因类型及来源,并结合构造演化史、生烃史分析,建立了Y气田成藏模式,提出了大中型气田的勘探方向。主要认识如下：（1）天然气组分碳同位素、轻烃和埋藏史分析表明,Y气田天然气为凹中始新统平湖组烃源岩在龙井运动期（距今13 Ma）生成的高成熟煤型气;（2）凝析油姥鲛烷/植烷、规则甾烷等特征,反映了凹中区平湖组烃源岩发育于弱氧化-弱还原潮坪、潟湖沉积环境,生烃母质中存在一定数量的低等水生生物;（3）Y气田具有“凹中区平湖组烃源岩、花港组大型水道砂储集体、挤压构造作用”时空耦合的成藏模式,明确了凹中挤压背斜带是X凹陷大中型气田勘探的主攻方向。     

川西坳陷中段沙溪庙组天然气成藏条件分析

探讨川西坳陷中段沙溪庙组天然气成藏地质条件,为油气勘探提供理论依据。从油气的烃源条件、储集条件、保存条件及成藏组合方面入手,结合构造史以及岩心、地震及钻井等资料进行分析,结果表明川西坳陷中段处于生烃坳陷中心地带,烃源岩丰富,具备生烃能力。晚三叠世中、晚期发育冲积扇—河流沉积相带,储集条件良好,后期构造运动使断层裂缝系统较发育,有利于储集条件改善和油气富集。其上有压力封存箱和巨厚的砂泥岩互层,保存条件良好。川西坳陷中段新场—盐亭地区近EW向古隆起及龙门山前缘扩展变形带中的鸭子河—石板滩地区是油气勘探的有利地带。     

南堡凹陷4号构造带蛤坨断层特征与油气成藏关系

南堡凹陷4号构造带断裂发育,既发育沟通烃源岩的深断裂,也发育沟通浅层圈闭的次级断裂。综合利用地震、测井、岩性等资料分析断层的空间展布,计算蛤坨断层的生长指数和断层泥比率（SGR）,分析断层的活动性、封堵性,评价其输导性能,并结合其与烃源岩生排烃期的匹配关系研究断裂与油气运移、聚集的关系及控制规律。在典型油气藏剖面解剖的基础上,建立了4号构造带油气运聚成藏模式。     

Hydrocarbon migration and accumulation of the Suqiao buried-hill zone in Wen'an Slope,Jizhong Subbasin,Bohai Bay Basin,China

The hydrocarbon migration and accumulation of the Suqiao deep buried-hill zone, in the Jizhong Subbasin, the Bohai Bay Basin, eastern China, was investigated from the perspective of paleo-fluid evidence by using fluid inclusions, quantitative fluorescence techniques (QGF), total scanning fluorescence method (TSF) and organic geochemical analysis. Results show that the current condensate oil-gas reservoirs in the study area once were paleo-oil reservoirs. In addition, the reservoirs have experienced at least two stages of hydrocarbon charge from different sources and/or maturities. During the deposition of the Oligocene Dongying Formation (Ed), the deep Ordovician reservoirs were first charged by mature oils sourced from the lacustrine shale source rocks in the fourth member of Shahejie and Kongdian Formations (Es₄+Ek), and then adjusted at the end of Ed period subsequently by virtue of the tectonic movement. Since the deposition of the Neogene Minghuazhen Formation (Nm), the reservoirs were mainly charged by the gas that consisted of moderate to high-maturity condensate and wet gas sourced from the Es₄+Ek lacustrine shale source rocks and mature coal-derived gas sourced from the Carboniferous-Permian (C-P) coal-bearing source rocks. Meanwhile, the early charged oil was subjected to gas flushing and deasphalting by the late intrusion of gas. The widely distributed hydrocarbon inclusions, the higher QGF Index, and FOI (the frequency of oil inclusions) values in both gas-oil and water zone, are indicative of early oil charge. In addition, combined with the homogenization temperatures of the fluid inclusions (<160 °C) and the existence of solid-bitumen bearing inclusions, significant loss of the n-alkanes with low carbon numbers, enrichments of heavier components in crude oils, and the precipitation of asphaltene in the residual pores suggest that gas flushing may have played an important role in the reservoir formation.     

Geological roles of the siltstones in tight oil play

Understanding the hydrocarbon accumulation pattern in unconventional tight reservoirs is crucial for hydrocarbon evaluation and oil/gas extraction from such reservoirs. Previous studies on tight oil accumulation are mostly concerned with self-generation or from source to reservoir rock over short distances. However, the Lucaogou tight oil in Jimusar Sag of Junggar Basin shows transitional feature in between. The Lucaogou Formation comprises fine-grain sedimentary rocks characterized by thin laminations and frequently alternating beds. The Lucaogou tight silt/fine sandstones are poorly sorted. Dissolved pores are the primary pore spaces, with average porosity of 9.20%. Although the TOC of most silt/fine sandstones after Soxhlet extraction is lower than that before extraction, they show that the Lucaogou siltstones in the area of study have fair to good hydrocarbon generation potential (average TOC of 1.19%, average S₂ of 4.33 mg/g), while fine sandstones are relatively weak in terms of hydrocarbon generation (average TOC of 0.4%, average S₂ of 0.78 mg/g). The hydrocarbon generation amount of siltstones, which was calculated according to basin modeling transformation ratio combined with original TOC based on source rock parameters, occupies 16%–72% of oil retention amount. Although siltstones cannot produce the entire oil reserve, they certainly provide part of them. Grain size is negatively correlated with organic matter content in the Lucaogou silt/fine sandstones. Fine grain sediments are characterized by lower deposition rate, stronger adsorption capacity and oxidation resistance, which are favorable for formation of high quality source rocks. Low energy depositional environment is the primary reason for the formation of siltstones containing organic matter. Positive correlation between organic matter content and clay content in Lucaogou siltstones supports this view point. Lucaogou siltstones appear to be effective reservoir rocks due to there relatively high porosity, and also act as source rocks due to the fair to good hydrocarbon generation capability.     

辽东湾地区锦州25—1油田油气成藏特点和运聚模拟研究

在对构造演化、成藏要素、油源对比、成藏期次分析的基础上,结合Trinity油气运移成藏模拟分析软件对锦州25—1油田的油气运聚模拟研究,分析了形成锦州25—1油田的成藏主控因素,建立了其成藏模式,指出了该地区有利勘探方向。模拟分析结果表明,锦州25—1构造是辽西凹陷沙三段烃源岩生成油气运聚的有利指向区,而优良成藏要素的优势时空配置则是形成锦州25—1油田的关键因素。其成藏模式为：辽西凹陷沙三段烃源岩在东下段时期进入了大量生排烃期,生成的油气为一期充注,充注时间发生在东营组末期,沿东下段时期强烈构造运动伴生的断裂系统、沙二段广泛发育的砂体、沙二段与沙三段之间大型不整合面以及古构造脊所构成的疏导体系运移至沙二段圈闭成藏,而沙三段砂体则可以近源优势成藏。辽西凹陷西斜坡、凹中隆以及古构造脊是今后较为有利的勘探区域。