西湖凹陷油气成藏的主控因素

西湖凹陷位于东海大陆架边缘,地壳为相对软弱的过渡壳。西湖凹陷中新世末以前属于萎缩型盆地,上新世伴随冲绳海槽的形成才成为扩张性盆地。受构造控制盆地萎缩期沉积有以下3个特点：第一,整体表现为海退;第二,沉积范围逐次减小;第三,泥岩百分比越来越低,盖层条件越来越差。平湖组存在区域盖层,钻遇断块气藏;花港组存在局部盖层,背斜充满度高,断背斜充满度低,断块未成藏;新近系盖层条件更差,断背斜亦未能成藏。由此可见保存条件是西湖凹陷油气成藏的主控因素,保存条件好的领域是西湖凹陷下一步勘探的方向。     

渤海湾盆地秦南凹陷油气成藏主控因素分析

秦南凹陷经历了46年勘探,只发现了秦皇岛29-2油气田,尤其是近9年勘探无一油气田发现,勘探工作陷入困境。为了弄清秦南凹陷油气成藏主控因素,指明油气勘探方向,利用三维地震、钻井及化验资料,梳理基础石油地质条件,通过已钻井成败分析和类比研究,明确各储盖组合的成藏主控因素,并预测有利勘探方向。研究表明：(1)秦南凹陷沙三段、沙一段烃源岩发育,TOC为1.5%～4%,类型为Ⅰ—Ⅱ1型,资源潜力大,发育潜山、沙河街组-东营组、馆陶组-明下段三套储盖组合。(2)潜山下组合成藏主控因素为储层非均质性;沙河街-东营组中组合成藏主控因素为圈闭有效性;馆陶-明化镇组上组合成藏主控因素为油源断层的运移能力。(3)东洼与东南洼间低隆起、东洼西斜坡、东洼和东南洼大断层下降盘,分别是下、中、上组合今后的有利勘探区带。本研究成果为今后秦南凹陷油气勘探提供了依据,也为类似地区油气勘探工作提供可借鉴的思路。     

费尔干纳盆地油气成藏特征及其主控因素分析

费尔干纳盆地是位于中亚地区南天山山系中呈负向地形的坳陷,受基底断裂和区域构造活动控制,形成3个不同的构造层系。盆地基底为褶皱造山条件下形成的强烈变质的古生代地层,中部的盆地盖层沉积为中生代至古近纪拉张裂谷稳定沉降条件下形成的,最上部为新近纪至现今造山阶段形成的磨拉石建造。费尔干纳盆地主要发育中下侏罗统湖相沼泽相泥页岩、上白垩统乌斯特里奇组区域海侵层和古近系海相泥岩和泥灰岩等3套烃源岩;发育侏罗系、白垩系、古近系及新近系等4套含油气储集层系;且区域性盖层、准区域性盖层和局部盖层发育,形成了良好的生储盖组合。受构造变形和沉积环境控制,主要发育构造型、构造—地层型和地层(岩性)型3大类型油气藏(田)。第四纪早期的构造活动控制了盆地内油气田的最终分布,扭断层破坏了已有的圈闭并为烃类向上覆新近系储层的运移提供了运移通道,造成大量烃类气体散失。     

辽河滩海地区油气成藏特征及其主控因素

辽河滩海地区为辽河油田重要的油气产量接替区,搞清其成藏特点与成藏主控因素对指导该区油气勘探意义重大.总体上,油气富集带围绕生烃洼陷呈环带状分布且已发现油气藏多分布于主干断裂附近.但不同地区油气分布存在差异性:西部和中部聚油,东部油气并存;西部缓坡带主要为反向正断层控制下的断块油气藏,中部和东部陡坡带为主干断裂控制下的断...     

埃斯皮里图桑托盆地盐上油气成藏特征及主控因素分析

大坎波斯盆地是世界深水沉积勘探的热点盆地,但针对其北段的埃斯皮里图桑脱盆地盐上油气富集规律的系统研究尚未展开。为进一步指导埃斯皮里图桑脱盆地盐上的油气勘探,综合利用钻井、测井和地震资料,对该盆地的油气成藏特征和主控因素进行了综合分析。研究表明：①埃斯皮里图桑托盆地发育盐下湖相和盐上海相2套烃源岩,且储层主要为盆地北部上白垩统—新近系深水水道砂岩;②依据盐岩层滑脱变形的构造特征,可将盐上构造格局划分为盐滑脱带、盐底辟带和盐推覆带;③盐滑脱带成藏模式表现为盐下和盐上烃源岩生成的油气分别通过盐窗和盐相关断裂运移,最终在盐滑脱形成的滚动背斜等圈闭中成藏;④盐底辟带成藏模式表现为盐上烃源岩生成的油气通过盐相关断裂运移,最终在盐底辟相关背斜和盐侧翼遮挡的圈闭中成藏;⑤储层、盐相关铲式断层和盐岩活动是油气成藏的主控因素。     

济阳坳陷商河油田断层与油气运聚的关系

利用断层落差法、生长指数法和泥岩涂抹SGR法分析了商河油田断层活动性和封闭性特征,并结合油气分布分析了断层与油气运聚之间的关系。研究结果表明,商河油田1号、2号、3号及6号断层在馆陶期持续活动,是油气向中浅部沙一段等储集层运移的有利垂向通道;同时,具有良好侧向封堵条件的断层容易使油气聚集成藏,认为SGR=0.75是断层侧向封闭的临界条件。     

济阳坳陷商河油田断层与油气运聚的关系

利用断层落差法、生长指数法和泥岩涂抹SGR法分析了商河油田断层活动性和封闭性特征,并结合油气分布分析了断层与油气运聚之间的关系。研究结果表明,商河油田1号、2号、3号及6号断层在馆陶期持续活动,是油气向中浅部沙一段等储集层运移的有利垂向通道;同时,具有良好侧向封堵条件的断层容易使油气聚集成藏,认为SGR=0.75是断层侧向封闭的临界条件。     

东海陆架盆地西湖凹陷油气成藏主控因素及成藏模式

以现代石油地质理论和油气复式成藏理论为指导,总结西湖凹陷已发现油气分布规律,认为西湖凹陷具有油气规模“深大浅小”、油气类型“上油下气”、油气富集“近源近断”的特征。分析了油气成藏主控因素,从而建立了特色的西湖凹陷“塔”式成藏模式。研究表明,中浅层花港组由于泥岩盖层条件相对较差以及晚期近EW向断裂对早期油气藏的破坏和改造作用,油气成藏条件不是非常有利;而深层-超深层具有形成大型油气田的有利地质条件：烃源岩持续生烃提供了充足的油气源,深层-超深层砂岩储集性能依然保持较好,异常高压改善了储层物性并提供油气运移的动力,“千层饼”式储盖组合和早期烃源断裂控制了油气纵向展布。因此,西湖凹陷深层-超深层砂岩气资源潜力较大,具有良好的勘探前景。     

西湖凹陷孔雀亭气田成藏主控因素

综合运用地质、钻井、生物标志物、碳同位素、储层流体包裹体等资料,在油气分布特征和来源分析的基础上,探讨了控制西湖凹陷孔雀亭气田油气成藏及富集的主要因素。研究结果表明,孔雀亭气田油气主要分布在始新统平湖组储层内,具有"上油下气"的纵向分布特征,以断块型凝析气藏为主,原油及天然气来源于自身和西部次洼平湖组源岩联合供烃。孔雀亭气田油气成藏及富集主要受断层封堵性、砂体厚度和储层物性及流体充注历史的联合控制,断层封堵性控制了油气藏的含油气性,砂体厚度和储层物性制约了油气层厚度和含油气饱和度,流体充注历史决定了油气藏的现今赋存相态。     

古近系油气初次运移有效性的主控因素——以珠江口盆地西江A和西江B构造圈闭油气勘探效果对比为例

通过珠江口盆地西江主洼地区古近系油气勘探实例,提出了油气初次运移有效性与初次运移有效区的概念。初次运移是否有效取决于烃源岩排出之油气进入邻近砂体后能否顺利二次分配。初次运移有效性的主控因素取决于2点：一是发育与烃源岩接触面积较大的规模性砂体;二是砂体中粗孔喉相对发育。前者可为初次运移有效性、提高运聚充注效率奠定基础;后者则决定了油气优先充注的运聚方向,其是决定初次运移最终有效的直接条件。据此,对比分析了西江A构造圈闭与西江B构造圈闭的钻探结果,并对西江A构造钻探失利进行了深入解剖,进而深化了该区古近系油气成藏规律的认识,且为进一步勘探寻找类似油气藏提供了参考和借鉴。     

松辽盆地新民油田下白垩统泉四段浅水三角洲骨架单砂体空间发育特征

以高分辨率层序地层学和储层构型理论为指导,利用岩芯、测井曲线和生产动态等资料,在沉积相分析的基础上,对松辽盆地新民油田白垩系泉四段浅水三角洲骨架单砂体空间发育特征进行系统研究并建立相关模式。研究表明,研究区泉四段主要发育浅水三角洲平原亚相和前缘亚相,分别以分支河道和水下分支河道为骨架砂体。泉四段整体处于湖平面上升的沉积背景,浅水三角洲不断向陆退积,骨架单砂体的空间发育特征表现出一定的规律性。可容空间与沉积物供应量的比值(A/S)是控制骨架单砂体空间发育特征的主要因素。A/S< <1时, 发育浅水三角洲平原沉积环境,分支河道单砂体垂向叠置样式主要为侧向切叠式和垂向切叠式,平面呈连片状展布;单砂体发育规模大,平均宽度为396~463m,平均厚度为5.2~5.8m。A/S≤1时,发育浅水三角洲平原沉积环境,分支河道单砂体垂向叠置样式主要为侧向叠加式和垂向叠加式,平面呈网状展布;单砂体发育规模较大,平均宽度为308~412m,平均厚度为4.2~5.2m。A/S>>1时,发育浅水三角洲前缘沉积环境,水下分支河道单砂体垂向叠置样式主要为孤立式,平面呈枝状展布;单砂体发育规模较小,平均宽度为165~325m,平均厚度为2.4~4.0m。     

北部湾盆地海中凹陷油气成藏条件分析

海中凹陷位于北部湾盆地西南部,其勘探程度低,对油气成藏条件欠缺系统的认识和深入的研究。以含油气系统理论为指导,在简要介绍地层与构造特征的基础上,重点论述了烃源岩、储集层、圈闭及输导介质等油气系统的基本要素,认为海中凹陷发育多套烃源岩、多套储集层、多种类型圈闭和复合的输导介质,具备油气系统形成的基本条件,具有较为广阔的油气勘探前景。     

Formation and distribution of coal measure source rocks in the Eocene Pinghu Formation in the Pinghu Slope of the Xihu Depression,East China Sea Shelf Basin

The Xihu Depression in the East China Sea Shelf Basin is a large petroliferous sedimentary depression, in which oil and gas reservoirs were mainly discovered in the Pinghu Slope and the central inversion zone. The oil-gas source correlation in the Xihu Depression was analyzed by hydrocarbon generating thermal simulation data via gold-tube pyrolysis experiments. The results indicated that the oil and gas in the Xihu Depression were mainly derived from coal measure source rocks of the Eocene Pinghu Formation. Therefore, the identification of coal seams is extremely crucial for evaluating coal measure source rocks in the Pinghu Formation in the Xihu Depression. Geochemical and petrological characterization pointed to input of terrigenous organic matter and redox conditions of the depositional environment as factors that govern the ability of the coal measure source rocks in hydrocarbon generation in the Xihu Depression. In this regard, the sedimentary organic facies in the Pinghu Formation were classified into four predominantly terrigenous and one mixed-source subfacies, which all varied in carbon and hydrogen content. The coal measure source rocks in the carbon- and hydrogen-rich tidal flat-lagoon exhibited the highest hydrocarbon generation potential, whereas the mudstone in the neritic facies was the poorest in its hydrocarbon yield. These results suggested that the coal measure source rocks in the Pinghu Formation likely developed in the Hangzhou Slope and the Tiantai Slope, both representing promising sources for oil and gas exploration.     

Enrichment and distribution of shale oil in the Cretaceous Qingshankou Formation,Songliao Basin,Northeast China

The Songliao Basin is a large-scale petroliferous basin in China. With a gradual decline in conventional oil production, the exploration and development of replacement resources in the basin is becoming increasingly important. Previous studies have shown that the Cretaceous Qingshankou Formation (K₂qn) has favorable geological conditions for the formation of shale oil. Thus, shale oil in the Qingshankou Formation represents a promising and practical replacement resource for conventional oil. In this study, geological field surveys, core observation, sample tests, and the analysis of well logs were applied to study the geochemical and reservoir characteristics of shales, identify shale oil beds, build shale oil enrichment models, and classify favorable exploration areas of shale oil from the Cretaceous Qingshankou Formation. The organic matter content is high in shales from the first member of the Cretaceous Qingshankou Formation (K₂qn¹), with average total organic carbon (TOC) content exceeding 2%. The organic matter is mainly derived from lower aquatic organisms in a reducing brackish to fresh water environment, resulting in mostly type I kerogen. The vitrinite reflectance (Ro) and the temperature at which the maximum is release of hydrocarbons from cracking of kerogen occurred during pyrolysis (T_max) respectively range from 0.5% to 1.1% and from 430 °C to 450 °C, indicating that the K₂qn¹ shales are in the low-mature to mature stage (Ro ranges from 0.5% to 1.2%) and currently generating a large amount of oil. The favorable depth for oil generation and expulsion is 1800–2200 m and 1900–2500 m, respectively as determined by basin modeling. The reserving space of the K₂qn¹ shale oil includes micropores and mircofractures. The micropore reservoirs are developed in shales interbedded with siltstones exhibiting high gamma ray (GR), high resistivity (Rt), low density (DEN), and slightly abnormal spontaneous potential (SP) in the well-logging curves. The microfracture reservoirs are mainly thick shales with high Rt, high AC (acoustic transit time), high GR, low DEN, and abnormal SP. Based on the shale distribution, geochemical characteristics, reservoir types, fracture development, and the process of shale oil generation and enrichment, the southern Taikang and northern Da'an are classified as two favorable shale oil exploration areas in the Songliao Basin.     

海上埕岛油田馆上段提液技术政策研究

针对目前胜利油区埕岛油田单井液量低、产油量低的问题展开提高采液量研究。应用油藏工程和数值模拟等方法,研究了该油藏的提液潜力和适合该油藏的提液时机及提液条件。研究结果表明：油藏具备提液的潜力和提液条件,在含水达到70％～80％时提液效果最佳,提液条件是恢复地层压力到原始压力的0．85倍,恢复压力的最佳注采比为1．1,提液最大生产压差为3．5MPa。矿场应用取得了提液增油的明显效果,对海上同类型油田提高注水开发效果具有积极的指导意义。     

Supply of terrigenous organic matter from tidal flat to the marine environment: An example of neritic source rocks in the Eocene Pinghu Formation,Xihu Depression,East China Sea Shelf Basin

The terrigenously-dominated marine shales which were deposited in the lower Eocene Pinghu Formation were thought to be a potential source rock in the Xihu Depression of the East China Sea Shelf Basin. However, the exceptionally high total organic carbon content (TOC, >6% on average) of the tidal sand ridge samples was not compatible with their sedimentary environment, indicating coal-bearing sedimentary debris may have been transferred from the coast to the ocean. In this study, new sights into the origins and supply of organic materials in the coastal environment were proposed in the neritic organic matter of the Eocene Pinghu Formation. A discriminant model was developed using plynofacies analysis data to pinpoint the source of organic materials in marine source rocks. The discrimination results suggested that marine mudstones were associated with tidal flat mudstones rather than deltaic ones. The biomarker characteristics of mudstones deposited in various environments support this assertion, indicating that the supply of plant materials in tidal flats is the primary organic matter source for the marine environment. The organic matter abundance was elevated in tidal flats due to their superior preservation conditions. Additionally, the lithological assemblage of tidal flats suggests that tidal currents can scour marshes and then transport dispersed terrigenous organic materials to neritic areas. These findings indicate that coal-bearing sedimentary debris was likely transferred from the coast to the ocean, and tidal currents are thought to be the dominant mechanism driving organic matter from the tidal to the marine environment.     

埕岛油田海底管道悬空特征及其影响因素

海底管道是海上油气生产的重要设施,而管道悬空是影响其安全运作的主要因素之一。根据海底管道复勘资料,利用ArcGIS对埕岛油田海底管道的在位状态以及分布情况进行分析,重点统计分析了管道悬空特征和悬空规律,并分析了海底管道悬空的原因以及影响因素。结果表明,悬空管道占总调查管道总长度的4.03%,主要分布在水深为5～15 m范围内的三角洲前缘斜坡上。近90%悬空管段的长度<60 m,其中以10～20 m最为常见。超过90%悬空管段的悬空高度<1 m,其中以0.2～0.4 m最为常见。研究区海底管道悬空的主要原因为海床冲刷,其影响因素主要包括沉积物特征、地形地貌以及海洋动力条件。     

青东凹陷断裂特征及其对沉积的控制作用

通过对青东凹陷古近纪的断裂体系和主要同沉积断裂的活动和特征分析,表明区内主要发育NNE、EW、NW向三组断裂体系,NNE向的凹陷边界断裂青东1号断层和EW向的主要二级同沉积断层f1、f2控制了凹陷内次级构造单元的划分,凹陷由北向南依次划分为北部深洼、北部凸起、中部次洼、南部凸起、南部次洼、西南缘缓坡带以及东部陡坡带等7个次级构造单元。研究表明,凹陷内各洼陷的沉降中心在古近纪发生了明显的分异和迁移,这些变化受控于区内主要同沉积断裂的差异活动和演化,青东1号断裂和f3断裂在古近纪的持续活动共同控制了北部深洼的沉积充填,f1和f4断裂分别控制了中部次洼和南部次洼的发育;主要断裂的活动及其组合样式控制着湖底扇、扇三角洲、辫状河三角洲等粗碎屑沉积体系的发育。与生油洼陷相邻的主要同沉积断裂形成的断裂带具备形成砂岩油气藏的各种有利条件,其中东部盆缘断裂带是区内砂岩油气藏勘探最有利的区带。     

蓬莱A油田馆上段Ⅰ油组储层非均质性及其对注水开发的影响

蓬莱A油田目前面临产量递减速度快、层间干扰突出、主力层水淹严重等一系列生产问题,为改善蓬莱A油田馆陶组上段（馆上段）Ⅰ油组的开发效果,明确剩余油的分布特征,开展了蓬莱A油田馆上段Ⅰ油组储层非均质性及其对注水开发的影响研究。结果表明：渗透率非均质性以及分层系数综合反映了Ⅰ油组强层间非均质性,强烈的层间差异导致I油组主力层形成高渗通道,导致综合含水快速上升,非主力层动用程度差;平面非均质性研究发现,平面高渗透率区与渗透率突进系数、渗透率级差高值区以及剩余油饱和度低值区有明显的对应关系,舌进现象严重,方向性强,平面矛盾明显;层内韵律性表明,馆上段Ⅰ油组以正韵律为主,其次是均质韵律,反韵律发育较少,正韵律易形成底部水淹,均质韵律的驱油效果较好。储层非均质性是影响油田开发效果最关键的地质因素,该研究成果为油田分层系开发和井网调整提供了直接的地质依据。     

辽东湾地区Z油田常规砂岩油藏流体分布控制因素

流体分布控制因素是油气勘探开发的重要研究方向。辽东湾海域Z油田沙河街组为典型的常规砂岩层状构造油藏,流体分布复杂。为进一步明确流体分布差异的控制因素,利用油田多年开发的动静态资料,系统梳理流体垂向及平面发育特征,总结沉积和构造双因素对流体分布的控制作用。研究结果表明：Z油田垂向流体分布可划分为连续集中型和多段分散型;平面流体分布主要表现为连片型、分散型、分块型和局部倒置型。平面流体的分布主要受控于砂体平面展布形态和连通性,断层封堵性和断裂组合方式,以及局部复杂化的构造形态;砂体间发育的隔层控制着垂向流体分布。沉积和构造因素的双重影响,加剧了研究区平面及垂向流体分布的差异性,呈现出多流体系统的流体分布特征。系统总结流体分布主控因素,对油田后续高效开发具有较好的指导意义。