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1.
深化含油气沉积盆地的压力结构研究,厘清异常压力的空间展布,对划分含油气系统、评价有利输导体系与明确勘探甜点区带具有重要的理论和实践意义。为深化渤海湾盆地富油凹陷的油气二次勘探,本文以歧口凹陷为研究对象,对其压力结构进行重点刻画。在实测地层压力的校正下,综合单井、连井和二维地震地层压力结构分析,厘清了歧口凹陷的压力结构特征,识别出4类纵向压力结构:①单超压带结构;②双超压带结构;③多超压带结构;④静水压力结构。纵向上,歧口地区存在3类纵向压力系统样式——单超压系统、双超压系统、静水常压系统。双超压系统是歧口凹陷的主要压力系统样式,广泛发育于主凹和各大次凹;从凹陷中心向盆地边缘,双超压系统逐渐向单超压系统、静水常压系统过渡。单超压系统主要分布于盆地边缘的斜坡和潜山区,如歧北高斜坡、羊三木-扣村潜山等。静水常压系统则主要分布在离深凹区更远的沈青庄潜山和埕北斜坡区域。上部超压系统和下部超压系统的顶板分别位于东营组和沙三段内部,侧向上受盆地边缘和深大断裂控制。上部超压系统的形成主要受欠压实作用控制,以歧口主凹为中心呈环带分布;而下部超压系统的形成主要受生烃作用控制,以主凹和几大次凹为中心分布。未来,下部超压系统中保存的天然气将成为歧口地区超深层天然气勘探的重点对象。  相似文献   

2.
渤海湾盆地车镇凹陷超压发育广泛,基于钻井实测(DST)资料和测井资料,对车镇凹陷地层超压特征及超压与油气的赋存关系进行了分析。研究结果表明,始新统沙河街组三段和四段地层发育异常高压,异常压力主要出现在埋深2 100m以下地层中,最大压力系数达到1.78。车镇凹陷泥岩声波时差对地层超压有较好的响应关系,在超压层段,声波时差明显偏离正常压实趋势,具有较高的声波时差值,通过典型单井泥岩声波时差确定了正常声波时差趋势线,并建立了地层压力预测模型,综合主要超压区域单井预测压力,分析了超压顶界面主要在2 100~3 200m之间,发育单超压系统。剖面上压力体分布特征表明,压力体形成以洼陷深部位为中心向周围逐渐递减的压力结构。超压对油气运移和赋存起着控制作用,套尔河洼陷油藏主要分布在压力系数为1.6的压力体外围;车西洼陷油藏主要分布在压力系数为1.4的压力体外围。  相似文献   

3.
异常地层压力是现今琼东南盆地深水区油气勘探面临的一个重要地质问题。运用最新构建的基于孔隙性岩石静力平衡方程的地层压力预测模型,确定了中央坳陷带异常地层压力分布特征,并分析了不同凹陷超压发育特征存在差异的原因。研究表明:(1)中央坳陷带单井压力剖面存在常压型、单段超压型、超压囊型和旋回超压型4种类型;(2)超压顶界面埋深从陆架向深海、从西向东逐渐增大;(3)纵向上,从浅水区到深水区、由西向东超压跨越层位逐渐增多,从浅层到深层超压强度逐渐增大,但乐东、宝岛和北礁凹陷具有"双层式"超压结构;平面上,以乐东、陵水、松南和宝岛4个凹陷为强超压中心,超压强度向南北两侧(低)凸起逐渐降低。总体上中央坳陷带超压分布具有一定规律性,但是不同凹陷间超压分布特征又具有差异性。这种差异主要受到晚期快速沉降速率、泥岩发育特征、烃源岩成熟度和断裂发育特征等因素的影响。  相似文献   

4.
歧南凹陷下第三系成岩阶段划分   总被引:2,自引:0,他引:2  
歧口凹陷位于渤海湾盆地黄骅坳陷中部,以南大港断裂带为界,分为歧北凹陷和歧南凹陷两个次级构造单元。新生界从下到上发育下第三系、上第三系和第四系。下第三系生、储油层发育,是主要的勘探目标层段。歧口凹陷已发现的油田大多分布在歧北凹陷,且以中、浅层居多。随着歧南凹陷油气勘探的突破,“十五”期间中国石油天然气股份有限  相似文献   

5.
以实测地层压力为限定,利用声波测井、波阻抗反演数据对南堡凹陷的地层压力进行了分析。结果显示,南堡凹陷在2.8 km以下开始出现较明显的异常压力现象;3 km以下,超压明显,最大压力系数可达1.6。压力异常现象主要出现在古近系东营组中下段以及沙河街组。纵向上,南堡凹陷存在常压带、第一超压带和第二超压带3层结构,中间由致密的岩性段分隔。平面上,剩余压力具有继承性分布特点,古近系剩余压力中心位于林雀次凹和曹妃甸次凹一带,由凹陷中心向周缘的南堡1、2号构造以及老爷庙构造剩余压力逐渐降低。异常压力分布与油气储量分布有明显关系,南堡凹陷已发现的石油储量主要分布于超压带顶部,超压对油气成藏控制作用明显。  相似文献   

6.
基于东营凹陷草113-郑气2地区现今实测地层流体压力和典型剖面压力分布特征,研究认为这个地区地层异常压力主要发育在Es3中、Es3下和Es4,纵向上可分为3个压力系统:正常压力、高压异常和异常高压。应用盆地数值模拟法恢复了草113-郑气2地区的压力演化史,结果表明超压主要经历了早期形成、下降调整和晚期发育3个阶段。分析证明超压主要由欠压实作用、烃类生成作用及蒙伊转化脱水作用造成,其演化阶段与油气成藏期具有很好的相关性,是油气运移的动力。  相似文献   

7.
异常地层压力是沉积盆地中的常见现象,其与成烃成藏关系密切。本文以欠压实带的有无、欠压实的幅度大小、持续的深度范围,将大民屯凹陷泥岩压实类型分为4种,即强烈欠压实型、欠压实型、局部欠压实型以及正常压实型。利用测井、地质和钻井资料,运用等效深度法分析了该区现今异常压力的展布特征并探讨了其成因机制。5条超压分布剖面揭示大民屯凹陷的超压体系在凹陷内分布较广泛,纵向上基本可分为上、中、下3套压力体系。①纵向上,上部即Es23段及其以上地层基本为正常压力系统;中部即Es33段为弱超压系统;下部即Es43和Es4地层为强超压系统。②横向上,超压在洼陷中心强烈发育,到斜坡和隆起带渐渐演变为正常压力。压实不均衡和生烃作用是大民屯凹陷超压发育的主要机制。  相似文献   

8.
库车坳陷东部气藏既有常压气藏,也有超压气藏,对气藏实测压力特征进行了系统分析,探讨了地层压力与油气成藏之间的关系。结果表明,库车坳陷东部地层压力在结构上划分为膏盐岩封闭层压力结构和泥岩封闭层压力结构,压力分布在22.8~107.5 MPa之间,压力系数分布在1.16~2.29之间,常压和超压并存,且以超压占优势。纵向上,浅部一般为常压,深部一般为超压;平面上,压力和压力系数均由南向北表现出逐渐降低的趋势。在源-储压差作用下,深部超压流体对浅部的储层发生强充注。气藏压力反映出各气藏保存条件存在差异,迪那地区地层保存条件最好,依南2井次之,依深4井最差。根据地层压力和油气藏剖面特征,库车坳陷东部存在远源封闭型强超压成藏、近源半封闭型超压成藏和远源封闭型常压成藏3种油气成藏模式。  相似文献   

9.
歧口凹陷复式含油气系统及构造控藏模式   总被引:2,自引:2,他引:0  
构造层序和沉降史分析表明,歧口凹陷在新生代具有显著的幕式构造-沉积演化特征,经历了古近纪裂陷期和新近纪裂后期二个构造活动期、古近纪的裂陷Ⅰ幕和Ⅱ幕、新近纪的稳定热沉降幕和加速沉降幕四幕构造运动。结合凹陷内部重要的构造转换界面、结构和构造演化特点,以及各阶段构造样式和油气成藏聚集规律,将歧口凹陷划分为四大含油气系统:孔店断陷-潜山型含油气系统(Ek)、歧口陡坡断阶型含油气系统(Es)、歧口缓坡断阶型含油气系统(Es1+Ed)、歧口坳陷型含油气系统(N)。通过构造组合样式和油气聚集关系研究,建立了凹陷内部掀斜断块-地垒潜山和凹陷边缘断阶-古隆起披覆潜山构造控藏模式。  相似文献   

10.
物源问题一度成为制约歧口凹陷歧南低斜坡沙三段油气勘探的焦点。在综合分析沉积期古地貌及沟谷展布特征、地震属性特征、碎屑颗粒组分、重矿物组合特征、砂体展布特征等资料基础上,探讨歧南低斜坡沙三段沉积时期物源体系特征及分布。结果表明:歧南低斜坡沙三段存在3大物源体系,其中,西部歧南水道物源体系延伸距离远,波及范围大,控制了歧南低斜坡沙三段沉积时期砂体的形成与分布。进一步研究表明,古物源与沉积体系具良好的空间配置关系。受歧南水道主物源体系控制,低斜坡发育辫状河三角洲前缘沉积,砂体分布具"埕宁隆起物源供砂,歧南水道沟槽输砂,物源体系-坡折带联合控砂"的内在机制。物源方向的确定对研究沉积体系展布、砂体分布及有利勘探区预测具重要意义。  相似文献   

11.
渤海湾盆地渤中坳陷储层超压特征与成因机制   总被引:1,自引:0,他引:1  
刘晓峰  解习农  张成 《地球科学》2008,33(3):337-341
对储层超压的分析,有助于理解渤中坳陷油气晚期快速成藏机理.利用RFT实测储层压力资料分析了渤中坳陷储层超压的特征和成因.渤中坳陷存在3套储层超压系统:浅层明化镇组-馆陶组储层超压系统、中层东营组-沙河街组-孔店组储层超压系统、基底(中生界及以下地层)储层超压系统.渤中坳陷的储层超压可能主要是由3种机制综合引起的,即不均衡压实作用、超压传递作用和裂解气的生成作用.少量保存的传递超压是深部超压流体注入的"化石",它是超压背景下油气快速充注成藏的结果.  相似文献   

12.
The distribution and genetic mechanisms of abnormal pressures in the Bohai Bay Basin were systematically analyzed. Abnormal pressures are widely developed in the Bohai Bay Basin, primarily in the Paleogene E2s4, E2s3, Es1, and Ed formations. From the onshore area of the Bohai Bay Basin to the center of the Bozhong area, the top depth of the overpressured zone in each depression increases gradually, the overpressured strata in each depression gradually move to younger formations, and the pressure structure successively alters from single-bottom- overpressure to double-bottom-overpressure and finally to double-top-overpressure. The distribution of overpressured area is consistent with the sedimentary migration controlled by the tectonic evolution of the Bohai Bay Basin, which is closely related to the hydrocarbon-generation capability of active source rocks. The overpressured strata are consistent with the source-rock intervals in each depression; the top of the overpressured zone is synchronous with the hydrocarbon generation threshold in each depression; the hydrocarbon generation capability is positively correlated with the overpressure magnitude in each formation. Undercompaction was the main mechanism of overpressure for depressions with fluid pressure coefficients less than 1.2, whereas hydrocarbon generation was the main mechanism for depressions with fluid pressure coefficients greater than 1.5.  相似文献   

13.
Overpressure systems are widely developed in the central depression and paleo-uplift in the Yinggehai and Qiongdongnan basins. They can be divided into three types according to the origin of abnormally high formation pressure in the reservoirs, i.e. the autochthonous, vertically-transmitted and laterally-transmitted types. The autochthonous overpressure system results from rapid disequilibrium sediment loading and compaction. In the allochthonous overpressure system, the increase of fluid pressure in sandstone originates from the invasion of overpressured fluid flowing vertically or laterally through the conduit units. The autochthonous overpressure system occurs in the deep-lying strata of Neogene age in the central depression of the Yinggehai and Qiongdongnan basins. The vertically transmitted overpressure system is developed in the shallow strata of Late Miocene and Pliocene ages in the diapiric zone of the central Yinggehai basin, and the laterally transmitted overpressure system occurs in the Oligo  相似文献   

14.
沉积盆地超压系统演化、流体流动与成藏机理   总被引:47,自引:1,他引:47  
压实不均衡和生烃 ,特别是生气作用是可独立产生大规模超压的主要机制。根据超压顶面的几何形态、超压的发育机制、超压系统的内部结构和演化 ,可将超压系统分为封隔型超压系统和动态超压系统 2类。超压流体的排放包含 2个层次 :从超压泥岩向邻近输导层的初次排放和从超压系统向上覆常压系统或相对低超压系统的二次排放。封隔型超压系统的流体排放主要通过周期性顶部封闭层破裂进行 ,动态超压系统的流体排放可能主要通过断裂或其它构造薄弱带、超压顶面隆起点和超压系统内构造高点处的水力破裂集中进行。超压盆地油气倾向于在静水压力系统富集 ,并具有幕式充注特征 ,但超压系统既可发育商业型油藏 ,也可形成大型气藏。  相似文献   

15.
歧口凹陷伸展滑脱构造系统的厘定及其地质意义   总被引:12,自引:11,他引:1  
歧口凹陷是渤海湾盆地中部黄骅坳陷的一个次级凹陷,凹陷内蕴藏着丰富的油气资源,是渤海湾盆地油气勘探的重点区块。在叠前三维地震剖面精细构造解释分析的基础上,识别和建立了歧口凹陷伸展滑脱构造系统。该系统分为南部伸展滑脱系统和北部伸展滑脱系统,南部滑脱系统以羊二庄滑脱断裂为主体,连接张东断裂、张北断裂、赵家堡断裂等伸展断裂组合而成,北部滑脱系统以沧东断裂为主体,连接大张坨断裂、海河断裂、港西断裂、港东断裂、南大港断裂等伸展断裂构成。在平面上两大滑脱系统各自构成一个帚状断裂体系,在剖面上表现为叠瓦式几何形态,与次级断裂常构成"Y"型或复"Y"型组合样式,向深部会聚到主滑脱面。歧口凹陷古近纪时期变形基本都限定在区域性底滑脱界面之上,并具有多层次滑脱构造特征,控制和影响了歧口凹陷不同级别的构造形态和组合样式,同时对盆地的沉降过程也有重要的控制作用。歧口凹陷伸展滑脱构造为本区的油气储集和运移提供了有利条件,并初步探讨了歧口凹陷伸展滑脱构造的动力学条件。  相似文献   

16.
The Damintun depression is one of the four depressions in the Liaohe basin in northern China, and is a rift basin developed in the Paleogene. This paper discusses in detail the characteristics of pressure and fluid potential of the Damintun depression based on a synthesis of the data from boreholes, well tests and seismic surveys. Data from sonic logs, well tests and seismic velocity measurements are used to study the pressure characteristics of the areas. From the sonic log data, shales can be characterized as normally pressured, slightly overpressured or highly overpressured; from the well test data, the pressure-depth gradient in oil-producing intervals implies hydrostatic pressure in general. Most seismic profiles in the Damintun depression are of sufficiently high quality for seismic velocities to be measured. The fluid pressures, excess pressures and pressure coefficients in 47 representative seismic profiles are predicted using formula calculation methods, and further transformed to fluid potenti  相似文献   

17.
Pressure measurements using drill stem tests and estimates from log data calculation indicate that three vertically stacked regional pressure compartments exist in the Qikou Depression of Bohai Bay Basin, N. China. The compartments comprise hydrostatic, upper weak, and lower overpressure systems. Laterally, overpressure (pressure coefficient > 1.2) occurs in the deeper areas and weakens gradually from the centre to the margin of the depression. The accumulation of oil and gas exhibits the interesting characteristics of oil‐bearing layers above gas‐bearing layers in the Qikou Depression. The pattern can be accounted for by the evolution of overpressure system, the maturity process of the source rock and the main fault activity. In the late Dongying Formation (Ed, 30 Ma), the lower overpressure system began to form shape, and the hydrocarbon sources generated a large volume of oil. However, because there was no migration pathway, the oil only accumulated in the original strata. In the late Guantao Formation (Ng, 12 Ma), the gas was generated, the upper overpressure system formed gradually, and the activity of the main fault gradually increased. Then, the overpressure pushed the early gathered oil to flow from the lower overpressure system into the upper overpressure system. Afterwards, the activity of the main fault decreased again and remains weak until now. Thus, later generated natural gas cannot keep migrating along the main fault and can only accumulate in the lower overpressure system. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

18.
The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient over 2.2. Two types of vertical overpressure configuration can be identified by electronic logs and mud pressure, based on the calibration with the test pressure. The first is a double overpressure configuration, in which the middle low overpressure zone divides the entire overpressure zone into two zones. The double overpressure configuration lies primarily in the western part of the basin. The second is a single overpressure configuration, in which overpressure increases with depth. The single overpressure configuration lies primarily in the eastern part of the basin. Distribution maps of the overpressure top and overpressure horizons show three important characteristics: (1) The distribution of the pressure coefficient is not uniform. There are many low overpressure zones against a background of high overpressure. (2) The pressure coefficient in the western area is greater than in the eastern area. The maximum pressure coefficient in the western area is greater than 2.2. (3) There is a low overpressure interval between the high overpressure zones in the western area. Based on the overpressure distribution, some important implications for hydrocarbon exploration can be drawn. In the Qiongdongnan Basin, it has been shown that normal pressure zones are favorable for hydrocarbon accumulation, and strongly overpressured zones (pressure coefficient greater than 1.8) are unfavorable for hydrocarbon accumulation. Accordingly, the NW low overpressure belt around wells R, Q and S should be beneficial for hydrocarbon accumulations, and should be considered as the next exploration play in the Qiongdongnan Basin. Theoretical hydrofracture calculation and interpretation of the sand injectites indicate the presence of widespread hydrofractures in the basin. Comparison between the sealing capacities of the double overpressure and single overpressure configurations shows that the former is superior for hydrocarbon accumulation and preservation. Because of the strong sealing capacity provided by the displacement pressure and pore pressure difference between the seal rock and reservoir in the double overpressure configuration zone, hydrocarbons barely penetrate the seal rock in the middle low overpressure zone. Therefore, the exploration interval should be within and below the middle low overpressure zone in the western basin.  相似文献   

19.
储层超压流体系统的成因机制述评   总被引:10,自引:2,他引:10  
储层超压流体系统的基本要素包括压力封闭层、超压流体、岩石骨架和输导通道;由于储层超压系统所处环境的差异,其超压强度可以大于、等于和小于环境的超压强度;超压传递、不均衡压实、裂解气的生成和浮力作用是储层超压形成的重要机制;大多数储层超压是油气聚集的结果;超压释放是超压流体系统内部油气成藏的必要条件,研究储层超压流体系统将更直接地揭示超压盆地中油气运移和聚集的过程。  相似文献   

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