共查询到17条相似文献，搜索用时 140 毫秒
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反韵律砂层石油运移模拟实验研究 总被引：13，自引：0，他引：13
反韵律砂层油的运移二维模拟实验研究表明:(1)反韵律砂层在油的运移过程中表现为顶部含油饱和度高,含油厚度小,含油层段平均运聚效率高,含油饱和度具有从上到下逐步降低的特点 ;(2 )在反韵律砂层,油气的运移方向、路径和通道总体表现为自下而上,由复杂趋于简单,并主要受油气充注方向、充注速率和渗透率级差等条件的影响 ;(3)水动力既可以增加反韵律砂层油的运移效率,减小散失量,亦可以降低油的运移效率,增加散失量。注水速率较小时,可以增加反韵律砂层油的运移效率,但注水速率较大时,主要表现为降低油的运移效率 ;(4 )水动力作用降低了反韵律砂层中油的运移速率 相似文献
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三角洲前缘砂体中石油二次运移与聚集过程物理模拟及结果分析 总被引：8，自引：1，他引：7
物理模拟是阐明油气二次运移的效率、机理及其在圈闭中的聚集过程的一个重要途径。针对三角洲前缘砂体这种最有利于油气藏形成的砂体类型,设计了石油在多层均质砂层构成的指状非均质储层运移物理模拟实验模型,来考查石油二次运移的通道、效率和速率。实验表明,石油二次运移的通道十分有限,石油在砂状体的最凸出部位进入储层后,主要沿指状砂体中央有限的通道（约5cm宽）由油源向圈闭运移,而且运移速度很快,约1．4cm/min,通道上含油饱和度较低,约16％。当到达顶部的封闭层后,石油开始聚集成藏。这就表明了石油二次运移、聚集成藏具有沿着有限通道快速、高效运移、聚集成藏的特征,揭示了石油运移“高速公路”的存在和油藏形成与大量排烃同步这一成藏规律。 相似文献
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低渗透砂岩油气成藏特征及其勘探启示 总被引：4，自引：3，他引：1
低渗透油气藏在国内外分布都非常广,占有很大的资源量和储量。低渗透砂岩具有特殊的成藏特征,主要表现在：（1）储层颗粒细、分选差、胶结物含量高,长石和岩屑含量普遍较高,成分成熟度和结构成熟度低,孔隙度、渗透率低,主要为细小孔微细喉型、微孔微喉型,裂缝相对发育,排驱压力大;（2）除了具有一般油气藏的异常高压外,低渗透砂岩油气藏还表现为异常低压,并且出现异常高压和异常低压共存;（3）油气藏内缺乏油（气）水分异,油水关系复杂,常出现油（气）水关系倒置;（4）浮力对低渗透砂岩油气运移的作用非常有限,油气运移的主要动力为异常高压等,油气的运移表现为非达西运移特征,输导体系以裂缝、相对高渗的砂体和局部不整合为主,运移距离比较短,侧向运移不强;（5）低渗透砂岩的含油（气）饱和度一般都小于60%,并且含油饱和度与孔隙度和渗透率的关系比较复杂,储量丰度比较低,主要聚集在岩性或岩性-构造复合圈闭中,受构造影响不大,油气呈大面积分布。因此,低渗透砂岩区的油气勘探应当突破传统的构造高点勘探油气的思想,在构造斜坡下倾部位或向斜区勘探油气,在勘探中注意寻找低渗透砂岩油气富集的“甜点”。
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一种有效追踪油气运移轨迹的新方法--断面优势运移通道的提出及其应用 总被引：16，自引：3，他引：13
作为油气运移的重要通道,断裂的不同部位对油气的输导能力具有很强的不均一性,从而造成沿油源断裂分布的油气圈闭具有明显的油气差异聚集结果。断而优势运移通道的提出改变了以往人们认为开启的断裂都是油气运移通道的错误观念,强调只有沿着断面优势运移通道寻找勘探目标,才可能发现油气藏。本文通过分析断裂带输导能力的不均一性,提出断而优势运移通道概念及其油气汇聚运移原理,断面优势运移通道分析步骤和方法,并以柴达木盆地北缘儿条主要的控油气断裂为例,分析了不同部他油气运移的优势运移通道并对其附近的油气圈闭含油气性进行了评价,结果与勘探成果相符。 相似文献
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断裂结构对油气运移的影响是当前油气输导体系研究的前沿与薄弱环节。本文在调研断裂结构及其流体流动机制的基础上,利用物理模拟实验研究断裂带油气幕式运移过程,探讨断裂带油气运移机理及相关问题。实验结果表明,断裂内部结构控制着油气运移的路径和方式,含油饱和度在一定程度上影响油气运移的路径;破碎带是油气幕式运移的优势通道,且油气聚集成藏的潜在圈闭为位于油源断裂主动盘一侧的圈闭。单次幕式充注过程中运移量与时间之间的对数型关系表明,流体沿断裂幕式运移具有非线性流的特征,且流动速率可能介于一个相对固定的范围,其数量级约为10~2~10~3m/a;流体沿断裂幕式流动过程包含高速非线性流、过渡流动机制和线性达西流3种流体流动机制,其间的相互转换是一个多物理场相互作用的复杂过程。此外,断层体油气藏的形成条件为油气沿断裂运移时,运移动力与阻力在断裂带内达成平衡状态。 相似文献
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泌阳凹陷孔隙流体压力及油气运移特征 总被引：4，自引：0，他引：4
本文依据流体压力、油气成熟度及泥岩孔隙含油饱和度,讨论了泌阳凹陷油气初次运移的深度、时期和动力,初次运移与二次运移的关系以及油气聚集等问题。并指出第四排液组合所排出的大量油气的下落有待进一步查明。 相似文献
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莲花油层中粘土矿物分布规律研究 总被引：3，自引：1，他引：3
辽河高升油田莲花油层富含稠油,搞清储层中粘土矿物的类型、含量、平面和纵向分布规律对整个稠油油藏开发方案的设计、油层保护、提高采收率等开发措施实施和稠油油藏形成条件等研究都具有极其重要的意义。本文利用X-衍射、电镜、热反应实验对高升油田莲花油层中的粘土矿物进行了系统研究。研究表明,莲花油层中的粘土矿物以蒙脱石为主,粘土矿物类型、含量分布主要受岩石类型和沉积相控制,含油饱和度大小对粘土矿物类型影响不大。蒸汽驱采油会导致储层中蒙脱石的含量减少,增加储层的微观非均质性. 相似文献
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利用填装玻璃微珠的玻璃管模型,观察静水条件下油在饱含水孔隙介质中靠浮力形成优势运移路径,以及随后沿已形成的路径运移的过程。实验发现,运移的形成过程、路径的形态以及油在已形成的路径内的运移均表现出强烈的非均一性;前缘跳跃、分段运移等现象揭示了运移过程的复杂性。运移路径一旦形成,直到运移结束,其形态和空间展布特征基本一致;再次注入的油仍基本沿原来的路径运移。连续油柱的浮力及该连续油柱所接触到的孔道的毛细管力之间的复杂关系决定了油气非均匀运移路径的形成过程及其形态特征。 相似文献
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Three-Phase Secondary Migration of Hydrocarbon 总被引：1，自引：0，他引：1
The objective of this work is to study the migration of hydrocarbons from a source rock into possible reservoirs. In particular, we consider simultaneous migration of gas and oil through a water-filled carrier bed and how this flow might result in characteristics that could be interpreted by nontraditional exploration methods. In the modeling, one-dimensional, immiscible, isothermal flow is assumed, and capillary effects are excluded. The seal is modeled as a layer of very low permeability. Our analysis is based on the method of characteristics and simple wave theory. Waves are changes in saturation(s) that move through a reservoir or carrier bed at a characteristic velocity. The analysis does not require capillary forces to trap hydrocarbons, but relies on nonlinear wave phenomena to explain migration and entrapment. No doubt, capillary forces are important in secondary migration and entrapment. Our treatment can be viewed as being part of a more complete theory on secondary migration, considering hydrodynamic effects here. We demonstrate that capillary forces are not the only mechanism that can cause trapping of hydrocarbons. We focus on the role of gas in the trapping of oil. If the seal is slightly permeable, some oil will flow through it. With gas present, the efficiency of the seal can increase, and oil can be completely trapped by a structure that would otherwise be permeable. For example, gas, being much more mobile than oil, can form a bank at the interface between two layers that have a modest permeability contrast. This gas bank will have a relatively large gas saturation. This will decrease the relative permeability to oil and completely trap subsequently migrated oil. Oil can also be trapped even when no gas bank is formed at the permeable seal. Features of this problem that might affect a seismic signal are (1) the existence of gas above (caused by a stow leakage of gas) and below a modest seal, (2) the gas leakage itself, (3) modest saturations in the oil column, and (4) overpressuring in the gas column. 相似文献
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The analysis of oil trapped during secondary migration 总被引：1，自引：0，他引：1
During secondary migration, there is an opportunity for oil to be trapped as fluid inclusions (FIs) within framework grains such as quartz and within diagenetic cements that have a crystalline structure. Oil saturation on migration pathways remains relatively low, so typically fewer oil inclusions get trapped compared with samples from an oil column. Geochemical analysis of the much smaller amounts of inclusion oil present in samples from interpreted oil migration pathways has been attempted for two samples from the Champagny-1 and Delamere-1 wells in the Vulcan Sub-Basin, northern offshore Australia. A combination of petrographic analysis, bulk geochemical inclusion analysis and log evaluation confirmed that both samples were from oil migration pathways. Despite the small number of oil inclusions, reliable geochemical data were acquired from both samples that were significantly above the levels detected for the system and outside-rinse blanks. The FI oil trapped on the interpreted oil migration pathway in Champagny-1 was generated from clay-rich marine source rock with little terrigenous organic matter input. It was generated at peak oil window maturity and correlates best with oils derived from the Late Jurassic Lower Vulcan Formation. In contrast, the Delamere-1 FI oil contains evidence of greater input of terrigenous organic matter and was generated at early oil window maturity. This FI oil also contains a signature of a biodegraded component, which could have been generated either from the Middle Jurassic Plover Formation, or from an older source rock. These data indicate that it is feasible to geochemically map migration pathways across prospects or basins, and to analyse palaeo-oil compositions in oil zones where the few inclusions get trapped. This also suggests that the few oil inclusions that sometimes occur in Proterozoic or Archaean rocks may be analysable in the future, which would provide relatively pristine and robust data on the composition and diversity of Earth’s early biosphere. 相似文献
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混合润湿孔隙介质普遍存在, 使得多相流体渗流过程十分复杂, 但对其研究和认识至今仍很肤浅, 是油气运移成藏、剩余油气分布等方面研究中必须解决的关键难题。本文通过对饱和水的混合润湿模型进行油自吸实验, 观察不同混合润湿程度条件下油自吸运移过程, 分析认识混合润湿孔隙介质中多相渗流的机理。实验结果表明, 在混合润湿孔隙介质中油是否能够自发地运移与介质中亲油颗粒的比例关系密切, 但并非简单的单调变化关系。研究认为, 亲油颗粒与亲水颗粒随机分布, 导致多种与喉道配位颗粒的亲油-亲水关系, 当亲油颗粒比例占优才表现为亲油喉道。机理上, 混合润湿孔隙介质中油自吸运移的发生与否及程度取决于亲油喉道在空间上的连通程度, 后者与孔隙介质中亲油颗粒比例相当。仅有当孔隙介质中亲油颗粒足够多, 且组成的亲油喉道能够相互接触形成连续亲油通道时, 油才能够通过自吸运移进入多孔介质。 相似文献
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《Applied Geochemistry》2006,21(7):1152-1168
Powder samples of two inactive borosilicate glasses (MW and SON68), used as references for vitrified nuclear waste in Switzerland, were leached statically in pure water over more than 12a at 90 °C. Solution aliquots were taken at regular intervals in order to investigate the glass dissolution kinetics and the retention of elements representing radionuclides. At 5.7 and 12.2a, single tests were interrupted to investigate the corroded samples.Boron and Li concentration data indicate that the glass corrosion kinetics of the MW glass is about 10 times faster than for the SON68 glass, both in the transient and asymptotic phase of the leaching process. The alteration products were studied by X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM-STEM) coupled with energy dispersive spectrometry (EDS) analyses. Alteration of the MW glass produced abundant magnesian clay minerals, as well as nanoparticles of lanthanide and Zr phosphates, whereas only small amounts Ca–Zn–Fe–Ni clay minerals were formed as alteration product of SON68.Retention factors were above 99% for most trace elements, indicating almost quantitative fixation of many radionuclides in the secondary phases. Solution concentration data were used to calculate aqueous speciations and saturation indices of potential secondary solids. The solutions are close to saturation with respect to simple lanthanide phosphates (in agreement with the TEM data) and quartz. The presence of quartz in the altered SON68 samples is corroborated by XRD data.In conclusion, the corrosion and radionuclide retention properties of SON68 seem to be more favorable than those of the MW glass. A major finding of this investigation was that glass degradation may strongly depend on minor compositional changes in the glass composition. The presence of Mg in the MW glass triggers the nucleation of secondary clay minerals, thereby promoting glass corrosion via silica removal. In the Mg-free SON68 glass the formation of clays, and hence the glass degradation, were considerably slower. 相似文献
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A dynamic theory of hydrocarbon migration 总被引：1，自引：0，他引：1
This paper presents a new analysis of secondary migration of hydrocarbon that does not require capillary forces for trapping, but instead uses the method of characteristics and wave theory. The waves change speed and either reflect or refract (or partially reflect and partially refract) as they contact with layers of different flow capacities. Reflection of a certain wave from a boundary starts hydrocarbon accumulation below that boundary. The method is easy to use and conforms readily to graphical solution. For the sake of simplicity there is only two-phase flow. The application of this method gives new insights into the physics of migration and entrapment of oil. The method gives realistic times for oil accumulation and points to oil generation rate as the most sensitive variable. Oil and water densities, viscosities, and permeability are also important. We find that at the very small generation rates usually assumed the time required to develop a given column thickness is insensitive to the distance from the source rock. In general, the method also predicts a non-uniform saturation in the oil column caused by an interaction between buoyancy and viscous forces. Being based on the dynamic interactions of viscous and buoyancy forces, our theory is considerably at odds with hydrostatic approaches. We assume no capillary pressure, one-dimensional flow, and no regional groundwater flow, conditions which are not realized in actual migration. The theory should be viewed therefore as an end member of a more general theory; nevertheless, the largely graphical solutions give fundamental insights that are difficult to obtain by other techniques. 相似文献