共查询到20条相似文献，搜索用时 15 毫秒
1.
Fluid overpressure as a control on sandstone reservoir quality in a mechanical compaction dominated setting: Magnolia Field,Gulf of Mexico 
下载免费PDF全文
下载免费PDF全文 The reservoir quality (porosity and permeability) of deeply buried hydrocarbon reservoir sandstones in sedimentary basins is significantly affected by burial diagenesis. Many deep reservoirs develop anomalous fluid overpressures during burial. Previous studies on the effect of fluid overpressure on reservoir quality in these deep reservoirs have been inconclusive because of the difficulty in constraining the individual contributions of various porosity preserving factors that are simultaneously active in these reservoirs. Owing to its rapid burial and low burial temperatures, the Neogene gravity‐flow sandstone reservoirs from the Magnolia Field, Gulf of Mexico, offers a unique opportunity to investigate in isolation the effect of fluid overpressure on reservoir quality. Examination of petrography, pore pressure and routine core analysis datasets showed a positive correlation between high fluid overpressure and enhanced reservoir quality. This study confirms that fluid overpressure preserves reservoir quality in deeply buried sandstone reservoirs in compaction dominated, high sedimentation basin settings. 相似文献
2.
A discussion is given of the impact of normal slant faults on basinal structure, compaction, fluid overpressure development, and thermal effects in sedimentary basins. Faults which are hydraulically closed or open to fluid flow are examined in a dynamical two-dimensional fluid/ flow compaction model.
From this numerical investigation three dominant factors characterize the effects of single and multiple faults with open or closed hydraulic behaviours: (i) there is a difference in excess pressure for fault planes with open or shut hydraulic conditions, but the neighbourhood where the effect of the fault is dominant is fairly localized (to within about half a kilometre or so laterally from the fault plane); (ii) the lateral and vertical motion of sediments between faulted blocks induces a thermal difference prior to, during, and post-faulting, which can play a role in influencing hydrocarbon generation, migration, and accumulation; (iii) porosity retention and permeability modification by fault development could influence hydrocarbon exploration decisions regarding sealing, migration pathways, and fluid retention.
The general patterns of slant fault effects described here should prevail in most geological situations, because the numerical experiments are designed to illuminate sharply the dominant response characteristics within the framework of simplified situations. 相似文献
From this numerical investigation three dominant factors characterize the effects of single and multiple faults with open or closed hydraulic behaviours: (i) there is a difference in excess pressure for fault planes with open or shut hydraulic conditions, but the neighbourhood where the effect of the fault is dominant is fairly localized (to within about half a kilometre or so laterally from the fault plane); (ii) the lateral and vertical motion of sediments between faulted blocks induces a thermal difference prior to, during, and post-faulting, which can play a role in influencing hydrocarbon generation, migration, and accumulation; (iii) porosity retention and permeability modification by fault development could influence hydrocarbon exploration decisions regarding sealing, migration pathways, and fluid retention.
The general patterns of slant fault effects described here should prevail in most geological situations, because the numerical experiments are designed to illuminate sharply the dominant response characteristics within the framework of simplified situations. 相似文献
3.
The confining pressure exerted by the prograding Tertiary clastic wedge has caused extensive salt deformation in the Gulf of Mexico. The high rates of lateral salt motion from the Louisiana shelf break to the Sigsbee Escarpment are expected to have significant impact on the dynamic evolution of the surrounding sedimentary formations. The evolution of fluid pressure in supra- and subsalt sediments has been modeled in a series of pseudo-wells along a profile intersecting numerous salt sheets and structures offshore Louisiana. Based upon the estimated rates of salt movement, the timing can be determined for insertion/depletion of salt in the sediments as the salt has moved through, and by, sediments on its way basinward. An execution of a series of I-D fluid/flow compaction models has enabled estimation of the spatial variation in overpressure build-up with time; indicating that overpressure uncertainty is about 10–20% about a mean of about 40 atmospheres, with uncertainties on salt thickness and salt speed roughly comparable in importance in contributing to the uncertainty. The quantitative behaviors suggest that the speed of lateral salt insertion and the thickness of the salt are the main factors causing anomalous overpressure build-up. A quantification of the dynamic behaviors is significant when modeling the timing of potential trapping of hydrocarbons beneath salt sheets and of the subsalt overpressure to be expected in subsalt drilling. 相似文献
4.
沉积盆地中超压广受关注,但对超压传导规律认识的不足制约了高压领域的油气勘探.以准噶尔盆地阜康凹陷侏罗系为例,通过超压类型地质综合判识、关键超压表征参数的理论计算及流体包裹体压力恢复,首次认识到了垂向传导对于储集层超压的重要贡献,结合压力垂向传导机制及过程,探讨了油气藏的运聚及泄露意义.研究结果表明,侏罗系超压由4类超压环境中7种致压因素引起,经历2期大规模压力跨层垂向传导,储集层段发育以垂向传导为主因的复合超压,形成3类不同动力特征的油气藏.压力垂向传导是储集层超压的主要成因机制,断-盖的力学性质、差应力及流体压力等3类因素控制压力垂向传导,传导背景下,形成3类与传导作用有关的油气藏:受断层垂向传导控制的超压油藏、受连通砂体侧向传导控制的超压油藏以及超压界面上的常压油藏,上述3类油气藏的运聚及泄露特征差异较大. 相似文献
5.
The dynamical evolution of sediments in basins, and their compaction, is the underpinning keystone on which rests the ability to model thermal history of the basin and hydrocarbon generation, migration, and accumulation histories. A presentation is given of the dynamical tomography method, which inverts dynamical indicators to evaluate the parameters in a 1-D fluid-flow/compaction model, including values dealing with geological events as well as values dealing with intrinsic, or assumed, lithologic equations of state. Synthetic tests illustrate the operation of the system. Using observed downhole quantities: total depth, formation thicknesses, variation of porosity, permeability, and total fluid pressure with depth from the Navarin Basin COST No. 1 well, Bering Sea, Alaska, the numerical algorithm was tested and found to be effective in a nonlinear inverse sense to determine and/or constrain the parameters entering quantitative models of dynamical sedimentary evolution. The predictions of present day total depth, formation thicknesses, porosity, permeability, and fluid pressure with depth are close to the measured data. The minimization provides the uncertainty in each parameter and so the geohistory of a well can be defined better. 相似文献
6.
莺歌海盆地高温超压环境下储层物性影响因素 总被引：7，自引：1，他引：6
莺歌海盆地由于独特的沉积地层和温压场特征, 使得盆地内的储层成岩演化也具有了与众不同的过程和特点.通过对莺歌海盆地内有钻井证实的两种超压体系类型(自源型和传导型) 的对比研究, 阐明了其成因差别及其石油地质意义, 并详细论述了高温超压环境下储层物性的影响因素: (1) 储层物性主要受沉积环境和成岩作用控制; (2) 高地温梯度使砂岩的孔隙度衰减较快; (3) 超压保存了一部分原生孔隙, 这是深部储层还具有高孔隙度的最主要原因; (4) 超压通过溶解等成岩作用产生了一些次生孔隙; (5) 流体压裂突破过程中产生了大量的裂缝, 有效地提高了储层渗透性. 相似文献
7.
评述异常压力研究中的石油地质学新思想 总被引：15，自引：1，他引：14
在对异常压力的认识不断深化的过程中,凝结出许多新的概念和思想,为现代石油地质学理论注入了新的内容。关于超压生成与有机质成熟-生烃的关系虽有争议,但大多数主张超压对有机质成熟和生烃起抑制作用;在超压的背景下,生烃、排烃以及烃类的运移和聚集常呈现出幕式的特征;压力驱动是流体活动和油气运移的重要动力;动态运移通道是油气运移的新型通道;通常压力过渡带是油气聚集的有利场所;在超压的含油气盆地中,可能发现的非传统油气聚集有异常压力的气饱和封存箱、水力破裂-泥岩裂缝油气藏、烃水倒置的油气藏等。异常压力的储层具有相对独立性。 相似文献
8.
Overpressure is a hot topic in the study of sedimentary basins. It is important in generation,maturation migration,and accumulation of hydrocarbon,but the effects of overpressure on rock frame have not been investigated. In this study,experiments were carried out to study the effects of overpressure on rock frame structures using five core samples from the Junggar basin,Northwest China. The deformations and velocities for the samples were measured at different effective pressures related to non-equilibrium compaction and fluid expansion overpressure mechanisms. The results show that the effect of overpressure on rock frames gradually increases when the effective pressure drops down to a certain value (called critical pressure). Moreover,non-equilibrium compaction mechanism has more effects on rock frames than fluid expansion mechanism under the same effective pressure. Furthermore to study rock frame structural changes,we use Kuster and Toks?z's expressions to simulate the effective aspect ratios of inclusions α (penny shapes) for different effective pressures. The results show that the α decreases dramatically when the effective pressure decreases from the critical pressure. Changes of α can be interpreted as responses to the rock frame changes when grains conform one another by rotating and self-adjusting. However,different mechanisms of overpressure have different effects on rock frames. The rock frame can be affected more easily by overpressure in shallow regions generated by non-equilibrium compaction mechanism. Once this kind of rock frames are preserved after overpressure releases to a normal hydrostatic pressure,they can be identified by their specific rock frame characters. This method provides a new way to study overpressure release and fluid migration and accumulation. 相似文献
9.
济阳坳陷古近系深部储层成岩演化模式 总被引：4，自引：0，他引：4
运用岩石薄片鉴定、扫描电镜分析、镜质体反射率分析、X-衍射分析和油层物性分析等手段,结合区域油气地质研究成果,以揭示济阳坳陷古近系深部碎屑岩储层的成岩演化模式和物性演化规律为目的开展工作。结果表明,济阳坳陷古近系深部碎屑岩储层主要受其所处构造背景、地层压力和流体环境的影响,发育6种成岩演化模式。弱陡坡/缓坡构造背景条件下发育早期中强超压-中强压实/胶结/溶蚀-多重介质成岩演化模式和晚期中强超压-（较）强压实/胶结/溶蚀-酸性介质成岩演化模式,超压形成的早晚是影响储层压实作用强弱的主要因素,而流体环境的差异与构造背景的差异有关。深洼陷发育弱超压/常压-（中）强压实/胶结-强溶蚀-热液酸性介质成岩演化模式和中弱超压-较强压实/胶结-强溶蚀-热液酸性介质成岩演化模式,热液活动加强了成岩流体对酸溶性组分的溶解,是该类成岩演化模式的主要影响因素。处于陡坡常压条件下的深层碎屑岩发育（中）强压实/胶结-弱溶蚀-热液酸性介质和强胶结-中弱溶蚀-多重介质成岩演化模式,早期沉积水体、后期成岩水体以及两者混合造成的多重介质是其主要影响因素。综合分析认为,层位和埋深是深部储层遭受成岩改造程度强弱的首要控制因素;构造位置是影响成岩压力场和流体场的基本前提;在不同的流体场背景中,深部热液对储层演化会不同影响;酸碱交替的多重成岩环境增加了次生孔隙带发育个数和次生孔隙垂向分布,但原始孔隙度保存率比以酸性介质为主的成岩环境低5%以上。 相似文献
10.
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
11.
Mudstone compaction and its influence on overpressure generation, elucidated by a 3D case study in the North Sea 总被引：1，自引：0，他引：1
H. Broichhausen R. Littke T. Hantschel 《International Journal of Earth Sciences》2005,94(5-6):956-978
Mudstones are one of the least permeable rocks in most sedimentary sequences. Accordingly they can act as seals for fluid
flow leading to abnormal overpressures. Nevertheless, mudstone compaction and related permeability and porosity decrease are
not adequately described in current basin modelling software, because only mechanical compaction is taken into account. In
reality, however, clay minerals undergo severe chemical diagenesis which certainly influences petrophysical properties and
compaction. In this context a mathematical approach which has been originally developed in soil mechanics has been adapted
to basin modelling. The underlying mathematical equations are carefully explained in the text. In the basic equation the compression
coefficient is a function of void ratio and effective stress. Using these equations, overpressure can be predicted by using
petroleum systems modelling techniques. This is shown for a real 3D case study in the North Sea, in which strong overpressure
occurs. A compaction model for mudstones that depends strongly on the clay content of the individual stratigraphic units is
used for the calibration of porosities in the 3D case study. In addition, a chemical compaction model that reduces porosities
by using a kinetic reaction is used for the deeper part of the basin where mechanical compaction processes are less important.
The pressure generation process depends strongly on permeability and compressibility of the porous medium. Therefore, the
use of mudstone compaction and permeability models is sufficient to produce pore overpressures. In the case studied, abnormal
overpressures are generated during burial together with the petroleum generation process. The mechanical and chemical compaction
mechanisms ensure that the pressures are preserved in the deeper part of the basin. 相似文献
12.
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
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
13.
为了解莺歌海盆地深部热流体主要类型,研究热流体特征,判断热流体活动范围,分析热流体对储层成岩-孔隙演化的影响,通过铸体薄片、扫描电镜、黏土矿物X射线衍射、物性、电子探针、包裹体均一温度、稳定同位素等分析测试手段,结合前人研究成果,对盆内LDX区中新统黄流组储层进行分析。结果表明,受构造热事件影响及深大断裂控制,在超压驱动下,热流体活动范围主要为3 900 m以下的黄流组中下部,以CO2热流体为主,H2S热流体次之。热流体影响下储层具有自生黏土矿物转化速率加快、镜质体反射率突变、地层水矿化度降低、包裹体均一温度大于正常地层最高温度、热液成因矿物发育等特点。将黄流组储层分为超压储层(黄流组中上部)及热超压储层(黄流组中下部)两类。其中,超压储层成岩作用阶段达中成岩A2亚期,压实及溶蚀作用较弱,胶结作用较强,孔隙演化经历了压实减孔、压实与胶结减孔、胶结减孔与有机酸溶蚀增孔3个过程,孔隙度从38.8%减少到现今的7.6%;热超压储层成岩作用阶段达中成岩B期,压实及溶蚀作用较强,胶结作用较弱,孔隙演化经历了压实减孔、压实与胶结减孔、胶结减孔与有机酸溶蚀增孔、胶结减孔与有机酸及无机酸溶蚀增孔4个过程,孔隙度从38.1%减少到现今的9.2%。有利储层主要发育在黄流组中下部黄二段的热超压储层中。 相似文献
14.
《Computers and Geotechnics》2006,33(6-7):316-329
The aim of the paper is to provide new elements concerning the constitutive behavior of sedimentary rocks and the numerical aspects for basin simulators. A comprehensive model for mechanical compaction of sedimentary basins is developed within finite poroplasticity setting. Particular concern is paid to the effects of large porosity changes on the poromechanical properties of the sediment material. A simplified micromechanics-based approach is used to account for the stiffness increase and hardening induced by large plastic strains.A key challenge for numerical assessment of sedimentary basin evolution is to integrate multiple coupled processes in the context of open material systems. To this end, a numerical approach inspired from the ‘deactivation/reactivation’ method used for the simulation of excavation process and lining placement in tunnel engineering, has been developed. Periods of sediments accretion are simulated by progressive activation of the gravity forces within a fictitious closed system. Fundamental components of the constitutive model developed before (hydromechanical coupling, dependence of poroelastic properties on large plasticity, impact of irreversible porosity changes on the hardening rule, evolution of permeability with porosity) are included into our finite element code.Illustrative examples of basin simulation are performed in the one-dimensional case. Various aspects of the constitutive model are investigated. Their influence on the corresponding basin response is analyzed in terms of compaction law, porosity and fluid pressure profiles. 相似文献
15.
时深效应指数TDI的计算受到多种因素影响,这些因素在一定程度上会制约实际应用效果。结合实际资料,分别针对TDI计算过程中的去压实恢复、压实系数与地表孔隙度的求取、超压和地层剥蚀恢复等因素,进行了不同计算条件下埋藏史演化曲线和TDI值的分析比较。结果表明:如果考虑压实作用的影响,将会使TDI值增大;如果考虑地层剥蚀的影响,将会使剥蚀前地层的TDI值增大;存在超压时地层的有效埋深比实际埋深小,因而考虑超压因素计算的TDI值将会有所减小,且其计算精度受反演的地震速度场的精度以及井点压力与速度间关系的可靠性的影响。 相似文献
16.
综合利用泥岩声波时差、实测地层压力和地震资料 ,分析了辽河盆地大民屯凹陷的地下流体压力场特征 .研究结果表明 :(1)本区泥岩压实类型可划分为正常压实 -常压型、单段欠压实 -弱超压型和双段欠压实 -强超压型三大类 ;(2 )油层压力梯度接近于 1,多属正常压力系统 ;(3)利用地震资料研究平、剖面压力场特征具有较高的可行性与可靠性 ;(4)现今剖面压力系统由浅部正常压力、中部弱超压和深部强超压 3个部分组成 ,断裂系统、不整合面和相互连通的孔隙系统及底辟构造组成了凹陷内流体纵、横向输导的复杂网络系统 ;(5 )规模较大断层两侧的剩余压力和压力系数具较明显的差异性 ,断层对压力的形成、演化与分布起着重要的控制作用 ;(6 )欠压实与烃类生成是本区超压形成的主导机制 相似文献
17.
A constitutive model for mechanical and chemo‐mechanical compaction in sedimentary basins and finite element analysis 下载免费PDF全文
下载免费PDF全文 Compaction and associated fluid flow are fundamental processes in sedimentary basin deformation. Purely mechanical compaction originates mainly from pore fluid expulsion and rearrangement of solid particles during burial, while chemo‐mechanical compaction results from Intergranular Pressure‐Solution (IPS) and represents a major mechanism of deformation in sedimentary basins during diagenesis. The aim of the present contribution is to provide a comprehensive 3D framework for constitutive and numerical modeling of purely mechanical and chemo‐mechanical compaction in sedimentary basins. Extending the concepts that have been previously proposed for the modeling of purely mechanical compaction in finite poroplasticity, deformation by IPS is addressed herein by means of additional viscoplastic terms in the state equations of the porous material. The finite element model integrates the poroplastic and poroviscoplastic components of deformation at large strains. The corresponding implementation allows for numerical simulation of sediments accretion/erosion periods by progressive activation/deactivation of the gravity forces within a fictitious closed material system. Validation of the numerical approach is assessed by means of comparison with closed‐form solutions derived in the context of a simplified compaction model. The last part of the paper presents the results of numerical basin simulation performed in one dimensional setting, demonstrating the ability of the modeling to capture the main features in elastoplastic and viscoplastic compaction. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
18.
沉积盆地超压普遍发育,形成机制多样,其演化过程对油气运聚成藏具有重要的影响作用。综合试油、测井资料并结合有效应力特征,分析了黄河口凹陷超压的成因机制,表明东营组超压形成受欠压实和生烃作用的共同影响,沙河街组超压成因以生烃作用为主。压力史演化数值模拟证实,构造活动控制的断层开启和砂岩夹层共同作用造成的超压释放是部分区域实测地层压力接近于常压的原因。超压发育与演化特征控制了黄河口凹陷现今不同类型油藏的垂向分布：在现今超压比较发育、未受断裂活动影响且压力释放作用不明显的区域,以寻找古近系原生油气藏为主;而在断裂沟通古近系与新近系的区域则有利于新近系次生油气藏的形成与勘探。 相似文献
19.
沉积盆地异常超压与岩石破裂耦合动力学模型综述 总被引：5，自引：0，他引：5
在回顾沉积盆地异常超压成因机制模型基础之上，讨论了构筑其模型的基本要素：封盖（层）的渗透率和化学增压的耦合，并通过动力学分析给出了异常超压与岩石破裂的耦合过程引起压力封礅箱内破裂一泄压－愈合－增压作用的动力学状态判据。 相似文献
20.
综合利用泥岩声波时差、实测地层压力和地震资料, 分析了辽河盆地大民屯凹陷的地下流体压力场特征.研究结果表明: (1) 本区泥岩压实类型可划分为正常压实-常压型、单段欠压实-弱超压型和双段欠压实-强超压型三大类; (2) 油层压力梯度接近于1, 多属正常压力系统; (3) 利用地震资料研究平、剖面压力场特征具有较高的可行性与可靠性; (4) 现今剖面压力系统由浅部正常压力、中部弱超压和深部强超压3个部分组成, 断裂系统、不整合面和相互连通的孔隙系统及底辟构造组成了凹陷内流体纵、横向输导的复杂网络系统; (5) 规模较大断层两侧的剩余压力和压力系数具较明显的差异性, 断层对压力的形成、演化与分布起着重要的控制作用; (6) 欠压实与烃类生成是本区超压形成的主导机制. 相似文献