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1.
在常规AVO理论的基础上,频变AVO属性计算方法利用多尺度裂缝介质模型中物性参数具有频变特征的优势,基于Zoeppritz方程建立反射系数与频率之间的数学关系,推导出截距、梯度、碳氢检测因子、流体检测因子、拟泊松比等AVO属性与频率之间的数学关系.应用地震反演方法,综合地质、地震、测井等数据,反演出高精度的频变AVO属性,在天然气敏感属性分析的基础上建立起频变AVO含气性识别技术.将该技术应用到川西新场陆相深层须家河组碎屑岩储层的含气性识别中,在孔隙度通常在1%~4%,渗透率普遍低于0.06×10-3µm2的致密背景下,较准确地预测了孔隙度大于4％、渗透性偏高的富气优质储层分布带,为该区含气性识别难题的解决和钻井成功率的提高,提供了重要的技术支撑. 相似文献
2.
《地球物理学进展》2015,(6)
储层含气时,岩石的弹性力学参数会发生改变,利用岩石的弹性性质可以对流体性质进行识别.引入流体敏感度评价参数,优选出反映储层含气性敏度高的5个弹性参数,并将这5个弹性参数作为流体识别算法的输入参数.分别利用贝叶斯算法、K近邻算法、广义神经网络算法、主成分分析算法、支持向量机算法对不同流体性质进行识别,并将识别结果采用投票从众的原则,构建多算法协同分类方法(BKGPS).采用BKGPS算法对苏里格气田西部盒8、山1致密砂泥岩储层6口井的75个样本进行判别,样本的识别符合率达到93%,BKGPS识别结果与5种单算法相比,能够提高流体识别的准确性与稳定性.对研究区致密砂岩储层实际资料处理,BKGPS算法处理结果与试气结论一致,验证了该方法的可靠性. 相似文献
3.
基于流体替换技术的地震AVO属性气藏识别(英文) 总被引：2，自引：1，他引：1
传统上,油藏地球物理工程师是基于测井数据进行流体替换,计算油藏饱和不同流体时的弹性参数,并通过地震正演模拟分析油藏饱和不同流体时的地震响应,从而进行油气藏识别研究。该研究方案为油藏研究提供了重要的弹性参数和地震响应信息,但这些信息仅限于井眼位置。对于实际油藏条件,地下储层参数都是随位置变化而变化的,如孔隙度、泥质含量和油藏厚度等,因此基于传统流体替换方案得到的流体变化地震响应信息对于油气藏识别具有很大的局限性。研究通过设定联系油藏弹性参数与孔隙度、矿物组分等参数的岩石物理模型,并基于三层地质模型,进行地震正演模拟与AVO属性计算。得到油藏孔隙度、泥质含量和储层厚度变化时地震AVO属性,并建立了饱和水储层和含气储层对应AVO属性(包括梯度与截距)之间的定量关系。建立的AVO属性之间的线性关系可以实现基于地震AVO属性直接进行流体替换。最后,应用建立的流体替换前后AVO属性之间线性方程,对模拟地震数据直接进行流体替换,并通过流体替换前后AVO属性交汇图分析实现了气藏识别。 相似文献
4.
《中国科学:地球科学》2015,(1)
地震流体识别指利用地震资料对储层含流体特征进行识别与描述.含流体储层地震岩石物理是地震流体识别的基础,是搭建储层弹性参数与物性参数的桥梁,是实现含油气储层流体定量表征的重要发展方向.岩石物理驱动下地震流体识别研究有助于认识地下油气储层含流体特征及分布规律.文章概述地震流体识别及相关基础研究中的关键科学问题,着重评述国内外岩石物理驱动下地震流体识别研究的主要进展,探究地震流体识别研究面临的机遇,挑战及未来的研究方向.理论研究和实际应用表明,地震流体识别要以岩石物理及数值模拟为理论基础,发展有效的流体敏感参数构建及评价方法;以地震资料为数据支撑,形成有效的地震资料品质评价方法;以地震反演为技术保障,发展可靠的地震反演策略. 相似文献
5.
利用核磁共振技术对致密砂岩储层岩心流体参数进行研究,简述致密砂岩储层流体参数核磁共振测量原理及计算岩心流体参数方法。实验确定了岩心流体动用参数T2截止值方法,进行了可动流体致密砂岩储层分类评价研究。油田矿场核磁共振测量岩心含油饱和度、可动流体饱和度,并对可动流体饱和度、含油饱和度识别油水层方法进行研究。表明:实验测定红河区块岩心T2截止值为4.06ms,利用致密砂岩储层岩心可动流体等级划分标准,对致密砂岩储层岩心单井及不同层位、多井之间进行储层比较分类评价。油田矿场核磁共振技术测量计算的含油饱和度结果与常规方法测量的含油饱和度结果对比,表明油田矿场核磁测量含油饱和度是可行且可靠的。岩心含油饱和度与可动流体饱和度比值大小可识别油水层。 相似文献
6.
地震数据中蕴含丰富的地层信息,裂缝孔隙度作为表征致密碎屑岩储层品质及产能评价的关键参数,目前无法利用常规线性反演方法从地震数据中挖掘出裂缝孔隙度的有效信息.为了有效获取致密碎屑岩地震信号中储层与非储层数据特征之间的差异,本文借助深度置信网络(DBN)强大的特征提取能力,利用回声状态网络(ESN)中的回归层代替DBN网络中的误差反向传播算法组合搭建出ES-DBN网络.ES-DBN网络能够较好的捕捉地震数据中的动态时序信息,每次训练都独立于前次的DBN学习过程,且只考虑回归层最终的输出权值矩阵,通过模型测试对比发现,该网络的学习效率和预测准确率均高于传统的DBN网络.以井中裂缝孔隙度为预测目标,基于提取的多种井旁敏感的叠前叠后裂缝属性,利用构建出的网络模型对研究工区地下地层裂缝孔隙度进行预测,预测结果表明：该网络能够较好的实现致密碎屑岩储层的裂缝孔隙度的三维表征,取得了良好的应用效果. 相似文献
7.
《地球物理学进展》2015,(1)
鄂尔多斯盆地SG气田是我国典型的低孔,低渗,致密砂岩气藏的代表.该区地震勘探开发面临着两大难题:一是含气砂岩和围岩的声波阻抗存在较大范围叠置,利用声波阻抗预测储层存在明显的多解性;二是SG气田局部地区气、水关系复杂,地质上不存在统一的气、水层分界面,产水井严重影响产能建设,流体类型的识别是面临的又一难题.为了降低声波阻抗预测砂岩储层的多解性,提高有效储层预测精度,定量识别储层中流体的类型,本文提出了叠前地震弹性参数交会定量解释技术,从横波测井资料不同岩性、流体的岩石物理参数分析入手,优选了能够区分岩性和流体的最佳敏感弹性参数,制作了敏感弹性参数交会模板,通过地震叠前反演获得反映储层物性和含气性的地震弹性参数体,最后进行地震弹性参数交会定量解释预测有效储层和识别流体.勘探实例证实了该技术方法在SG地区对有效储层的预测是有效的,能够为井位优选提供可信的依据.地震弹性参数交会技术将纵向分辨率较高的测井岩石物理分析和横向分辨率较高的地震叠前反演结合在一起,使用了多个弹性参数交会,减少了以往单一弹性参数预测储层的多解性,最终获得比较可靠、更量化的反映储层物性和含气性的地震弹性参数交会体,为有效储层预测和流体识别探索出了新的途径,这一技术的应用和推广可以降低地震解释的风险,提高储层预测精度. 相似文献
8.
低孔低渗储层流体含量较少,流体性质在测井上的响应特征不够明显.因此,需要一套更有效地流体性质识别方法.基于文献调研和案例研究,本文系统考察了低孔低渗储层现有的测井、录井识别技术,给出了综合应用测井、录井资料识别低渗透储层流体性质的工作流程,并对技术发展方向做了展望.研究认为:可依据方法原理、使用资料特点将测井识别技术分为电法、声波、核测井、核磁共振四类;录井技术分为交会图、油气含量对比、参数对比三类;测录井综合识别技术分为简便分析和数据挖掘技术两类;通过选取适当数据挖掘技术进行测录井综合识别,符合率约90%,比单独使用测井资料和录井资料识别符合率提高了约10%,有明显提升;在使用数据挖掘技术时,敏感参数选取、模式识别方法的选择等都是值得考虑的重要问题,这些问题是低孔低渗储层流体性质识别技术的难题和主攻方向. 相似文献
9.
阿姆河右岸麦捷让地区碳酸盐岩气藏非均质性强,储层横向厚度变化大,前期研究多结合地震波场模拟进行储层预测,气藏流体检测工作较少,新钻井情况表明内部流体关系复杂,需要开展流体检测工作对气藏内部流体分布进行全面认识.本文从岩石物理模型入手,分析石灰岩纵横波速度、弹性参数与岩石基本性质之间的定量关系,寻找对流体敏感的弹性属性,认为纵横波速度比能较好地识别气水分布.通过测井弹性参数交会和流体替换,以实际资料验证岩石物理分析结果并选择气藏敏感参数,建立了适合本地区的气藏预测模版.利用叠前时间偏移得到的共反射点道集,开展三维叠前同时反演,利用反演结果进行了储层流体识别.预测结果与验证井吻合良好,且含气分布范围揭示了两个气藏存在. 相似文献
10.
碳酸盐岩储层的AVO响应要比碎屑岩储层响应微弱,因此,弹性阻抗（EI）即使在确定了最佳入射角的情况下,要判断碳酸盐岩储层中的流体性质,依然十分困难.本文提出了一种多角度扩展弹性阻抗（MEEI）反演进行碳酸盐岩储层流体识别方法.利用已有钻井的测井数据,通过计算目的层段的MEEI,建立相应的含流体模式,进而建立了碳酸盐岩储层流体检测中的有效气水判据.通过不同入射角下EEI随入射角变化的不同趋势,可以有效识别储层中含气或含水情况,判别储层好坏.本文方法的有效性在四川盆地某地区实际资料应用中取得了良好的流体检测效果. 相似文献
11.
Abdolrasool Anooshehpoor James N. Brune 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):917-922
Precariously balanced rocks in seismically active regions are effectively upper-limit strong motion seismoscopes that have been in place for thousands of years. Thus, estimates of the dynamic toppling acceleration of these rocks (through rigid body rocking) can provide constraints on the peak ground accelerations experienced during past earthquakes. We have developed a methodology that uses a two-dimensional numerical code to calculate the dynamic rocking response of precarious rocks to realistic ground acceleration time histories. Statistical analyses of the dynamic response of these rocks to a range of synthetic seismograms, as well as strong motion records, can provide important information about the ground motion attenuation curves and seismic hazard maps. We use shake table tests to investigate the dynamic rocking response of 13 wooden rectangular blocks of various sizes and aspect ratios subjected to realistic seismograms and compare the results with those of numerical tests. Our results indicate good agreement between the shake table and numerical results. 相似文献
12.
A series of rock friction experiments has been carried out to study the complexities in rock fracture and rock friction. Intact Westerly granite samples were loaded to shear failure in a laboratory polyaxial loading apparatus. The resultant fractured samples were reloaded to cause frictional sliding. Both polyaxial loading (1 > 2 > 3 > 0) and equal confining condition (1 > 2 = 3 > 0) were used. The deformation processes were monitored by macroscopic axial stress-strain, optical holography, and ultrasonic velocity measurements.Intense localized deformation along the fracture occurred very early in the loading of fractured samples. Contacts on the fracture surfaces continuously broke during loading. No acoustic velocity anomaly was observed for the fractured sample, in contrast to a 25% drop in the velocity before the failure of the corresponding intact sample. The current study and previous research suggest that the deformation localization is an important process in governing the instability of rock friction. Instability analysis of rock friction needs to include not only the deformation processes along the sliding surfaces, but also those adjacent to the fractures such as the localized deformation along the fractures observed in the current study. The instability analysis of rock friction with rate- and state-dependent friction laws does not specifically include the deformation localization adjacent to the faults and thus ignores an important class of instability as described byRudnicki (1977).A dependence of frictional strengths on the stress components normal to the sliding and in the plane of the fracture surface was observed. This dependence can be understood by considering the loading of the irregular fracture surface under polyaxial loading conditions. This observation requires the friction laws in the macroscopic scale to be modified for those cases where the three principal stresses (1, 2, and 3) are significantly different. 相似文献
13.
Permeability is a transport property which is currently measured in Darcy units. Although this unit is very convenient for most purposes, its use prevents from recognizing that permeability has units of length squared. Physically, the square root of permeability can thus be seen as a characteristic length or a characteristic pore size. At the laboratory scale, the identification of this characteristic length is a good example of how experimental measurements and theoretical modelling can be integrated. Three distinct identifications are of current use, relying on three different techniques: image analysis of thin sections, mercury porosimetry and nitrogen adsorption. In each case, one or several theoretical models allow us to derive permeability from the experimental data (equivalent channel models, statistical models, effective media models, percolation and network models). Permeability varies with pressure and temperature and this is a decisive point for any extrapolation to crustal conditions. As far as pressure is concerned, most of the effect is due to cracks and a model which does not incorporate this fact will miss its goal. Temperature induced modifications can be the result of several processes: thermal cracking (due to thermal expansion mismatch and anisotropy, or to fluid pressure build up), and pressure solution are the two main ones. Experimental data on pressure and temperature effects are difficult to obtain but they are urgently needed. Finally, an important issue is: up to which point are these small scale data and models relevant when considering formations at the oil reservoir scale, or at the crust scale? At larger scales the identification of the characteristic scale is also a major goal which is examined. 相似文献
14.
Drill and blast is a commonly used method for rock slope excavation in hydropower engineering.During blasting excavation of rock slopes,far-field vibration monitoring on the first upper berm for statutory compliance is usually performed to control the blast-induced rock damage to the final slope face.In this study,for the rock slope excavation in the Jinping-I hydropower station,the field vibration monitoring and acoustic testing are presented to investigate the vibration characteristics on the first upper berm and the damage depth in the current bench.The relationship between the PPV on the first upper berm and the PPV damage threshold on the damage zone boundary is also studied through three-dimensional FEM simulations.The results show that on the first upper berm,the maximum vibration velocity component occurs in the vertical direction.While on the blasting damage zone boundary,the horizontal radial vibration velocity is the maximum component.For the Jinping-I slope with a bench height of 30 m,the radial PPV on the inner side of the first upper berm is 2.06%of the PPV threshold on the damage zone boundary.This ratio is increased as the bench height decreases.Therefore,the bench height of the rock slope is an important factor that cannot be ignored in determining the allowable vibration velocity for rock damage control. 相似文献
15.
G. R. Douglas 《地球表面变化过程与地形》1987,12(3):301-310
Manganese-rich rock coatings are widespread in Iceland, especially in fractures in basalt lavas. Three common types of coating are described. A thick subsurface coating is found on whaleback forms on high plateaux. The most common type is thinner and occurs in hydrothermal clay-filled fracture systems which are especially well developed in tholeiite lavas. A third type occurs in younger rocks and is associated with tephra-rich, loessic sediment which fills open fractures and vesicles. There are differences in the chemistry, morphology, and mineralogy of these coatings which are interpreted as being due to the different microenvironments in which they form. The fracture microenvironment is regarded as being of much more importance to coating thickness and chemistry than simple age and in this respect the hydrothermal clays seem to favour rapid manganese concentration. On the other hand, there are variations in coating type, both laterally and vertically through the lava succession, which are related to regional distribution of hydrothermal alteration and rock type. The regional patterns are the result of Iceland's lateral drift and as a result there is an incidental connection between coating type and rock age. There is some evidence to suggest that the manganese coatings may be both forming and being degraded rapidly in the present environment. 相似文献
16.
应力作用对岩石磁性的影响对于地震磁效应、磁性构造学、下地壳与上地幔物质磁性结构及陨石磁学研究等具有潜在的意义.本文对上世纪50年代以来,有关应力作用下,岩石(或磁性矿物)的磁化率及其各向异性、剩磁、磁滞特征和磁性(高温、低温)转换点等磁性特性的变化特征及影响岩石磁性对应力作用响应特性的主要因素进行了系统地总结.结果表明... 相似文献
17.
经典的微分等效介质(DEM)理论可用于确定多孔介质的弹性性质,但由于缺乏多重孔DEM方程,其估计的多重孔岩石的等效弹性模量依赖于包裹体(即不同孔隙纵横比的孔或缝)的添加顺序.本文首先从Kuster-Toksöz理论出发建立了Zimmermann和Norris两种形式的多重孔DEM方程.Norris形式的多重孔DEM方程预测的等效弹性模量总是位于Hashin-Shtrikman上下限内,而Zimmermann形式的多重孔DEM方程有时会越界.然后,通过使用干燥岩石模量比的解析近似式,对两个相互耦合的Norris形式DEM方程进行解耦得到干燥多重孔岩石的体积和剪切模量解析式.用全DEM方程的数值解对解析近似式的有效性进行了测试,解析公式的计算结果在整个孔隙度分布区间与数值解吻合良好.对实验室测量数据在假设岩石含有双重孔隙的情形下用双重孔DEM解析公式对岩石的弹性模量进行了预测,结果表明,解析式准确地预测了弹性模量随孔隙度的变化.双重孔(即软、硬孔)DEM解析模型可用来反演各孔隙类型的孔隙体积比,它可以通过实验室测量与理论预测之间的平方误差最小反演得到.砂岩样品的反演结果揭示,软孔的孔隙体积百分比与粘土含量没有明显的相关性. 相似文献
18.
Manganiferous rock varnish, silica glaze and iron skins have formed on 20- to 40-year-old slag piles near Fontana, southern California. Rapid rock-varnish formation is associated with an unidentified cocci bacterium that grows rapidly in culturing experiments, combined with the likelihood that Mn-rich solutions flow over slag surfaces. A new model is proposed for the formation of silica glaze, involving soluble Al-Si complexes and the nature of wetting films. Iron skins occur where runoff is concentrated, and where iron bacteria grow. Observations indicate: (i) substrate can be important in supplying Mn, as well as maintaining a stable surface and channelling runoff to microspots where varnish grows; (ii) ignorance of boundary layer pH/Eh conditions makes chemical-physical models of varnish formation speculative; (iii) the balance between cementation of recently nucleated varnishes and erosional shear stresses is poorly understood, but is probably an important limiting factor on varnish growth rates; and (iv) there must be at least two steps in biotic varnishing-accretion of Mn-Fe in casts, followed by cementation of clays by either in situ cast residue or Mn-Fe remobilized from casts. Varnish accretion may be limited by the rate at which both steps occur. Rapid development of readily distinguishable manganiferous rock varnishes at this post-1952 site highlights the danger of speculation on the ages of landforms based solely on the appearance of rock-varnish coatings. 相似文献
19.
J. P. McGreevy 《地球表面变化过程与地形》1985,10(2):125-136
Four rock types (basalt, sandstone, granite, and chalk) are examined with respect to the maximum surface temperatures which they experience when subjected to similar conditions of exposure. Rock temperature measurements are reported for an urban environment and for two experimental situations in which an infrared lamp is used to simulate heating under cold and hot conditions. Differences in rock temperatures are discussed with reference to thermal rock properties (albedo, specific heat capacity, and thermal conductivity). Some natural situations are suggested in which thermal rock properties could conceivably play a role in determining the extent to which rocks would be affected by particular weathering processes. 相似文献
20.
由于煤岩冲击破裂过程中,裂缝的形成和颗粒的摩擦会产生电磁辐射,因此,可采用电磁辐射技术来预测煤矿的冲击矿压危险.研究表明,电磁辐射基本上随着加载及变形速率的增加而增强;在发生冲击性破坏以前,电磁辐射强度一般在某个值以下,而在冲击破坏时,电磁辐射强度突然增加;煤体应力越大,变形破裂越强烈,电磁辐射信号也越强.煤岩变形破坏的弹塑脆性模型分析表明,煤岩体的损伤速度与电磁辐射脉冲数、声发射事件数成正比,与瞬间释放的能量、变形速度成正比.对具有强冲击危险工作面进行的研究表明,电磁辐射完全可以预测煤矿冲击矿压危险,检验卸压爆破效果,而且准确率高,效果明显. 相似文献