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1.
提出了各向异性页岩储层统计岩石物理反演方法.通过统计岩石物理模型建立储层物性参数与弹性参数的定量关系,使用测井数据及井中岩石物理反演结果作为先验信息,将地震阻抗数据定量解释为储层物性参数、各向异性参数的空间分布.反演过程在贝叶斯框架下求得储层参数的后验概率密度函数,并从中得到参数的最优估计值及其不确定性的定量描述.在此过程中综合考虑了岩石物理模型对复杂地下介质的描述偏差和地震数据中噪声对反演不确定性的影响.在求取最大后验概率过程中使用模拟退火优化粒子群算法以提高收敛速度和计算准确性.将统计岩石物理技术应用于龙马溪组页岩气储层,得到储层泥质含量、压实指数、孔隙度、裂缝密度等物性,以及各向异性参数的空间分布及相应的不确定性估计,为页岩气储层的定量描述提供依据. 相似文献
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龙马溪组页岩是目前国内页岩气勘探的主要层位之一.由于岩石物理实验结果具有区域性,龙马溪组页岩的岩石特征与其地震弹性性质的响应规律需要开展相关的实验和理论研究工作予以明确.本研究基于系统的微观结构观察(扫描电镜和CT成像技术)和岩石物理实验来分析龙马溪组页岩样品地震弹性性质的变化规律,并依据微观结构特征建立相应的地震岩石物理表征模型.研究结果表明,石英含量对龙马溪组页岩的孔隙度以及有机碳(TOC)含量具有一定的控制作用,TOC和黄铁矿主要赋存于孔隙中;岩石骨架组成亦受控于石英或粘土含量,在石英含量大于40%(对应粘土含量小于30%)时,以石英、粘土共同作为岩石骨架,而粘土含量大于30%时,则以粘土作为岩石的骨架.因此,岩石骨架组成矿物、TOC含量、孔隙度共同制约龙马溪组页岩的地震弹性性质,富有机质储层岩石通常表现出低泊松比、低阻抗和低杨氏模量的特征,但由于支撑矿物的转换,某些富有机质页岩亦可表现为高阻抗特征.粘土矿物的定向排列仍然是造成页岩样品表现出各向异性的主要原因,各向异性参数与粘土含量具有指数关系.基于龙马溪组页岩的岩性特征及微观结构特征,可以利用自洽模型(SCA)、微分等效模量模型(DEM)和Backus平均模型的有效组合较为准确地建立龙马溪组页岩的地震岩石物理模型,实验结果和测井数据验证了模型的准确性.研究结果可为龙马溪组页岩气储层的测井解释和地震"甜点"预测提供依据. 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
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对于富含有机质的页岩储层来说,孔隙度是评价油气储量的关键参数之一,有机孔隙的存在又对岩石孔隙空间具有重要贡献,因此,研究页岩储层有机孔隙空间是有必要的。本文结合氩离子抛光扫描电镜（SEM）资料和图像分割技术,以川南永川区块YY2井龙马溪组页岩储层为例,对纳米有机孔隙的形态特征和有机孔隙度进行分析研究,研究表明:YY2井龙马溪组有机孔隙较发育,SEM图像中有机孔隙直径差异很大,对龙马溪组6块岩样的SEM图像进行处理,得到的有机质面孔率在0.97％～8.90％之间,个别样品孔径较小,面孔率在1％以下。利用面孔率和有机质含量计算有机孔隙度,计算得到的有机孔隙度在0.12％～0.75％范围内,均值为0.39％,占据岩石孔隙度的10.66％。 相似文献
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洪泽地区由于沉积的特点，储层横向变化快，油藏受构造、岩性、油源多因素控制。在对该区三维AVO属性体解释中，利用多元回归方法求取了横波曲线，分岩性和含油气性统计了纵、横波、泊松比参数分布规律，建立了本区的含油砂岩的正演模型，从而降低了AVO解释的多解性。通过井-震结合对四种AVO属性数据体进行了标定，并确定了各属性体应用范围，进而进行了储层和含油气检测。实践表明，该方法能有效地利用AVO属性数据体进行储层预测及油气检测，具有一定的推广价值。 相似文献
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五峰-龙马溪组页岩是目前国内页岩气勘探的首选层位,而其地震岩石物理特征是利用地震方法进行"甜点"预测的重要基础之一,但对五峰-龙马溪组页岩地震弹性特征变化规律的研究并未考虑沉积、成岩过程的影响,致使相应的规律性认识缺乏地质意义.在对五峰-龙马溪组页岩样品系统声学测量基础上,分析了页岩样品地震弹性性质的变化规律.利用X射线衍射分析、扫描电镜（SEM）、阴极发光（CL）与能谱分析确定了五峰-龙马溪组页岩在不同沉积环境下的成岩过程,并讨论了成岩过程与地震弹性性质变化规律的因果关系.研究结果表明,页岩中有机质（TOC）受高热演化程度的影响,其密度通常高于1.4 g·cm-3,并接近于有机碳密度上限1.6 g·cm-3（石墨密度）.五峰-龙马溪组页岩地震弹性性质变化规律整体受沉积环境控制,沉积环境的差异形成不同的成岩过程,致使地震弹性特征也表现出不同的变化规律.表现在五峰-龙马溪页岩样品动态岩石物理特征主要受岩石结构控制（支撑颗粒弹性性质）,而孔隙度、TOC含量以及孔隙形状则为对地震弹性特征影响的次一级因素.五峰-龙马溪组页岩上段为浅水陆棚相,机械压实与化学压实（硅质胶结）为先后两个过程,造成样品表现出高的速度-孔隙度变化率、高速度比（泊松比）、高各向异性以及低TOC含量的特征.五峰-龙马溪组页岩下段为深水陆棚相,机械压实过程中同时伴有生物成因的硅质胶结,造成岩石样品表现出较高TOC含量与孔隙度、各向异性较弱以及较小的速度-孔隙度变化率.研究结果可为五峰-龙马溪页气储层的测井解释和地震"甜点"预测提供依据. 相似文献
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碳酸盐岩、致密砂岩和页岩等储层具有孔隙类型多样、孔隙结构复杂和非均质性强等特征,属于典型的多重孔隙储层,孔隙结构表征是多重孔隙储层预测和流体识别的关键.现有的孔隙结构表征方法大多利用孔隙纵横比或者构建一种新参数来描述孔隙结构.岩石临界孔隙度模型是一种常用的岩石物理模型,具有一定的物理意义和地质含义.本文推导了岩石临界孔隙度与岩石孔隙结构(孔隙纵横比)之间的关系,进而利用极化(形状)因子建立临界孔隙度与弹性参数之间的关系,构建了能够包含多种孔隙类型的多孔可变临界孔隙度模型.利用多孔可变临界孔隙度模型由储层的弹性参数反演不同孔隙类型的体积含量.实验室测量数据和实际测井数据表明,多孔可变临界孔隙度模型能够适用于多重孔隙储层岩石物理建模和孔隙结构表征. 相似文献
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致密砂岩储层普遍具有孔隙度低、微裂隙发育的特点,岩石内部常含有强烈的结构非均质性.致密砂岩发育的微裂隙使储层具有良好的连通性,促成高饱和气的天然气成藏.针对川西某探区须家河组高含气饱和度致密砂岩,本文选取致密砂岩岩心样本,进行了不同围压下的超声波实验测量.考虑储层完全饱气情况下的粒间孔隙、微裂隙双重孔隙结构,采用Biot-Rayleigh双重孔隙方程,构建致密砂岩岩石物理模型,进而分析了裂隙含量对纵波频散和衰减的影响.基于地震波衰减,构建了致密砂岩多尺度岩石物理图板.采用谱比法和改进频移法估算致密砂岩样本及储层衰减,对超声和地震频带下的图板进行校正.将校正后的图板应用到研究工区,选取二维测线和三维区块,进行储层孔隙度和裂隙含量的定量预测.对比实际资料进行分析,结果显示,本文预测的孔隙度和裂隙含量与三口测井的孔隙度曲线和实际产气情况基本吻合,基于孔隙-裂隙衰减岩石物理模型有效地预测了优质储层的分布区域. 相似文献
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首先研究了天然气AVO技术的岩石物理基础--Gassmann方程和Biot理论(以下统称为"Gassmann-Biot理论")--对煤层气AVO技术的适用性.根据该理论创始人在建立其理论时的假设条件、煤层气储层的双相孔隙特征、煤层气的双相赋存特征,本文推理认为,由于煤层气储层的基质型孔隙体系的连通性差,裂隙性孔隙在宏观上是非均质的,并且是各向异性的,因此,总体上来说,Gassmann-Biot理论不完全适用于煤层气储层.特别地,当煤层的水饱和状态保持不变而煤层的含气量变化时,因为煤层中孔(裂)隙中流体的体积压缩模量不变或基本不变,即使煤层的弹性参数发生变化,Gassmann-Biot理论也不可能预测其变化趋势.因此,天然气AVO技术的岩石物理基础完全地不适用于水饱和煤层气储层.研究发现,煤层气储层含气量与其密度、纵波速度、横波速度之间存在负相关关系,即含气量高,密度小、纵波速度小、横波速度小;含气量低,密度大、纵波速度大、横波速度大.但是,这些负相关关系不是现有岩石物理理论能够预测或能够解释的.依据煤层气地质学理论以及负相关关系与现有岩石物理理论的一致性,本文提供了对某勘探区A号煤层含气量与其密度、纵波速度、横波速度之间负相关关系的解释,并认为煤层气储层的含气量与其弹性参数之间的负相关关系可能是这类储层内在的固有的规律性的关系.本文证明含气量与其密度、纵波速度、横波速度之间负相关关系可以作为煤层气AVO技术的岩石物理基础,建立了AVO异常与煤层气储层"甜点(即富集高渗部位)"之间的关系,从而能够使用AVO异常探测煤层气富集高渗部位. 相似文献
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传统基于单相介质理论的储层参数反演方法将孔隙流体与固体骨架等效为单一固体,弱化了孔隙流体的影响,反演结果精度不高.本文提出根据双相介质理论反演储层参数的方法.首先,在前人研究的基础上,利用岩石物理模型建立弹性参数与孔隙度、饱和度、泥质含量等储层参数间的关系,进而将双相介质反射系数推导为储层参数的函数;其次,根据贝叶斯反演理论,在高斯噪声假设的基础上,采用更加符合实际情况的修正柯西分布函数描述反射系数的稀疏性,推导出储层物性参数目标反演函数;最后,应用差分进化非线性全局寻优算法来求解目标反演函数,使得反演结果与实际资料间误差最小.新方法旨在突出流体对介质反射系数的影响,以期得到较高的储层参数反演精度.模型与实际资料测试均表明该方法可行、有效且反演精度较高. 相似文献
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The shales of the Qiongzhusi Formation and Wufeng–Longmaxi Formations at Sichuan Basin and surrounding areas are presently the most important stratigraphic horizons for shale gas exploration and development in China. However, the regional characteristics of the seismic elastic properties need to be better determined. The ultrasonic velocities of shale samples were measured under dry conditions and the relations between elastic properties and petrology were systemically analyzed. The results suggest that 1) the effective porosity is positively correlated with clay content but negatively correlated with brittle minerals, 2) the dry shale matrix consists of clays, quartz, feldspars, and carbonates, and 3) organic matter and pyrite are in the pore spaces, weakly coupled with the shale matrix. Thus, by assuming that all connected pores are only present in the clay minerals and using the Gassmann substitution method to calculate the elastic effect of organic matter and pyrite in the pores, a relatively simple rock-physics model was constructed by combining the self-consistent approximation (SCA), the differential effective medium (DEM), and Gassmann’s equation. In addition, the effective pore aspect ratio was adopted from the sample averages or estimated from the carbonate content. The proposed model was used to predict the P-wave velocities and generally matched the ultrasonic measurements very well. 相似文献
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发展了应用数值计算方法获取页岩储层的速度、各向异性参数的计算岩石物理系列方法.该系列方法包括了大尺度精细地质模型数值建模、计算网格尺度的地球物理建模和地震波数值模拟提取岩石物理弹性参数.本文方法利用储层的统计数据而不是具体岩心的测量数据,可获得储层岩石物理弹性参数的变化规律.相比于基于岩心测试的岩石物理方法,本文方法可精细考虑实际储层的非均匀特征,可得到岩心测试难以求取的与尺寸效应高度相关的弹性参数,也避免了求取弹性参数变化规律时获取不同地质特征岩心的困难.本文发展了计算岩石物理方法,为计算岩石物理面临的大尺度地质建模和计算能力限制问题提供了有效的解决方案.文中以胜利罗家的页岩储层为例,求得了储层TOC含量从3%到21%变化情况下储层的P波、S波速度以及各向异性参数变化规律. 相似文献
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The discovery of Puguang Gas Field provides the exploration of China deep marine carbonate rock with important references. In Puguang Gas Field, the dolomite reservoirs discovered in the deep are the best in the present of China, which present big thickness and wide-range distribution, and develop abundant secondary porosity. The researches show that Puguang Gas Field bears the characteristics of early gas-filling time, deep burial, high matured organic matter and long-term interaction of hydrocarbon (oil and gas)-water-rock (carbonate reservoir). The developments of secondary pores in this area are affected by multiple diagenesis and their formation mechanisms are complicated. Through the research on depositional environment, sedimentary facies and reservoir porosity characters of Changxing and Feixianguan Formations, it is thought that high-quality dolomite reservoirs of Puguang Gas Field form on the favorable sedimentary facies belts, which are the integrate result affected by several factors including superficial corrosion, burial corrosion, overpressure and tectonic movement, among which burial corrosion of TSR to reservoir and overpressure formed by thermal evolution of organic matter have great effect on the formation of secondary porosity of Changxing and Feixianguan Formations. 相似文献
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The formation mechanism of high-quality dolomite reservoir in the deep of Puguang Gas Field 总被引：1，自引：0，他引：1
《中国科学D辑(英文版)》2008,(Z1)
The discovery of Puguang Gas Field provides the exploration of China deep marine carbonate rock with important references.In Puguang Gas Field,the dolomite reservoirs discovered in the deep are the best in the present of China,which present big thickness and wide-range distribution,and develop abundant secondary porosity.The researches show that Puguang Gas Field bears the characteristics of early gas-filling time,deep burial,high matured organic matter and long-term interaction of hydrocarbon(oil and gas)-water-rock(carbonate reservoir).The developments of secondary pores in this area are affected by multiple diagenesis and their formation mechanisms are complicated.Through the research on depositional environment,sedimentary facies and reservoir porosity characters of Changxing and Feixianguan Formations,it is thought that high-quality dolomite reservoirs of Puguang Gas Field form on the favorable sedimentary facies belts,which are the integrate result affected by several factors including superficial corrosion,burial corrosion,overpressure and tectonic movement,among which burial corrosion of TSR to reservoir and overpressure formed by thermal evolution of organic matter have great effect on the formation of secondary porosity of Changxing and Feixianguan Formations. 相似文献
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孙林洁 《CT理论与应用研究》2020,29(5):566-575
优质气层与低含气饱和度的差气层、气水同层均呈现"亮点"强振幅的地震响应特征,利用振幅类属性或者常规弹性参数难以进行有效判识。考虑到密度参数随含气饱和度的高敏感性,本文在贝叶斯叠前反演框架下,以三变量柯西分布为先验正则约束进行叠前地震反演,减小了纵波速度、横波速度与密度三参数统计相关性造成的参数估算误差,进一步提高了弹性参数的可靠性,模型测试表明新方法反演的密度精度及稳定性更高。将方法应用于马达班湾盆地X区块,在流体替代及岩石物理统计分析的指导下,利用基于三变量柯西分布的叠前地震反演方法提取密度参数,预测优质气层富集区,实钻结果与预测结果吻合度高,表明该方法具有较高的实用性。 相似文献
17.
The organic reef is a special type of carbonate reservoir which always dominates the spatial distribution, reserves and accumulations of natural gas. However, it is difficult to determine the organic reef’s internal structure and gas reservoirs due to numerous adverse factors such as the low resolution of seismic data, depth of burial, strong anisotropy, irregular spatial distribution and complex internal structure. A case study of wavelet decomposition and reconstruction technology applied to elucidate the features of organic reef reservoirs in the Changxing formation from Yuanba gas field shows that the seismic record reconstructed by high frequency signal can adequately describe the internal properties of organic reef reservoirs. Furthermore, the root mean square amplitude ratio of both low and high frequency data obtained from the reconstructed seismic data clearly show spatial distribution of gas and water in reef reservoirs. 相似文献
18.
Changcheng Liu Deva Prasad Ghosh Ahmed Mohamed Ahmed Salim Weng Sum Chow 《Geophysical Prospecting》2019,67(1):140-149
Amplitude interpretation for hydrocarbon prediction is an important task in the oil and gas industry. Seismic amplitude is dominated by porosity, the volume of clay, pore-filled fluid type and lithology. A few seismic attributes are proposed to predict the existence of hydrocarbon. This paper proposes a new fluid factor by adding a correct item based on the J attribute. The algorithm is verified through stochastic Monte Carlo modelling that contains various rock physical properties of sand and shale. Both gas and oil responses are separated by the new fluid factor. Furthermore, an approach based on the neural network model is trained using the deep learning method to predict the new fluid factor. The confusion matrix shows that this model performs well. This model allows the application of the new fluid factor in the seismic data. In this study, the Marmousi II data set is used to examine the performance of the new fluid factor, and the result is good. Most hydrocarbon reservoirs are identified in the shale–sandstone sequences. The combination of deep learning and the new fluid factor provides a more accurate way for hydrocarbon prediction. 相似文献
19.
Linqi Zhu Chong Zhang Chaomo Zhang Xueqing Zhou Jun Wang Xiu Wang 《Acta Geophysica》2018,66(5):983-1000
The total organic carbon (TOC) content reflects the abundance of organic matter in marine mud shale reservoirs and reveals the hydrocarbon potential of the reservoir. Traditional TOC calculation methods based on statistical and machine learning have limited effect in improving the computational accuracy of marine mud shale reservoirs. In this study, the collinearity between log curves of marine mud shale reservoirs was revealed for the first time, which was found to be adverse to the improvement of TOC calculation accuracy. To this end, a new TOC prediction method was proposed based on Multiboost-Kernel extreme learning machine (Multiboost-KELM) bridging geostatistics and machine learning technique. The proposed method not only has good data mining ability, generalization ability and sound adaptivity to small samples, but also has the ability to improve the computational accuracy by reducing the effect of collinearity between logging curves. In prediction of two mud shale reservoirs of Sichuan basin with proposed model, the results showed that the predicted value of TOC was in good consistence with the measured value. The root-mean-square error of TOC predicting results was reduced from 0.415 (back-propagation neural networks) to 0.203 and 1.117 (back-propagation neural networks) to 0.357, respectively; the relative error value decreased by up to 8.9%. The Multiboost-KELM algorithm proposed in this paper can effectively improve the prediction accuracy of TOC in marine mud shale reservoir. 相似文献
20.
Quantitative characterization of reservoir space in the Lower Silurian Longmaxi Shale,southern Sichuan,China 总被引：1，自引：0，他引：1
WANG YuMan DONG DaZhong YANG Hua HE Ling WANG ShiQian HUANG JinLiang PU BoLing WANG ShuFang 《中国科学:地球科学(英文版)》2014,57(2):313-322
Based on the drilling data of the Upper Ordovician Wufeng Shale and the Lower Silurian Longmaxi Shale in southern Sichuan Basin,the construction of matrix pores and the development condition of fractures in a marine organic-rich shale are quantitatively evaluated through the establishment of the reservoir petrophysical models and porosity mathematical models.Our studies show that there are four major characteristics of the Longmaxi Shale confirmed by the quantitative characterization:(1)the pore volume of per unit mass is the highest in organic matter,followed in clay minerals,finally in brittle minerals;(2)the porosity of the effective shale reservoir is moderate and equal to that of the Barnett Shale,and the main parts of the shale reservoir spaces are interlayer pores of clay minerals and organic pores;(3)the porosity of the organic-rich shale is closely related to TOC and brittle mineral/clay mineral ratio,and mainly increases with TOC and clay mineral content;(4)fractures are developed in this black shale,and are mainly micro ones and medium-large ones.In the Longmaxi Shale,the fracture density increases from top to bottom,reflecting the characteristics with high brittle mineral content,high Young’s modulus,low Poisson's ratio and high brittleness at its bottom. 相似文献