砂砾岩体跨频段地震岩石物理响应特征——以东营凹陷陡坡带为例  

Investigation on Elastic Parameters of Glutenite by Multi-Frequency-Band Measurements:A case study for rocks from the steep slope zone in Dongying Sag

作　　者：孙超 岳建华[1] 蔡来星 潘冬明[1] SUN Chao;YUE JianHua;CAI LaiXing;PAN DongMing(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]成都理工大学沉积地质研究院,成都610059

出　　处：《沉积学报》2023年第5期1543-1558,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42104111,41906188);油气资源与探测国家重点实验室开放课题(PRP/open 2207);徐州市科技局青年人才项目(KC22018)。

摘　　要：砂砾岩体不仅是重力流沉积的主要研究对象,在油气勘探和水文地质勘探领域同样占据重要地位。选用东营凹陷北部陡坡带典型砂砾岩样品,分析其物性,测量其超声频段弹性波速度,依据统计学理论计算指示因子,寻找岩性及流体敏感参数;基于超声频段弹性波速度反演裂隙密度和软孔隙特征,计算砂砾岩频散特征并与地震频段弹性参数测量结果对比,分析跨频段(地震频段和超声频段)岩石物理响应特征。结果表明:(1)依据敏感参数,砂砾岩与泥岩、砾岩差异明显,但砂砾岩与砂岩之间不易区分;对于流体,砂砾岩储层中气和水易区分,但油和水不易区分;(2)在原位储层压力下,相较于砂岩、砾岩、泥岩和灰岩,砂砾岩纵波速度频散范围更大,裂隙密度更大,相应的闭合压力范围也较大;(3)频散特征满足“喷射流”机制,其中微裂隙纵横比为一组分布,频散发生的频率范围及幅度可作为区分油和水的敏感参数。研究成果为区分砂砾岩储层中不同频段地震波响应特征及进一步识别流体类型提供了理论依据,有助于实现储层与非储层的地震精准预测。Glutenites,which significantly contribute to gravity flow sedimentation studies,have become prime tar⁃gets for oil,gas,and groundwater exploration,owing to their advantageous reservoir conditions.However,their com⁃plex depositional attributes,heterogeneous composition,and intricate pore structures pose challenges,affecting the elastic response of seismic waves.This complexity can compromise the reliability of fluid inversion methodologies and the outcomes of fluid identification processes.Consequently,a comprehensive understanding of the interrelationship between reservoir lithology,its physical properties,involved fluids,and seismic attributes is vital.Such understand⁃ing,attainable through petrophysical experiments,is critical for accurately deciphering the petrophysical response characteristics of glutenites.We undertook multi-frequency-band measurements(employing seismic frequencies at 1⁃100 Hz and ultrasonic frequency at 1 MHz)on the elastic parameters of the glutenite from the Dongying Sag in the Bo⁃hai Bay Basin.Initially,we selected a series of samples from each grain level for porosity and permeability tests,fol⁃lowed by classification and analysis of the rock types and physical properties.We then measured the P-and S-wave ul⁃trasonic velocities in samples saturated with varying fluids,assessing the effects of fluid,lithology,and pressure on velocity.This led to the determination of the relationship between pressure and velocity by evaluating different watersaturated samples,followed by the calculation of indicative factors to identify rock types and fluid sensitivity parame⁃ters.Furthermore,we measured the Young’s modulus and Poisson’s ratio to calculate the P-and S-wave velocities of the seismic band.Lastly,we computed the crack density and soft porosity using ultrasonic velocity and compared the velocity dispersion with the seismic frequency band measurements.Our results suggest that:(1)sensitive parametersρ,K,λ,λρ,andλϕhelp distinguish glutenite from shale and conglomerate,b

关 键 词：砂砾岩 储层敏感参数 低频岩石物理 频散 裂隙密度 

分 类 号：P618.13[天文地球—矿床学]