潜江组页岩弹性性质分析及各向异性岩石物理建模  

Analysis of elastic properties and anisotropic rock physics modeling of Qianjiang Formation shale

作　　者：闫博鸿 赵建国[1] 肖增佳 钟庆良[2] 欧阳芳 王斌[1] 李智 马铭[1] YAN BoHong;ZHAO JianGuo;XIAO ZengJia;ZHONG QingLiang;OUYANG Fang;WANG Bin;LI Zhi;MA Ming(State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Geophysical Research Institute,Jianghan Oilfield Company,SINOPEC,Qianjiang Hubei 434124,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油化工股份有限公司江汉油田分公司物探研究院,湖北潜江434124 [3]中国地震局地震预测研究所,北京100036

出　　处：《地球物理学报》2024年第7期2802-2819,共18页Chinese Journal of Geophysics

基　　金：国家自然科学基金联合基金重点基金项目(U20B2015);国家自然科学基金项目(41974120)联合资助。

摘　　要：岩石物理建模是定量描述页岩油气储层弹性性质的重要手段,然而不同地质成因、不同相态油气藏的弹性响应机理存在差异,需要结合岩石物理实验与地质特征分析予以明确,进而合理地开展理论建模研究.本研究针对江汉盆地潜江组盐间页岩油储层,综合数字岩心微观结构表征与岩心测试分析,在考虑研究区地质背景、岩石学特征、孔隙结构特征与弹性各向异性规律的基础上,提出了一套各向异性岩石物理建模流程,联合岩心数据与测井资料对本文构建的岩石物理模型以及由此获得的岩石物理解释量版进行了验证.进一步,基于该各向异性岩石物理模型与Metropolis-热浴算法提出了一种各向异性参数反演策略,并在潜江凹陷B井潜四下段展开应用,预测的纵、横波速度平均相对误差分别为-1.32%和-2.39%.研究结果表明,矿物的纹层特征、黏土的定向排列以及水平层理缝的存在共同影响着潜江组页岩的各向异性,将各向异性SCA、Backus平均、T-matrix理论组合后建立的岩石物理模型能够比较准确地描述潜江组页岩弹性响应规律.此外,基于该各向异性岩石物理模型的反演可以获得不同类型的孔隙含量、层理缝纵横比及各向异性,结果可为页岩储层力学性质评价、精确的速度建模以及工程地质参数分析提供依据.Rock physics modeling is an important method to quantitatively describe the elastic properties of shale oil and gas reservoirs.However,there are differences in the elastic response of oil and gas reservoirs with different geological genesis and hydrocarbon phases.Therefore,a combination of rock physics experiments and geological characterizations are required to clarify and then develop theoretical modeling.The study area is the inter-salt shale oil reservoir of Qianjiang Formation in Jianghan Basin.Through digital core microstructure characterization and core experiment analysis,an anisotropic rock physics modeling process is proposed based on the geological background,lithological,pore structure,and elastic anisotropy law of the study area rock.The rock physics model and the interpretation template are validated by core and logging data,respectively.Further,we propose an anisotropic parameter inversion strategy based on this anisotropic rock physics model and the Metropolis-thermal bath algorithm.The application results in the lower Eq4 in well B of the Qianjiang Depression show that the average relative errors of the predicted P-wave and S-wave velocities are−1.32%and−2.39%,respectively.The results show that the anisotropy of the Qianjiang Formation shale is influenced by the stratification of multiple minerals,the directional arrangement of clays,and the horizontal fractures.The rock physics model established by combining anisotropic SCA,Backus average,and T-matrix theory can accurately describe the elastic properties of the Qianjiang Formation shale.In addition,the inversion based on the anisotropic rock physics model can obtain multiple pore contents,fracture aspect ratios and anisotropy.These results can provide the foundation for shale reservoir mechanical property evaluation,accurate velocity modeling,and engineering geological parameter analysis.

关 键 词：潜江组页岩 盐湖页岩油藏 各向异性 岩石物理量版 Metropolis-热浴算法 

分 类 号：P631[天文地球—地质矿产勘探]