饱和碳酸盐岩地震频带弹性参数响应的实验机理分析研究:压力与孔隙流体影响  

Experimental mechanism of elastic parameters in saturated carbonate at seismic frequencies:role of pressure and pore fluid

作　　者：贺艳晓[1] 闫国庆 未晛 唐跟阳 王尚旭[1] 李皓 张家良[4] 潘树林[5] 马宵一 刘卫华[6] HE YanXiao;YAN GuoQing;WEI Xian;TANG GenYang;WANG ShangXu;LI Hao;ZHANG JiaLiang;PAN ShuLin;MA XiaoYi;LIU WeiHua(National Key Laboratory of Petroleum Resource and Engineering,CNPC Key Laboratory of Geophysical Exploration,China University of Petroleum(Beijing),Beijing 102249,China;Beijing Vocational College of Labour and Social Security,Being 100029,China;Yangtze Delta Region Institute(Huzhou),University of Electronic Science and Technology of China,Huzhou 313001,China;PetroChina Dagang Oilfield Company,Tianjin 300280,China;Southwest Petroleum University,Chengdu 610500,China;Sinopec Geophysical Research Institute,Nanjing 211103,China)

机构地区：[1]中国石油大学(北京)油气资源与工程全国重点实验室,CNPC物探重点实验室,北京102249 [2]北京劳动保障职业学院,北京100029 [3]电子科技大学长三角研究院(湖州),湖州313001 [4]中国石油大港油田公司,天津300280 [5]西南石油大学地球科学与技术学院,成都610500 [6]中国石化石油物探技术研究院,南京211103

出　　处：《地球物理学报》2023年第12期5141-5156,共16页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41930425),国家自然科学基金企业创新发展联合基金(U19B6003-04-03);北京市自然科学基金(8222073);中国石油天然气集团有限公司科技管理部资助项目“物探应用基础实验和前沿理论方法研究”(2022DQ0604-01);中国石油天然气股份有限公司科学研究与技术开发项目(2021DJ1206);国家重点研发计划(2018YFA0702504);中国石化地球物理重点实验室开放基金(33550006-20-ZC0699-0001)联合资助。

摘　　要：碳酸盐岩储层中蕴藏着全球近一半油气储量,也是我国深层、超深层的重点勘探领域.然而,深层碳酸盐岩复杂孔隙结构导致其储层条件下岩石物理响应机理不明,这对有效地震储层表征与流体预测带来了巨大挑战.目前,国内尚缺乏系统开展针对深层碳酸盐岩储层的地震频带岩石物理实验测试研究.厘清深层油藏开发中因流体流动而引起的储层压力场与孔隙流体性质变化对地震频带弹性参数影响机制,在一系列地球物理应用中具有十分重要的意义.通过开展跨频带(地震低频+超声高频)弹性参数实验测试,本文系统研究了压力与孔隙流体对深层碳酸盐岩弹性模量及其衰减的影响机制.针对中低孔渗碳酸盐岩储层岩芯,分别测量了其在干燥、饱和盐水与甘油下的弹性参数,分析了弹性模量对压力与频率敏感性.干燥岩芯杨氏模量频变特性显著低于饱和流体岩芯实测数据,且饱和甘油岩芯模量及其衰减均高于饱和盐水测量结果.部分饱和盐水岩芯的地震频带实测结果表明,杨氏模量与泊松比均随含水饱和度升高而增大,其频散程度却略有降低.此外,基于干燥岩芯弹性参数不依赖频率的前提,受迫振动法低频实验所得岩石弹性模量和衰减数据与三孔隙类型喷射流模型预测结果相一致,证实喷射流是引起复杂孔隙微观结构储层岩芯频变黏弹性响应的主控因素.A significant portion of the global hydrocarbon reserves are found in carbonate reservoirs,and these reservoirs are also key to the exploration in deep and ultradeep reserves in China.However,the complex pore structure leading to unclear understanding of the petrophysical properties of deep carbonates,resulting in a number of challenges to reservoir characterization and fluid prediction.Up to now,there is a lack of systematic rock physics experimental studies in deep carbonates at seismic frequencies.It is thus of great significance in a series of geophysical applications to clarify the role of reservoir pressure and pore fluid variations,due to hydrocarbon depletion induced fluid movements in producing fields,on seismic elastic properties.In this laboratory study,we investigate the influence of pressure and pore fluid on rock elastic moduli and its associated attenuation,through experimental measurements of elastic properties of a saturated tight carbonate at low seismic and ultrasonic frequencies.For the carbonate core with low porosity and low permeability,we evaluate the sensitivity of measured elastic moduli under dry,brine and glycerin saturation to pressure and frequency.We demonstrate that the frequency-dependence of dry Young's modulus is significantly lower than those of fluid saturated core and,the moduli and attenuation in glycerin saturated case are higher than the measurements in brine saturation.The measurements with partial brine saturation show that both Young's modulus and Poisson's ratio increase with brine saturation,yet their dispersion magnitude decreases slightly.Under the assumption of frequency-independent dry elastic properties,the measured Young's modulus and its associated attenuation of the saturated rocks from forced oscillation experiments,which are still scarcely investigated,are in fairly good agreement with predictions of the squirt model with three porosity types at seismic frequencies.

关 键 词：地震频带 频散与衰减 致密碳酸盐岩 喷射流 孔隙结构 

分 类 号：P631[天文地球—地质矿产勘探]