Rock physical characteristics of deep dolomite under complex geological conditions:A case study of 4th Member of Sinian Dengying Formation in the Sichuan Basin,China  

作　　者：Chuang Li Shu-Xin Pan Hong-Bin Wang Ji-Xin Deng Jian-Guo Zhao Zhi Li Yu Zhang 

机构地区：[1]Northwest Branch of Research Institute of Petroleum Exploration&Development,Lanzhou,730020,Gansu,China [2]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing,102249,China [3]Department of Geophysics and Exploration,College of Geophysics,Chengdu University of Technology,Chengdu,610059,Sichuan,China

出　　处：《Petroleum Science》2024年第4期2370-2382,共13页石油科学（英文版）

基　　金：funded by the CNPC (China National Petroleum Corporation)Scientific Research and Technology Development Project (Grant No.2023ZZ0205,2021DJ0506);sponsored by the National Natural Science Foundation of China (41774136,41374135)。

摘　　要：The deep-ultra deep carbonate reservoir in China,commonly subjected to modification of multi-stage diagenesis,has extremely high heterogeneity.Conventional rock physics analysis cannot accurately identify the elastic responses of reservoir.Here,the rock physics properties of the dolomite from the 4th Member of the Sinian Dengying Formation are experimentally measured,and the change law of rock physics characteristics is investigated within the framework of the diagenetic processes by the analysis of the elastic and petrologic characteristics,pore structure,and sedimentary environments.The results show that the differentiated diagenesis results in different pore structure characteristics and microtexture characteristics of the rock.The microbial dolomite of the algal mound-grain beach facies is subjected to the contemporaneous microbial dolomitization and seepage-reflux dolomitization,penecontemporaneous selective dissolution,burial dolomitization,and hydrothermal dolomitization.The resultant crystalline dolomite is found with one main type of the dolomite crystal contact boundaries,and the dissolution pore is extensive development.The siliceous,muddy,and limy dolomite of the interbeach sea environment mainly experiences the weak capillary concentration dolomitization,intensive mechanical compaction-induced densification,and burial dolomitization.Such crystalline dolomite is observed with four types of contact boundaries,namely the dolomite contact,clay contact,quartz contact,and calcite contact boundaries,and porosity mostly attributed to residual primary inter-granular or crystalline pores.The samples with the same crystal boundary condition have consistent correlations between the compressional-and shear-wave velocities,and between the compressional-wave velocity and the velocity ratio.Additionally,the variation of the acoustic velocity with effective pressure and the intensity of pore-scale fluid-related dispersion are controlled by the differentiation of pore structure types of the samples.The varied effects

关 键 词：Deep-ultra deep carbonate reservoirs Rock physics properties DOLOMITE Seismic elastic properties MICRO-CRACK Pore structure types 

分 类 号：P618.13[天文地球—矿床学] TE311[天文地球—地质学]