Petrophysical properties and their influencing factors of carbonates in the fourth member of Sinian Dengying Formation, Sichuan Basin, SW China  

作　　者：WANG Jiaqing DENG Jixin LIU Zhonghua YAN Longlong XIA Hui 

机构地区：[1]Key Laboratory of Earth Exploration and Information Technology of Ministry of Education,Chengdu University of Technology,Chengdu 610059,China [2]College of Geophysics,Chengdu University of Technology,Chengdu 610059,China [3]PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China

出　　处：《Petroleum Exploration and Development》2023年第6期1358-1373,共16页石油勘探与开发（英文版）

基　　金：Supported by the National Natural Science Foundation of China(41774136)。

摘　　要：Based on the measurements of petrological, petrophysical and elastic properties of the samples of different sedimentary facies in the fourth member of Sinian Dengying Formation (Deng 4 Member) in the Sichuan Basin, the diagenetic processes of reservoirs of different sedimentary facies and their controls on the petrophysical properties were discussed. The results show that cracks and mineral composition jointly control the petrophysical properties, and both are significantly influenced by sedimentary environment and diagenesis. The microbial dolomite of mound-shoal facies mainly experienced multi-stage dolomitization, penecontemporaneous dissolution, tectonic rupture and hydrothermal/organic acid dissolution processes, giving rise to cracks and dissolved pores. The grannular dolomite of inter-mound-shoal bottomland or dolomitic lagoon facies mainly underwent mechanical compaction, burial dolomitization and tectonic-hydrothermal action, creating cracks and intercrystalline pores. The diagenesis related to crack development increases the pressure- and saturation-dependent effects of samples, leading to significant decrease in the compressional wave impedance and Poisson's ratio. Dolomitization changes the properties of mineral particles, resulting in a Poisson's ratio close to dolomite. The muddy, siliceous and calcareous sediments in the low-energy environment lead to the decrease of impedance and the differential change of Poisson's ratio (significantly increased or decreased). The samples with both cracks and dissolved pores show high P-wave velocity dispersion characteristics, and the P-wave velocity dispersion of samples with only fractures or pores is the lowest.

关 键 词：Sichuan Basin Sinian Dengying Formation carbonate rock sedimentary environment DIAGENESIS petrophysical properties wave impedance Poisson’s ratio P-wave velocity dispersion 

分 类 号：P618.13[天文地球—矿床学]