四川盆地震旦系灯影组四段碳酸盐岩岩石物理特征及影响因素  

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

作　　者：王佳庆 邓继新 刘忠华[3] 闫龙龙[1,2] 夏辉 WANG Jiaqing;DENG Jixin;LIU Zhonghua;YAN Longlong;XIA Hui(Key Laboratory of Earth Exploration and Information Technology of Ministry of Education,Chengdu University of Technology,Chengdu 610059,China;College of Geophysics,Chengdu University of Technology,Chengdu 610059,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]地球勘探与信息技术教育部重点实验室(成都理工大学),成都610059 [2]成都理工大学地球物理学院,成都610059 [3]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2023年第6期1185-1198,共14页Petroleum Exploration and Development

基　　金：国家自然科学基金“流体饱和致密砂岩多频段岩石物理实验及理论解释模型”项目(41774136)。

摘　　要：通过对四川盆地震旦系灯影组四段不同沉积相带样品岩石学、物性和弹性参数测量,分析不同沉积相带储集层的成岩过程及其对岩石物理性质的影响。结果表明:裂隙和矿物组分共同控制岩石物理性质,且两者受沉积环境和成岩作用影响显著。丘滩相微生物白云岩主要经历多期白云石化、准同生期溶蚀、构造破裂和热液有机酸溶蚀作用,发育裂隙和溶蚀孔洞;丘滩间洼地或云质潟湖晶粒白云岩主要经历机械压实、埋藏白云石化和构造-热液作用,发育裂隙和晶间孔。与裂隙发育相关的成岩作用造成样品压力效应、水饱和效应增加,纵波阻抗和泊松比显著下降。白云石化作用改变矿物颗粒的性质,造成泊松比接近于白云石,低能环境的泥质、硅质和灰质沉积物致使波阻抗降低、泊松比差异性变化(显著增加或减小)。同时,裂隙与溶蚀孔洞均发育的样品表现出高纵波速度频散特征,仅含裂隙或孔隙的样品纵波速度频散最小。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：四川盆地 震旦系灯影组 碳酸盐岩 沉积环境 成岩作用 岩石物理特征 波阻抗 泊松比 纵波速度频散 

分 类 号：TE122.2[石油与天然气工程—油气勘探]