四川盆地川西坳陷须三段砂岩储层致密化过程定量模拟  

Quantitative simulation of the densification process of sandstone reservoir in the Xu 3 Member of Xujiahe Formation in western Sichuan Depression, Sichuan Basin

作　　者：常宇 刘明洁[1,2] 张庄[3] 叶素娟[3] 杨映涛[3] 伍玲[3] 张玲[3] 南红丽[3] 谭秀成 曾伟[1,2] 连承波[1,2] Chang Yu;Liu Mingjie;Zhang Zhuang;Ye Sujuan;Yang Yingtao;Wu Ling;Zhang Ling;Nan Hongli;Tan Xiucheng;Zeng Wei;Lian Chengbo(Natural Gas Geology Key Laboratory of Sichuan Province,Southwest Petroleum University,Chengdu 610500,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Research Institute of Exploration and Development,SINOPEC Southwest Oilfield Company,Chengdu 610000,China)

机构地区：[1]西南石油大学天然气地质四川省重点实验室,成都610500 [2]西南石油大学地球科学与技术学院,成都610500 [3]中国石化西南油气分公司勘探开发研究院,成都610041

出　　处：《地质科技通报》2023年第1期311-323,349,共14页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(41872154);中国博士后科学基金(2016M600752);中国石化科技部项目(P20061-3)。

摘　　要：为了明确川西坳陷须三段砂岩储层致密化过程,定量恢复致密砂岩储层孔隙度演化,综合利用常规薄片、铸体薄片、扫描电镜和包裹体等资料,对须三段成岩作用进行了系统分析,探讨了成岩作用与孔隙度演化之间的关系。在此基础上,结合地层埋藏史和热演化史研究,基于效应模拟原则,即不对具体成岩作用进行模拟,而是通过地质参数来模拟各种成岩作用的综合叠加结果,从而建立须三段砂岩孔隙度演化数学模型,明确砂岩储层致密化过程。研究结果表明:须三段主要发育岩屑石英砂岩和岩屑砂岩;砂岩经历压实、胶结、溶蚀等成岩作用,其中压实作用和胶结作用是主要的破坏性成岩作用,且一直存在于砂岩储层演化过程中;溶蚀作用是主要的建设性成岩作用,且只出现在特定的60~120℃温度窗口。基于对现今砂岩孔隙度与深度关系的观察,明确砂岩先后经历了压实、胶结作用和溶蚀作用,以及溶蚀后的压实、胶结作用。因此,可将孔隙度演化划分为正常压实与胶结阶段、溶蚀增孔阶段和溶蚀后正常压实与胶结3个阶段。此外,将孔隙度演化分解为孔隙度减小模型和孔隙度增大模型,这2种模型在孔隙度演化的3个阶段分别叠加,可得到模拟孔隙度演化的三段式分段函数模型,进而实现砂岩储层孔隙度演化过程模拟。通过应用该模型对典型砂岩储层孔隙度演化过程的模拟表明,川西坳陷须三段因压实作用和早期胶结作用影响,具有早期致密的特点。In order to clarify the densification process and quantitatively restore the porosity evolution of the Xu 3 Member sandstone reservoir in western Sichuan Depression, the diagenesis of the Xu 3 Member was system atically analyzed using thin sections, scanning electron microscope and fluid inclusion analysis. Meanwhile, the relationship between diagenesis and porosity evolution was discussed.Based on the study of formation burial history and thermal evolution history, a mathematical model of porosity evolution for the Xu 3 Member sandstone was established to clarify the densification process of sandstone reservoir using the principle of effect simulation, that is, the specific diagenesis was not simulated, but the comprehensive superposition results of various diagenesis were simulated through geological parameters.It found that lithic quartz sandstone and lithic sandstone were mainly developed in the Xu 3 Member, and sand stone underwent compaction, cementation, dissolution and others. Among them, compaction and cementation are the main destructive diagenesis and occur in the whole evolution process, while dissolution is the main constructive diagenesis and only occurs in a specific evolution stage with window characteristics.Based on the current observation of the relationship between porosity and depth of sandstone, the sandstone had undergone compaction and cementation, corrosion, and compaction and cementation after corrosion.As a result, the porosity evolution could be divided into three stages: normal compaction stage, pore increasing stage during corrosion andnormal compaction after corrosion.Furthermore, the porosity evolution could be divided into porosity decreasing model and porosity increasing model.These two models were superimposed on the three stages of porosity evolution, and a three-stage piecewise function characterized the porosity evolution was proposed.Using this function, the total porosity evolution simulation of sandstone reservoir could be realized.Simulation results found that the Xu 3 Me

关 键 词：致密砂岩 储层成岩作用 效应模拟 孔隙度演化 须三段 川西坳陷 

分 类 号：TE122.221[石油与天然气工程—油气勘探]