四川盆地高石梯-磨溪地区震旦系灯影组白云岩溶蚀差异实验研究  

Experiment for the differential dissolution of dolomite of Sinian Dengying Formation in the Gaoshiti-Moxi area,the Sichuan basin

作　　者：罗文军[1] 季少聪 刘曦翔 淡永[2,3] 梁彬 聂国权[2,3] LUO Wenjun;JI Shaocong;LIU Xixiang;DAN Yong;LIANG Bin;NIE Guoquan(Institute of Exploration and Development,PetroChina Southwest Oil and Gas Field Company,Chengdu,Sichuan 610041,China;Institute of Karst Geology,CAGS/Key Laboratory of Karst Dynamics,MNR&GZAR/International Research Center on Karst under the Auspices of UNESCO,Guilin,Guangxi 541004,China;Pingguo Guangxi,Karst Ecosystem,National Observation and Research Station,Pingguo,Guangxi 531406,China)

机构地区：[1]中国石油西南油气田分公司勘探开发研究院,四川成都610041 [2]中国地质科学院岩溶地质研究所/自然资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心,广西桂林541004 [3]广西平果喀斯特生态系统国家野外科学观测研究站,广西平果531406

出　　处：《中国岩溶》2023年第6期1312-1321,共10页Carsologica Sinica

基　　金：中国地质调查局地质调查项目(DD20190723、DD20221658);中石油“高磨地区灯四段台内产能主控因素及开发目标优选技术研究”项目(20190303-06);广西重点研发计划项目(桂科AB23026062)。

摘　　要：近年来,高石梯—磨溪地区灯影组天然气勘探取得重要发现,其含气储层主要位于灯四段,储层岩石类型以藻凝块白云岩、藻砂屑白云岩、藻叠层白云岩为主。为了研究该地区灯影组白云岩的溶蚀差异,本文采用岩石切片和薄片同时进行溶蚀实验的方法,实验过程中定时记录实验数据,对灯影组白云岩的溶蚀速率、表面形貌和微观特征进行研究。实验结果既有溶蚀量化指标——溶蚀速率,又能直观掌握溶蚀特征及溶蚀后的孔隙结构变化。溶蚀实验结果表明:(1)所有样品的溶蚀启动速率均较高,随溶蚀时间增加,溶蚀速率呈现大幅度衰减并趋于稳定;(2)不同样品的溶蚀速率有明显差异,藻叠层白云岩、藻砂屑白云岩溶蚀速率最高,藻凝块白云岩次之,藻叠层硅质白云岩溶蚀速率最低;(3)通过观察比较不同反应时间内样品的微观溶蚀特征,发现沿粒间、晶间孔隙以及微裂隙溶蚀程度较高;(4)灯影组藻白云岩储层发育可能与藻间白云石的溶蚀作用有关。通过溶蚀实验,掌握了研究区不同白云岩的溶蚀差异,进而对预测优质储层分布、指导油气勘探具有重要意义。In recent years,important discoveries have been made in natural gas exploration of Dengying Formation in Gaoshiti-Moxi area of the Sichuan basin.The gas-bearing reservoirs are mainly located in the fourth member of the Dengying Formation,and the reservoir rock types are mainly algal agglomerate dolomite,algal arenaceous dolomite,and algal-laminated dolomite.Though many previous studies on the dolomite of Dengying Formation in the Gaoshiti-Moxi area of the Sichuan basin have been conducted,they mainly focus on reservoir characteristics,paleogeomorphology characterization,gas reservoir productivity,etc.There are relatively few studies on simulation experiments of dolomite dissolution.The carbonate rock dissolution experiment is an important method to study the favorable conditions and distribution laws of carbonate rock dissolution.Since the 1970s,scholars at home and abroad have successively carried out simulation experiments of carbonate rock dissolution to explore the influence of composition,structure,temperature,pressure,fluid and other factors on dissolution.Early dissolution experiments mainly simulated surface environments,with experimental temperatures below 100℃.In the 1980s,scholars at home and abroad mainly studied the dissolution mechanism of carbonate rock in a deep burial environment.The experimental method was the surface reaction between fluid and rock particles or blocks.This study takes the algal dolomite of the Dengying Formation in the Gaoshiti-Moxi area as the research object.The dissolution rate,surface morphology,and microscopic characteristics of the dolomite of Dengying Formation are studied based on dissolution experiments with rock slices and thin sections.Meanwhile,the effects of lithology,structure,and reaction time on the dissolution degree of the dolomite are analyzed.The experimental results can not only display the quantitative indicator of dissolution—the dissolution rate,but also directly demonstrate dissolution characteristics and changes in pore structure after dissolution.

关 键 词：四川盆地 灯影组 白云岩 溶蚀实验 溶蚀机理 碳酸盐岩储层 

分 类 号：P618.13[天文地球—矿床学]