松辽盆地长岭断陷深层凝灰质碎屑岩储层特征及致密化机理  

Reservoir characteristics and densification mechanism of deep tuffaceous clastic rocks in the Changling Fault Depression,Songliao Basin

作　　者：周龙飞 郭小波 沈霞[3] 李立立[3] 薛松 高劲 丁超 谷晓强 ZHOU Longfei;GUO Xiaobo;SHEN Xia;LI Lili;XUE Song;GAO Jin;DING Chao;GU Xiaoqiang(School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an 710065,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an 710065,China;Exploration and Development Research Institute of PetroChina Jilin Oilfield Company,Songyuan 138000,China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]陕西省油气成藏地质学重点实验室,西安710065 [3]中国石油吉林油田分公司勘探开发研究院,吉林松原138000

出　　处：《成都理工大学学报(自然科学版)》2025年第2期301-314,I0009,I0010,共16页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国石油天然气集团公司“十四五”前瞻性基础性重大科技项目(2021DJ0205);陕西省重点基金(2023-JCZD19);陕西省教育厅项目(20JS115);西安石油大学研究生创新与实践能力培养项目(YCS22113095)。

摘　　要：为明确松辽盆地长岭断陷神字井洼槽深层凝灰质碎屑岩储层特征及其致密化机制,以营一段和沙河子组砂岩储层为研究对象,应用碳和氧稳定同位素、流体包裹体测温及原位微区电子探针测试等方法,从岩石学、储集特征、成岩作用类型及储层形成机制等方面,探讨了深层凝灰质碎屑岩储层致密化控制因素和形成时间及其与天然气充注期次的时序关系。结果表明:营一段及沙河子组岩性主要为杂色凝灰质砂砾岩及凝灰质中−细砂岩;储集空间类型以次生孔隙为主,发育少量微裂缝;胶结作用是储层致密的关键因素,碳酸盐胶结物为最主要的胶结物类型,按胶结次序可分为3期。营一段砂砾岩储层约80 Ma开始致密,天然气主要充注于90~80 Ma,反映以先成藏后致密为主的天然气充注特征;沙河子组砂岩储层约90 Ma开始致密,沙二段天然气主要充注于98~88 Ma,既存在先成藏后致密的充注关系,又具有边成藏边致密的充注特征。研究深化了深层凝灰质碎屑岩储层致密化机制及成藏认识,可为深层致密气藏勘探开发提供参考。To clarify the reservoir characteristics and densification mechanism of deep tuffaceous clastic rocks in Shenzijing Sag,sandstone reservoirs in the first member of the Yingcheng Formation and Shahezi Formation are taken as the research target.The densification characteristics,controlling factors,and formation time of the deep tuffaceous clastic reservoir and its relationship with the gas filling period are discussed from the aspects of petrology,reservoir characteristics,diagenetic types,and reservoir formation mechanism.The methods used here consist of carbon and oxygen stable isotope analysis,fluid inclusion temperature measurements,and in situ microprobe measurements.The results show that the reservoir lithology in the first member of the Yingcheng Formation and Shahezi Formation is dominated by mixed tuffaceous conglomerate and tuffaceous medium-fine sandstone,which contain mainly secondary pores with a few microfractures.Cementation is a key factor in the densification of the reservoir.Carbonate cement is the most important type of cement present,which can be divided into three stages according to the cementation order.The sandy conglomerate reservoir of the first member of the Yingcheng Formation began to densify around 80 Ma,and the gas was mainly charged 90~80 Ma,reflecting the characteristics of gas accumulation followed by densification.The sandstone reservoir of the Shahezi Formation began to densify around 90 Ma,and the natural gas of the second member of the Shahezi Formation mainly charged 98~88 Ma,i.e.,they occurred around the same time.This means that there are two charging processes:gas accumulation followed by densification and simultaneous gas accumulation and densification.This study deepens our understanding of the densification mechanism and accumulation in deep tuffaceous clastic reservoirs and can be used as a reference for the exploration and development of deep tight gas reservoirs.

关 键 词：致密化机理 凝灰质碎屑岩储层 神字井洼槽 长岭断陷 松辽盆地 

分 类 号：P618.13[天文地球—矿床学]