四川盆地大安探区须家河组致密气成藏条件与勘探领域  

The formation conditions and exploration fields of tight gas of Xujiahe Formation in Da'an exploration area,Sichuan Basin

作　　者：罗瑀峰 厚刚福 刘占国 熊加贝 伍松林 芮昀 陈星渝 袁晓俊 宋兵 伍劲 刘少治 LUO Yufeng;HOU Gangfu;LIU Zhanguo;XIONG Jiabei;WU Songlin;RUI Yun;CHEN Xingyu;YUAN Xiaojun;SONG Bing;WU Jin;LIU Shaozhi(Research Institute of Exploration and Development,PetroChina Zhejiang Oilfield Company;PetroChina Hangzhou Research Institute of Geology)

机构地区：[1]中国石油浙江油田公司勘探开发研究院,浙江省杭州市311100 [2]中国石油杭州地质研究院,浙江省杭州市310023

出　　处：《海相油气地质》2025年第2期157-166,共10页Marine Origin Petroleum Geology

基　　金：中国石油天然气股份有限公司基础性前瞻性重大科技专项(编号:2023ZZ02)资助。

摘　　要：四川盆地大安探区为复杂构造变形区,为了厘清须家河组致密气成藏条件,落实下一步勘探领域,对其烃源岩、沉积体系、致密砂岩储层和圈闭条件开展系统研究。结果表明:①大安探区须家河组发育浅水三角洲沉积体系,须四段和须六段发育多期三角洲平原亚相辫状分流河道,砂体叠置连片分布,受压实作用和胶结作用的影响,储层普遍致密,后期溶蚀作用和裂缝有效改善了储层物性。②须三段和须五段为研究区主力烃源岩层,烃源岩厚度大、面积广、有机质丰度高,以Ⅲ型和Ⅱ2型干酪根为主,目前处于成熟—高成熟阶段,为大安探区致密气成藏奠定了资源基础。③须四段和须六段致密砂岩储层在垂向上与须三段和须五段烃源岩成不等厚互层,构成下生上储式源储组合,有利于形成构造气藏;须三段和须五段主力烃源岩层内部发育“泥包砂”型曲流河河道致密砂岩储层,源储一体,构成自生自储式源储组合,有利于形成透镜状构造-岩性气藏。提出了丹凤场构造带背斜主体部位和临江向斜北、临江向斜中、临江向斜南、云锦向斜东等构造翼部的须四段和须六段为下一步构造气藏重点接替领域;丹凤场背斜、来苏向斜北和临江向斜中部的须三段和须五段源储一体,有利于形成“泥包砂”型构造-岩性气藏,为下一步致密气的潜在探索领域。In order to clarify the conditions for the formation of tight gas reservoirs in complex structural deformation zones and implement the next exploration areas,a systematic study is conducted on the hydrocarbon source rocks,sedimentary systems,tight sandstone reservoirs,and trap conditions of the Xujiahe Formation in Da'an exploration area of Sichuan Basin.The results show that:(1)The Xujiahe Formation in the Da'an exploration area has developed a shallow water delta sedimentary system,and the multi-stage sand bodies of the delta plain braided distributary channels in the 4th and 6th members are stacked and connected.Due to compaction and cementation,the reservoirs were generally dense,and later dissolution and fractures effectively improved the physical properties of the reservoirs.(2)The 3th and 5th members are the main source rock layers in the study area.The source rocks are thick,wide distribution in area,and have high organic matter content,mainly consisting of typeⅢand typeⅡ2 kerogen.Currently,they are in the mature to high mature stage,laying a resource foundation for the formation of tight gas reservoirs in Da'an exploration area.(3)The tight sandstone reservoirs of the 4th and 6th members are interbedded with the source rocks of the 3th and 5th members in an uneven thickness in the vertical direction,forming a lower source-upper reservoir combination,which is conducive to the formation of structural gas reservoirs.The main source rock layers of the 3th and 5th members are developed with"mudstone wrapping sandstone"type meandering river channel sand bodies and tight sandstone reservoirs,forming a self generating and self storing combination,which is conducive to the formation of lens-shaped lithological gas reservoirs.The main part of Danfengchang anticline belt and the north,middle,and south wings of Linjiang syncline,as well as the east wing of Yunjin syncline are proposed as the key replacement areas of structural gas reservoir of the 4th and 6th members in Da'an exploration area.Of the Danfengchang

关 键 词：浅水三角洲 致密砂岩气 成藏模式 勘探领域 须家河组 大安探区 四川盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]