四川盆地及周缘地区震旦系灯影组白云岩岩石类型及沉积相划分方案  

Rock types and sedimentary facies division scheme of the Sinian Dengying Formation dolomite in the Sichuan Basin and its periphery

作　　者：文华国[1,2,3] 文龙[4] 丁一[1,2,3] 周刚 钟怡江[1,2,3] 严威[5] 马奎[5] 钟原 王文之[5] 张亚[5] 武鲁亚[5] 何宇 邹浩文 许亚鑫 WEN Huaguo;WEN Long;DING Yi;ZHOU Gang;ZHONG Yijiang;YAN Wei;MA Kui;ZHONG Yuan;WANG Wenzhi;ZHANG Ya;WU Luya;HE Yu;ZOU Haowen;XU Yaxin(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Chengdu University of Technology,Chengdu,Sichuan 610059,China;Key Laboratory of Deep-Time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources//Chengdu University of Technology,Chengdu,Sichuan 610059,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室•成都理工大学 [2]自然资源部深时地理环境重建与应用重点实验室•成都理工大学 [3]成都理工大学沉积地质研究院 [4]中国石油西南油气田公司 [5]中国石油西南油气田公司勘探开发研究院

出　　处：《天然气工业》2024年第7期27-41,共15页Natural Gas Industry

基　　金：国家自然科学基金项目“上扬子地区震旦系灯影组巨厚组构保存型白云岩形成过程及模式”(编号:42372140);四川省自然科学基金面上项目“川西南地区震旦系灯影组微生物席生态演化与沉积过程研究”(编号:2023NSFSC0276);中国石油西南油气田公司“揭榜挂帅”科技攻关项目“四川盆地及邻区震旦纪—侏罗纪岩相古地理研究与勘探新领域”(编号:JS2022-007)。

摘　　要：四川盆地震旦系灯影组有巨大的天然气勘探潜力,但其储层白云岩岩石类型划分和沉积环境解析方面尚存较大争议,不利于沉积相及有利储集相带展布的精确刻画,制约了下一步油气勘探开发进程。为此,针对四川盆地及周缘地区大量的露头和钻井开展了系统的岩相和沉积环境分析,在明确白云岩类型的基础上,结合岩性组合方式进一步识别了沉积相,并与前人提出的岩性和沉积相划分方案进行了对比与总结,建立了一套既适用于油气勘探又满足沉积学研究的白云岩岩石类型和沉积相划分方案。研究结果表明:①按结构成因可将灯影组白云岩划分为2大类6种类型16种亚类,即保留原始沉积结构的白云岩大类,包括颗粒白云岩、泥晶白云岩、微生物(藻)黏结白云岩,并进一步细分了9种亚类;原岩经过成岩改造形成的白云岩大类包括葡萄状白云岩、角砾白云岩、晶粒白云岩,并可进一步细分7种亚类。②研究区白云岩可识别出台地边缘和局限台地2个相带,共包含8种亚相和17种微相,其中台地边缘相可以划分为微生物(藻)丘、丘滩间洼地、浅滩3个亚相8种微相;局限台地相可划分为微生物(藻)丘、丘滩间海、浅滩、台内洼地、潟湖5种亚相9种微相。③台地边缘相比局限台地相具有丘滩占比大,单层厚度大和叠覆式产出的特征。④丘基—丘核—丘坪—丘盖生长序列反映了微生物丘完整生长—淹没过程,丘基—丘核—丘坪序列可以与潮下—潮间—潮上米级向上变浅旋回相匹配。结论认为,研究提出的丘滩微相划分方案丰富和完善了该区沉积环境解释的理论基础,并具有较强的油气勘探适用性。The Sinian Dengying Formation in the Sichuan Basin shows immense potential in natural gas exploration,but there are more disputes on the rock classification of dolomite and the interpretation of sedimentary environment,which is not beneficial for the precise characterization of the distribution of sedimentary facies and favorable reservoir belts,restricting the subsequent petroleum exploration and development.In this paper,the lithofacies and sedimentary environments in the Sichuan Basin and its periphery are analyzed systematically based on outcrops and wells.Based on the types of the dolomite determined,sedimentary facies are identified using the lithological combination method,and then the scheme proposed in this paper is compared with the lithology and sedimentary facies division schemes proposed in previous studies.Finally,a set of dolomite rock type and sedimentary facies classification scheme suitable for oil and gas exploration and sedimentological research is established.The following results are obtained.First,based on texture genesis,the Dengying Formation dolomite is divided into two categories,including sixteen subtypes of six types.The first category is the dolomite with original sedimentary texture,including granular dolomite,micritic dolomite and microbe(algae)bounded dolomite,which are divided into nine subtypes.The second category is the dolomite reworked from protolith through diagenesis,including grape-like dolomite,breccia dolomite and crystalline dolomite,which are divided into seven subtypes.Second,in the dolomite of the study area,two facies belts are identified,i.e.,platform margin facies and restricted platform facies,which are divided into seventeen microfacies of eight subfacies.The platform margin facies consists of three subfacies,i.e.,microbial(algal)mound,intermound/shoal bottomland and shallow shoal,which are subdivided into eight microfacies.The restricted platform facies consists of five subfacies,i.e.,microbial(algal)mound,intermound/shoal sea,shallow shoal,intraplatform bottom

关 键 词：四川盆地 震旦系 灯影组 白云岩 岩石类型 沉积相 

分 类 号：TE121.3[石油与天然气工程—油气勘探]