地震沉积学在碳酸盐岩中的应用——以四川盆地高石梯—磨溪地区寒武系龙王庙组为例  

Carbonate seismic sedimentology: A case study of Cambrian Longwangmiao Formation, Gaoshiti-Moxi area, Sichuan Basin, China

作　　者：曾洪流 赵文智[2] 徐兆辉[2] 傅启龙 胡素云[2] 汪泽成[2] 李伯华[2] ZENG Hongliu;ZHAO Wenzhi;XU Zhaohui;FU Qilong;HU Suyun;WANG Zecheng;LI Bohua(Bureau of Economic Geology,Jackson School of Geosciences,The University of Texas at Austin,Texas 78712,USA;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

机构地区：[1]Bureau of Economic Geology,Jackson School of Geosciences,The University of Texas at Austin [2]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2018年第5期775-784,共10页Petroleum Exploration and Development

基　　金：国家科技重大专项(2016ZX05004);中国石油天然气股份有限公司项目(2016B-0401;2018A-0104)

摘　　要：应用地震沉积学对中国西部深层古老海相碳酸盐岩进行分析,将岩心、测井和三维地震资料的综合解释纳入地震沉积学研究流程,定性恢复碳酸盐岩沉积古地貌,定量预测白云岩储集层厚度。四川盆地高石梯—磨溪地区寒武系龙王庙组形成于碳酸盐台地相沉积环境,岩相包括从白云石化颗粒岩到泥质岩几乎所有类型,主要发育颗粒滩、潟湖和深水陆棚亚相,其中高孔隙度(大于4%)储集层主要发育在滩相沉积中。采用地震地貌学研究思路,利用印模法和残厚法并经钻井资料标定,重建龙王庙组沉积古地貌。研究认为,帚状断裂体系控制了古地貌和沉积相展布。采用地震岩性学研究思路,引入多频道振幅主因子计算高孔隙度储集层厚度,定量确定相边界;优选反映岩体内部横向变化的相似性方差地震属性,刻画碳酸盐岩溶蚀成岩相。研究表明,将地震地貌学和地震岩性学相结合的研究思路行之有效,可为其他盆地中的碳酸盐岩地震沉积学研究提供参考。This study applied seismic-sedimentological workflow to deeply buried marine carbonate sequences in western China.The workflow aimed at integrating core,wire line log and 3D seismic data to investigate the paleogeomorphology qualitatively and reservoir thickness quantitatively in the carbonate systems.In Gaoshiti-Moxi area of Sichuan Basin,the Longwangmiao Formation was formed in sedimentary environment of carbonate platform facies.Lithofacies vary from dolomitize grainstone to mudstone,which formed shoal,lagoon,and deep shelf sub-facies.The high-porosity(porosity>4%)reservoir rocks are related to shoal sub-facies.Seismic geomorphology was employed to restore paleostructure of Longwangmiao Formation in the study area by methods of cast and isopach,which were calibrated by well data.It was found that the paleogeomorphology and depositional facies were largely controlled by a syndepositional,en echelon fault system.Following the strategy of seismic lithology,quantitative distribution of reservoir rocks and sedimentary facies was assessed by applying principle component analysis on amplitude attributes generated from multiple frequency panels.Seismic prediction of diagenetic facies(selective dissolution)was achieved by interpreting similarity variance,a seismic geometric attribute.In summary,the procedure,combining seismic geomorphology and seismic lithology,is effective and can be used as a reference for seismic-sedimentological study in other carbonate basins in China and elsewhere.

关 键 词：地震沉积学 地震地貌学 地震岩性学 地震成岩相 碳酸盐岩 碳酸盐台地 四川盆地 高石梯-磨溪地区 寒武系龙王庙组 

分 类 号：TE122.2[石油与天然气工程—油气勘探]