川中地区须二段气藏地震预测陷阱分析及对策——以龙女寺区块为例  

Analysis and countermeasures of seismic prediction traps for Xu-2 gas reservoir in central Sichuan Basin:a case study from Longnyusi block

作　　者：李新豫[1] 张静[1,2] 包世海[1] 张连群[1] 朱其亮 闫海军[1] 陈胜[1] LI Xinyu;ZHANG Jing;BAO Shihai;ZHANG Lianqun;ZHU Qiliang;YAN Haijun;CHEN Sheng(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration and Development-Northwest,Lanzhou 730020,China;Downhole Operation Company,Bohai Drilling Engineering Co.,Ltd,CNPC,Renqiu 062552,Hebei,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油勘探开发研究院西北分院,兰州730020 [3]中国石油集团渤海钻探工程有限公司井下作业分公司,河北任丘062552

出　　处：《岩性油气藏》2020年第1期120-127,共8页Lithologic Reservoirs

基　　金：国家“十三五”科技重大专项“致密气富集规律与勘探开发关键技术”（编号：2016ZX05047）资助

摘　　要：四川盆地川中地区上三叠统须家河组二段天然气资源丰富,勘探开发潜力巨大,但近年来既无重大勘探发现又无很好的开发经济效益,究其原因是对须二气藏富集区的分布认识不清。通过研究总结了须二气藏富集区地震预测中存在3类致命预测陷阱:①没有充分认识须二段有效储层纵向分布位置及其对应的地震反射特征;②须二上段泥岩夹层发育,泥岩夹层和有效储层反射特征相似;③气层与水层、干层地震反射特征差异小;形成了模型正演识别纵向上不同位置储层反射特征、地震分频反演识别泥岩、叠前AVO技术区分气层、水层、干层等针对性技术对策,在川中地区龙女寺区块须二段气藏预测中进行了应用,新完钻井预测符合率达到90%以上。这些技术提高了须二上段气藏预测精度,有效地支撑了须二段气藏勘探开发工作。The second member of Xujiahe Formation of Upper Triassic in central Sichuan Basin is rich in natural gas resources and has great potential for exploration and development.However,in recent years,there are nei‐ther significant exploration discoveries nor good economic benefits.The reason is the unclear understanding of the distribution of the enriched area of Xu-2 reservoir.Based on study,three kinds of fatal prediction traps in the seismic prediction of the Xujiahe gas reservoir enrichment area were summarized:(1)Insufficient understanding of the vertical distribution of the effective reservoir and its corresponding seismic reflection characteristics;(2)the mudstone interlayer in upper Xu-2 were well developed,the reflection characteristics of mudstone interlayer and effective reservoir are similar;(3)the difference of seismic reflection characteristics between gas layer,water layer and dry layer is small.According to the three kinds of prediction traps in the prediction process,some tar‐geted technical countermeasures were formed,such as forward modeling to identify reservoir characteristics,fre‐quency division inversion to identify mudstone,prestack AVO technology to distinguish gas layer,water layer and dry layer,which were applied in the prediction of Xu-2 gas reservoir in Longnyusi block,central of Sichuan Basin,and the new drilling forecast compliance rate was more than 90%.These techniques improve the prediction accuracy of Xu-2 gas reservoir and effectively support the exploration and development of the Xu-2 gas reservoir.

关 键 词：地震反射特征 预测陷阱 模型正演 分频反演 叠前AVO技术 须二段 四川盆地 

分 类 号：P631.4[天文地球—地质矿产勘探]