基于井控层速度插值模型的盐下气藏地震精细解释——以川中磨溪地区雷口坡组为例  

Detailed seismic interpretation of pre-salt gas reservoirs based on well-controlled interval velocity interpolation model: A case study of Leikoupo Formation in Moxi Gas Field, central Sichuan Basin

作　　者：唐松 陈安清[2] 罗倩 刘博文 李正勇 杨欧文 李睿璇 夏文鹏 钱杨娇娇 马梓珂 TANG Song;CHEN Anqing;LUO Qian;LIU Bowen;LI Zhengyong;YANG Ouwen;LI Ruixuan;XIA Wenpeng;QIAN Yangjiaojiao;MA Zike(Central Sichuan Oil and Gas District,PetroChina Southwest Oil&Gas Field Company,Suining 629018,Sichuan,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;College of Earth Science,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国石油西南油气田公司川中油气矿,四川遂宁629018 [2]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [3]成都理工大学地球科学学院,四川成都610059

出　　处：《大庆石油地质与开发》2022年第4期138-145,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“下古生界构造岩相古地理研究”(2017ZX05008005-010)。

摘　　要：四川盆地磨溪地区中三叠统雷口坡组T_(2)l_(3)^(2)亚段含有厚度快速变化的低速盐层,造成地震成像产生“下拉”作用,常规地震解释速度模型难以准确刻画下伏雷口坡组T_(2)l_(1)^(1)亚段气藏的构造形态。通过对比2种盐层速度换算方法,建立了考虑盐层低速异常体的正演模型,提高了T_(2)l_(1)^(1)亚段的储层成像效果,刻画了储层的构造形态。在合成地震记录和井—震剖面层位标定的基础上建立基于井控层速度插值方法的速度模型,克服了T_(2)l_(3)^(2)亚段盐层低速异常体及其厚度变化对下伏地层成像产生的干扰,应用模型对磨溪地区的三维地震数据进行重新解释,有效提高了T_(2)l_(1)^(1)亚段顶界构造形态刻画的精度。基于井控层速度插值模型的盐下气藏地震精细解释为川中磨溪地区雷口坡组盐下气藏的储层预测与评价提供了有力的依据。The sub-member T_(2)l_(3)^(2) of the Middle Triassic Leikoupo Formation in Moxi area,Sichuan Basin contains a low-velocity salt bed of rapidly varying thickness which causes a“pull-down”effect in seismic imaging.It’s difficult for the conventional velocity seismic interpretation model to accurately describe the structural morphology of the sub-member T_(2)l_(1)^(1) of the Lower Leikoupo Formation.In this paper,we establish the forward model considering the low-velocity anomalous body of the salt bed through the comparison of the two methods of the salt bed velocity conversion,which improved the imaging quality of the T_(2)l_(3)^(2) sub-member reservoirs and described the structural mor⁃phology of the reservoirs.Based on the synthetic seismogram and well-seismic profile level calibration,we establish the velocity model based on the well-controlled velocity interpolation method to overcome the interference of the lowvelocity anomalous body and its thickness variation in T_(2)l_(3)^(2) sub-member salt bed on the imaging of underlying strata,The model is applied to the 3D seismic data of Moxi area,which greatly improves the precision of the structural morphology characterization of the top boundary of the sub-member T_(2)l_(1)^(1).Seismic interpretation of the pre-salt gas reservoirs based on the well-controlled interval velocity interpolation model provides a powerful basis for the reservoirs prediction and evaluation of the pre-salt gas reservoirs in Leikoupo Formation,Moxi area,central Sichuan.

关 键 词：正演模型 低速盐层 地震解释 磨溪气田 雷口坡组 

分 类 号：P631[天文地球—地质矿产勘探]