基于岩性数据重构的叠前快速反演技术研究及应用  

Research and application of pre-stack fast inversion technology based on lithologic data reconstruction

作　　者：章雄 李玉雯 关旭 隆季原 熊艳 张菁蕾 ZHANG Xiong;LI Yuwen;GUAN Xu;LONG Jiyuan;XIONG Yan;ZHANG Jinglei(Southwest Geophysical Research Institute,BGP Inc.,CNPC,Chengdu,Sichuan 610213,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gas field Company,Chengdu,Sichuan 610041,China;Southwest Geophysical Company,BGP Inc.,CNPC,Chengdu,Sichuan 610213,China)

机构地区：[1]中国石油集团东方地球物理勘探公司西南物探研究院,四川成都610213 [2]中国石油西南油气田公司勘探开发研究院,四川成都610041 [3]中国石油集团东方地球物理勘探公司西南物探分公司,四川成都610213

出　　处：《石油地球物理勘探》2024年第5期1141-1154,共14页Oil Geophysical Prospecting

基　　金：中国石油西南油气田分公司重大科技专项“四川盆地中西部地区致密气勘探开发理论及关键技术研究”之课题“四川盆地中西部地区致密气成藏条件及物探关键技术研究”(2022ZD01-01)资助。

摘　　要：四川盆地中部地区是致密气核心建产区,其中侏罗系沙溪庙组是近几年致密气藏勘探开发的重要层系。由于沙溪庙组河道砂体横向变化快、纵向叠置关系复杂、储层非均质性强,导致叠后波阻抗岩性反演方法的精度低,而叠前岩性反演计算流程繁杂、耗时长,无法满足快速增储上产的需求。为此,提出了基于岩性数据重构的叠前快速反演技术。首先,利用纵、横波阻抗结合地质先验信息,重构岩性阻抗测井曲线,明确岩性识别门槛值,并建立岩性阻抗解析式;其次,开展AVO属性分析,推导出以截距P与梯度G表征的岩性阻抗反射数据表达式,并重构地震响应特征明显的目标岩性阻抗反射数据;最后,利用叠后反演快速获取高精度三维岩相体,作为后续相控叠前地质统计学反演的三维空间约束项。在川中金秋区块1.3×10^(4) km^(2)连片三维的应用表明,该技术在减少耗时的同时有效提升了反演流程的平稳性和可靠性,反演结果具有更高的精度和分辨率,储层刻画与实钻井吻合率达90%以上,探井实施成功率达100%,推动了沙溪庙组致密气藏的高效勘探开发。The central part of the Sichuan Basin is a core production area for tight gas,where the Jurassic Shaximiao Formation is an important formation for the exploration and development of tight gas reservoirs in recent years.The channel sand body of the Shaximiao Formation exhibits rapid lateral changes,complex vertical overlapping relationships,and strong reservoir heterogeneity,which leads to low accuracy of the inversion method for post-stack wave impedance lithology.Meanwhile,the calculation process of pre-stack lithology inversion is complex and time-consuming and cannot meet the needs of rapid increase in reservoirs and production.Therefore,the pre-stack fast inversion technology based on lithologic data reconstruction is proposed in this paper.Firstly,by combining both P-wave and S-wave impedance with geological prior information,the lithology impedance logging curves are reconstructed,the lithology identification threshold is determined and the lithology impedance analytical formulas are established.Secondly,the AVO attribute analysis is carried out to derive the lithologic impedance reflection data expression characterized by intercept P and gradient G,and to reconstruct the lithologic impedance reflection data which characterizes a more prominent seismic response.Finally,high-precision three-dimensional lithofacies are quickly obtained through post-stack inversion,which is used as a three-dimensional spatial constraint for subsequent pre-stack geostatistical inversion.The application results of the technologyin a 13,000 km^(2) contiguous three-dimensional area in the Central Sichuan Jinqiu Block show that this technology can effectively improve the stability and reliability of the inversion process while reducing time consumption.The inversion results achieve higher precision and resolution.The match rate between reservoir characterization and actual drilling exceeds 90%,and the success rate for its implementation in the exploration wells reaches 100%.Thus,the application of the technology promotes a high-eff

关 键 词：致密气藏 AVO 属性 岩性反演 岩相体 叠前地质统计学反演 

分 类 号：P631[天文地球—地质矿产勘探]