龙门山前侏罗系沙溪庙组致密砂岩储层叠前地震预测  

Prestack seismic prediction of tight sandstones for Jurassic Shaximiao Formation in front of Longmenshan

作　　者：刘玲[1] 沃玉进[1] 孙炜[1] 陈霞[1] 徐美娥[1] 刘力辉[2] Liu Ling;Wo Yu-jin;Sun Wei;Chen Xia;Xu Mei-e;Liu Li-hui(Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;Rockstar Petroleum Science and Technology Limited Company Beijing 100192,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]北京诺克斯达石油科技有限公司,北京100192

出　　处：《天然气地球科学》2019年第7期1072-1082,共11页Natural Gas Geoscience

基　　金：国家科技重大专项“中西部重点碎屑岩领域油气富集规律与分布预测”(编号:2016ZX05002-006);中国石化科技部重点攻关项目“龙门山前侏罗系天然气成藏主控因素与有利区”(编号:P18069-1)联合资助

摘　　要：龙门山前侏罗系沙溪庙组致密砂岩横向变化快、非均质性强、孔隙结构复杂,储层与围岩阻抗差异小,岩石物理规律不清,且地震叠前道集资料品质差、测井横波资料匮乏,优质储层预测困难.针对以上问题,通过叠前反褶积、阿尔法滤波、剔除拟合振幅补偿优化处理了叠前CRP道集,采用改进的Xu-White模型预测了横波,并通过贝叶斯稀疏脉冲反演获得了叠前弹性参数V P/V S,预测了砂体边界,最后在砂体边界控制下,利用蒙特卡罗—贝叶斯分类方法反演了孔隙度,预测了致密砂岩有利储层发育区.研究表明:贝叶斯稀疏脉冲反演简化了稀疏脉冲反演过程,求解更稳定,砂岩边界控制下的孔隙度反演排除了泥岩影响,提高了孔隙度预测精度,该技术在龙门山前侏罗系沙溪庙组致密砂岩有利储层预测中取得了较好的效果,具有一定的推广应用价值.The tight sandstones of Jurassic Shaximiao Formation had the features of rapid lateral changes,strong heterogeneities and complex pore structure in front of Longmenshan.Rock physics characteristics were similar between tight sandstones and mudstones.In addition,the quality of prestack data was poor and the shear wave logging was scarce.This made reservoir prediction difficult.The CRP gather was optimized by a series of corresponding methods,including Decon,Alpha Filter and AMP Compensation.Shear wave was predicted with modified Xu-White model.After that,the prestack parameter of VE/VS was acquired by Bayesian sparse pulse inversion.And sandstone boundary was predicted using Vp/Vs.Finally,reservoir po rosity was calculated by Monte Carlo-Bayesian classification under the control of sandstone boundary,and the effective reservoirs were determined.Research indicated that Bayesian sparse pulse inversion simplified the sparse pulse inversion process and its solution was more stable.Porosity inversion with the control of sandstone boundary avoided the mudstone affect and improved the accuracy of porosity prediction.The new method had achieved excellent results in the effective reservoir prediction of tight sandstone for Jurassic Shaximiao Formation in front of Longmenshan and had significant implications for late exploration.

关 键 词：道集优化处理 横波预测 叠前弹性参数 孔隙度反演 致密砂岩 沙溪庙组 

分 类 号：TE132.1[石油与天然气工程—油气勘探]