基于统计学岩石物理模型的火山岩横波速度预测方法  

S-Wave Velocity Prediction Method of Volcanic Rock Based on Statistical Rock-Physics Model

作　　者：乔汉青 刘财[3] 方慧[1,2] 朱威 Qiao Hanqing;Liu Cai;Fang Hui;Zhu Wei(Institute of Geophysical and Geochemical Exploration,CAGS,Langfang 065000,China;Laboratory of Geophysical EM Probing Technologies,MLR,Langfang 065000,China;College of Geo-Exploration Science and Technology,Jilin University,Changchun 130026,China)

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [2]国家现代地质勘查工程技术研究中心,河北廊坊065000 [3]吉林大学地球探测科学与技术学院,吉林长春130026

出　　处：《地球科学》2023年第8期2993-3006,共14页Earth Science

基　　金：中国地质调查项目(No.DD20221638);中国地质调查局基本科研项目(No.AS2022J04);中国地质调查局基本科研项目(No.AS2020J02);中国地质调查局基本科研项目(No.AS2020P01)。

摘　　要：火山岩储层因蕴藏地热、矿产、油气等资源,受到各国学者的广泛关注.横波速度是地震AVO分析、储层特征描述和流体识别的必要信息,因受限于采集技术和采集成本等因素,测井资料中常常缺失横波速度信息.基于统计学岩石物理反演方法和Xu-White岩石物理模型,提出了一种适用于火山岩储层的统计学岩石物理模型横波速度预测方法.该方法利用XuWhite模型中砂的纵、横波速度和粘土相关孔隙纵横比作为关键岩石物理参数对岩石速度的影响,根据统计学岩石物理反演方法,首先通过已知参考井常规测井资料和Xu-White模型构建关键岩石物理参数的先验分布,其次利用先验分布代替固定参数值初始化Xu-White模型建立统计学岩石物理模型,再次基于贝叶斯反演理论,匹配目标井位实际纵波速度与模拟纵波速度,计算目标井位关键岩石物理参数后验信息,最后利用统计学岩石物理模型和目标井关键岩石物理参数的后验分布反演出目标井的横波速度信息.将该方法应用于中国东部南堡凹陷5号构造实际测井数据,得到的横波速度预测结果优于常规方法,证明了该方法的有效性和准确性.研究将为火山岩储层的后续勘探开发提供更准确的横波速度资料.Because of its geothermal,mineral,and oil and gas resources,volcanic rock reservoirs have piqued the interest of scholars from all over the world.Shear-wave velocity is crucial for seismic AVO analysis,reservoir characterization,and fluid identification.Shear wave velocity information is often missing in logging data due to limitations in acquisition technology and acquisition cost.Based on the statistical petrophysical inversion method and Xu-White model,this paper proposes a S-wave velocity prediction method of statistical rock-physics model suitable for volcanic reservoirs.This method uses the P-wave and S-wave velocity of sand and the aspect ratio of clay-related pores in the Xu-White model as the key petrophysical parameters affecting rock velocity.Firstly,according to the statistical rock physical inversion method,the prior distribution of key petrophysical parameters is constructed by the conventional logging data of reference wells and the Xu-White model.Secondly,the prior distribution is used to initialize the Xu-White model instead of the fixed parameter value to establish the statistical rock-physics model.Thirdly,based on the Bayesian inversion theory,the actual P-wave velocity and the simulated P-wave velocity of the target well are matched to calculate the posterior information of key petrophysical parameters of the target well.Finally,the S-wave velocity information of the target well is inversed by using the statistical rock-physics model and the posterior distribution of key petrophysical parameters of the target well.This method is applied to the actual logging data of No.5 structure in Nanpu Sag,eastern China,and the S-wave velocity prediction results are better than those of the conventional method,which proves the effectiveness and accuracy of this method.This study will provide more accurate S-wave velocity for the subsequent exploration and development of volcanic reservoirs.

关 键 词：火山岩储层 横波速度预测 XU-WHITE模型 统计学岩石物理模型 贝叶斯反演 地球物理 

分 类 号：P31[天文地球—固体地球物理学]