基于贝叶斯理论的反射率法煤田地震波阻抗反演  

Seismic impedance inversion of coal field with reflectivity method based on Bayesian theory

作　　者：杨真 高振宇[1] 刘兴业 YANG Zhen;GAO Zhenyu;LIU Xingye(Buertai Coal Mine,Shenhua Shendong Coal Group Corporation Limited,Ordos 017000,China;College of Geology and Environment,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]神华神东煤炭集团有限责任公司布尔台煤矿,内蒙古鄂尔多斯017000 [2]西安科技大学地质与环境学院,陕西西安710054

出　　处：《煤田地质与勘探》2020年第3期204-210,218,共8页Coal Geology & Exploration

基　　金：国家自然科学基金项目(41904116);陕西省煤炭绿色开发地质保障重点实验室基础研究计划项目(MTy2019-20)。

摘　　要：地震波阻抗反演可以直接提供地下介质的弹性信息,为后续的煤层识别,水通道预测以及陷落柱识别等提供可靠的资料。在面对复杂地质条件时,现有的波阻抗反演方法精度较低,不能满足实际勘探的需求。反射率法通过求解弹性波动方程获得弹性参数信息,能够模拟全波场响应以及地震波的各种传播效应,能更精确地考虑透射损失、多次波等引起的地震波振幅和相位变化,精度较高,且计算效率高于其他波动方程求解方法。因此,基于贝叶斯框架,建立了反射率法的反演目标函数并通过引入柯西分布作为先验分布提高反演结果的分辨率,形成了一种基于贝叶斯的反射率法波阻抗反演方法。将该方法应用于布尔台煤矿地震数据中,获得的波阻抗反演结果与测井资料匹配度较好,相比于常规方法分辨率更高,精度高,能够有效识别薄煤层和深部煤层分布,有效验证了新方法的可行性和有效性。该方法能为利用地震反演技术识别煤层及陷落柱等小构造,预测顶底板水分布提供有力的资料。Seismic inversion can reflect the morphology of subsurface formation and facies information more intuitively.Seismic impedance inversion can directly produce elastic information of underground media,providing reliable information for subsequent coal identification,water channel prediction and collapse column distinguishing.A Bayesian-based inversion of reflectivity method was developed.It can consider the various propagation effects of seismic waves and solve the objective function nonlinearly,which can more accurately calculate the impedance and improve the inversion resolution.The method is applied to the actual data from Buertai coal mine and satisfactory results are output,which effectively verifies the feasibility and effectiveness of the new method.Compared with traditional inversion method,the resolution and accuracy are improved.It can effectively identify the distribution of thin coal and deep coal.It can provide valuable information for identifying the coal and the collapse column by using seismic inversion technology and predicting the water distribution in the roof and the floor.

关 键 词：地震反演 反射率法 贝叶斯理论 波传播效应 煤田勘探 

分 类 号：P631.4[天文地球—地质矿产勘探]