实际单井微测井资料Q值估计方法的改进  

Improvement of Q value estimation method for actual single micro-logging data

作　　者：张子良 李振春[1] 郭见乐[2] 张学涛[2] 张凯[1] 董伟[2] 王静轩[2] ZHANG ZiLiang;LI ZhenChun;GUO JianLe;ZHANG XueTao;ZHANG Kai;DONG Wei;WANG JingXuan(College of Geoscienses,China University of Petroleum,Qingdao 266580,China;Shengli Geophysical Research Institute of Sinopec,Dongying 257022,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,青岛266580 [2]中国石化胜利油田分公司物探研究院,东营257022

出　　处：《地球物理学进展》2022年第2期721-730,共10页Progress in Geophysics

基　　金：国家自然科学基金(41774133,42074133);中国石油重大科技合作项目(ZD2019-183-003)联合资助.

摘　　要：近地表对地震波有强烈的吸收衰减作用,严重影响地震数据的分辨率,利用微测井资料对近地表吸收结构进行估算,可以为高分辨率地震勘探提供技术支撑.采用频谱比等主流方法对实际单井微测井数据进行Q估计时,观测到的微测井数据需要满足微测井Q估计的假设条件和Q衰减理论模型,但是由于采集因素的影响,实际微测井数据会存在“限幅”、初至时间异常、激发子波不一致等问题,造成单井微测井Q估计不稳定、不可靠,甚至会估计出负的Q值.本文在梳理实际单井微测井数据存在问题的基础上,对这几个问题采用针对性策略进行了处理,缓解了实际单井微测井数据的缺陷对Q估计带来的影响,实际数据的Q估计结果验证了本文方法的可靠性和有效性.The actual earth medium is viscoelastic,and the seismic waves propagating in it will absorb and attenuate.Especially,nearsurface medium has strong absorption and attenuation effects on seismic waves,which seriously affects the resolution of seismic data.Using micro-logging data to estimate the near-surface absorption structure can provide technical support for high-resolution seismic exploration.When using mainstream methods such as spectrum ratio to perform Q estimation on actual single micro-logging data,the observed micro-logging data needs to meet the hypothetical conditions of micro-logging Q estimation and the Q attenuation theoretical model.In other words,micro-logging data needs to comply with attenuation logic.For example,when the propagation path is longer,the attenuation is more serious,the dominant frequency is lower,the frequency band is narrower,and the attenuation of high frequency is greater than that of low frequency.However,due to the influence of acquisition factors,the actual single micro-logging data will have problems such as“amplitude limit”,first break anomaly and inconsistent excitation wavelet,resulting in unstable and unreliable Q estimation of single microlog,and even negative Q value.On the basis of combing the problems existing in the actual single micro-logging data,this paper adopts targeted strategies to deal with these problems.The combination of cubic spline and compressed sensing is used to solve the“amplitude limiting”problem,the polynomial fitting strategy is used to solve the problem of abnormal first break time,and the trend fitting and energy matching strategy are used to solve the problem of inconsistent excitation wavelet.This alleviates the impact of the defects of the actual single micro-logging data on Q estimation.The stability and reliability of Q estimation of single micro-log are enhanced and negative Q values are eliminated.An actual micro-logging data is tested and the Q estimation results of the actual data verify the correctness and effectiveness of th

关 键 词：微测井 Q估计 实际数据 子波一致性 

分 类 号：P631[天文地球—地质矿产勘探]