速度、加速度检波器在超深层地震勘探中应用效果分析——以川南赤水地区为例  

Analysis and application of velocity and acceleration geophone in ultra deep seismic exploration:a case study of Chishui area in south Sichuan basin

作　　者：文雪康[1] 袁莹 唐建明[1] 刘胜 陈明春 WEN Xue-kang;YUAN Ying;TANG Jian-ming;LIU Shen;CHEN Ming-chun(Sinopec Southwest Oil and Gas Company,Chengdu 610016,China;Sinopec Geophycical Company Nanfang Branch,Chengdu 610016,China)

机构地区：[1]中国石化西南油气分公司,成都610016 [2]中石化石油工程地球物理有限公司南方分公司,成都610016

出　　处：《地球物理学进展》2020年第4期1489-1496,共8页Progress in Geophysics

基　　金：国家自然科学基金项目(41804137);中国地质调查局滇东北地区页岩气地质调查项目(DD20190080);中石化地勘项目(34450790-18-FW0301-0001)联合资助。

摘　　要：川南地区重要产气层之一的震旦系灯影组埋深约9000 m,以往多期地震勘探未能取得高品质资料,原因之一就是灯影组反射信息频率较低,而常规检波器(六串两并20DX-10 Hz速度型检波器)在低频段衰减严重,未能完整接收到地震反射信息.为得到深层高品质的资料,在川南赤水地区开展了不同类型检波器试验研究工作,首先研究了3种检波器(20 DX-10 Hz速度型检波器、自然频率5 Hz速度型检波器、单点陆用压电加速度检波器)的幅频特征,分析了不同检波器对低频信号接收能力的差异;对比测试了3种检波器对主频为25 Hz的雷克子波的波形、频率响应;结合实际地震资料,分析了加速度型检波器的实际地震资料在加速度域和速度域的频率特征;最后将加速度检波器地震资料转换至速度域,与其他两种速度型检波器地震资料对比分析得到以下认识:(1)加速度检波器具有宽频带特性,对提高分辨率较为有利,适用于勘探目的层相对较浅地区的高分辨率勘探.(2)加速度检波器地震资料在加速度域、速度域两种不同域的资料差别较大,前者积分转换虽然提高了低频段响应但频带变窄,不利于提高分辨率,生产中使用原始域数据更为合适.(3)野外实际资料表明,低频速度型检波器在保持常规20DX-10 Hz的勘探效果的基础上提高了低频段的响应,与加速度检波器转域后的低频效果接近,频带比加速度检波器转域后要宽,更加适合超深层地震勘探.Dengying formation is one of the most important gas producing layers in south Sichuan basin,which is underground about 9000 m.In the past,high-quality data were not obtained seismic exploration in the past.One of the reasons is that the reflection information frequency of Dengying formation is very low,while the conventional geophone attenuates seriously in the low-frequency,so the seismic reflection information could not be received completely.In order to get high-quality seimic data,three different types of geophones were tested in Chishui area.Firstly,we analysed the amplitude and frequency characteristics of the three types of geophones,and the ability of receiveing low-frequency signal.then,we tested the responses of the three types of geophones excited by the ricker singal with the main frequency of 25 Hz.Based on the actual seismic data,this paper analysed the frequency characteristics of the actual seismic data of the acceleration geophone in the acceleration domain and the velocity domain.then,the acceleration geophone seismic data is converted to the velocity domain,and compared with the other two velocity geophone seismic data,the following knowledge is obtained:(1)The acceleration geophone has the broadband characteristics,which can improve the resolution It is suitable for high resolution exploration in areas with relatively shallow exploration target.(2)The seismic data of accelerometers are quite different in acceleration domain and velocity domain.Although the integration conversion of the former improves the low-frequency response,but the frequency band becomes narrow,which is not conducive to improving the resolution.It is more appropriate to use the original domain data in production.(3)The actual field data shows that the low-frequency velocity detector has improved the response of the low frequency band on the basis of maintaining the conventional 20 DX-10 Hz exploration effect,which is close to the low-frequency effect after the acceleration detector is transformed,and the frequency band is

关 键 词：川南赤水 超深层 低频信号 幅频特征 检波器 震旦系灯影组 

分 类 号：P631[天文地球—地质矿产勘探]