一种混叠激发控制时间产生方法  

A shooting time generation method for blended acquisition

作　　者：甘志强 孙祥娥[1] 魏建 GAN Zhiqiang;SUN Xiang’e;WEI Jian(School of Electronic Information and Electrical Engineering,Yangtze University,Jingzhou,Hubei 434023,China;Xi’an Geophysical Prospecting Equipment Company of BGP,CNPC,Xi’an,Shaanxi 710061,China)

机构地区：[1]长江大学电子信息与电气工程学院,湖北荆州434023 [2]东方地球物理公司西安物探装备分公司,陕西西安710061

出　　处：《石油地球物理勘探》2023年第5期1053-1061,共9页Oil Geophysical Prospecting

基　　金：中国石油天然气集团公司科研计划项目“石油天然气量值溯源和传递技术研究”(2021DJ2901)资助。

摘　　要：激发源启动时间的设计是高效混叠采集的关键技术之一。高效混叠采集是随高密度地震勘探而产生的采集作业新模式,它能显著缩短地震勘探周期、降低采集成本,但激发源启动时间的随机程度直接影响采集资料的品质。为此,文中创新性地提出一种地震勘探随机激发时间产生算法。首先,利用卫星授时技术和压控晶振在较短时间内的电压变化与振荡频率呈近似线性关系的特点,以固定时间间隔方式进行本地时钟的校准和卫星时间同步;然后,根据激发源位置、准备好的炮点激发顺序、时距规则参数等信息,计算出偏差不大于10μs的预计激发时间;最后,基于该预计激发时间,以实时采集的振动传感数据作为种子,随机产生一个指定窗口内小抖动的随机数作为炮点激发的整毫秒时间,确保生成激发时间的随机性。对测试结果的分析表明,所提方法计算得到的随机激发时间的抖动值具有数值大小与范围可控、随机性强的特征,满足工业应用的实际需求。The design of excitation source start⁃up time is one of the key technologies for efficient aliasing acquisition.The high⁃efficiency aliasing acquisition is a new acquisition mode produced by high⁃density seismic exploration,which can significantly shorten the seismic exploration period and reduce the acquisition cost,but the random degree of excitation source start⁃up time directly affects the quality of the acquired data.Therefore,this paper proposes an innovative algorithm for generating random excitation time in seismic exploration.Firstly,the local clock calibration and satellite time synchronization in a fixed time interval is carried out with using the satellite timing technology and the voltage⁃frequency linear relationship of a voltage⁃controlled crystal oscillator in a shorter period of time.Then the expected excitation time with a deviation of less than 10μs is calculated based on the information of the source location,ready shot point excitation order,and time⁃distance rule parameters.Lastly,based on the predicted excitation time,the vibration sensor data collected in real time are used as the seed to randomly generate a random number of small jitter in a specified window as the source start⁃up time in millisecond to ensure the randomness of the production excitation time.The test solution shows that the dithered value of the random excitation time by the proposed algorithm has the characteristics of numerical size,controllable range,and strong randomness,which is closer to the actual needs of industrial applications.

关 键 词：振动传感 卫星授时 随机激发时间 压控晶振 周期性时间同步 

分 类 号：P631[天文地球—地质矿产勘探]