利用三分量微测井技术调查表层纵、横波速度
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摘要
为了给多波多分量地震勘探提供准确的近地表纵横波速度和厚度模型,在中国江苏省东北部N地区的大陆科学钻探井区采用三种不同的观测方法进行了三分量微测井近地表调查:①地面炸药激发,井中三分量检波器接收;②地面重锤横向锤击枕木激发,井中三分量检波器接收;③井中炸药激发,地面τ值检波器、地面三分量检波器和VSP子波三分量检波器同时接收。本文详细描述了在这三种不同观测方法下三分量微测井资料的采集、装备和数据处理方法,并得出以下认识:在地面炸药激发的垂直分量中可拾取可靠的纵波初至,但利用水平分量很难准确地拾取横波波至;地面重锤横向敲击枕木激发的水平分量的SH型横波数据信噪比较高,其垂直分量纵波初至的信噪比不高;在井下激发、地表接收的垂直分量中可拾取可靠的纵波初至,在水平分量中也可以观测到横波波至,但横波波至前、后的同相轴有多组,难以辨认真正的横波,但是利用水平分量的波形特征或动力学特征,能够识别横波速度分层的深度位置。通过对工区微测井资料解释,获得了纵横波静校正所需的较精确的表层信息,并对今后三分量微测井所用装备和采用的观测方法提出了一些建议。
In order to provide accurate model of near-surface P- and S-wave velocity and thickness, in the continent scientific drilling sites in N area of the northeast of Jiangsu Province, China, the three different surveying methods of 3-C uphole survey for near-surface surveying were used: ①shooting by dynamite on surface and receiving by 3-C geo-phones in the hole; ②shooting by using hammer on the surface to hammer at sleeper laterally and receiving by 3-C geophones in the hole; ③shooting by dynamite in the hole and receiving simultaneously by T geophone, 3-C geophones and VSP wavelet 3-C geophones on surface. The paper described in detail the acquisition, equipment and processing methods of 3-C uphole surveying data in these three different surveying methods and gained the following knowledge: the reliable first breaks of P-wave can be picked up in vertical components shooting by dynamite on the surface, but the first breaks of S-wave are difficult to be accurately picked up by using horizontal components; the S/N ratio in SH-wave data of horizontal components shooting by hammer on the surface hammering at sleeper laterally is higher, but S/N ratio of the first breaks of P-wave in vertical components is not high; the reliable first breaks of P-wave can be picked up in vertical components shooting in the hole and receiving on the surface, the S-wave arrivals can be observed in horizontal components, but there are multiple group of events before and after S-wave arrivals that makes difficult to recognize true S-wave, nevertheless, using waveform feature or dynamic feature in horizontal components can i-dentify the depth position of layered S-wave velocity. The accurate near-surface information, the P-and S-wave static corrections needs were gained by interpretation of uphole surveying data in the work area. At meantime, some suggestions about equipments and surveying methods of next 3-C uphole survey technique are also presented in the paper.
In order to provide accurate model of near-surface P- and S-wave velocity and thickness, in the continent scientific drilling sites in N area of the northeast of Jiangsu Province, China, the three different surveying methods of 3-C uphole survey for near-surface surveying were used: ①shooting by dynamite on surface and receiving by 3-C geo-phones in the hole; ②shooting by using hammer on the surface to hammer at sleeper laterally and receiving by 3-C geophones in the hole; ③shooting by dynamite in the hole and receiving simultaneously by T geophone, 3-C geophones and VSP wavelet 3-C geophones on surface. The paper described in detail the acquisition, equipment and processing methods of 3-C uphole surveying data in these three different surveying methods and gained the following knowledge: the reliable first breaks of P-wave can be picked up in vertical components shooting by dynamite on the surface, but the first breaks of S-wave are difficult to be accurately picked up by using horizontal components; the S/N ratio in SH-wave data of horizontal components shooting by hammer on the surface hammering at sleeper laterally is higher, but S/N ratio of the first breaks of P-wave in vertical components is not high; the reliable first breaks of P-wave can be picked up in vertical components shooting in the hole and receiving on the surface, the S-wave arrivals can be observed in horizontal components, but there are multiple group of events before and after S-wave arrivals that makes difficult to recognize true S-wave, nevertheless, using waveform feature or dynamic feature in horizontal components can i-dentify the depth position of layered S-wave velocity. The accurate near-surface information, the P-and S-wave static corrections needs were gained by interpretation of uphole surveying data in the work area. At meantime, some suggestions about equipments and surveying methods of next 3-C uphole survey technique are also presented in the paper.
引文
[1]侯念利等．GDZ-24小型地震仪实用技巧．石油仪器, 2002,16(5):44～45
[2]李驰等．合理选择炸药震源最佳激发条件的因素分析． 石油物探,1997．36(3):105～111
[3]夏显佰等．夏盐南三维静校正方法．石油物探,2004,43 (2):188～191
[4]刘振夏等．高分辨率三维地震勘探数据采集技术．石油 地球物理勘探,1999,34(1):37～44,64
[5]吕公河．地震勘探虚反射界面的测定及其利用．石油 地球物理勘探,2002,37(3):295～299
[6]白旭明等．低信噪比强线性干扰区地震采集方法探 讨——南鄱阳凹陷西区地震采集方法初探．石油地球 物理勘探,2003,38(2):122～125
[7]张竹生等．陆上地震激发因素的选择方法探讨．石油物 探,2004,43(2):153～158
[8]李天树等．双井微测井技术在表层结构调查中的应 用．石油物探,2004,43(5):471～474
[9]胡中平等．纵横波浅层折射和纵横波微测井方法联合 应用研究．石油物探,1998,37(1):89～94
[10]杨海申等．VSP三分量微测井技术在表层调查中的应 用．石油地球物理勘探,2005,40(1):97～102
[11]李刚等．微测井技术在地震资料静校正处理中的应 用．大庆石油地质与开发,2002,21(4):80～82
[12]郭桂红等．转换波的静校正．吉林大学学报(地球科学 版),2003,33(4):542～544,554
[2]李驰等．合理选择炸药震源最佳激发条件的因素分析． 石油物探,1997．36(3):105～111
[3]夏显佰等．夏盐南三维静校正方法．石油物探,2004,43 (2):188～191
[4]刘振夏等．高分辨率三维地震勘探数据采集技术．石油 地球物理勘探,1999,34(1):37～44,64
[5]吕公河．地震勘探虚反射界面的测定及其利用．石油 地球物理勘探,2002,37(3):295～299
[6]白旭明等．低信噪比强线性干扰区地震采集方法探 讨——南鄱阳凹陷西区地震采集方法初探．石油地球 物理勘探,2003,38(2):122～125
[7]张竹生等．陆上地震激发因素的选择方法探讨．石油物 探,2004,43(2):153～158
[8]李天树等．双井微测井技术在表层结构调查中的应 用．石油物探,2004,43(5):471～474
[9]胡中平等．纵横波浅层折射和纵横波微测井方法联合 应用研究．石油物探,1998,37(1):89～94
[10]杨海申等．VSP三分量微测井技术在表层调查中的应 用．石油地球物理勘探,2005,40(1):97～102
[11]李刚等．微测井技术在地震资料静校正处理中的应 用．大庆石油地质与开发,2002,21(4):80～82
[12]郭桂红等．转换波的静校正．吉林大学学报(地球科学 版),2003,33(4):542～544,554
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