变扫描技术用于高分辨率采集可能性探讨

Feasibility of high-resolution acquisition using variable sweep technique

地矿部石油物探研究所, 南京 210014

Research Institute of Geophysical Prospecting for Petroleum, Nanjing 210014

常规的变扫描技术, 由于发送的信号谱与大地自然响应特性基本一致, 频带较窄, 不能用来进行高分辨率采集。单纯加定变扫描组的频带或使变扫描组向高频上移, 则因高频易被地层衰减, 记录信号频带仍难以拓宽, 收效甚微。本文认为, 只有吸取联合扫描技术选取扫描组的灵活性, 进行拟反转级联式非线性扫描设计, 才能赋予变扫描技术新的生命, 在高分辨率采集方面发挥作用。

Conventional varisweep techniques can not be used for high-resolution acquisition due to the little difference between signal spectrum and response characteristics of the earth and the narrow frequency band.Broadening the band of the variswecp group or moving it toward high frequency brings little effect because high-frequency components attenuate drastically through strata,therefore the frequency band of the signal acquired is still difficult to broaden. This paper concludes that that the varisweep techniques will play an active role in the high-resolution acquisition if the method for selecting sweep group in combisweep technique is used to do quasi-reverse cascade nonlinear sweep design.