柴达木盆地东部高分辨率地震勘探应用研究与效果

柴达木盆地东部第四系蕴藏着丰富的天然气资源,由于表层地震地质条件的复杂性和含气异常的特殊性,致使含气异常或浅层地质条件的变化都可能造成“低频、低速、低信噪比,同相轴下拉”的地震异常现象,使得对气区的地震勘探和认识较为困难,在理论分析的基础上,柴达木盆地东部高分辨率地震技术采用小道距,小组合距,小井深,小炮检距,高采样间隔,高覆盖次数、多井组合激发,多检波器组合接收,突出气区低频信息,突出目的层勘探的采集技术,依据工区的特点,资料处理重点突出含气异常区的去噪、反褶积、分频叠加技术等,总结了一套适合盆地气区勘探的高分辨率技术方法。

Applied study and effect of high-resolution seismic exploration in east of Qaidam Basin.

There is abundant gas resource in Quatarnary in east of Qaidam Basin.Because of the complexity of shallow seismic geologic condition and speciality of gas bearing anomlay,both the gas bearing anomaly and the change of shallow geologic condition can cause such seismic anomaly as"low frequency,low velocity,poor signal to noise ratio and pulling event down",which bring a lot of difficulties in seismic exploration of gas besring area and in explanation of the phenomena.On the basis of theoretical analysis,the high resolution seismic exploration in east of Qaidamu Basin adopted the acquisition techniques such as short group interval,short geophone distance,shallow shot hole depth,short offset,dense sample interval,high multiplicity,shooting in multiple shot holes,receiving in array of multiple geophone,highlighting the low frequency information having in gas area and highlighting target of exploration and according to the characters of work area,the data processing adopted such techniques as noise suppression,deconvolution and stack by frequency division that place emphasis on gas bearing anomaly ares,which sum up a suit of high resolution techniques suitable for the exploration of gas bearing zone in that basin.