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相比于常规的石油和煤炭地震勘探,砂岩型铀矿地震勘探过程中存在着诸多难点问题:勘探目标层埋藏深度浅,一般小于1000 m,浅层地震资料信噪比低,且易受采集噪声的影响;目标层砂体与围岩的物性差异小,致使有效的地震信息较微弱;砂泥薄互层多,砂岩型铀矿往往存在于“泥砂泥”、“煤砂泥”等互层结构的砂体之中,且含矿砂层厚度通常较小,在十米至几十米不等,识别难度较大.据此,开展了大量的地震数据采集、处理和解释技术试验以及应用研究工作,基本明确了从采集面元优化、精细叠前去噪和速度分析方面解决目标层埋藏深度浅所致问题;从采集覆盖次数优化和保幅处理方面解决物性差异小所致问题;从采集的激发和接收参数的优化、提频处理以及波阻抗反演方面解决砂泥薄互层所致问题.实际应用效果证明采用的技术方案具有一定的针对性,是砂岩型铀矿地震勘探有效可行的技术手段.
Compared with the conventional oil and coal seismic exploration, there are many difficult problems in the seismic exploration of sandstone-type uranium deposits: the exploration targets are shallow buried depth, generally less than 1000 m, shallow seismic data have low SNR and are vulnerable to acquisition Noise; the difference between the physical properties of the target sand body and the surrounding rock is small, resulting in weak seismic information; sand and sand thin interbedded layers, sandstone-type uranium deposits are often found in the “mud”, “ ”And other interbedded sand bodies, and the thickness of ore-bearing sand layer is usually small, ranging from tens to tens of meters, so it is more difficult to identify. Therefore, a great deal of seismic data collection, processing and interpretation Technical tests and applied research work, the basic clear from the collection facet optimization, fine pre-stack noise and speed analysis of the target layer to solve the problem caused by the shallow depth of burial; from the collection of the number of coverage optimization and preservation of physical properties to solve small The problems caused by the thin interbeds of sand and sand are solved from the optimization of excitation and receiving parameters collected, the frequency-raising processing and the inversion of wave impedance.The practical application results prove that the technical scheme adopted has certain pertinence and is sandstone-type uranium mine Seismic exploration feasible and effective techniques.