南海北部陆坡崎岖海底区地震成像:OBS旅行时反演

发布时间：2019-06-16 15:52

【摘要】：深水陆坡油气资源丰富,是油气勘探的重要领域。由于陆坡水深变化较大、海底地形崎岖、地质构造复杂,地震成像存在诸多难点,其中,速度模型的建立是最大的难题之一。利用OBS(ocean bottom seismometer)数据上丰富的折射初至信息,采用旅行时反演方法建立崎岖海底区速度模型。OBS数据由广州海洋地质调查局在南海北部陆坡珠江口盆地东部海域采集,数据质量良好,存在大量的初至折射波。地震成像结果表明,在深水崎岖海底区,利用OBS的初至旅行时能够获得地震成像所需要的背景速度场。受限于高频近似的假设,初至旅行时反演结果分辨率较低。全波形反演可以提供精度更高的速度结构,初至旅行时反演结构可用作全波形反演的初始模型。
[Abstract]:Deep-water continental slope is rich in oil and gas resources, which is an important field of oil and gas exploration. Due to the great change of water depth on land slope, rugged seafloor topography and complex geological structure, there are many difficulties in seismic imaging, among which the establishment of velocity model is one of the most difficult problems. Based on the abundant refraction first arrival information on OBS (ocean bottom seismometer) data, the velocity model of rugged sea floor area is established by travel time inversion method. Obs data are collected by Guangzhou Marine Geological Survey in the eastern waters of Pearl River Estuary Basin on the northern continental slope of the South China Sea. The data are of good quality and there are a large number of first arrival refraction waves. The results of seismic imaging show that the background velocity field needed for seismic imaging can be obtained by using the first arrival travel of OBS in the rugged sea floor of deep water. Due to the assumption of high frequency approximation, the resolution of the inversion results at the first arrival travel time is low. Full waveform inversion can provide more accurate velocity structure, and the inversion structure can be used as the initial model of full waveform inversion.
【作者单位】：国土资源部海底矿产资源重点实验室;广州海洋地质调查局;
【基金】：国土资源部海底矿产重点实验室开放课题基金(KLMMR-2013-A-18)
【分类号】：P631.46;P618.13

【相似文献】