渤海A油田由于构造主体大面积(约20km2)浅层气形成的"气云"带,常规纵波反射频率及能量都受到严重损失,致使深层目的层地震成像不能准确反映地下地质构造特征.转换波(PS)含有有效入射P波信息,从中能获得转换S波.由于S波基本不受地层屏蔽的影响,从而能够获得深层较好的地震成像.为此在该构造上实施了浅海四分量地震采集.通过现场地质勘测,以及浅层钻井分析及多波地震试验,确定了海上采集流程.经过多次试验,确定了合理的转换波处理流程和关键参数,从而得到了较好的二维转换波剖面.通过正确识别波形特征,利用全波列测井,生成合成转换波地震记录,进行层位标定,指导构造解释及进行油田整体储量评价.%In Oilfield A, of south Bohai, the large area (20km2) of gas in the shallow layer of the main structure makes a "gas cloud" effect in the seismic section. It makes the seismic migration imaging of the deeper aim layer inconsistent with the actual features of a geologic structure. But, the converted waves,PS waves, containing effective information of incident compressed (P) waves, can create converted S waves. The S wave is affected little by the shallow layer screen, allowing better imaging of the deeper layer. So, 4C seismic acquisition was carried out on the structure. Through geologic reconnaissance on the site, shallow layer drilling analysis and multicomponent seismic experiments, the offshore acquisition flows are designed. Choosing appropriate processing flows for converted waves and paying attention to the key tache of processing, a high quality 2D converted wave section was obtained. By identifying the character of the seismic wave correctly, making use of the full wave logging, producing synthetic converted wave seismogram, and identifying horizon, we can carry out structure interpretation and reserve evaluation of the oilfield.
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