论文详情
西湖凹陷平北斜坡带平湖组储层受薄煤层影响易形成强反射，从而造成地质假象。储层反演时，薄煤层对储层分布和厚度的预测准确性有较大影响。消除煤层影响对提高储层预测精度至关重要。从煤层的地震反射特征出发，根据煤、泥、砂各岩性组合的反射系数差异，建立了一套提取、识别和消除煤层强反射系数的地震叠前优化处理技术流程。该技术通过叠前分角度地震道集处理，弱化了煤层强反射及其旁瓣造成的影响，提高了叠前地震道集的质量，突出了砂体分布特征，消除了煤层强反射造成的地质假象。在叠前地震反演技术的实际资料应用中，弱化煤层强反射处理后的地震数据有效地压制了煤层假象，降低了煤层强反射导致的储层预测多解性，在斜坡带平湖组储层预测中效果显著，有效支持了开发井的实施及钻后评价。
Thin coal seams in the Pinghu Formation, Pingbei slope zone of the Xihu sag, cause strong seismic reflections and geologic misinterpretation. These strong reflections have a remarkable negative impact on reservoir prediction, including lateral extension and vertical thickness prediction, through seismic inversion. Based on different reflection coefficients of coal-mud-sand associations, we propose an angle-gather conditioning technique to identify and eliminate strong reflections and thus weaken the effect of coal seams. Gather conditioning suppresses strong reflections of coal seams and side lobes and highlights effective signals of sandstone reservoirs. A prestack inversion shows improved reservoir prediction with decreased uncertainties, which offers support to development well drilling and post-drilling evaluation of the Pinghu Formation in the slope zone.