Extrapolate well logs based on the constrained interpolation algorithm

Based on a detailed analysis of differences between seismic data and well logs, we discuss the problem of matching seismic traces and well logs and present a new matching method based on event search in instantaneous phase which greatly improves seismic resolution. The method is based on flattening events in instantaneous phase to compare the seismic traces to the well log traces with the same phase. We calculate the coefficients using the singular value decomposition method to extrapolate the well logs. As a result, the events in the seismic profile are continuous and match well with well logs. We apply this method to the Mao-2 well in Daqing Oilfield with good results.

叠前道集优化处理在浅层气预测中的应用

叠前AVO属性分析技术在浅层气地震预测中应用广泛,叠前道集作为AVO属性分析的主要输入数据,道集资料品质对气藏的预测结果影响较大。文中以ALX工区为例,针对常规道集处理中存在的信噪比低、道集不平、远偏移距频率低等问题,在AVO正演的指导下,应用均值滤波、无速度道集拉平、远近道频谱能量补偿的道集优化处理技术,提高叠前CRP道集资料品质,并运用优化处理前后的道集对比、气层顶面AVO曲线对比、叠加剖面对比及平面属性对比的方式,对优化处理后的道集进行质控。实际资料应用效果表明,优化后道集气层处AVO曲线与正演道集曲线更加接近,叠加剖面上气藏低频"亮点"特征更加明显,应用优化后道集提取的叠前AVO属性预测气藏的精度较优化前有明显提高。