强反射背景下不整合圈闭储层描述方法——以济阳坳陷长堤地区中生界为例

Description technology for unconformity trap reservoirs with strong seismic reflections: a case of the Mesozoic unconformity reservoir in Changdi area, Jiyang depression

为解决强反射背景下不整合圈闭薄储层难以准确描述的问题,以济阳坳陷长堤地区中生界不整合圈闭为例,研究强反射分离方法,建立分离流程,讨论分离过程中关键参数的选取,并构建模型验证分离方法的可行性,选择储层预测敏感参数。研究表明,加入局部频率约束算子的匹配追踪算法能够有效避免异常值、加强运算稳定性和提高运算速度;结合目标区测井资料、井旁道数据确定尺度因子λ为0.6时能够实现强反射的合理分离,凸显有效储层信息。分离后的数据体中,振幅类属性与有效储层厚度具有正相关关系,能够反映储层的平面展布特征。所部署井位钻探结果与预测吻合,验证了该方法的可靠性。

It is difficult to accurately describe the thin reservoirs in unconformity traps with strong seismic reflections. Taking the Mesozoic unconformity trap in the Changdi area in the Jiyang depression as a case, the method for strong reflection separation is studied, the separation process is established, the selection of key parameters in the separation process is discussed, and the models are established to verify the feasibility of the separation method and select sensitive parameters for reservoir prediction. The study shows that the matching tracing algorithm with local frequency as a constraint can effectively avoid outliers, enhance the stability and increase the speed of calculation. Considering well logging data and near-well seismic data, it is proved that a 0.6λ （scale factor） can find out strong reflections and highlight effective reservoir information in the target area. In the separated data volume, there is a positive correlation between the amplitude attribute and the effective reservoir thickness, which can reflect the lateral distribution characteristics of the reservoir. The drilling results of the wells are consistent with the predictions, which verifies the reliability of the method.