井震结合的曲流河储层构型表征方法及其应用--以秦皇岛32-6油田为例

Meandering fluvial reservoir architecture characterization method and application by combining well logging and seismic data:a case study of QHD32-6 oilfield

以曲流河定量构型模式为指导,采用地震正演、分频地震属性分析与分频反演相结合的方法,在海上大井距条件下,对渤海秦皇岛32-6油田明化镇组曲流河储层进行了多级次精细构型解剖。首先,提出了先优选地震数据频段,再优选地震属性的分频属性优选方法,精细刻画了复合曲流带的分布;其次,采用"井震结合""规模控制""动态验证"的方法,在复合曲流带内部识别了单一曲流带和单一点坝。研究结果表明:(1)三种河道边界砂体叠合方式均表现为在叠合部位振幅减弱的特征,正演响应规律为应用波形预测井间砂体分布提供了可靠依据;(2)分频地震属性优选方法明显提高了地震属性与砂体厚度的相关性,从而提高了复合曲流带预测精度;(3)在研究区目的层地震数据中心频率55Hz的情况下,采用分频地震属性分析、分频反演和正演相结合的方法,在大井距条件下精确刻画了单一曲流带及内部点坝分布,在研究区识别出了5个单一曲流带与19个保存完整的点坝,将对秦皇岛32-6油田下一步高效开发与剩余油挖潜起到有效的指导作用。本文提出的方法对相似沉积特征和资料基础的油田构型分析具有借鉴意义。

Minghuazhen Formation in QHD32-6 oilfield is meandering fluvial reservoir.With the guidance of meandering fluvial quantitative architecture model,the reservoir architecture is characterized finely by combining forward seismic modeling,spectral-decomposed seismic attributes analysis and spectral-decomposed inversion under the condition of relatively sparse well data.Firstly,this paper proposes an effective method of seismic attributes optimization that optimizes the frequency in advance of seismic attributes,and the distribution of compound meander belt was depicted accurately with the optimized seismic attributes.Secondly,applying the methods of well logs and seismic data combination,architecture scale controlling,production verification,most single point bars and single meander belts were recognized finely in compound meandering belt.The result shows:(1)The positon at boundaries of three types of stacked channels is characterized by the decrease of amplitude.The response patterns of seis-mic forward modeling provide a reliable basis for predicting interwell distribution of sand bodies through seismic waveform responses.(2)The correlation between seismic attributes and sand thickness is improved significantly by this method,and the predication accuracy of meander belt is enhanced accordingly.(3)With the central frequency of 55 Hz for the target formation in the study area,single meander belt and internal point bar can be described accurately by the method of combining forward seismic modeling,spectral-decomposed seismic attributes and spectral-decomposed inversion.In the study area,five single meander belts and 19 completely preserved point bars were identified,which can guide the further effective development and remaining oil development of QHD32-6 oilfield.This method can provide reference for the architecture analysis on the oilfield with similar sedimentary characteristics and data conditions.