石臼坨凸起陡坡带高速异常区时深转换研究

A study of time-depth conversion of high-velocity anomaly area in the steep slope zone of Shijiutuo uplift

时深转换是利用地震资料进行构造和储层解释的重要环节。前人针对不同地质条件,采用不同方法开展了大量卓有成效的工作。然而凸起陡坡带近源扇体所造成的高速异常具有分布局限、异常显著、变化剧烈的特征,常规时深转换方法均存在一定适用性不足。针对研究区的特定地质条件,提出了石臼坨凸起陡坡带东营组地层高速异常区时深转换技术对策:在成因分析的基础上利用地震相技术刻画高速异常区边界,应用地震速度异常识别技术描述高速异常幅度;地震相、地震速度、井点误差相结合实现时深转换,最终获得更具有地质意义的时深转换结果。实际应用表明,该方法在常速区的时深转换与常规方法基本一致,而在异常区的时深转换更符合地质规律,从而取得了良好的应用效果,有力支持了该含油气构造的储量评价。

Time-depth conversion is an important link in the use of seismic data for structural and reservoir interpretation.Previous researchers carried out a lot of fruitful work by using different methods in different geological conditions.However,the high-velocity anomaly caused by the near-source fan on the steep slope of the uplift has the characteristics of limited distribution,significant anomaly and acute change.There are some problems in the applicability of the conventional time-depth conversion method. According to the specific geological conditions of the study area,this paper proposes the technical countermeasures of time-depth conversion of the high-velocity anomaly area in Dongying Formation strata of the steep slope zone of Shijiutuo uplift. Based on an analysis of the genesis,the seismic phase technology is used to describe the high-velocity anomaly zone boundary; the seismic velocity anomaly identification technique describes the high-velocity anomaly amplitude; combined with the seismic phase,the seismic velocity and the well depth error,this method achieves the time-depth conversion,and finally obtains a more geologically meaningful time-depth conversion result.The practical application shows that the method is consistent with the conventional one in the constant velocity region,and is more consistent with the geological regularity in the anomaly area.Therefore,this methods has achieved good effect in the time-depth conversion which can strongly support the reserve evaluation of the oil and gas structure.