基于双聚焦成像理论,本文提出一种共聚集点(CFP)道集交互速度分析方法,用于建立初始成像速度模型,完成从时间层位到深度层位、从时间域速度场到深度域速度场的转换。该方法根据旅行时相等原理确定地层速度,以成像质量最优作为速度正确性的判别标准。根据时间解释结果计算CFP响应曲线和时移曲线是CFP道集交互速度分析方法从理论到实践过渡的关键一环,也是本文在理论和实践上的一个新贡献。此方法具有实现灵活、过程稳定、分析结果比较准确的特点。通过对大庆地震数据模型和实际地震数据的速度建模验证了方法的稳定性、有效性和实用性。
Based on double focusing imaging theory, the paper presented the method of interactive velocity analysis on common focus gathers (CFP), which is used to build up preliminary imaging velocity model and finish the transform from time horizons to depth layers and from velocity field in time domain to that in depth domain. The method follows the principle of travel time being equal to determine the velocity of horizons and takes optimized imaging quality as judge standard of velocity correctness. The key ring transformed from theory to practice for the method of interactive velocity analysis on CFP gathers is computation of CFP response curves and time-shifted curves according to the results of time interpretation, which is also the new contribution of the paper in theory and practice. The method is characteristics of flexible implementation, stable procedure and accurate analyzed results. The stableness, effectiveness and practice of the method has been confirmed by the velocity model building of seismic data in Daqing model and real seismic data.