互相关时差分析技术及其应用 ——以胜利油田三维地震资料连片处理为例

Crosscorrelation moveout analysis and its application: case study on 3-D multisurveys merged processing in Shengli Oilfield

(1.中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074;2.中国石油化工股份有限公司胜利油田分公司物探研究院,山东东营 257022;3.中国石油化工股份有限公司胜利油田分公司东辛采油厂,山东东营 257022)

Institute of Geophysics and Geomatics,China University of Geosciences(Wuhan),WuHan 430074,China

针对三维地震资料连片处理不同区块资料拼接中存在的时差问题,提出了一种基于互相关的最大能量时差识别算法。通常相邻区块的三维地震资料有一部分是重叠的,重叠部分对应的是地下同一区域的地层,地震反射波的性质基本相同,具有良好的相关性。互相关函数是对两个地震信号相似程度的比较,因此,可以利用互相关函数对同一位置的两个地震道进行互相关分析,定量描述两个信号的时间延迟。阐述了互相关时差定量识别技术的方法原理,讨论了影响互相关时差分析的因素,并将该技术应用于胜利油田青东5区块与周边区块的三维地震资料拼接处理,以及东营东部大规模连片叠前时间偏移处理中。互相关时差定量识别技术的实际应用表明,该技术减少了由人为因素导致的误差,提高了时差分析的客观准确性,使连片处理结果的质量得到了提高。

Aiming at the moveout problems existing in 3-D multisurveys merged processing,we proposed a crosscorrelation-based maximum energy moveout idenfication algorithm.Generally,the 3-D multisurveys of adjacent blocks is partly overlapped.The overlapped parts are corresponding to the formations in the same region,where the properties of seismic waves are almost the same and with good correlation.Crosscorrelation function is a comparison on the similarity degree of two seismic signals,therefore,we can use crosscorrelation function to carry out crosscorrelation analysis of two seismic traces at the same position,and quantitatively describe the time delay between the two signals.The method principles were elaborated,and the factors impacting corsscorrelation moveout analysis was discussed.Then,the method was applied to 3-D multi-surveys merged processing at Qingdong5 block and its neighboring blocks at Shengli Oilfield,as well as large-scale merged pre-stack time migration at the east of Dongying.The application results of crosscorelation moveout quantitative identification technique indicates that it can reduce the error caused by artificial factors and increase the accuracy of moveout analysis objectively;as a consequence the quality of merged processing is improved.