非重复性采集随时间推移地震勘探实例研究

Case study of non-repeatability acquisition in time-lapse seismic exploration

(1.中国石油东方地球物理公司凌云研究组，河北涿州072751；2.国际金鹰旭日有限公司，北京100101)

Lingyun Research Group, BGP CNPC, Zhuozhou 072751, China

随时间推移地震（TL）勘探已经逐步成为油田开发中重要的监控方法和油田管理工具。从其成功的研究实例分布看，它主要集中在海上和少数陆上油田中。而陆上的成功实例又主要集中在埋深较浅的重油注气热采方式的油田中，这表明该项技术仍存在一些应用限制和应用条件。为此，针对中国西部某油田1991年和2001年两次采集的地震数据进行了时移地震处理技术的研究。解释和开发验证表明，陆上时移地震数据仅通过互均衡处理难以克服非重复性采集因素的影响，仍需要特殊的针对非重复性因素的处理技术才能有效地克服其影响；同时还应充分考虑陆上近地表空间变化的影响，尽可能获得相对保持了储层振幅、频率、相位和波形的提高分辨率处理的成像结果。在此基础上进行时移地震信息结合地质和开发的综合解释，才可能获得剩余油气的分布以及解决开发中的问题。

Time-lapse(TL) seismic exploration has already become an important tool in oilfield development and management. Now, its successful cases are mainly distributed in offshore oilfields and a few onshore oilfields. The successful onshore cases focus on shallowly buried heavy-oil reservoirs with steam-flood and thermal recovery, indicating that the application of this technique is still limited by certain conditions. To solve this problem, the research on TL seismic processing technique has been carried out based on seismic data acquired in 1991 and 2001 from an oilfield in western China. Both data interpretation and oil development practice prove that it is difficult to overcome the non-repeatability impact only through applying cross-equalization to onshore TL seismic data, however, a certain special processing technique aiming at non-repeatability can effectively remove the impact. At the same time, the space-varying influence from near surface should be fully taken into consideration so as to obtain the imaging results of which the resolution is improved and the reservoir amplitude, frequency, phase, and waveform are well preserved. Only by doing so, can the integrated data interpretation of TL seismic exploration, geology, and exploitation depict the distribution of the residual oil/gas and solve the problems in oil development.