互均化方法在非重复时移地震数据处理中的应用

Application of cross-equalization processing method in non-repeated time-lapse seismic data processing

时移地震是一种先进的现代油藏管理与监测技术,在油气田开发中发挥了重要的作用。非重复时移地震资料在两次采集时并未考虑时移地震监测的需要,重复性差,即使经过叠前一致性处理,两期资料在时间、能量、带宽和相位等方面仍存在明显差异。互均化处理方法通过求取各个校正算子,得到最佳匹配滤波器,对监测数据进行校正处理,可以有效提高两期地震资料的一致性。为了验证方法的有效性,模拟了水驱油藏的时移地震响应,同时加入了时间、振幅、带宽和相位的变化等非重复性影响因素,并结合零时重复/非重复采集的试验数据,分析了互均化处理方法的应用效果。结果表明,通过互均化处理可以大大削弱非重复性因素的影响,得到理想的差值响应。应用互均化方法对采集时间相隔13年的实际地震资料进行处理,降低了非期望的地震响应差异,突出了长期开采导致储层流体变化引起的时移地震响应。

Time-lapse seismic exploration is advanced in reservoir management and monitoring,which plays an important role in the development of oil and gas field.Non-repeated time-lapse seismic acquisition doesn't consider the requirement of time-lapse seismic monitoring;therefore,the two non-repeated datasets has obvious difference in time,energy,bandwidth and phase feature.So we introduced cross-equalization method,which can improve the consistency of two datasets effectively by two steps:firstly,best matching filter was obtained by computing correctors,then applying the filter to the monitoring data.To verify the validity of the method,we applied cross-equalization technology to simulate the response of time-lapse seismic data of water-drive reservoir under different water saturation with non-repeated time,amplitude,bandwidth and phase.Meanwhile,the testing data of zero-time repeated/non-repeated acquisition was used for analyzing the application effect.The result shows that the impact of inconsistency factors was eliminated effectively and ideal time-lapse responses were obtained.Moreover,we applied the cross-equalization method to process the real non-repeated datasets with thirteen years' acquisition time interval,which weakened the unexpected differences of seismic responses and highlighted the time-lapse seismic response of reservoir fluid variation caused by long-term production.