时移地震气藏监测技术在崖城13-1气田的应用

崖城13-1气田是我国海上第一个大型整装气田,经过20多年的高效开发,已经处于开发后期。在超低压储层中寻找相对高压区,并且在多口井水淹的情况下,对气田进行深度挖潜,势必要对气藏进行动态监测。为了实现低成本气藏监测,在2018年重新采集了9条宽线二维地震数据,采集参数与2001年三维地震采集参数保持一致。根据2018年宽线二维地震测线的坐标,抽取2001年三维地震对应坐标的测线,保持相同的处理参数,采用鬼波压制、联合建模稀疏域匹配衰减多次波等技术进行保真、保幅处理,重点关注气水界面的变化。在此基础上采用一致性处理技术,对同一位置、相同覆盖次数的反射信号进行振幅、相位及频率的匹配,重点关注振幅属性的变化。最后结合1992年采集的三维地震数据,采用目标性地震资料解释技术进行时移地震研究,结果表明,时移地震均能够很好地监测由于开采导致的气水界面抬升、振幅属性变弱、剩余气分布等变化。研究结果为崖城13-1气田深度挖潜及管理决策提供了重要依据。

The Yacheng 13-1 gas field,Chinas first offshore large-scale gas field,comes into its late production stage after 20 years of high-efficient development.Dynamic monitoring of gas reservoirs is necessary in order to identify regions with relatively high pressure in ultra-low pressure reservoirs with multiple flooding wells.In order to achieve low-budget gas reservoir monitoring,a time-lapse seismic monitoring was conducted as follows.Firstly,nine two-dimensional(2D) seismic lines were re-acquired in 2018,using acquisition parameters consistent with those of the three-dimensional(3D) seismic acquisitions carried out in 2001.Then,the survey line corresponding to the 2018 2D seismic line was extracted from the 3D seismic data from 2001.Fidelity-preserving data-processing techniques with consistent processing parameters-such as the matching attenuation in sparse domain for multiples suppression-were utilized,focusing on identifying changes of the gas-water interface.The reflected signals identified at the same position and with the same coverage were matched for amplitude,phase,and frequency,focusing on the changes in amplitude attributes.Finally,the time-lapse seismic model was constructed by incorporating also a target-focused interpretation of 3D seismic data collected in 1992.The results showed that the time-lapse seismic monitoring is able to identify the gas-water interface uplift,amplitude attribute weakening,and residual gas distribution changes caused by the exploitation of the gas field.The results provide an important basis for the future potential exploitation and management of the Yacheng 13-1 gas field.

中海石油(中国)有限公司科研项目“南海西部气田开发末期超低压储层岩石物理与地震响应特征研究”(ZYKY-2019-ZJ-01)资助。