浅水环境下气云发育区高孔低胶结地层地震资料成像策略研究——以渤海莱北地区A油田为例

Seismic data imaging strategy of high-porosity and low-cementation strata in the gas cloud development area of a shallow water environment: Case study of an oilfield in the Bohai Laibei area

中海石油(中国)有限公司天津分公司,天津300459

CNOOC China Limited Tianjin Branch,Tianjin 300459,China

随着渤海油田浅层勘探方向由构造勘探向规模岩性勘探转变,气云发育区高孔低胶结地层地震资料品质较差的问题变得愈加突出,严重影响储层发育模式的判别。针对浅水环境下气云发育区多次波干扰严重、吸收衰减作用强、常规处理手段难以适用的问题,结合正演模拟对浅水环境下地震资料处理难点进行了系统分析,利用改进的浅水多次波压制技术实现了极浅水环境下多次波压制,采用回转波与反射波联合层析技术开展了气云发育区速度精细建模,应用基于复谱分解的井震联合Q值估算和黏声介质逆时偏移成像技术进行地震资料保幅成像处理,形成了相应的地震资料成像策略,有效解决了渤海气云发育区高孔低胶结地层地震资料成像质量差的问题。在渤海莱北地区A油田的实际应用结果表明,该策略能够有效提升气云发育区高孔低胶结地层地震资料成像品质,为以岩性油气藏为主的大型油气田勘探突破提供了重要的地震资料。

Shifting from structural to large-scale lithological exploration of a shallow reservoir in the Bohai Oilfield,poor quality seismic data of the high-porosity and low-cementation strata in the gas cloud development area has increasingly affected the subsequent discrimination of the reservoir development model.Owing to serious seismic multiple interference,strong absorption and attenuation,and difficulty in applying conventional processing methods in the gas cloud development area of shallow water environments,the difficulties of seismic data processing in shallow water environments are systematically analyzed using forward modeling.An improved shallow water multiple suppression method is proposed to suppress multiples in shallow water environments.Combined tomographic velocity modeling technology of turning wave and reflected wave was performed to obtain more accurate velocity results in the gas cloud development area,and well-seismic combined Q value estimations based on complex spectrum decomposition and reverse-time migration technology for visco-acoustic media have been used in amplitude preserving imaging of seismic data.Thus,a seismic data imaging strategy was developed,which effectively solved the problem of poor imaging quality of seismic data of high-porosity and low-cemented formations in the gas cloud development area.The results of this application in an oilfield in the Laibei area of Bohai Bay showed that this technical strategy effectively improved the imaging quality of seismic data from high-porosity and low-cementation strata in gas cloud development areas,providing an important seismic data foundation for breakthroughs in large-scale lithological oil and gas field exploration.

“渤海油田稳产3000万吨,上产4000万吨关键技术研究”项目(CNOOC-KJ135ZDXM36TJ)资助。

10.3969/j.issn.1000-1441.2023.01.009