摘要
海上油田在世界原油产量中占有很大比重,但广泛分布的气云区成为制约海上油田勘探开发的重要难题,传统地震资料处理及偏移成像采用振幅一致性补偿对地震资料能量进行恢复,采用反射波走时层析方法进行层速度场建立,采用基于射线理论的Kirchhoff方法进行偏移成像.本文以渤海湾某大型油气田为例,通过对大范围气云区三维拖缆地震资料分析研究,结合正演模拟结果证实气云区含气非均质体散射效应造成的复杂波场畸变是地震波难以成像的主要原因,利用传统方法对气云区地震资料偏移成像误差较大.通过以上分析,本文对气云区地震资料处理及偏移成像传统流程进行了创新性改进,分别利用时频域气云衰减补偿技术、浅层潜波+深层反射波层析速度建模技术和FFD(傅里叶有限差分)叠前深度Q偏移技术对传统流程进行改进.通过实际数据应用证明,本文提出的新流程进行气云区偏移成像是有效可行的,该流程在保证计算效率的同时大幅提高了偏移成像质量,为后续的勘探开发奠定坚实的基础.
Offshore oil fields account for a large proportion of the world’s crude oil production. However, the exploration and development of offshore oilfields are seriously restricted by the widely distributed gas cloud. Traditional seismic data processing and offset imaging use amplitude consistency compensation to recover seismic data energy. Interval velocity model is established by reflected wave travel time tomography and migration is achieved by Kirchhoff method based on ray-tracing theory. This paper takes a large oil field in the Bohai Bay as an example, the research utilize gas cloud affected three-dimensional seismic data analysis and forward modeling. The main reason that seismic waves are difficult to be imaged within gas cloud area is the complex wavefield distortion caused by gas-bearing heterogeneous body scattering effect. Traditional processing methods are not applicable toward gas cloud seismic data because of the large migration imaging error. Through the above analysis, this paper innovatively improves the seismic data processing and migration imaging process in gas cloud area. The traditional processing methods are improved by using the time-frequency domain gas cloud attenuation compensation technique, the shallow diving wave + deep reflection wave tomographic velocity modeling technique and The FFD(Fourier Finite Difference) prestack depth Q-migration technique. Through the application of actual data, the new process proposed in this paper is effective and feasible for the imaging of gas cloud. This process greatly improves the quality of migration imaging while ensuring the computational efficiency and lays a solid foundation for subsequent oilfield exploration and development.
作者
周东红
夏同星
曹盛
周学锋
ZHOU Dong-hong;XIA Tong-xing;CAO Sheng;ZHOU Xue-feng(Bohai Oilfield Research Institute of CNOOC Limited Tianjin,Tianjin 300452,China;Research Institute of BGP,Hebei Zhuozhou 072751,China)
出处
《地球物理学进展》
CSCD
北大核心
2018年第6期2613-2618,共6页
Progress in Geophysics
基金
"十三五"国家科技重大专项-大型油气田及煤层气开发(2016ZX05058)资助
关键词
气云衰减补偿
气云区速度建模
傅里叶有限差分
层析成像
gas cloud attenuation compensation
gas cloud velocity modeling
FFD(Fourier Finite Difference)
tomographic imaging
