高原冻土地表地震勘探技术及应用  

作　　者：王海立 王永生[2] 李伟波 武威威 马立新 何丽 

机构地区：[1]中国石油东方地球物理公司,河北涿州072750 [2]中国石油青海油田公司,甘肃敦煌736202

出　　处：《科技创新与应用》2024年第25期178-180,184,共4页Technology Innovation and Application

摘　　要：青藏高原是国家的能源战略后备区之一,油气资源储藏丰富,但表层冻土发育,地震波场复杂,油气地震勘探面临诸多挑战。针对青藏高原冻土地表特点,一是采用“低频可控震源激发、高密度宽线观测、长排列+小组合接收”技术,克服冻土对中深层的反射能量屏蔽和噪音干扰,降低地震工程作业对环境的影响;二是通过低信噪比初至处理技术、高精度约束层析反演技术、空变多域初至波剩余静校正技术提高冻土地表初至拾取精度和层析反演模型精度,解决冻土表层速度剧烈变化带来的静校正问题;三是采用基于冻土层有效反射频带的去噪技术、基于AMT反演约束的冻土层速度拾取技术、基于分偏移距叠加成像的精细切除技术,有效去除冻土地表噪音影响,指导速度拾取和精细切除。上述技术可以获得高品质的地震资料,为油气及矿产资源等地震勘探奠定坚实的基础。The Qinghai-Tibet Plateau is one of the national energy strategic reserve areas,which is rich in oil and gas resources,but the surface permafrost is developed,the seismic wave field is complex,and oil and gas seismic exploration is faced with many challenges.In view of the surface characteristics of the permafrost on the Qinghai-Tibet Plateau,first,the techniques of"low frequency vibroseis excitation,high density wide line observation,long arrangement+small combination reception"are adopted to overcome the reflection energy shielding and noise interference of the middle and deep layers of the permafrost.Reduce the impact of seismic engineering operations on the environment.Second,low SNR first arrival processing technology,high-precision constrained tomography inversion technology and space-varying multi-domain first arrival residual statics technology are used to improve the accuracy of first arrival picking and tomographic inversion model,and solve the static correction problem caused by drastic changes in permafrost surface velocity.Thirdly,denoising technology based on effective reflection band of frozen soil layer,velocity picking technology based on AMT inversion constraint and fine cutting technology based on sub-offset superposition imaging are adopted to effectively remove the influence of frozen soil surface noise and guide velocity picking and fine cutting.The above-mentioned techniques have obtained high-quality seismic data and laid a solid foundation for seismic exploration of oil,gas and mineral resources.

关 键 词：冻土 低频震源 静校正 地震成像 青藏高原 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]