基于观测系统退化的气云区地震资料采集参数分析与建议  

Analysis and suggestion of seismic data acquisition parameters in gas cloud area based on geometry degradation

作　　者：丁洪波 徐德奎 段新意 马振 DING Hongbo;XU Dekui;DUAN Xinyi;MA Zhen(Tianjin Branch,China National Offshore Oil Corporation Ltd,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《石油地球物理勘探》2024年第1期51-60,共10页Oil Geophysical Prospecting

基　　金：中海石油(中国)有限公司“七年行动计划”重大科技专项“渤海油田稳产3000万吨,上产4000万吨关键技术研究”(CNOOC⁃KJ 135 ZDXM 36 TJ)资助。

摘　　要：渤海湾浅层气云广泛发育,气云影响区在地震剖面上多表现为模糊带,无法准确描述构造和储层特征,但学术界针对气云区地震资料采集方面的研究较少。文中以渤海湾X油田先后采集的三套关键采集参数存在较大差异的地震数据为基础,通过对实际采集观测系统进行退化处理,在保证其他采集参数一致的前提下,分别研究采集方向、面元尺寸、覆盖次数等单一采集参数对气云区地震成像的影响规律。得到能够指导海上气云区地震资料采集设计的三点认识:①采集方向对条带状气云成像影响非常大,沿气云短轴方向采集时气云内部成像品质相对更好,而沿气云长轴方向采集时气云平面影响范围相对更小,对于方向特征比较明显的条带状气云,宜采用双方位采集及融合处理改善气云区成像;②不同面元尺寸气云区成像品质及气云平面影响范围差异均较小,缩小面元尺寸对气云区成像贡献不大,建议气云区地震资料采集时采用常规面元尺寸,不必过分追求小面元;③覆盖次数增加到一定程度,继续增加对非气云影响区成像贡献不大,但对气云区成像仍然很有意义,建议地震资料采集时增加气云区的有效覆盖次数。Shallow gas clouds are widely developed in Bohai Bay.The seismic profiles of areas affected by gas cloud are mostly shown as fuzzy zones,so it is difficult to describe the characteristics of the structure and reser⁃voir accurately.However,there is less academic research on the seismic acquisition of gas cloud area.There⁃fore,based on the three sets of seismic data with big differences in key acquisition parameters successively ac⁃quired in X oilfield of Bohai Bay,this paper performed degradation treatment on the actual geometry and studied the influence of a single acquisition parameter on the seismic imaging of gas cloud area,including acqui⁃sition direction,bin size,and fold,on the premise that other acquisition parameters are consistent.Finally,the paper obtained three conclusions that could guide seismic acquisition designs of offshore gas cloud areas.①The imaging of banded gas clouds is greatly affected by acquisition direction,and the imaging quality inside gas cloud is relatively better when the acquisition is performed along the short axis of gas clouds.The plane influence range of gas cloud is relatively smaller when the acquisition is performed along the long axis of gas cloud.It is suggested that the shape of gas clouds should be fully considered in seismic acquisition.In addi⁃tion,bidirectional acquisition and fusion processing should be used to improve the imaging of gas cloud areas for banded gas clouds with obvious directional characteristics.②The differences in imaging quality of gas cloud areas and plane influence range of gas cloud under different bin sizes are small,and the reduction of bin size contributes little to the imaging of gas cloud areas.It is suggested that conventional bin size should be adopted in seismic acquisition of gas cloud areas,instead of emphasizing small bin size.③After reaching a cer⁃tain number of folds,the increase of fold contributes little to the imaging of area not affected by gas cloud,while it is still significant to the imaging of gas cloud area

关 键 词：气云区 观测系统退化 采集方向 面元尺寸 覆盖次数 

分 类 号：P631[天文地球—地质矿产勘探]