摘要
在深水油气勘探中,海水水体的声学物理特征直接影响到后续地震资料处理及地球物理技术应用的效果。为了解决该类区域地震资料的保幅性问题,采用深水机器人、海水实验室测量及深水VSP等多种方法定量测量了地震波在海水中的速度(以下简称海水速度),明确了海水速度具有明显的分层特征并建立了分层模型;进而基于地震波在海水、地层中振幅的衰减差异,提出了变参数振幅恢复技术,有效解决了浅水—坡折带—深水区域地震资料的保幅性问题。研究结果表明:①海水和地层的振幅衰减规律存在着巨大的差异,地震波传播相同的距离,其在海水中的振幅衰减比在地层中要弱很多;②较之于常数海水速度偏移剖面,层状海水速度偏移效果具有同相轴更为连续、信噪比更高的优点,提高了整体成像分辨率与成像精度;③在偏移距方向,近、中、远偏移距的地震振幅变化更加合理,避免了远偏移距的强振幅异常现象,使AVO属性更加合理。结论认为:①准确利用海水分层速度特征,可以使变水深区域地震成像质量得到明显的改善;②在琼东南盆地陵水深水区实际地震资料处理中,变参数振幅恢复技术获得的振幅更加均衡,同一反射地层可以被连续追踪;③该项研究成果可以为后续的储层预测和烃类检测奠定基础。
In deep-water oil and gas exploration,the acoustic physical characteristics of seawater body have direct effects on the results of subsequent seismic data processing and geophysical technological application.In order to solve the amplitude preservation problem of seismic data in deepwater areas,this paper quantitatively measures the velocity of seismic wave in sea water(hereinafter referred to as seawater velocity)using multiple methods,such as deepwater robot,laboratory seawater measurement and deepwater VSP.Then,it clarifies that seawater velocity has obvious stratified characteristics,and a stratification model is established.Finally,based on the amplitude attenuation difference of seismic wave in sea water and strata,the variable-parameter amplitude recovery technology is put forward,which effectively solves the amplitude preservation problem of seismic data in the shallow water-slope break belt-deep water area.And the following research results were obtained.First,the amplitude attenuation law in sea water is quite different from that in the strata.As for the same propagation distance,the amplitude attenuation of seismic wave in sea water is much weaker than that in the strata.Second,compared with the constant seawater velocity offset section,the stratified seawater velocity offset effect is more advantageous with a continuous event and a high signal-to-noise ratio,which improves overall image resolution and image accuracy.Third,the seismic amplitude change of near,middle and far offset is more reasonable in the direction of offset,which avoids the strong-amplitude anomaly of far offset and makes AVO attributes more reasonable.In conclusion,by making use of the characteristics of the seawater stratified velocity accurately,the quality of seismic image in the areas with variable water depth can be improved significantly.In addition,when the variable-parameter amplitude recovery technology is applied to process the actual seismic data in Lingshui deepwater area of the Qiongdongnan Basin,the amplitude is more balanced and the same reflection formation can be tracked continuously.What's more,the research results lay a foundation for the subsequent reservoir prediction and hydrocarbon detection.
作者
陈殿远
刘仕友
孙万元
CHEN Dianyuan;LIU Shiyou;SUN Wanyuan(CNOOC China Limited Zhanjiang Company,Zhanjiang,Guangdong 524057,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2020年第12期41-51,共11页
Natural Gas Industry
关键词
深水油气勘探
坡折带
地震资料处理
水体声学
物理特征
海水分层
衰减差异
变参数振幅恢复
AVO
Deepwater oil and gas exploration
Slope break belt
Seismic data processing
Acoustics of water body
Physical characteristic
Seawater stratification
Attenuation difference
Variable-parameter amplitude recovery
AVO
作者简介
陈殿远,1966年生,正高级工程师,硕士,主要从事储层预测和烃类检测、信息技术等方面研究工作。地址:(524057)广东湛江市坡头区22号信箱南海西部石油研究院。ORCID:0000-0002-4776-277X。E-mail:chendy@cnooc.com.cn。
