三维三分量地震采集技术在川西地区的应用

3D3C seismic acquisition in Western Sichuan

四川盆地川西拗陷深层须家河组致密砂岩气藏属于典型的非常规气藏,其储层具有超致密、裂缝发育的特点,应用常规三维地震难以解决该区储层识别、裂缝检测及油气藏描述等问题。基于此,本文论述了三维三分量(3D3C)地震勘探观测系统设计的思路和方法,提出了多波三分量检波器埋置的矢量误差分析与控制、多波勘探激发参数的选择等技术,尤其推出了高效利用有限设备、快速越过大型障碍或重干扰区的"分片分步采集"方法,最终获得了可用于储层精细描述的高品质转换波地震资料。

Tight sandstone gas reservoirs of Xujiahe group deeply buried in West Sichuan Depression belong to non-conventional reservoirs with super density and rich fracture development.It is very difficult to detect fractures and identify reservoirs on conventional 3D seismic data.To solve these problems,this article proposes a 3D3C seismic geometry design method and proposes a series of 3D3C seismic techniques in the field,such as analysis and control of three-component geophones,and source parameter optimization etc.A new way called by'acquisition by steps and blocks' is also introduced for overcoming large obstacles with limited equipment.Finally,high-quality 3D3C seismic data are acquired for reservoir characterization.