济阳坳陷古潜山地震采集技术研究

济阳坳陷碳酸盐岩古潜山以前地震资料存在信噪比低、速度陷阱、分辨率低、施工过程中缺炮、空道、内幕反射品质差或无反射等问题。造成上述问题除了野外施工工艺、室内处理流程和参数的影响外,在采集参数方面主要影响因素有覆盖次数低、炮检距与方位角不均匀、面元太大等。针对济阳坳陷古潜山三维地震资料采集应以目标设计为指导思想,以基于模型分析的三维采集参数论证为主线,最终优化各种采集参数。建立了拱张褶皱型、断裂块断型和风化残丘型三个具有代表性的古潜山地质理论模型。使用先进的“绿山”地震采集观测系统设计软件,采用“块”来描述任意复杂地质模型结构,分别设计出各自的地震采集观测系统。以林樊家潜山为例,采用12线18炮束状新观测系统模拟单炮发射接收,对各主要目的层能追踪的地层信息比原始6线9炮束状观测系统采集的地震信息丰富,能准确反映地下构造形态与地质体的物理属性。

The seismic acquisition method of buried-hills in jiyang depression

The previous seismic data of carbonate buried-hills have a series of problems in Jiyang Depression, which includes poor ratio of signal-to-noise, speed pitfall, poor resolution, shot and gather vacancy during field operating, week reflection and even no reflection in interior seismic data of buried-hills, and so on. The causes of the above problems mainly have two, one involving in the field operating, data dealing and parameters, and another including lower coverage, asymmetric shot offset and azimuth, bigger bin size, etc. The paper is under the dominant ideas of three-dimensions seismic acquisition method of buried-hills which should be given priority to objective design, and mainly concentrates on demonstrating acquisition parameter based on model analysis, and the acquisition parameters are optimized finally. Through foregoing research, the paper give three representative buried-hill models in theory which are arched-extension fold, fractured-blocked fault, weathered-remaining hillock. At the same time, seismic acquisition and respective observing system are given by using advanced software and using "BLOCK" for the sake of describing any complex geological model. The paper gives an example of LinPanjia buried-hills, the updated observing system of 12 lines and 18 shots which simulates single shot's transmitting and receiving can trace more abundant information of target strata than that previous setup of 6 lines and 9 shots does, thus it can reflect underground structures and physical attributes of geological bodies with higher accurately.