论文详情
二连盆地朝克乌拉凹陷是白垩系沉积盆地,油气资源丰富。由于岩浆多期次喷发,新生界巨厚火成岩广泛分布于近地表,火成岩表面粗糙、成不规则块状,内部多孔,分布零散、破碎,其间有第四系黄土不同程度填充,地震勘探激发接收条件极差,地震资料反射能量弱、信噪比低、成像困难。针对这一问题,对地震波在近地表的传播过程进行了分析,认为表层不规则火成岩散射和巨厚火成岩屏蔽作用是造成这一问题的主要原因,严重的静校正问题进一步影响了本区目的层的成像效果。为此提出了一套以高精度可控震源低频激发、宽线、长排列、高覆盖接收为主的地震资料采集技术和以综合静校正、多域去噪和基于散射波理论的高精度速度分析为主的处理方法。应用后,新采集的地震数据主要目的层反射波清楚,地质现象清晰,新剖面较老剖面成像质量有很大提高,满足了油田勘探需要。
The Chaokewula Sag in the Erlian Basin is a Cretaceous sedimentary basin with abundant oil and gas resources.Due to multiple eruptions of magma,very thick igneous rock formations of the Cenozoic are widely distributed in the near surface.The igneous rocks have rugged surface,are irregularly blocky,internal porous,scattered and broken,and filled by Quaternary loess deposits to different extents.This leads to poor excitation during seismic exploration.Therefore,the acquired seismic data have weak reflection energy and low signal-to-noise ratio.Imaging,therefore,is difficult.To address this issue,the near-surface propagation of the seismic waves was analyzed.The irregular scattering and shielding effects of the igneous rocks were found to be the main causes of the issue.In addition,the serious static correction also affected the imaging of the target layers in the studied area.Therefore,a set of seismic data acquisition and processing techniques was proposed.The suggested acquisition method features high-precision vibration and low-frequency excitation,uses wide acquisition lines and long arrays,and offers high coverage.The seismic processing techniques include the integrated static correction,multi-domain denoising,and high-precision velocity analysis based on the scattering wave theory.Using the seismic data obtained with the proposed technique,the reflection and geological characteristics of the target layers could be depicted more clearly,and the imaging quality was greatly improved,thereby assisting the seismic exploration in the study area more effectively.
东方地球物理公司华北物探处自立科研项目“二连盆地火成岩发育区地震勘探技术研究”(编号:12-10-4-2016)资助。