溶洞充填物判识的频率差异分析技术
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摘要
寻找碳酸盐岩油藏的关键就是要找到充满流体的大型溶洞。塔河油田的勘探实践表明 ,应用频率差异分析技术可以有效的鉴别溶洞充填物的性质。当溶洞全为流体充填时 ,其地震波具有强振幅、低速度及调谐性的特征 ;当充填粘稠的半流体时 ,其调谐反射相当于绝对反射的 90 ;当充填物为疏松沉积物时 ,其调谐反射也相当于绝对反射的 77 。以上几种介质 ,都很有可能是油的储集体。对于主频集中在 2 0～ 30Hz的反射波而言 ,只要溶洞高度在 2～ 3m以上就能识别。该技术在塔河油田进行了应用 ,其连片三维区溶洞分布层及纵、横向连通情况清晰可见 ;在S4 8井中的风化面下 ,发现了 4层古暗河
The key of searching for carbonate reservoirs is to find large solution cavities full of fluids. Using frequency difference analysis can identify the nature of the cavity fillers.When the cavity filler is fluid,it has intense amplitude,low velocity and tuning property;when the filler is quasi viscous fluid,its tuning reflection is 900/0 of absolute reflection;when the filler is loose deposit,its tuning reflection is 770/0 of the absolute reflection.These media are most possibly oil preserving bodies.When the master frequency focuses 20～30Hz,and the cavity height is higher than 2～3 m,the natnre of the filler could be easily identified.This technique was used in Tahe Oilfield,four horizons of underground fossil river channels were discovered under the weathered surface in S 48 Well.
The key of searching for carbonate reservoirs is to find large solution cavities full of fluids. Using frequency difference analysis can identify the nature of the cavity fillers.When the cavity filler is fluid,it has intense amplitude,low velocity and tuning property;when the filler is quasi viscous fluid,its tuning reflection is 900/0 of absolute reflection;when the filler is loose deposit,its tuning reflection is 770/0 of the absolute reflection.These media are most possibly oil preserving bodies.When the master frequency focuses 20～30Hz,and the cavity height is higher than 2～3 m,the natnre of the filler could be easily identified.This technique was used in Tahe Oilfield,four horizons of underground fossil river channels were discovered under the weathered surface in S 48 Well.
引文
1 唐文榜地震反射法中薄煤层分辨能力的研究[J]地球物理学报,1987,30:641～652
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