摘要
针对陕甘宁盆地下古生界奥陶系民化亮地层沉积的多旋回性和上古生界石盒子组和山西组地层沉积的韵律性，本文运用分形几何学方法研究了该区的实际测井的声阻抗曲线。研究表明，声用抗增量的功率诺与频率的平方成反比，与反射系数的功率港成正比；在双对数坐标系下，只在一定的标度区间，拟会功率谱与频率的关系才能表示成S（f），亦即将会分形几何学定义。β是刻画地层结构的分形标应参数。本区的声阻抗测井曲线在一定标度区间具有统计定义上的自相似性，即具有分形特征。文中给出工区内20口井的分形标度参数β值，并绘制了相应的平面图，发现该回的β低值区与已知的含气区位置比较一致，并指出有利区的延伸部位。用此法研究合成声阻抗剖面上的地层结构和含油气性，也得到了较好的效果。
To cope with the sedimentary multicycle of Ordovician weathering crust in Lower Palaeozoic group and the sedimentary rhythm of Shihezi & Shanxi formations in Upper Palaeozoic group in the Shanganning basin, we use fractal geometry method to analyse the field acoustic impedance log data- Research led to the conclu-sion: the power spectrum of acoustic impedance increment is inversely proportional to squared frequency, but is directly proportional to the power spectrum of reflec-tion coefficient; and only in a certain scaling area in dual logarithmic coordinate sys-tem, can the relation between fitted power spectrum and frequency be expressed as S(f), which coincides with the definition of fractal geometry. In the expres-sion β is the fractal scaling parameter that describes formation structure. Acoustic impedance logging curve in this area is of statistical self-similarity (i. e- fractal property ) in a certain scaling interval. The corresponding β contour map involving 20 boreholes is given in the article. We can see from this map that the low P area is coincident with the known hydrocarbon area quite nicely, and that the stretch ten-dency of favourable hydrocarbon area is shown clearly. The method also brings good effect in analysing the formation structure and hydrocarbon-bcaring character-istic of synthetic acoustic impedance sections.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
1996年第6期815-825,共11页
Oil Geophysical Prospecting
关键词
分形
油气预测
标度律
储集层
油气勘探
formation, sedimentary cycle,sedimentary rhythm, fractal, self similarity, power spectrum, frequency, hydrocarbon prediction,scaling law
