山前复杂岩性地区低频模型的构建方法

The establishment of the low frequency mode in piedmont complex lithology area

山前地带复杂油气藏的准确勘探一直是地球物理勘探中的难题,由于山前地带的地质构造复杂、地层岩性变化大,分析和预测其储层砂体的展布规律很困难。笔者以均匀介质背景下的楔状体模型为例,研究了低频模型对反演结果影响的重要性,并针对塔里木盆地神木地区白垩系舒善河组砂岩的勘探难点,提出利用速度体及反映沉积趋势的属性体补充3Hz以下甚低频成分以及利用构造层位控制下的井插值模型补充3～10Hz频率成分,来构建山前地带复杂地质体低频模型的新方法。该方法在库车前陆深层油气勘探目标评价中取得了良好的应用效果。

The accurate exploration of piedmont complex reservoir is a major problem in geophysical exploration.It’s difficult to analyze and predict the distribution law of reservoir sand bodies in piedmont zone because of its complex structural features,rapid formation of lithology and unclear geological structure.In this paper,the importance of low frequency model to the inversion results is studied by taking wedge model in homogeneous medium as an example.And to solve the exploration problems in Shenmu area of Tarim basin of Cretaceous Shushanhe Formation sandstone,we proposed a new method for constructing low frequency model of piedmont complex geological body by using velocity body and attribute body which reflects the sedimentary tendency to supplement the very low frequency(0 to 3 Hz)components,and by using well interpolation model which is controlled by tectonic horizon to supplement3 Hz to 10 Hz frequency.The method has achieved good results in the evaluation of the target oil and gas exploration in the Kuche foreland basin.