波数域重力归一化总梯度法中的圆滑滤波因子

A STUDY OF SMOOTHING FILTER OPERATOR FOR NORMALIZED FULL GRADIENT OF GRAVITY ANOMALY IN WAVE-NUMBER DOMAIN

讨论了波数域重力归一化总梯度法,提出在位场转换的向下延拓和求导过程中分别引入圆滑滤波因子,该方法增强了计算的可靠性和稳定性,扩大了可延拓深度;通过模型实验和数据分析,确定了向下延拓和导数因子中圆滑滤波因子指数参数的取值规律,指出了欲求地质体越浅(深),采用的谐波数越大(小)的地质体质心埋深与谐波数N之间的变化规律;发现了均匀密度三度背斜模型和非均匀密度储油背斜模型与二度模型相似的GH场等值线特征,为地质体质心埋深计算及储油构造研究提供了思路。

This paper has discussed the method of normalized full gradient of gravity anomaly in wave-number domain and suggested the introduction of smoothing filter operator in the process of downward continuation and derivation for potential field conversion. This technique helps increase the reliability and stability of calculation and extend the depth of continuation. Based on lots of model experiments and data analysis, the authors have determined the experiential value of exponential parameter about smoothing filter operator in calculating downward continuation and derivation, and pointed out the variational regularity between the depth of the geologic body and the harmonic number N: the lower (deeper) the depth of geologic body, the bigger (lesser) the value of N. It is also discovered that there exist similar characteristics of contour GH field between the three dimension model of symmetrical density anticline and asymmetric oil storage anticline and the two dimension model, and this offers the new thought for calculating the center of gravity and investigating the oil storage structure.