关于归一化总梯度异常多解性问题的研究

Study of nonuniqueness of the solution to normalized total gradient method

1. Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Production, Nanjing 210014, China;2. Northwest Petroleum Company of SINOPEC Star Petroleum Exploration Company, Urumchi, 830011, China

归一化总梯度法是直接找油气的非地震物探方法中最常用的处理方法之一。由于方法简便, 并能半定量地确定地质体的位置, 从而被广泛用于研究含油气构造或检测油气。但是, 任何反演方法都不可避免地存在多解性问题, 因此, 研究地质体的变化对归一化总梯度异常的影响, 了解它们的变化规律, 就显得十分必要了。在前人工作的基础上, 用模型分析研究了地质体的变化对归一化总梯度异常特征的影响, 所得结论对用此方法直接找油气者能起到有益的作用。

Normalized total gradient method, which is easy to use and can determine the position of geologic body semi-quantitatively, is one of the methods that are most commonly used to detect hydrocarbon directly in non-seismic geophysics and is widely used to study hydrocarbon-bearing structures or detect hydrocarbons. Nonuniqueness is inevitable for solutions of any inversion methods. Therefore it is necessary that the study of normalized total gradient responses to various geologic bodies be carried out. Based on previous work, this paper studied the normalized total gradient responses to various geologic bodies on physical models. Hopefully the results will be helpful in detecting hydrocarbon directly.