摘要
瞬变电磁测探法是一种以电磁感应为原理的时间域电磁法,简称TEM,是电法勘探的常用方法之一。该方法利用确定波形的电流场来激发一次场,并在一次场断电后观测二次场的衰减特性随时间的变化。由于该方法有着很多特有的优点,近年来运用于不同的工作场景。该法具有压制随机干扰、提高信噪比和观测精度、增加勘探深度和提高信噪比、有效地压制地质噪声等优点。通过均匀半空间和层状介质条件下电偶源的电磁分量进行了计算与分析,研究了多参数对不同电性层的反映特征。对瞬变电磁观测阵列获得的实测资料进行多参数提取,并对实测资料进行综合处理,利用剖面上的电性变化特征,与已知井资料进行比较和校准用于地质解释。从剖面实例可以看出,该方法研究深层的电性结构比较有效,相比于其他频域电磁探测方法,具有较强的抗噪声干扰,垂向分辨率高等优点,具有一定的实用性。
Transient electromagnetic sounding (TEM) is a time-domain electromagnetic method based on electromagnetic induction, which is one of the common methods of electromagnetic exploration. It is used to determine the waveform of the current field excitation, according to the field after a power off, to observe the secondary field, with the change in time and the attenuation characteristics. Because this method has many unique advantages, it has been used in different work scenarios in recent years. This method has the advantages of suppressing random interference, improving the SNR and the accuracy of observation, increasing the exploration depth and the SNR, and suppressing geological noise effectively. The electromagnetic components of electric couple are calculated and analyzed under the conditions of uniform half space and layered medium. The measured data obtained from the transient electromagnetic observation array were extracted with multiple parameters, and the measured data were comprehensively processed. The electrical variation characteristics of the profile were used to compare and calibrate the measured data with the well-known data for geological interpretation. It can be seen from the section example that this method is more effective in studying the deep electrical structure. Compared with other electromagnetic detection methods in the frequency domain, this method has the advantages of strong anti-noise interference, high vertical resolution and certain practicability.
出处
《地球科学前沿（汉斯）》
2023年第9期1095-1113,共19页
Advances in Geosciences
