基于平移算法的大定源回线瞬变电磁法在地热勘探中的应用

Application of Large Fixed Loop Transient Electromagnetic Method in Geothermal Exploration based on Translation Algorithm

地热资源是一种绿色资源,对低碳经济的发展具有强大的推进作用。瞬变电磁法对低阻异常反映灵敏,在探寻水热型地热资源中得到广泛应用。传统的瞬变电磁处理方法是对观测的感应电动势来计算归一化函数并进一步通过迭代算法来计算视电阻率,但该处理方法计算效率较低。通过研究大定源回线装置计算全区视电阻率的迭代算法和平移算法,比较并分析了三层理论地电模型的正演结果及运算误差。结果表明:平移算法计算速度快,且精度满足要求,方便了大量实测数据的快速处理解释,并对实测地热资料进行处理,该方法用来计算全区视电阻率在实际工程中是可行性的。

As a kind of green resources,geothermal plays a powerful role in promoting the development of low-carbon economy.Transient electromagnetic method is sensitive to low resistance anomalies and can be used to explore hydrothermal geothermal resources.The traditional transient electromagnetic processing technology is calculating the normalized function of the observed induced electromotive force and further calculate the apparent resistivity through an iterative algorithm.By studying the iterative algorithm and translation algorithm for calculating the apparent resistivity of the whole region by the large fixed-source loop device,the forward evolution results and operation errors of the three-layer theoretical geoelectric model are compared and analyzed.The results show that the translation algorithm is fast in calculation and the accuracy meets the requirements,it facilitates the rapid processing and interpretation of a large number of measured data,and processes the measured geothermal data,which verifies the feasibility of calculating the apparent resistivity of the whole region by the translation algorithm in engineering practice.