琼北干热岩勘探中大功率时频电磁法的应用

Application effect of high-power time-frequency electromagnetic method in hot-dry-rock exploration in northern Hainan region

干热岩是一种极具竞争力的可再生能源,能量巨大、分布广泛、清洁低碳、热能稳定,是具有极佳开发前景的战略性接替能源。海南岛北部酸性侵入岩发育,具有花岗岩型干热岩资源成藏条件。电磁法是探测隐伏花岗岩体分布情况与评价干热岩发育前景的重要手段,但由于琼北地区电网、公路、铁路、工厂等人文电磁干扰严重,天然场源电磁法难以采集到高质量数据。大功率时频电磁法采用人工场源,与天然场源电磁法相比,抗电磁干扰能力强,深层分辨能力高。选择时频电磁法在琼北云龙凸起区域开展干热岩勘探工作,通过时频电磁剖面综合处理解释,明确了测区地层分布、断裂展布,重点落实了隐伏花岗岩体的空间分布,综合分析认为测区具备良好的干热岩勘探开发前景。

Hot-dry-rock is a kind of highly competitive renewable energy source with huge energy,wide distribution,clean and low-carbon,and stable thermal energy.It is a kind of strategic alternative energy with excellent development prospects.The development of acid intrusive rocks in the northern part of Hainan Island has favorable conditions for the accumulation of granite type hot-dry-rock resources.Electromagnetic method is an important means to detect the distribution of concealed granite body and evaluate the development prospect of hot-dry-rock.However,due to the serious human electromagnetic interference from power grids,highways,railways,factories and other places in northern Hainan,it is difficult to collect high-quality data with natural field source electromagnetic method.The high-power time-frequency electromagnetic method uses an artificial field source,which has strong anti-interference ability and high ability of deep layer resolution compared to the natural field source electromagnetic method.Therefore,the time-frequency electromagnetic method was chosen to carry out hot-dry-rock exploration in the Yunlong uplift area of the northern Hainan.Through comprehensive processing and interpretation of time-frequency electromagnetic profiles,the stratigraphic distribution and fault distribution in the survey area have been clarified,with a focus on the spatial distribution of concealed granite bodies.Through comprehensive analysis,it is believed that the survey area has good prospects for hot-dry-rock exploration and development.