The Application Ahead Of Geological Exploration Of Transient Electromagnetic Technology In The Mine

Hydro-geological conditions in Mines in China which has lots of water-disastersof mine especially coal mine are mostly complex. And the direct economic lossescaused by the flooding have been ranked at the top of the various mine disasters,which have brought economic loss and personal injury to the country and thepeople extremely heavy. In order to solve the flooding and water leakage of mines andtunnels, it is necessary to probe ahead of the mine head (working face) to predict thelocation and size of geological bodies which contain water, which make mine workbetter and more reasonable and reduce unnecessary losses.Transient Electromagnetic Method (TEM) is a prospecting method which hasdeveloped rapidly and been widely used in recent years. The method which isresponsive to the low resistivity, observes the secondary field in the near zone. Whatis more its volume effect is small with high vertical and horizontal resolution and it isconvenient, fast, high efficiency. As a result of this it has great value in the minegeological exploration and is considered as one of the most promising geophysicalexploration methods in the mine geological exploration. Because of its good directionit is can be used to probe in the hole mine of every direction. And it is essential tocarry out mine transient electromagnetic method as its outstanding advantages of alarge detection range and high resolution.It is affected by the all kinds of noise when we collected the data of the transientelectromagnetic field. It is the noise that has an adverse impact on the follow-upsignal processing and masks useful signal. Therefore, removing noise must be done tomeasured transient electromagnetic data before the signal processing, so as toeliminate the noise signal and extract the useful information in the signal. Then, it canbe well used to draw diagram and explain the geological conditions.Mine transient electromagnetic technology has the character of full space whichis different from half space. So it is important to research the full space individual todetermine the theoretical model of time-depth conversion of full space. Through thetheoretical model, it can locate the abnormal body. Due to this, it provides thereasonable reference for guiding the work of the mine.This subject analyzes the regular patterns of the distribution of the transientelectromagnetic field in full space and the transient electromagnetic response of thetypical aquifer structure by the transient electromagnetic data from the field. Then, a series of mathematical means such as digital filtering, excluding confounding factorsand so on has to be done. At last, we got the material information of the surroundingrocks and the apparent resistivity values of the geological bodies and surroundingrocks by formula of apparent resistivity and two-dimensional inversion of time-depthconversion model. Only then the apparent resistivity contour map andthree-dimensional anomaly map by which we delineate abnormal bodies and lowresistivity anomaly zone to guide underground drilling can be drawn.