Research On The Interpretation Method Of 3D Seismic And Electromagnetic Methods In The Identification Of Coalfield Collapse Columns

Coalfield collapse column is an abnormal disastrous geologic body which could not be ignored. Its existence not only undermines the continuity and stability of the coal seam, and prejudice to coal mining, but also forms a good water channel, and become a potential dangerous threat to mine safety in production. Therefore, it is very important to identify the exact location and water gushing of collapse column for controlling flood of coal mine. With the further development of 3D seismic and electromagnetic exploration techniques, the accuracy and reliability of the exploration results have been very greatly improved. Three-dimensional seismic exploration can identify a diameter greater than or equal to 20 m collapse column, but it can not make a judgment on the water gushing of collapse column, and needs a larger investment. Electromagnetic exploration has unique advantages in the detection of the collapse column for Water, but the resolution of the results according to the traditional inversion method is low and difficult to compare to the accuracy of seismic exploration, and there is a larger error in identifying the space distribution range of the collapse column. To take fully advantage of the relatively mature technology of seismic exploration and improve the accuracy of the prospecting of electromagnetic method, the pseudo-seismic imaging technology based on the wave field conversion could convert electromagnetic fields to pseudo-wave field to compute a reflective function. But the technology is still in the research stage and appears many problems in the implementation process.Take the Zhaozhuang Mine exploration data as an illustration, this paper would study the interpretation methods of the 3D seismic and electromagnetic exploration in the identification of collapse column to play their respective advantages and potential in identifying the collapse column and water gushing. Firstly, the author analyzed the geological and geophysical conditions of study area, and then created the forward model of collapse column of the 2D seismic and one-dimensional electromagnetic method. The characteristics of the seismic and electrical response which came from the different types of column model were analyzed, and proved that the delay diffracted wave was uniquely existed in the rift point of the collapse column. Secondly, the data interpretation of 3D seismic mainly utilized 3D offset data volume and auxiliary utilized overlay data volume. The author analyzed the performance characteristics of the collapse column in the time profiles, and used coherence technology and variance technology and some preferred seismic attributes along the layer to finely interpret the collapse column, and suggesting that some seismic attributes of amplitude and spectrum and coherence could used to effectively identify collapse column. Thirdly, the author analyzed the sizes and distribution characteristics of the resistivity of internal formation in the collapse column, and judged the water gushing of the collapse column in the interpretation of the electromagnetic data. In addition, the author studied the basic theory and implementation process of the pseudo-seismic imaging technology on the basis of previous research, and analyzed the calculation of model by writing computer process, then discussed the feasibility in the improving resolution of the electromagnetic method, yet to be tested by the practice.