Analysis and solution of underground interference factors of multi electro-prospectors

Since the introduction of high-resolution electric instrument adhere to the "forecast ingress, suspicious, first exploration, first after excavation, first cure and then mining" principle of water exploration, has carried out high-resolution advanced detection more than 20 times, effective detection distance of 2400m, many times accurate prediction of water-rich abnormal areas.

In this technology application after continuous exploration and exploration, it is found that there are huge differences in the use of high-resolution electrometer in coal alleys and rock alleys, mainly manifested in: coal alleys to complete the electrode laying by the electrode near the injection water treatment, through the adjustment instrument equipped with the limiting box resistance, can smoothly pass the electrode Emission and reception detection, and in the measured electrode current is generally stable at 45 to 60mA, can collect high-quality data, in the rock lane according to the same operating procedures as coal alley, adjust the limiting box resistance to the maximum 2K , the emission electrode current is difficult to stabilize at more than 30mA, and the three emission electrode emission current changes greatly, even if it can barely pass the inspection, in the construction to the second emission electrode, the emission current suddenly reduced to about 2mA, or even the emergence of unable to collect qualified data, after repeated retesting can complete a set of data collection, and after repeated reset, will inevitably affect the reliability of the data, and greatly reduce the efficiency.

During the contact of many relevant scientific research units, there is no good solution, after summing up the past detection experience and repeated underground coal rock lane different conditions and ground test comparative analysis, found that the instrument emission current in 30mA below the situation, mainly appeared in the roadway large area of water, roof water, water flow in the ditch and other humid environment, and the high pore rate of sandstone formation-based whole rock roadway. The analysis showed that the reason slower and unstable emission current was the wet and low resistance in the field environment, and the limited adjustment of infinite long distance and current-limiting box was the main cause of the problem.

In the well detection instrument, by adjusting the resistance value of the limiting box, it is found that when the resistance value is adjusted to 1K, the emission current representation of the three emission electrodes and the underground detection is not qualified, when the resistance value is increased on the well, the emission current can reach more than 30mA, that is, in the wet underground environment, as long as the resistance value increases, limit the emission limit protection, the emission current can be controlled at more than 30mA. To test this scenario, multiple detections have been unsuccessful and the environment is wet in the southern backwind alleys. Detection is divided into two times, under the premise of the same conditions of the electrode laying, the first time only with the limit box to adjust the resistance value, the emission electrode detection emission current maximum value is about 20mA, and the gap between the three electrodes is large, can not pass the detection.

(1) High-density electric meter due to its own current-limiting resistance box maximum resistance of 2K, in the wet underground work place can not work properly, through the addition of the same resistance resistance in the double circuit, can effectively improve the application range of high-resolution meter, can effectively avoid the poor operating environment caused by the instrument can not work properly, improve work efficiency, and timely collection of high-quality raw data, improve the accuracy of high-resolution meter detection, for underground water damage prediction and prevention and control to provide a reliable basis. 

(2) High-resolution electrometer electrode laying should be as far as possible to choose the drying site to lay the emission electrode and infinity electrode. As far as possible, the interference of underground wet environment to data collection and analysis is reduced in order to improve detection accuracy and quality.