While-drilling borehole electromagnetic wave tomography advanced detection device and method

Abstract

The invention discloses a while-drilling borehole electromagnetic wave tomography advanced detection device and method. A detection probe is arranged in a detection drill pipe and used for drilling with a drilling rig; the detection probe automatically detects according to the working state of the drilling rig; during the detection, the stratum conditions of stratum geologies with different radii around a drill hole is detected through transmitting and receiving a group of electromagnetic waves with different frequencies; when the drill hole is finished and the detection probe exits in the drill hole, the data of the detection probe can be transmitted to a site host; the site host can compute the apparent resistivity of the stratums with different radii around the drill hole at each detection point and generate an apparent resistivity atlas with different radii around the whole drill hole depth; according to the apparent resistivity atlas, the geologic feature in a cylindrical space which takes the axis of the drill hole as center can be judged and whether the stratums have water-containing bodies or water-containing geologic structures can be analyzed and judged.

Description

technical field [0001] The invention relates to the field of drilling technology, in particular to a drilling-while-drilling electromagnetic tomography advanced detection device and method. technical background [0002] Advanced detection is mainly to use direct or indirect methods to detect the tunnel, roadway excavation direction and working face at the head of the tunnel, to detect whether there are harmful geological structures or rich water bodies and water guide channels ahead, and to provide detailed detection for safe tunneling material. [0003] At present, the direct method used for advanced detection of coal mines is the drilling method, and the indirect method is the geophysical method. Although the drilling results of the drilling method are relatively reliable, the construction period is long and the cost is high, which has a great impact on the normal production of tunnels and roadways. [0004] At present, there are five main geophysical methods that can be ...

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Problems solved by technology

[0005] The above geophysical methods are all drilling detection methods after tunnels, roadways, working faces or boreholes are drilled. Various metal facilities such as steel support, bolt support, and conveyor belt support have a great influence on the observation results of the three-pole method and the mine transient electromagnetic method. The parameter is single, only one parameter of resistivity is used, and the ability to eliminate multiple solutions is poor, resulting in multiple solutions

If the above-mentioned multiple methods are used in combination, the forecasting cost of advanced forecasting will be greatly increased; and the drilling detection method performed after the hole is drilled is unable to detect because the coal seam is soft and the drilling hole often collapses.

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