Time-shift controlled source audio-frequency magnetotellurics detection method applied to coalbed methane development process

Abstract

The invention relates to a time-shift controlled source audio-frequency magnetotellurics detection method applied to a coalbed methane development process. According to the method, a plurality of actual measurement point apparent resistivity curves are repeatedly acquired a plurality of times for the same target region or test region according to a certain time interval and a "six-identical requirement" with the same observation method adopted before and during the coalbed methane development of the target region, wherein the six-identical requirement is explained in the descriptions of the invention; and the above data are processed, so that an along-coalbed differential apparent resistivity data body is obtained, and coal reservoir water system dynamic change during a coalbed methane well draining and mining process and a range influenced by the coalbed methane development process can be obtained, and coalbed methane development can be quantitatively monitored. The method has been applied to the coalbed methane development of some regions in the Zhijin County of the Guizhou Province and the southern region of the Yanchuan County with successful experience achieved.

Description

technical field [0001] The invention relates to the application of time-shifting controllable source audio magnetotelluric (CSAMT) technology in the field of coalbed methane development. In the coalbed methane development target area, based on the constraints of the seismic geological model, the controllable source audio frequency magnetotelluric (CSAMT) technology is applied to obtain the hydrodynamic change information of the coal reservoir and the upper and lower formations through time-shift observation of the apparent resistivity change, so as to monitor the coalbed methane The purpose of developing effects. Background technique [0002] The theoretical research and discussion of dynamic detection in the process of coalbed methane development have been published at home and abroad. The Key Laboratory of Coalbed Methane Resources and Accumulation Process of China University of Mining and Technology of the Ministry of Education and the College of Geology and Mining Engin...

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Problems solved by technology

[0010] 3) The application of the above method obviously does not consider the influence of seasonality on electrical observations, and the half-year time difference is exactly the opposite of the season

Because the same target area is observed in the rainy season and the dry season, the difference in electrical properties will increase;

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