Multi-scale ground microseism inverse time interference positioning method

Abstract

The invention discloses a multi-scale ground microseism inverse time interference positioning method. The inverse time positioning and multi-scale variational mode decomposition are combined, the original microseism data is decomposed into multiple scale domains with different vibration characteristics through the multi-scale decomposition technology, the noise amplitude is gradually reduced alongthe increasing of the decomposition scale, the amplitude of the effective signal is gradually increased, the proportion of the background noise can be reduced, and then the precision of the seismic source positioning is improved; furthermore, the original microseism data is decomposition into multiple scale domains through the multi-scale variational mode decomposition, the characteristics of theeffective signals extracted from multiple scales are enhanced, the disadvantage of the sampling information caused by a sparse observation system can be remedied; the product of the effective scale inverse time interference positioning can improve the focusing and resolution of an inverse time interference positioning imaging ellipse, and then an imaging illusion is suppressed.

Description

technical field [0001] The invention relates to a ground microseismic positioning method, in particular to a multi-scale ground microseismic reverse time interference positioning method, which belongs to the technical field of microseismic monitoring. Background technique [0002] In recent years, microseismic monitoring technology has been widely used in hydraulic fracturing monitoring of tight oil and gas reservoirs, mine rockburst monitoring, carbon dioxide geological storage monitoring and conventional oil and gas field injection-production induced seismic monitoring. Especially in the development of tight oil and gas reservoirs, microseismic hydraulic fracture monitoring is the only far-field technique capable of imaging induced fracture geometry. By real-time microseismic monitoring of the time and space distribution of the source, the geometric occurrence of the induced fracture, the change of the ground stress and the connectivity of the fracture grid can be estimate...

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Problems solved by technology

[0020] It can be seen from Fig. 3(a) and Fig. 3(b) that the sparse observation system leads to strong imaging noise in reverse time interferometric positioning imaging, and there are obvious imaging artifacts in shallow areas, which are more serious in three-dimensional complex media , which interferes with the determination of the true source location

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