Method for positioning microseism event point

Abstract

The invention provides a method for positioning a microseism event point. The method comprises the following steps: (a) determining a cross wave speed model and a longitudinal wave speed model according to acoustic logging data, a cross wave first arrival time from a predetermined perforation hole to a wave detector and a longitudinal wave first arrival time from the predetermined perforation hole to the wave detector; (b) determining a target function of the position about the microseism event point according to the cross wave speed model, the longitudinal wave speed model, the longitudinal wave actual first arrival time from the microseism event point to be positioned to every wave detector, and the cross wave actual first arrival time from the microseism event point to be positioned to every wave detector; (c) determining position of the microseism event point to be positioned by iterative operation on determined target function. The method for positioning the microseism event point avoids the problem of low resolution rate on depth direction for only adopting the positioning data of the longitudinal wave information, and improves the microseism positioning precision.

Description

technical field [0001] The present invention generally relates to the technical field of microseismic ground monitoring, and more specifically, relates to a method for locating microseismic event points. Background technique [0002] At present, in the field of hydraulic fracturing microseismic ground monitoring technology, the microseismic event point location technology is generally based on layered velocity models or uniform velocity models. For fracturing wells with relatively simple underground structures and small lateral velocity changes, Accurate position, but there are obvious positioning errors for fracturing well areas with deep formations, complex underground structures or severe lateral velocity changes; in terms of positioning methods, the method of superposition of longitudinal wave energy is generally used, which will make the positioning data The resolution is lower in the depth direction. Contents of the invention [0003] An exemplary embodiment of the ...

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Problems solved by technology

[0003] An exemplary embodiment of the present invention is to provide a method for locating microseismic event points, which can solve the problem that the positioning data of existing microseismic event point locating methods have low resolution in the depth direction and are relatively difficult for deep formations and underground structures. The positioning accuracy of fractured well areas with complex or severe lateral velocity changes is not high

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