US 2026/0147131 A1Published application

Microseismic interference positioning method and system based on time-shift correlation coefficient, electronic device, and storage medium

AssigneeSouthwest Petroleum University

InventorsYuwei Wang, Zixiu Wang, Cheng Yin, Yang Lin, Hu Zhao, Shulin Pan, Wei Liu, Zhiguo Fu

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Abstract

A microseismic interference positioning method and system based on a time-shift correlation coefficient, an electronic device and a storage medium are provided. The method includes: constructing a DTW time-shift correlation coefficient by using a DTW algorithm; multiplying the constructed time-shift correlation coefficient by an imaging operator; stacking all time-shift correlated gathers at a same grid point to obtain an imaging result for a single grid point; and stacking imaging results of all grid points to obtain a final imaging map characterizing a location of a microseismic source. A position with a maximum imaging value is the location of the microseismic source, thereby positioning the microseismic source. The method can solve a problem of reduced imaging resolution of cross-correlation imaging operators caused by wave propagation effects and noise, and improves the positioning performance under the influence of noise contamination.

Claims8

Dependent claims

A microseismic interference positioning method based on a time-shift correlation coefficient, comprising:

obtaining a velocity model and microseismic records of a monitoring area;
dividing, based on a preset grid size, the velocity model into a plurality of grid points, and performing a travel time calculation on each of the plurality of grid points to obtain a travel-time table containing theoretical travel time data;
performing a dynamic time warping (DTW) calculation on each pair of traces in the microseismic records to obtain a time-shift amount of a sampling point corresponding to each pair of the traces, picking a first arrival time of a microseismic event, constructing, based on a time-shift of the first arrival time, a time-shift sequence of each sampling point relative to the first arrival time, and calculating, based on the time-shift sequence, a time-shift correlation coefficient for each pair of the traces to obtain time-shift correlated gathers containing information on actual observed travel time differences;
wherein a specific calculation formula of the calculating, based on the time-shift sequence, a time-shift correlation coefficient for each pair of the traces to obtain time-shift correlated gathers containing information on actual observed travel time differences is as follows:
C
TC
(
τ
,
i
,
j
)
=
∑
t
i
=
t
first
t
max
∑
u
⁢
(
t
i
,
i
)
⁢
u
⁢
(
t
i
+
τ
+
τ
TC
(
t
i
)
,
j
)
wherein i and j each represent a receiver number, τ represents the time-shift amount of the sampling point corresponding to each pair of the traces, τTC represents a relative time-shift amount, u(ti, i) represents a time sequence corresponding to a receiver i, u(ti+τ+τTC(ti), j) represents a relative time-shift sequence of a receiver j relative to the receiver i, ti represents a time corresponding to the sampling point, tfirst to tmax represents a range of the time corresponding to the sampling point, and CTC represents the time-shift correlation coefficient for each pair of the traces based on DTW;
obtaining, based on the time-shift correlated gathers and the travel-time table, an imaging result corresponding to each of the plurality of grid points;
and
constructing, based on the imaging result corresponding to each of the plurality of grid points, a final imaging map characterizing a location of a microseismic source, and determining, based on the final imaging map, the location of the microseismic source.

50 more elements

A microseismic interference positioning system based on a time-shift correlation coefficient, comprising:

a data acquisition module, configured to obtain a velocity model and microseismic records of a monitoring area;
a travel-time table calculation module, configured to divide the velocity model into a plurality of grid points based on a preset grid size, and perform a travel time calculation on each of the plurality of grid points to obtain a travel-time table containing theoretical travel time data;
a time-shift correlation coefficient calculation module, configured to perform a DTW calculation on each pair of traces in the microseismic records to obtain a time-shift amount of a sampling point corresponding to each pair of the traces, pick a first arrival time of a microseismic event, construct a time-shift sequence of each sampling point relative to the first arrival time based on a time-shift of the first arrival time, and calculate a time-shift correlation coefficient for each pair of the traces based on the time-shift sequence to obtain time-shift correlated gathers containing information on actual observed travel time differences;
wherein a specific calculation formula of the time-shift correlated gathers is as follows:
C
TC
(
τ
,
i
,
j
)
=
∑
t
i
=
t
first
t
max
∑
u
⁢
(
t
i
,
i
)
⁢
u
⁢
(
t
i
+
τ
+
τ
TC
(
t
i
)
,
j
)
wherein i and j each represent a receiver number, τ represents the time-shift amount of the sampling point corresponding to each pair of the traces, τTC represents a relative time-shift amount, u(ti, i) represents a time sequence corresponding to a receiver i, u(ti+τ+τTC(ti), j) represents a relative time-shift sequence of a receiver j relative to the receiver i, ti represents a time corresponding to the sampling point, tfirst to tmax represents a range of the time corresponding to the sampling point, and CTC represents the time-shift correlation coefficient for each pair of the traces based on DTW;
and
a positioning module, configured to obtain an imaging result corresponding to each of the plurality of grid points based on the time-shift correlated gathers and the travel-time table, construct a final imaging map characterizing a location of a microseismic source based on the imaging result corresponding to each of the plurality of grid points, and determine the location of the microseismic source based on the final imaging map.

49 more elements

Dependencies are inferred from the claim text.