CN106353805A - Intuitive microearthquake event classification method - Google Patents

Abstract

The invention discloses an intuitive microearthquake event classification method. The technical scheme includes: firstly, performing de-noising processing on original observation records and increasing signal-to-noise ratio of the records; finding out possible microearthquake events by a long time window and short time window proportion method; collecting first arrivals of the microearthquake events according to continuity of synthetic shafts, performing arrangement processing on the acquired first arrivals and finally superimposing all the first arrivals of the microearthquake events to display. According to distribution of the superimposed first arrivals, the microearthquake events similar in first arrival forms are defined as the same microearthquake event group, unified selection of parameters in post-processing is facilitated, and the events with the curve forms different from the overall trend are defined as stray events or invalid microearthquake events. The intuitive microearthquake event classification method has the advantages that classification of the microearthquake events is convenient, intuitive and reliable.

Description

One kind intuitively micro-seismic event sorting technique

Technical field

The present invention relates to fracturing micro-seismic monitoring field, specifically one kind intuitively microseism Event classification method.

Background technology

Hydraulic fracturing technology is the main path improving the unconventionaloil pool reservoir recovery ratios such as shale oil gas, micro-ly Shake monitoring is by gathering the signal that fracturing causes catalase to produce, rupture location being positioned, thus Instruct pressing crack construction and pressure break result is evaluated.Typically pick up in existing microseism data processor Directly positioned after taking micro-seismic event first arrival, then the distribution situation according to micro-seismic event positioning result Carry out the division of microseismic event.There is following point in this handling process: one is not have priori to microseism Event is classified, and would generally select identical positional parameter in position fixing process, so often affects micro- The precision of seismic events positioning；Two is that micro-seismic event to all pickups positions, so can be greatly Waste computing resource, it is particularly evident that this embodies during real-time monitoring.

Content of the invention

The purpose of the present invention is for solving problem present in above-mentioned tradition microseism data handling procedure, improving The location efficiency of micro-seismic event and positioning precision, provide a kind of convenient, intuitively micro-seismic event classification Method.

The present invention can by the following method measure realizing:

One kind intuitively micro-seismic event sorting technique, comprising:

1) protocol is carried out with denoising, improves the signal to noise ratio of record；

2) micro-seismic event is found out according to energy ratio between the long window and the short window method；

3) determine the first arrival of micro-seismic event；

4) the micro-seismic event first arrival in step 3 is carried out regular process；

5) by step 4) in microseism first arrival be plotted in the same coordinate system；

6) according to step 5) in the form of coordinate system first arrival micro-seismic event is classified.

Such scheme further includes:

The first arrival of the determination micro-seismic event described in described step 3 comprises the steps of

A) according to micro-seismic event according to the seriality of axle in the same direction, first break picking；

B) the corresponding crest of first break picking method choice pickup, trough or three kinds of modes of zero crossing, will Corresponding sampling point position is multiplied by the sampling interval to be recorded as first arrival.

The micro-seismic event first arrival of described step 4 carries out regular comprising the steps of

C) set first most [t1 t2 ... the tn] of micro-seismic event, in formula, n is cymoscope series, meter Calculate the average of pickup micro-seismic event first arrival, then average utilizes following formula to calculate

$t_{ave}=\underset{i=1}{\overset{n}{\σ}}{t}_i/n---\left(1\right)$

D) the first arrival unification of micro-seismic event is deducted the average calculating in step c), advised First arrival [t1 t2 ... tn]-t after whole_ave.

Described step 6 is classified to micro-seismic event, the following sorting criterion of application:

E) using the micro-seismic event with shooting point first arrival plesiomorphism as validity event；

F) first arrival plesiomorphism micro-seismic event is divided into same event group；

G) the microseism leave of absence larger for first arrival morphological differencess is defined as the event of peeling off or anomalous event.

One kind of the present invention intuitively micro-seismic event sorting technique, by original observational record Carry out denoising, improve the signal to noise ratio of record, then find out possibility using long short time-window than method Micro-seismic event, pick up the first arrival of micro-seismic event according to the seriality of axle in the same direction, will obtain First arrival carry out regular process, finally all of micro-seismic event first arrival is overlapped display. pass through The first arrival distribution situation of the micro-seismic event of superposition, the micro-seismic event of first arrival plesiomorphism is fixed Justice is same micro-seismic event group, to facilitate the unified selection entering line parameter in last handling process, The event definition simultaneously tracing pattern being different from overall trend is the event that peels off or invalid micro- Shake event.The feature of the method is convenient, directly perceived, reliable for the classification of micro-seismic event.

Brief description

Accompanying drawing 1 is this invention flow chart.

Accompanying drawing 2 is original three-component borehole microseismic logout.

Record section after accompanying drawing 3 protocol denoising.Wherein grey lines are according to axle in the same direction The first arrival of seriality pickup.

Accompanying drawing 4 renders to display in the same coordinate system for regular rear microseism first arrival.Wherein: 1 is The corresponding first arrival of micro-seismic event in Fig. 3,2,3 is two micro-seismic event groups, and 4,5 are two Peel off event.

Specific embodiment

Above and other objects, features and advantages for enabling the present invention become apparent, hereafter Especially exemplified by going out preferred embodiment, and coordinate institute's accompanying drawings, be described in detail below.

One kind intuitively micro-seismic event sorting technique, comprising:

1) protocol is carried out with denoising, improves the signal to noise ratio of record；

2) micro-seismic event is found out according to energy ratio between the long window and the short window method；

3) determine the first arrival of micro-seismic event；

4) the micro-seismic event first arrival in step 3 is carried out regular process；

5) by step 4) in microseism first arrival be plotted in the same coordinate system；

6) according to step 5) in the form of coordinate system first arrival micro-seismic event is classified.

Such scheme further includes:

The first arrival of the determination micro-seismic event described in described step 3 comprises the steps of

A) according to micro-seismic event according to the seriality of axle in the same direction, first break picking；

B) the corresponding crest of first break picking method choice pickup, trough or three kinds of modes of zero crossing, will Corresponding sampling point position is multiplied by the sampling interval to be recorded as first arrival.

The micro-seismic event first arrival of described step 4 carries out regular comprising the steps of

C) set first most [t1 t2 ... the tn] of micro-seismic event, in formula, n is cymoscope series, meter Calculate the average of pickup micro-seismic event first arrival, then average utilizes following formula to calculate

$t_{ave}=\underset{i=1}{\overset{n}{\σ}}{t}_i/n---\left(1\right)$

D) the first arrival unification of micro-seismic event is deducted the average calculating in step c), advised First arrival [t1 t2 ... tn]-t after whole_ave.

Described step 6 is classified to micro-seismic event, the following sorting criterion of application:

E) using the micro-seismic event with shooting point first arrival plesiomorphism as validity event；

F) first arrival plesiomorphism micro-seismic event is divided into same event group；

G) the microseism leave of absence larger for first arrival morphological differencess is defined as the event of peeling off or anomalous event.

1-4 is described further to above-mentioned embodiment below in conjunction with the accompanying drawings.

First, original three-component microseismograms (as shown in Figure 2) is carried out by direct current, goes The denoisings such as exceptional value, bandpass filtering, obtain the record shown in Fig. 3.

Second, it is as shown in Figure 3 to apply energy ratio between the long window and the short window method to find out micro-seismic event.

Third, picking up the first arrival of outgoing event according to the consistent principle of crest, (as Fig. 3 gray line institute Show), calculate the true first arrival of this micro-seismic event according to the sampling interval simultaneously.

Fourth, by step 3 pickup first arrival carry out regular process and project to coordinate system, such as In Fig. 4 shown in mark 1.

Fifth, repeat step 3-4, the first arrival of all of regular micro-seismic event is thrown the most at last It is put in coordinate as shown in Figure 4.

Finally, according to the first arrival form according to micro-seismic event in Fig. 4 coordinate system, according to invention Judgment criterion, can by micro-seismic event be divided into 2 microseismic event groups (in Fig. 4 mark 2, 3) and 2 events that peel off (mark 4,5) in Fig. 4, it is achieved thereby that micro-seismic event point Class.

Claims (4)

1. one kind intuitively micro-seismic event sorting technique it is characterised in that include,

1) protocol is carried out with denoising, improves the signal to noise ratio of record；

2) micro-seismic event is found out according to energy ratio between the long window and the short window method；

3) determine the first arrival of micro-seismic event；

4) the micro-seismic event first arrival in step 3 is carried out regular process；

5) by step 4) in microseism first arrival be plotted in the same coordinate system；

6) according to step 5) in the form of coordinate system first arrival micro-seismic event is classified.

2. the intuitively micro-seismic event sorting technique according to claim 1, its feature It is that the first arrival of the determination micro-seismic event described in described step 3 comprises the steps of

A) according to micro-seismic event according to the seriality of axle in the same direction, first break picking；

B) the corresponding crest of first break picking method choice pickup, trough or three kinds of modes of zero crossing, will Corresponding sampling point position is multiplied by the sampling interval to be recorded as first arrival.

3. the intuitively micro-seismic event sorting technique according to claim 2, its feature exists Micro-seismic event first arrival in described step 4 carries out regular comprising the steps of

C) set first most [t1 t2 ... the tn] of micro-seismic event, in formula, n is cymoscope series, meter Calculate the average of pickup micro-seismic event first arrival, then average utilizes following formula to calculate

$t_{ave}=\underset{i=1}{\overset{n}{\σ}}{t}_i/n---\left(1\right)$

D) the first arrival unification of micro-seismic event is deducted the average calculating in step c), advised First arrival [t1 t2 ... tn]-t after whole_ave.

4. the intuitively micro-seismic event sorting technique according to claim 3, its feature exists In described step 6, micro-seismic event is classified, the following sorting criterion of application:

E) using the micro-seismic event with shooting point first arrival plesiomorphism as validity event；

F) first arrival plesiomorphism micro-seismic event is divided into same event group；

G) the microseism leave of absence larger for first arrival morphological differencess is defined as the event of peeling off or abnormal thing Part.