CN105589100A - Micro-seismic source location and velocity model simultaneous inversion method - Google Patents

Abstract

The invention provides a micro-seismic source location and velocity model simultaneous inversion method, and belongs to the field of source locating in micro-seismic monitoring. The method comprises the following steps: (1) picking up the first arrival time of a micro-seismic event; (2) building an initial velocity model based on acoustic logging data, and acquiring the initial source location and origin time of earthquake of the micro-seismic event; (3) calculating the theoretical travel time of the micro-seismic event based on two-point ray tracing, and building a joint tomography equation set; (4) solving the joint tomography equation set, and working out the parameter update amount delta(u), delta(x) and delta(tau); (5) judging whether termination conditions are met, turning to step (6) if the termination conditions are met, or, using the parameter update amount to update the velocity model, the source location and the origin time of earthquake and turning to step (3); and (6) outputting the final velocity model, source location and origin time of earthquake.

Description

A kind of microseism hypocentral location and rate pattern Simultaneous Inversion method

Technical field

The invention belongs to focus positioning field in micro seismic monitoring, be specifically related to a kind of microseism hypocentral location and speedDegree model Simultaneous Inversion method, information Simultaneous Inversion hypocentral location and rate pattern while utilizing microseism event to walk.

Background technology

Microseismic is the development nineties in 20th century and an active new Non-traditional Techniques,It can be applied to the numerous areas such as Reservoir Development, Mine Monitoring, Geological Hazards Monitoring. Microseism monitoringPosition, the origin time of earthquake, source level and the rate pattern of middle focus is all unknown, determines that these parameters areThe top priority of microseism monitoring.

In microseism when location,, because hypocentral location and rate pattern are all unknown quantitys, both are coupled.When microseism detects, the positioning precision of event largely depends on the precision of rate pattern. Conventional location sideMethod is all to utilize based on well-log information and the one dimension rate pattern after perforation is proofreaied and correct to position. LocalPositioning precision based on one dimension rate pattern when lower rate pattern exists lateral velocity variation will reduce, and therefore just needsTo carry out inverting to hypocentral location and rate pattern simultaneously.

Thuber (1983,1992) proposes local earthquake's chromatography method, and the method is utilized Local Subspace invertingTechnology separates focal shock parameter with speed parameter, thereby realizes Simultaneous Inversion three-dimensional velocity model and hypocentral location.Seismologist is widely applied in earthquake location and velocity inversion both at home and abroad.

Zhang (2003) sends out on two poor positioning modes (Waldhauser and Fllsworth, 2000) basisPut on display two poor chromatography methods, this has effectively been drawn the advantage of two poor location and has taken into account inversion speed. ZhangThe efficiency of inverse process of method is better than local earthquake's chromatography method.

But the method for Zhang (2003) ray path in the time of structure chromatography equation overlaps substantially at shallow-layer,Be unfavorable for shallow-layer velocity inversion.

Summary of the invention

The object of the invention is to solve the difficult problem existing in above-mentioned prior art, a kind of microseism focus is providedPosition and rate pattern Simultaneous Inversion method, introduce the two poor chromatography equations of wave detector, combine common chromatography equation,The two poor chromatography equations of focus, three builds associating chromatography equation. Compared with two poor chromatography algorithms of zhang,Shallow-layer velocity inversion precision will be conducive to improve, the precision of microseism inversion speed model can be further improvedAnd positioning precision.

The present invention is achieved by the following technical solutions:

A kind of microseism hypocentral location and rate pattern Simultaneous Inversion method, comprising:

(1), pick up the first arrival time of microseism event;

(2), utilize Sonic Logging Data, build initial velocity model, then obtain microseism event at the beginning ofBeginning hypocentral location and the origin time of earthquake;

(3),, when the theory based on two spots ray tracing calculating microseism event is walked, build associating chromatography equationGroup;

(4), solve described associating chromatography equation group, calculate parameter renewal amount δ u, Δ x and Δ τ;

(5), judge whether to meet end condition, if so, proceed to step (6), if not, profitRate pattern, hypocentral location and the origin time of earthquake are upgraded with described parameter renewal amount, then return to step(3)；

(6), export final rate pattern, hypocentral location and the origin time of earthquake.

Described step (3) is achieved in that

Set up associating chromatography equation group, comprise that common chromatography equation, the two poor chromatography equations of focus and wave detector are twoPoor chromatography equation, wherein common chromatography equation is as shown in formula (2):

$r_k^i=\mathrm{\Δ}{\mathrm{\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^i}{\∂x_l^i}\mathrm{\Δ}{x}_l^i+{\∫}_i^k\mathrm{\δuds}---\left(2\right)$

Wherein,For microseism event i is to the calculating whilst on tour of acceptance point k with pick up the residual error between whilst on tour; δ u isSlowness model modification amount;Be respectively microseism event i hypocentral location x, y, z directionRenewal amount; Δ τⁱFor the origin time of earthquake renewal amount of microseism event i; Focus partial derivativeFor focus placeSlowness vector, for:

$\frac{\∂T_k^i}{\∂x_l^i}=-\frac{1}{V}\left(\frac{{\mathrm{dx}}_l^i}{\mathrm{ds}}\right)---\left(3\right)$

The two poor chromatography equations of described focus are as shown in formula (4):

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j=\mathrm{\Δ}{\mathrm{\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^i}{\∂x_l^i}\mathrm{\Δ}{x}_l^i+{\∫}_i^k\mathrm{\δuds}-\mathrm{\Δ}{\mathrm{\τ}}^j-\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^j}{\∂x_l^j}\mathrm{\Δ}{x}_l^i-{\∫}_j^k\mathrm{\δuds}---\left(4\right)$

Wherein,Be respectively microseism event i, j to the calculating whilst on tour of acceptance point k and pick up whilst on tour itBetween residual error; Δ τ^jFor the origin time of earthquake renewal amount of microseism event j;For two poor time of focus, it is noteWhilst on tour residual error poor of the same detection of two events of record:

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j={(t_k^i-t_k^j)}^{\mathrm{obs}}-{(t_k^i-t_k^j)}^{\mathrm{cal}}---\left(5\right)$

The two poor chromatography equations of described wave detector are as shown in formula (6):

${\mathrm{dt}}_{\mathrm{mn}}^i=r_m^i-r_n^i={\∫}_i^m\mathrm{\δuds}-{\∫}_i^n\mathrm{\δuds}---\left(6\right)$

Wherein,For two poor time of wave detector, record whilst on tour residual error poor of two wave detectors of same event:

${\mathrm{dr}}_{\mathrm{mn}}^i=r_m^i-r_n^i={(t_m^i-t_n^i)}^{\mathrm{obs}}-{(t_m^i-t_n^i)}^{\mathrm{cal}}---\left(7\right)$

In described step (4), be to utilize damping LSQR method to solve described associating chromatography equation group.

In described step (5), utilize described parameter renewal amount to enter rate pattern, hypocentral location and the origin time of earthquakeRow upgrades and is achieved in that

Parameter in step (2) is added respectively to renewal amount δ u, the Δ x corresponding with it that step (4) obtainsWith Δ τ.

End condition in described step (5) is as follows:

Average whilst on tour residual error,Absolute value arithmetic mean of instantaneous value is less than a certain constant or parameter renewal amount is littleIn a certain constant. Threshold values is set to respectively these four parameters, these four constants are artificial given very littleAmount, as can be with 0.00001.

Compared with prior art, the invention has the beneficial effects as follows:

1), inverting stability is stronger.

2),, compared with the poor localization method of traditional double, microseism focus positioning precision is high;

3),, compared with two poor chromatography methods, inversion result is conducive to improve shallow-layer velocity inversion precision.

Brief description of the drawings

XY view in the two poor chromatography positioning results of Fig. 1 a

XZ view in the two poor chromatography positioning results of Fig. 1 b

YZ view in the two poor chromatography positioning results of Fig. 1 c

XY view in Fig. 2 a this method positioning result

XZ view in Fig. 2 b this method positioning result

YZ view in Fig. 2 c this method positioning result

The accurate rate pattern of Fig. 3 (degree of depth 400m)

The two poor tomographic inversion rate patterns of Fig. 4 (degree of depth 400m)

Fig. 5 this method inversion speed model (degree of depth 400m)

The step block diagram of Fig. 6 this method.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Associating chromatography equation equation group

1) common chromatography equation: microseism event i is to the actual observation whilst on tour of acceptance point k

$t_k^i={\mathrm{\τ}}^i+T_k^i={\mathrm{\τ}}^i+{\∫}_i^k\mathrm{uds}---\left(1\right)$

Wherein, u is slowness field (inverse of speed), τⁱFor the origin time of earthquake. When microseism the location, focus coordinate(x₁，x₂，x₃), the origin time of earthquake and slowness field be all unknown parameter.

When arrival that wave detector receives(P ripple or S ripple), utilizes the hypocentral location of testing, while sending out shakeWhen quarter and initial velocity model (prior information) are carried out theory of computation arrivalThe residual error of both whilst on tours is

Calculate whilst on tour and observation whilst on tour residual errorCan be approximately by the disturbance linearity of focus and rate pattern

$r_k^i=\mathrm{\Δ}{\mathrm{\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^i}{\∂x_l^i}\mathrm{\Δ}{x}_l^i+{\∫}_i^k\mathrm{\δuds}---\left(2\right)$

Wherein, focus partial derivativeFor the slowness vector at focus place, for

$\frac{\∂T_k^i}{\∂x_l^i}=-\frac{1}{V}\left(\frac{{\mathrm{dx}}_l^i}{\mathrm{ds}}\right)---\left(3\right)$

2) the two poor chromatography equations of focus: for identical wave detector k, receive different microseism event i, j, tripWhen row, residual error is poor, can obtain following equation (Zhang, 2003)

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j=\mathrm{\Δ}{\mathrm{\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^i}{\∂x_l^i}\mathrm{\Δ}{x}_l^i+{\∫}_i^k\mathrm{\δuds}-\mathrm{\Δ}{\mathrm{\τ}}^j-\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{\∂T_k^j}{\∂x_l^j}\mathrm{\Δ}{x}_l^i-{\∫}_j^k\mathrm{\δuds}---\left(4\right)$

Wherein,For two poor times of focus (Waldhauser and Fllsworth, 2000), for recording two eventsWhilst on tour residual error poor of same detection.

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j={(t_k^i-t_k^j)}^{\mathrm{obs}}-{(t_k^i-t_k^j)}^{\mathrm{cal}}---\left(5\right)$

3) the two poor chromatography equations of wave detector: for same microseism event i, two different wave detectors, acceptance point k'sAnother microseism event j, also has similar expression formula; Both subtract each other can obtain following equation

${\mathrm{dt}}_{\mathrm{mn}}^i=r_m^i-r_n^i={\∫}_i^m\mathrm{\δuds}-{\∫}_i^n\mathrm{\δuds}---\left(6\right)$

Wherein,For two poor time of wave detector, record whilst on tour residual error poor of two wave detectors of same event.

${\mathrm{dr}}_{\mathrm{mn}}^i=r_m^i-r_n^i={(t_m^i-t_n^i)}^{\mathrm{obs}}-{(t_m^i-t_n^i)}^{\mathrm{cal}}---\left(7\right)$

Common chromatography equation, the two poor chromatography equations of focus and the two poor chromatography equations of wave detector, i.e. equation (2), (4)(6), simultaneous forms final associating chromatography equation. In addition, can be three kinds of given differences of chromatography equationWeight coefficient w₁，w₂，w₃, control three's weight proportion.

As shown in Figure 6, the concrete implementation step of the inventive method is as follows:

(1), pick up the first arrival time of microseism event;

(2), utilize Sonic Logging Data, build initial velocity model (horizontal layer); By artificially givenOr other microseism localization method (such as Gaiger method, grid search method etc.), obtains microseism thingInitial hypocentral location and the origin time of earthquake of part;

(3) when, the theory based on two spots ray tracing calculating microseism event is walked; According to formula (2), (4)(6) tectonic syntaxis chromatography equation (comprises that common chromatography equation, the two poor chromatography equations of focus and wave detector are twoPoor chromatography equation);

(4), utilize damping LSQR method to solve associating chromatography equation, calculate parameter renewal amount (δ u, Δ xWith Δ τ), and then renewal speed model, hypocentral location and the origin time of earthquake;

(5), repeating step (3) (4), until meet end condition, whilst on tour residual error is less than a certain normalNumber or parameter renewal amount are less than a certain constant;

(6), the parameters such as final rate pattern, hypocentral location and the origin time of earthquake are exported as Output rusults.

Be utilized as an embodiment below, be used for checking validity of the present invention, specific as follows:

Fig. 1 a-Fig. 1 c is two poor chromatography positioning results, is respectively XY view, XZ view and YZ view, figure2a-Fig. 2 c is positioning result of the present invention, is respectively XY view, XZ view and YZ view; Comparison diagram 1a-Fig. 1 c and Fig. 2 a-Fig. 2 c can find out, the hypocentral location that inverting of the present invention obtains is more accurate. Fig. 4 is two poorThe rate pattern (degree of depth 400m) that tomographic inversion obtains, Fig. 5 is that the rate pattern that obtains of inverting of the present invention is (darkDegree 400m), contrasting true velocity model (as shown in Figure 3) can find out, the present invention is at inversion speed modelFine degree on be also better than two poor chromatography methods.

The present invention relates to focus localization method in micro seismic monitoring, is in the time that initial velocity model is inaccurate, improvesThe method of positioning precision Simultaneous Inversion rate pattern. The present invention utilizes associating chromatography equation to carry out Simultaneous Inversion to go out micro-Earthquake source position, the origin time of earthquake and rate pattern; Associating chromatography equation has comprised common chromatography equation, shakeThe two poor chromatography equations in source and the two poor chromatography equations of wave detector. Owing to having adopted travel time residual and travel time residual simultaneouslyDifference as optimized variable, improved the inversion accuracy of focus positioning precision and rate pattern, especially in speedIn the inaccurate situation of degree model, also improve the stability of inversion result.

Technique scheme is one embodiment of the present invention, for those skilled in the art,The invention discloses on the basis of application process and principle, be easy to make various types of improvement or distortion,And be not limited only to the described method of the above-mentioned detailed description of the invention of the present invention, therefore previously described mode is justPreferably, and do not there is restrictive meaning.

Claims (5)

1. microseism hypocentral location and a rate pattern Simultaneous Inversion method, is characterized in that: described method comprises:

(1), pick up the first arrival time of microseism event;

(2), utilize Sonic Logging Data, build initial velocity model, then obtain microseism event at the beginning ofBeginning hypocentral location and the origin time of earthquake;

(3),, when the theory based on two spots ray tracing calculating microseism event is walked, build associating chromatography equationGroup;

(4), solve described associating chromatography equation group, calculate parameter renewal amount δ u, Δ x and Δ τ;

(5) judge whether to meet end condition, if so, proceed to step (6), if not, utilizeDescribed parameter renewal amount upgraded rate pattern, hypocentral location and the origin time of earthquake, then returned to step (3);

(6), export final rate pattern, hypocentral location and the origin time of earthquake.

2. microseism according to claim 1 hypocentral location and rate pattern Simultaneous Inversion method, its feature existsIn: described step (3) is achieved in that

Set up associating chromatography equation group, comprise that common chromatography equation, the two poor chromatography equations of focus and wave detector are twoPoor chromatography equation, wherein common chromatography equation is as shown in formula (2):

$r_k^i={\mathrm{\Δ\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{{\∂}_k^i}{{\∂x}_l^i}{\mathrm{\Δx}}_l^i+{\∫}_i^k\mathrm{\δuds}---\left(2\right)$

Wherein,For microseism event i is to the calculating whilst on tour of acceptance point k with pick up the residual error between whilst on tour; δ u isSlowness model modification amount;Be respectively microseism event i hypocentral location x, y, z directionRenewal amount; Δ τⁱFor the origin time of earthquake renewal amount of microseism event i; Focus partial derivativeFor focus placeSlowness vector, for:

$\frac{{\∂T}_k^i}{{\∂x}_l^i}=-\frac{1}{V}\left(\frac{{\mathrm{dx}}_l^i}{\mathrm{ds}}\right)---\left(3\right)$

The two poor chromatography equations of described focus are as shown in formula (4):

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j={\mathrm{\Δ\τ}}^i+\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{{\∂T}_k^i}{{\∂x}_l^i}{\mathrm{\Δx}}_l^i+{\∫}_i^k\mathrm{\δuds}-{\mathrm{\Δ\τ}}^j-\underset{l=1}{\overset{3}{\mathrm{\Σ}}}\frac{{\∂T}_k^j}{{\∂x}_l^j}{\mathrm{\Δx}}_l^j-{\∫}_j^k\mathrm{\δuds}---\left(4\right)$

Wherein,Be respectively microseism event i, j to the calculating whilst on tour of acceptance point k and pick up whilst on tour itBetween residual error; Δ τ^jFor the origin time of earthquake renewal amount of microseism event j;For two poor time of focus, it is noteWhilst on tour residual error poor of the same detection of two events of record:

${\mathrm{dr}}_k^{\mathrm{ij}}=r_k^i-r_k^j={(t_k^i-t_k^j)}^{\mathrm{obs}}-{(t_k^i-t_k^j)}^{\mathrm{cal}}---\left(5\right)$

The two poor chromatography equations of described wave detector are as shown in formula (6):

${\mathrm{dr}}_{\mathrm{mn}}^i=r_m^i-r_n^i={\∫}_i^m\mathrm{\δuds}-{\∫}_i^n\mathrm{\δuds}---\left(6\right)$

Wherein,For two poor time of wave detector, record whilst on tour residual error poor of two wave detectors of same event:

${\mathrm{dr}}_{\mathrm{mn}}^i=r_m^i-r_n^i={(t_m^i-t_n^i)}^{\mathrm{obs}}-{(t_m^i-t_n^i)}^{\mathrm{cal}}---\left(7\right).$

3. microseism according to claim 2 hypocentral location and rate pattern Simultaneous Inversion method, its feature existsIn: in described step (4), be to utilize damping LSQR method to solve described associating chromatography equation group.

4. microseism according to claim 3 hypocentral location and rate pattern Simultaneous Inversion method, its feature existsIn: in described step (5), utilize described parameter renewal amount to enter rate pattern, hypocentral location and the origin time of earthquakeRow upgrades and is achieved in that

Parameter in step (2) is added respectively to renewal amount δ u, the Δ x corresponding with it that step (4) obtainsWith Δ τ.

5. microseism according to claim 4 hypocentral location and rate pattern Simultaneous Inversion method, its feature existsIn: the end condition in described step (5) is as follows:

Average whilst on tour residual error,Absolute value arithmetic mean of instantaneous value is less than a certain constant or parameter renewal amount is littleIn a certain constant.