KR101811284B1 - Microseismic location determining device and microseismic location determining method - Google Patents

Abstract

The present invention relates to an apparatus to determine a microseismic event position and a method to determine the microseismic event position. According to the present invention, the apparatus to determine the microseismic event position is an apparatus to determine the position of a microseismic event which occurs when a subject geological structure is crushed, comprising: a first estimated position determination unit which determines the first estimated position of the microseismic event based on an initial speed model of the subject geological structure, a plurality of arriving time measured by a plurality of receivers, and the positions of the plurality of receivers; a transformed speed model calculation unit which calculates a transformed speed model for the subject geological structure transformed based on the first estimated position, the initial speed model, and the plurality of arriving time; and a second estimated position determination unit which determines the second estimated position of the microseismic event based on the transformed speed model, the plurality of arriving times, and the positions of the plurality of receivers. The present invention provides the apparatus to determine the microseismic event position and the method to determine the microseismic event position, which are able to detect the precise position of a microseismic event.

Description

TECHNICAL FIELD [0001] The present invention relates to a micro vibration event location determining apparatus and a micro vibration event location determining method,

The present invention relates to a micro vibration event position determination apparatus and a micro vibration event position determination method.

Geothermal heat is an alternative energy source that can be operated year-round without being influenced by external heat source supply requirements such as seasonal influences and climatic conditions. In recent years, EGS (Enhanced / Engineered Geothermal System) technology has been developed to enable geothermal power generation in non- France, Germany, and Australia are actively conducting research.

EGS geothermal power generation technology is a technology of repairing the reservoir for securing the commerciality of geothermal power generation. It drills underground water several kilometers deep and then injects water to generate artificial geothermal reservoir, uses groundwater heated by geothermal energy as energy, It is a technology that circulates water. In this EGS geothermal power generation technology, it is very important to improve the connectivity of cracks, which is the moving path of ground water, and information of cracks generated in multi-stage crushing can be confirmed by microscopic vibration monitoring method.

Accurate positioning of micro-vibration events is important to understand the development of cracks through micro-vibration monitoring. Generally, the velocity structure of the underground lower part used in positioning the micro vibration event uses the structure before the hydraulic crushing, but the velocity structure of the underground part is changed by the crack generated in the hydraulic crushing at each step. If the minute vibration monitoring is performed using the structure before the hydraulic crushing without considering the changed velocity structure, the position error of the micro vibration event is generated due to the erroneous velocity structure at the time of positioning, and the wrong crack information is obtained .

Related prior art documents include Patent Documents 1 and 2 below.

Korean Patent Registration No. 10-1347969 (December 27, 2013) Japanese Patent Registration No. 4,324,126 (Jun., 2009)

A technical problem to be solved is to provide a micro-vibration event position determination device and a micro-vibration event position determination method capable of detecting an accurate position of a micro-vibration event by reflecting a changed velocity structure of a lipid when a target lipid is broken.

An apparatus for positioning microvibration event according to an embodiment of the present invention is an apparatus for microvibration event position determination that determines a position of a microvibration event that occurs upon fracture of a target lipid, A first estimated position determining unit for determining a first estimated position of the micro vibration event based on a plurality of arrival times measured through a receiver and a position of the plurality of receivers; A deformation rate model calculation unit for calculating a deformation rate model for the target lipid deformed by the crushing based on the primary estimated position, the initial velocity model, and the plurality of reaching times; And a secondary estimated position determining section for determining a secondary estimated position of the micro vibration event based on the deformation velocity model, the plurality of arrival times, and the positions of the plurality of receivers.

The primary estimation position determination unit may calculate a plurality of computation observations corresponding to the plurality of receivers through an Eikonal equation based on the positions of the plurality of receivers and the initial velocity model.

The primary estimation position determining unit may determine the primary estimation position to minimize the difference of the time residuals between the combinations of the plurality of receivers, and the time residual may be a difference between the arrival time corresponding to the receiver and the calculated attention.

The primary estimation position determining unit may use the change amount of the difference of the time residuals between the combinations of the plurality of receivers for each direction, the increment of the position coordinates with respect to each direction, the difference between the arrival time of the combinations of the plurality of receivers, So that the primary estimated position can be determined.

The strain rate model calculator may calculate a Jacobian by approximating the Fresnel volume.

In using the Fresnel volume, the deformation velocity model calculator may calculate a first calculation view for the entire model from a receiver, and calculate a second calculation view within a reference range from the first estimated position.

The reference range may be a certain range based on the area where the shredding is performed.

In calculating the first calculation view and the second calculation view, an Iconal equation can be used.

A microvibration event positioning method according to an embodiment of the present invention is a microvibration event positioning method for determining a position of a microvibration event that occurs upon fracture of a target lipid, the microvibration event positioning method comprising: A first estimated position determining step of determining a first estimated position of the micro vibration event based on a plurality of arrival times measured by the receiver and a position of the plurality of receivers; A strain rate model calculation step of calculating a strain rate model for the subject lipid deformed by the crushing based on the primary estimated position, the initial velocity model, and the plurality of arrival times; And a secondary estimated positioning step of determining a secondary estimated position of the micro vibration event based on the deformation velocity model, the plurality of arrival times, and the position of the plurality of receivers.

Wherein the microvibration event positioning method comprises the steps of: calculating, at the first estimation position determining step, a plurality of calculations corresponding to the plurality of receivers, Can be calculated.

Wherein the microvibration event positioning method comprises the steps of: determining, in the primary estimation positioning step, the primary estimated position to minimize a difference in time residuals between combinations of the plurality of receivers; The arrival time, and the difference of calculation observation.

Wherein the microvibration event positioning method further comprises: a step of calculating, at the first estimation position determining step, a change amount of a difference in time residual between combinations of the plurality of receivers in each direction, an increment of position coordinates with respect to each direction, The primary estimated position can be determined using the difference between the arrival times of the combinations and the calculation view.

The microvibration event positioning method may calculate the Jacobian by approximating the Fresnel volume in the strain rate model calculating step.

The method of determining microvibration event according to claim 1, wherein, in using the Fresnel volume in the deformation velocity model calculation step, a first calculation view is calculated for the entire model from a receiver, The second calculation view can be calculated.

The reference range may be a certain range based on the area where the shredding is performed.

In calculating the first calculation view and the second calculation view, an Iconal equation can be used.

The microvibration event position determination apparatus and microvibration event position determination method according to the present invention can accurately detect the microvibration event position by reflecting the changed velocity structure of the lipid when the target lipid is broken.

FIG. 1 is a diagram illustrating a micro vibration event location apparatus according to an embodiment of the present invention.
2 is a diagram for explaining an exemplary initial velocity model for a target lipid.
Figure 3 is a diagram for explaining an exemplary strain rate model for a subject lipid.
4 is a diagram for explaining positions of an exemplary micro vibration event and positions of a plurality of receivers.
FIG. 5 is a view of FIG. 4 viewed from the vertical direction. FIG.
FIG. 6 is a view for explaining an error in a direction of a primary estimation position of a micro vibration event determined by a primary estimation position determination unit according to an embodiment of the present invention.
7 is a diagram for explaining the Fresnel volume among the algorithms of the strain rate model calculation unit according to an embodiment of the present invention.
FIG. 8 is a diagram for explaining a first calculation view calculated from a receiver using a Fresnel volume; FIG.
FIG. 9 is a diagram for explaining a second calculation view calculated from the primary estimated position by using the Fresnel volume; FIG.
10 is a view for explaining a strain rate model calculated by the strain rate model calculation unit according to an embodiment of the present invention.
11 is a view for explaining an error in a direction of a secondary estimation position of a micro vibration event determined by a secondary estimation position determination unit according to an embodiment of the present invention.
12 is a diagram for comparing the position of the actual micro vibration event, the primary estimated position, and the secondary estimated position with each other.
13 is a table for comparing the estimated position error in the case of using the initial velocity model and the case of using the updated strain rate model.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. Therefore, the above-mentioned reference numerals can be used in other drawings.

In addition, since the sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses may be exaggerated for clarity of presentation of layers and regions.

FIG. 1 is a diagram illustrating a micro vibration event location apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a micro vibration event location determination apparatus 10 according to an exemplary embodiment of the present invention includes a primary estimation position determination unit 110, a deformation speed model calculation unit 120, and a secondary estimation position determination unit 130).

The microvibration event position determination apparatus 10 is a device that determines the position of a micro vibration event that occurs when a target lipid is broken. The micro vibration event location determination apparatus 10 may be a computing device including at least one processor and a memory. The primary estimated position determining unit 110, the deformation speed model calculating unit 120, and the secondary estimated position determining unit 130 may be units that can distinguish hardware devices of a computing device, It may be a unit.

Before describing the configuration of the micro vibration event location determining apparatus 10, the modeling of Figs. 2 to 5 will be referred to first in order to compare the hydraulic pressure before crushing and the post-hydraulic crushing.

FIG. 2 is a view for explaining an exemplary initial velocity model for a target lipid, FIG. 3 is a diagram for explaining an exemplary strain rate model for a target lipid, FIG. FIG. 5 is a view showing the position of the receiver of FIG.

An exemplary initial velocity model for the subject lipid shown in Figure 2 includes three lipid layers with different velocity structures. The lipid layer 210 may have a velocity structure of 1000 m / s, the lipid layer 220 may have a velocity structure of 2500 m / s, and the lipid layer 230 may have a velocity structure of 4000 m / s.

The injection well 240 can be inserted into the lipid as shown through the borehole. Thereafter, the water discharged through the injection well 240 may cause hydraulic fracturing of the target lipid.

Referring to FIG. 3, a strain rate model of the deformed target lipid is shown after hydraulic fracturing is performed through the injection well 240. The strain rate model further includes a lipid layer 250 having a velocity structure of 3600 m / s in addition to the conventional lipid layers 210, 220, and 230.

Referring to Figure 4, the location of the microvibration events generated by hydraulic fracturing and the location of a plurality of receivers are illustratively shown in the planar direction.

Referring to Figure 5, the locations of the microvibration events in the vertical direction are shown.

The primary estimation position determination unit 110 determines the primary estimation position of the micro vibration event based on the initial velocity model for the target lipid, the plurality of arrival times measured through the plurality of receivers, and the positions of the plurality of receivers .

The initial velocity model for the target lipid can be obtained using sound wave survey method during drilling such as logging. The obtained initial velocity model is similar to that of FIG. 2 since it is a velocity model before hydraulic fracture.

A plurality of receivers may be located, for example, as shown in FIG. 4 above the surface of the subject lipid. In FIG. 4, although the twelve receivers are arranged in a matrix form on the ground surface, the number and arrangement of the plurality of receivers may vary according to the embodiment.

The plurality of receivers records the time of arrival of the waves (P waves and S waves) according to the generated micro vibration events and the distance between the micro vibrations and the receivers when a micro vibration event occurs due to hydraulic fracturing.

First, the first-order estimation position determination unit 110 can calculate a plurality of calculation observations corresponding to a plurality of receivers through an Eikonal equation by inputting the positions and initial velocity models of a plurality of receivers .

The Iconel equation can be expressed as Equation 1 below.

[Equation 1]

This means the time that the wave reaches from the microvibration event to the receiver. The calculation means the attention calculated through the receiver, not the computed attention. Ray tracing and the Iconald's equation can be used to calculate the computed attention.

The dashed line tracking method has problems such as a shadow zone in a complex velocity model or a plurality of dashed paths between two points.

On the other hand, in the case of calculating the observations using the Iconald equation, since the time required for propagating the energy of the microvibration generated to all the lattice points can be obtained only by a single calculation, the efficiency is high in the calculation time. At this time, a method of solving the Icornal equation by a finite difference method can be used. In addition, it can be applied to complex speed models, and the problem of shadow area generated by the dashed line tracking method can be solved, so accurate micro vibration monitoring is possible. Therefore, in the present embodiment, calculation observation is calculated by a finite difference method using an Iconar equation.

On the other hand, in microvibration position inversion, it is necessary to calculate the attention from the microvibration generation position newly changed at every repetition to the receiver. Generally, in EGS geothermal power generation, hundreds or more microvibration events are located using a small number of receivers, and the calculation time required for the calculation of the observations increases rapidly due to repeated calculations at each iteration. In this embodiment, an algorithm is constructed to calculate the number of viewpoint calculations by the number of receivers rather than the number of transmitters by calculating the attention at all lattice points using the receiver as a source by using the principle of reciprocal of the transmit / receive period .

As long as the calculated velocity model and the position of the receiver are not changed, the calculation efficiency can be increased as the number of micro vibration events is increased, regardless of the number of micro vibration events.

Next, the primary estimation position determination unit 110 may determine the primary estimation position to minimize the difference in time residuals between the combinations of the plurality of receivers. At this time, the time residual may be the arrival time corresponding to the receiver and the difference value of the calculation watch.

Will be described with reference to Equation (2) below.

&Quot; (2) "

를 최소화하는 x, y, z의 좌표가 미소진동 이벤트의 1차 추정 위치가 될 수 있다.The objective function of Equation (2)

The coordinates of x, y, and z that minimize x, y, and z may be the primary estimated position of the microvibration event.

은 i 번째 수신기에서 측정된 파(wave)의 도달 시각이고,

은 i 번째 수신기에 대응하는 계산 주시이고, 은 j 번째 수신기에서 측정된 파의 도달 시각이고,

은 j 번째 수신기에 대응하는 계산 주시이다. 파는 S파 또는 P파일 수 있다.Where N is the number of receivers,

Is the arrival time of the wave measured at the i < th > receiver,

Is a calculation watch corresponding to the i < th > receiver, Is the arrival time of the wave measured at the jth receiver,

Is the computation attention corresponding to the jth receiver. The wave can be S-wave or P-wave.

은 i 번째 수신기의 시간 잔차이고,

은 j 번째 수신기의 시간 잔차일 수 있다.At this time,

Is the time residual of the i < th > receiver,

May be the time residual of the jth receiver.

Generally, it is often difficult to extract a first wave of a P wave having a relatively small amplitude due to a low signal-to-noise ratio. According to the embodiment of the present invention, when only one of the P wave or S wave is extracted, This is possible.

Equation (2) has an advantage that information on the generation time of the micro vibration event is not necessary.

In addition, even when both the P wave and the S wave are extracted, the number of combinations of the time residuals can be increased by Equation (2), which makes it possible to perform more accurate positioning.

According to one embodiment, the first-order estimation position determination unit 110 calculates a variation amount of time difference between the combinations of a plurality of receivers for each direction, an increment of position coordinates for each direction, And the difference between the calculated distances can be used to determine the primary estimated position.

Will be described with reference to the following equations (3) to (6). The terms in equations (3) and (4) correspond in order.

&Quot; (3) "

&Quot; (4) "

&Quot; (5) "

&Quot; (6) "

은 각 방향에 대한 위치 좌표의 증분이고, r_i,j은 i 번째 수신기의 시간 잔차와 j 번째 수신기의 시간 잔차의 차이를 의미한다.Where the matrix G is the variation of the difference in time residuals between the combinations of the plurality of receivers for each direction,

Is the increment of the position coordinate for each direction, and r _{i, j} is the difference between the time residual of the i-th receiver and the time residual of the j-th receiver.

Applying a grid search to the objective function of Equation (2), an optimal solution can be found regardless of the initial model within a desired error range. However, in the case of EGS geothermal power generation, There is a problem that calculation time is long to apply to the model.

Therefore, in this embodiment, a method of minimizing the difference in time residual between receiver combinations is applied to enable accurate positioning of micro vibration events. Instead of the grid search method, a determinant is constructed as shown in Equation (3) ), It is possible to improve the positioning algorithm so that the positioning of the generated micro vibration event can be performed quickly even for a large scale 3D model.

가 0에 도달하면, 초기 입력값에 증분 값을 더하여 미소진동 이벤트의 1차 추정 위치를 결정할 수 있게 된다.Incremental

The initial estimated position of the micro vibration event can be determined by adding the increment value to the initial input value.

FIG. 6 is a view for explaining an error in a direction of a primary estimation position of a micro vibration event determined by a primary estimation position determination unit according to an embodiment of the present invention.

Referring to FIG. 6, the first-order estimated position determined by applying the initial velocity model has a relatively accurate result due to an average error of 1.26 m in the x-direction and 1.42 m in the y-direction, Shows a relatively large error of 6.16 m on average.

The strain rate model calculation section 120 calculates a strain rate model for a target lipid deformed by fracture based on a primary estimated position, an initial velocity model, and a plurality of arrival times.

One of the most widely used methods for imaging velocity changes among many elastic inversion methods is to perform inversion using the first-order observation, and the tomography method is a typical method for analyzing the underwater velocity structure using this first-order observation. In typical tomography, the inversion problem is linearized and the dashed path is calculated based on the initial velocity model. However, in the case of micro vibration generated by hydraulic fracturing such as EGS geothermal power generation, hundreds or more of events are generated, and since the amount of data is very large in calculating the dashed path and view of this event and the receiving period, And limited coverage problems.

Therefore, in this embodiment, to calculate the shortest observation at all lattice points efficiently by performing the finite difference calculation using the Iconal equation applied to the position inversion, A nonlinear inversion method is applied to incorporate various constraints on the model parameters into the inversion process.

In the iterative nonlinear calculation based on the least squares method applied in this embodiment, the increment of the model variable that minimizes the prediction error is calculated by using the objective function of Equation (7) below. In order to overcome this instability and to obtain a meaningful solution in real terms, the inverse unsteadiness of the inverse unsteadiness (Smoothness constraint) (see Equation 9) and the structural limit The conditional structure (see Equation 10) was added to construct the objective function.

&Quot; (7) "

&Quot; (8) "

&Quot; (9) "

&Quot; (10) "

는 관측된 주시와 계산된 주시간의 데이터 오차항(data misfit), ??

와??

는 모델변수 증분에 대한 제한조건 사이의 균형을 위한 라그랑지 승수(Lagrangian multiplier)이며, 수학식 9와 수학식 10은 각각 구하고자 하는 모델변수의 증분에 대한 제한조건을 나타낸다. 수학식 9에서 행렬??C는 모델변수의 거칠기(roughness)를 계산하기 위한 7점 유한차분 연산자이고, 수학식 10의 P는 대각행렬로서 주대각 성분의 값이 구조적 제한여부에 따라 0 또는 1을 갖게 된다.here,

Is the data misfit of the observed observations and the calculated weekly time, ??

Wow??

Is a Lagrangian multiplier for balancing the constraints on model parameter increments, and Equations (9) and (10) represent constraints on the increment of the model variable to be obtained, respectively. In Equation (9), the matrix ?? C is a 7-point finite difference operator for calculating the roughness of a model parameter, and P in Equation 10 is a diagonal matrix in which the value of the main diagonal element is 0 or 1 .

은 아래 수학식 11과 같이 표현이 가능하며, 수학식 11을 계산함으로 미소진동 자료를 이용한 수압파쇄시 변화된 속도구조를 계산하게 된다.This inversion problem is a problem of obtaining a solution of a normal equation in which the partial derivative of the objective function is 0 for the increment of the model variable.

Can be expressed as shown in Equation (11) below. By calculating Equation (11), the velocity structure changed when hydrodynamic fracture using micro vibration data is calculated.

&Quot; (11) "

는 자료 오차로써 관측된 주시와 계산된 주시의 차를 나타낸다.Where J is the Jacobian matrix as the sensitivity calculated as the derivative of the model parameter for the data,

Represents the difference between the observed and calculated observations as data errors.

Jacobian's calculation is the most important part of nonlinear inversion. In general, the simplest method for calculating Jacobian is the incremental method using the finite difference calculation formula. The finite difference calculation equation is used to approximate the derivative, .

&Quot; (12) "

Where t is the observed observation, s is the inverse velocity vector, N _data is the number of observations, and N _block is the number of inverse blocks.

만큼의 주시 모델링이 필요하게 된다. 또한 이 과정은 매 반복시마다 새로운 속도모델에 대해서 수행되어야 하므로 이런 방법으로 자코비안 행렬을 구성하기에는 엄청난 계산시간이 소요되게 된다.These characters to the Jacobian matrix construction with the principle of reciprocity for a given reference model also is a need for eye models of as many as the number N _crv of the receiver, the eye model increment is considered the as the number N _block of the inversion block reclaimed Therefore,

As shown in FIG. In addition, since this process has to be performed for each new speed model in each iteration, it takes a lot of computation time to construct a Jacobian matrix in this way.

Therefore, in this embodiment, a Jacobian can be constructed using a method of approximating the Fresnel volume to solve this problem and increase the efficiency of inversion.

7 is a diagram for explaining the Fresnel volume among the algorithms of the strain rate model calculation unit according to an embodiment of the present invention.

In general, seismic waves have a frequency domain width, and the actual waves affect the propagation of waves to the area around the dashed line as well as the dashed line assumed to be the line. The path of such a wave is defined as a Fresnel volume as shown in FIG. 7, and the Fresnel volume is configured as shown in Equation (13) as a function of the acoustic wave propagation time and frequency according to the positions of the transmission source S and the receiver R.

&Quot; (13) "

Where t _SR is the shortest observation from the source to the receiver, t _SP is the observation from the source to an arbitrary point (P), t _PR is the observation from any point (P) to the receiver, and f is the main frequency of the acoustic wave do.

The Jacobian is constructed using the Fresnel volume representing the path of the wave using Equation 14 using the area of the inversion block versus the area of the entire Fresnel volume. Therefore, according to Equation (14) and the above-described equations, the strain rate model calculating unit 120 can calculate the Jacobian by approximating the Fresnel volume.

&Quot; (14) "

는 i번째 파선이 이루는 프레넬 볼륨의 면적,

는 i번째 파선 중 k번째 역산블록에 해당하는 면적을 의미한다. 하지만 이 경우는 가중치가 프레넬 볼륨내에서 차별없이 적용되게 되는데 이를 개선하기 위해 아래 수학식 15와 같은 가중함수를 적용하여 수학식 16과 같이 자코비안을 구성할 수 있다.here

Is the area of the Fresnel volume formed by the ith broken line,

Denotes the area corresponding to the kth inverse block of the ith broken line. However, in this case, the weights are applied without discrimination in the Fresnel volume. To improve this, a Jacobian can be constructed by applying a weighting function as shown in Equation (15) below.

&Quot; (15) "

,

,

&Quot; (16) "

는 i번째 파선의 k번째 역산블록에 대한 가중계수를 의미하며,

는 i번째 파선에 해당하는 모든 역산블록의 가중계수의 합으로 표현된다.here

Denotes a weighting coefficient for the k-th inverse block of the i-th broken line,

Is expressed by the sum of the weighting coefficients of all the inversion blocks corresponding to the i-th broken line.

According to the present embodiment, the calculation time of the velocity inversion can be drastically reduced by configuring the calculation of Jacobian, which takes the longest computation time in inversion, as described above, and the limited transmission and reception coverage problem of general tomography using the dashed line tracking method is also solved This is possible.

However, this method also requires one-time observation modeling in the transmitter / receiver. Therefore, it takes a long time to calculate the time when the lower part of a few km is used as in EGS.

FIG. 8 is a view for explaining a first calculation view calculated from a receiver using a Fresnel volume, and FIG. 9 is a view for explaining a second calculation view calculated from a first estimated position by using a Fresnel volume Fig.

According to one embodiment, the deformation velocity model calculator 120 calculates the first calculation view for the entire model from the receiver 810 using the Fresnel volume, and calculates the deformation velocity model from the first estimated position 820 to the reference range The second calculation view can be calculated within the first calculation view 910.

In this case, the reference range may be a certain range based on the area where the fracture is to be performed, and the Iconald's equation may be used to calculate the first calculation view and the second calculation view.

?個? t_SR과 t_PR을 계산하지만, 송신원(1차 추정 위치)(820)에서는 제한된 속도역산의 대상지역(910)에 대해서만 주시 모델링을 수행하여 t_SP를 구함으로서 역산시 소요되는 계산시간을 더욱 단축시켰다.In this embodiment, the receiver 810 limits the inversion region to the portion where the hydrodynamic fracture is performed,

? Piece? t _SR and t _PR are computed. However, by calculating the t _SP by performing the view modeling only on the target area 910 of the limited velocity inverse transmission in the transmission source (primary estimation position) 820, the calculation time required for the inverse calculation is further shortened .

The increment of the model variable obtained through Equation (11) may be rapidly increased or decreased due to the variables related to the inverse calculation, thereby causing a problem causing a large error. In order to solve such a problem and to secure the resolution and stability of the inversion, the method of directly introducing information on the geologically significant underground velocity distribution directly into the model parameters can be applied in this embodiment. The constraint factors represented by the upper and lower limits of the velocity can be expressed by a new variable x as shown in Equation (17).

&Quot; (17) "

는 다음 수학식 18과 같이 주어질 수 있다.

Can be given by the following equation (18).

&Quot; (18) "

The update of the speed using the increment of the model variable obtained from the equation (18) can be defined as shown in equation (19).

&Quot; (19) "

The computed model parameters are limited to the upper and lower limits of the value, so that a more meaningful solution can be obtained in which the prior information is reflected, and the scope of the increase or decrease of the model parameters is limited, thereby making it possible to perform inversion more stably.

10 is a view for explaining a strain rate model calculated by the strain rate model calculation unit according to an embodiment of the present invention.

It can be seen that the strain rate model calculated by the strain rate model calculator 120 is very similar to the originally intended rate modeling of FIG.

The secondary estimation position determination unit 130 determines secondary estimation positions of the micro vibration events based on the strain rate model, the plurality of arrival times, and the positions of the plurality of receivers.

In the present embodiment, the primary estimation position determination unit 110 and the secondary estimation position determination unit 130 are described as separate functional units, but they may be the same functional unit according to the embodiment. For example, when the first-order estimation position determination unit 110 updates and applies the strain rate model calculated by the strain rate model calculation unit 120 instead of the initial velocity model, the first-order estimation position determination unit 110 derives the second- .

11 is a view for explaining an error in a direction of a secondary estimation position of a micro vibration event determined by a secondary estimation position determination unit according to an embodiment of the present invention.

Referring to FIG. 11, the secondary estimation position shows an average error of 1.40 m in the x direction, 1.41 m in the y direction, and 3.97 m in the z direction. Therefore, it can be seen that the average error in the z direction is greatly improved when compared with the mean error of the primary estimated position in Fig.

FIG. 12 is a diagram for comparing the position, the primary estimated position, and the secondary estimated position of the actual micro vibration event with each other, FIG. 13 is a graph for comparing the estimated position error in the case of using the initial velocity model and in the case of using the updated strain model . ≪ / RTI >

12, the vertical direction error from the position 1210 of the 10 actual micro vibration events to the primary estimation position 1220 is relatively large, and the second estimated position 1230 from the position 1210 of the actual micro vibration event ) Is relatively small in the vertical direction.

The table in Fig. 13 shows specific error data corresponding to each micro vibration event. The left side is the error corresponding to the primary estimated position and the right side is the error corresponding to the secondary estimated position.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are illustrative and explanatory only and are intended to be illustrative of the invention and are not to be construed as limiting the scope of the invention as defined by the appended claims. It is not. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: Micro vibration event position determination device
110: primary estimation position determining section
120: strain rate model calculation unit
130: Secondary estimation position determining section

Claims (15)

An apparatus for positioning a micro vibration event that determines the position of a micro vibration event that occurs upon fracture of a target lipid,
A first estimated position determining unit for determining a first estimated position of the micro vibration event based on an initial velocity model for the target lipid, a plurality of arrival times measured through a plurality of receivers, and a position of the plurality of receivers;
A deformation rate model calculation unit for calculating a deformation rate model for the target lipid deformed by the crushing based on the primary estimated position, the initial velocity model, and the plurality of reaching times; And
And a secondary estimated position determining section for determining a secondary estimated position of the micro vibration event based on the deformation velocity model, the plurality of arrival times, and the positions of the plurality of receivers
A device for positioning a micro vibration event. The method according to claim 1,
The primary estimated position determining unit
Calculating a plurality of computation observations corresponding to the plurality of receivers via an Eikonal equation, with the inputs of the plurality of receivers and the initial velocity model,
A device for positioning a micro vibration event. 3. The method of claim 2,
The primary estimated position determining unit
Determine the primary estimated position to minimize the difference in time residuals between the combinations of the plurality of receivers,
Wherein the time residual is a difference value between arrival time and calculation time corresponding to the receiver,
A device for positioning a micro vibration event. The method of claim 3,
The primary estimated position determining unit
Using the difference of the difference of the time residuals between the combinations of the plurality of receivers for each direction, the increment of the position coordinates with respect to each direction, the arrival time between the combinations of the plurality of receivers and the difference between the calculation observations, Lt; / RTI >
A device for positioning a micro vibration event. The method according to claim 1,
The strain rate model calculation unit
The Jacobian is calculated by approximating the Fresnel volume,
A device for positioning a micro vibration event. 6. The method of claim 5,
The strain rate model calculation unit
Calculating a first calculation view for the entire model from the receiver using the Fresnel volume and calculating a second calculation view within a reference range from the primary estimated position,
A device for positioning a micro vibration event. The method according to claim 6,
Wherein the reference range is a predetermined range based on an area where shredding is performed,
A device for positioning a micro vibration event. The method according to claim 6,
In calculating the first calculation viewing and the second calculation viewing, it is preferable to use the Iconal equation
A device for positioning a micro vibration event. A microvibration event positioning method for determining a position of a microvibration event occurring upon fracture of a target lipid,
A first estimated position determining step of determining a first estimated position of the micro vibration event based on an initial velocity model for the target lipid, a plurality of arrival times measured through a plurality of receivers, and a position of the plurality of receivers;
A strain rate model calculation step of calculating a strain rate model for the subject lipid deformed by the crushing based on the primary estimated position, the initial velocity model, and the plurality of arrival times; And
A second estimated position determining step of determining a second estimated position of the micro vibration event based on the deformation velocity model, the plurality of arrival times, and the position of the plurality of receivers,
Method for determining location of microvibration event. 10. The method of claim 9,
In the primary estimation and positioning step,
Calculating a plurality of computation observations corresponding to the plurality of receivers through the Iconald equation by taking the positions of the plurality of receivers and the initial velocity model as inputs,
Method for determining location of microvibration event. 11. The method of claim 10,
In the primary estimation and positioning step,
Determine the primary estimated position to minimize the difference in time residuals between the combinations of the plurality of receivers,
Wherein the time residual is a difference value between arrival time and calculation time corresponding to the receiver,
Method for determining location of microvibration event. 12. The method of claim 11,
In the primary estimation and positioning step,
Using the difference of the difference of the time residuals between the combinations of the plurality of receivers for each direction, the increment of the position coordinates with respect to each direction, the arrival time between the combinations of the plurality of receivers and the difference between the calculation observations, Lt; / RTI >
Method for determining location of microvibration event. 10. The method of claim 9,
In the strain rate model calculation step,
Calculating the Jacobian by approximating the Fresnel volume,
Method for determining location of microvibration event. 14. The method of claim 13,
In the strain rate model calculation step,
Calculating a first calculation view for the entire model from the receiver using the Fresnel volume and calculating a second calculation view within a reference range from the primary estimated position,
Method for determining location of microvibration event. 15. The method of claim 14,
Wherein the reference range is a predetermined range based on an area where shredding is performed,
Method for determining location of microvibration event.

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