Deviation eliminating method for improving accuracy of structural diagram

Technical Field

The invention relates to the petroleum exploration and development of technology, in particular to a two-dimensional seismic data interpretation mapping in improving the construction of a method for eliminating deviation of the accuracy of the plan.

Background Art

In the petroleum exploration, often adopt the two-dimensional seismic information formed after the treatment of the interpretation of seismic data, data formed in this way, in the transverse direction are by saying , can be a plurality of, each in longitudinal direction of a plurality of time according to the number of dots the territory is separate , map display of the seismic section. Two-dimensional seismic data interpretation is a two-dimensional seismic data to obtain to horizon, fault identification and tracking, after processing and analysis, structure diagram form, and then carry on the petroleum geological comprehensive evaluation.

Two-dimensional seismic data space correction and structure pattern is a two-dimensional seismic data interpretation an important step in the links and the key. The accuracy of the structure diagram of the region directly influences the geologist, and trap oil reservoir of the comprehensive evaluation of geological reserves, at the same time also affects the determining of the position of the actual drilling. Usually the imaging mode is first when intercalated bed of the seismic data to two-dimensional position data and plane combined fault space correction, then using homing the data after the configured to map directly. Such as is characteristic of the earth's surface, underground structure gentlely the eastern region comparison result pattern of impact is not great, however, the complex structure of the western the mountainous areas, the final imaging result will be to produce a greater impact, and may even affect the entire trap and geological reserves the oil reservoir to the correct evaluation. This is because the western mountains with the complex characteristic of the earth's surface, underground stratum dip angle is relatively large, often because of the processing procedure of the static correction factors is not accurate, the time profile of a time error, what is more important is that in the later stage in the process of free-space correction structure, because the offset speed and other factors is inaccurate , the space also often have a negative impact on homing result, it is difficult to completely accurately obtained real space underground reflection point position, can only get an approximate spatial position (X, Y, T or X, Y, H), is therefore reset after a certain when intercalated bed the deviation of the data still exists. This kind of deviation is reset after the specific performance of a horizon data forming underground reflection point of intersection point position of the on-line with when intercalated bed bit data.

Figure 1 is is a certain work area data time difference pile lean towards when intercalated bed spread chart, the straight line in the Figure indicates that the work area of the two-dimensional deployment practical exploration seismic line, in the Figure these two-dimensional digital representation of the pile lean towards when intercalated bed seismic line is the position of the intersection point of the data size of the time difference. In Figure 1 the position of the intersection point can be seen in a large time difference. Figure 1 of the time difference is composed of two components: one is initial seismic data processing error caused by the bit data when intercalated bed ; another is the tendency of the structure caused by the time difference. Pile lean towards section through the space homing of time horizon, can only to a large extent eliminate structure (not completely) the time difference to, previous seismic data can not eliminate a horizon data error caused by processing.

Figure 2 is Figure 1 the direct measuring line in when intercalated bed bit data after correcting the time variance of the space spread Figure. The bending lines in the Figure or new line that of Figure 1 in the measures the line straightwhen intercalated bed bit data after correcting the space, a reflecting point of the connecting line of the ground, in the digital representation of the intersection point position of the new line size of the time deviation value. Compare Figure 2 and Figure 1 position through the space can be found in the new intersection point position of the fracture is reduced a lot time difference, however, there are still many areas larger than 30ms. If no space for such period of time the structure of the correction will be free to a great impact on the results, fig. 3 that is, the direct utilization of Figure 2 is shown the time after the reset space data structure diagram motherland time, as can be seen from the map a in the structure diagram of the distortion structure, causing imaging result is not allowed, even if the artificial by post also difficult to obtain the ideal imaging results. This is not accurate often directly by the drilling of the errors.

Content of the invention

The Purpose of the invention is to offer a kind of imaging result is more accurate, improving the construction of the method for eliminating deviation of the accuracy of the plan.

Specific realizing process of this invention are as follows:

1) acquisition of two-dimensional seismic data in the work area, pickup when intercalated bed position data and plane combined fault, then interpolation on the plane, form a uniform time-level data, the initial structural model is reset;

Step 1 the plane interpolation refers to a horizon data will not evenly arranged into uniform mesh layer bit data.

2) model according to the initial structure, in accordance with the usual method of the time horizon and plane combined fault space correction, various sets of data points by each fault and reset after each breakpoint space position;

Step 2) the spatial location is the approximate location of the reflecting point.

3) data sets in accordance with the original combination mode of the reflection point position is, new-line, and calculating the new line in crossingpoint position for a period of time of the deviation;

Step 3) the original line is the actual recherches deployment of two-dimensional seismic line.

Step 3) the new line is an underground reflection point connection.

Step 3) the data points refer to the combination mode can only make one and the same line the underground reflection point connection, different line the underground reflection point can not be connected with each other.

Step 3) the combination of the data points is not repositioned in accordance with the order the data is connected with the reset of the reflection point.

Step 3) the new line through space homing of the underground reflection point connection.

Step 3) the new position of the point of intersection of the sets of the time deviation value is calculated is the process of:

According to the new line of the geodetic coordinates of each data point, calculate the new intersection sets the coordinates of the position, then according to the two intersection points each other and the position of the new sets of time information on-line, the intersection point position calculated new line on two mutually the respective time, achieve time deviation value.

4) according to the position of each intersection in cheng Tuqu time deviation value, computing each new line time constant deviation correction value;

Step 4) the each line time constant deviation correction value calculation process is:

New-line after a time constant deviation after correcting the position of the point deflection time remaining ε_i

ε_i = d_i-(x_l(i)-x_k(i))     (1)

d_i i is a section of the new intersection of the fracture in the constant deviation correction of the deviation of the time before, x_l(i) and x_k(i) are new l Criminalization k section and sets the new line time constant deviation, that is to be calculated in this step the line constant deviation correction value.

After correcting the constant deviation, each intersection point position overall residual deviation is the most under the condition of a small, that is, ε → 0 time, the formula (1) can be further written as:

x_l(i)-x_k(i) = d_i     (2)

The new cheng Tuqu of the number of the intersection points of the fracture M, the new test lines under the condition of N, M a can be obtained as the formula (2) shown by a linear equation.

Increasing the constraint equation:

Σi=1Nxi=0---(3)

Equation (3) in the Said new line correction amount in all cheng Tuqu algebraic and, x_i said new line constant deviation, said new N the number of sets.

Equations 2 and constraint equation 3 M + 1 of the joint by forming a linear equation of the equations, the equations of the least squares solution for each new line of the constant deviation correction value.

5) use of step 4) calculate the new line of the correction value of the constant deviation, the new line of constant deflection correction;

Step 5 the constant deviation correcting means: each new line each data points only one unified correction amount.

Correction formula is:T_ij = t_ij-x_i     (4)

In the formula: t_ij i section the strip measures the line section said j data points of the original time value, T_ij i section the strip measures the line section said j data points constant deviation of the time values of corrected, x_i expressed by the step 4) the calculated section i the deviation of the time constant of the fracture;

6) in accordance with step 3) re-calculating new way of line through the constant deviation after correcting the position of the point of intersection of the residual deviation;

7) according to the new position of the point of intersection of the lines of the remaining deviation calculation map each of the fracture in the region of each data point of the time variable correction value;

Step 7) the variable is corrected in the step 5) the constant correction remaining deviation more one-step correction.

Step 7) the calculation is:

(1) according to the constant deviation after correcting the position of each intersection point of the remaining deviation, computing each new line variable correction weight.

wi=kiΣl=1ki[xi(l)]2---(5)

Formula (5) in x_i^(l) section the strip measures the line l section i a time deviation values remaining at the intersection point of, K_i i the strip measures the line is the number of the intersection points with the remaining line, w_i i of lines to variable deflection of the correction weight.

(2) calculating two intersecting line of the new correction factor variable deflection of the m:

m=(wjwi)n,(n=1,2,3,4,5)---(6)

Formula (6) of the in w_i and w_j is through the formula (5) of the two calculated intersecting line variable offset correction weight. N is an integer, the value range of 1-5 between. cheng Tuqu specific is based on the determined line crossingpoint deviation distribution situation, if the map individual line and the remaining of the fracture value of the deviation is relatively large compared with large, otherwise the value is small; if all the weights of the relatively close to w of the fracture, is the n 1, under normal conditions, the value of 3, the maximum of not more than 5.

(3) calculate the strip measures the line i and after correcting the variable j, intersection point position of the time value of the fracture T_ij:

Tij=Ti+Tj*m1+m---(7)

Formula (7) in T_i and T_j respectively before correcting the variable section i and the strip measures the line the position of the point of intersection of the line j-time value.

(4) calculating the intersection point position section i the strip measures the line and j-line variable offset correction amount.

Δ T_i = T_ij-T_i     (8)

Δ T_j = T_ij-T_j     (9)

(5) repeat many times (2)-(4), the position of all the calculated correcting variable deflection of the intersection point.

(6) according to each of the new intersection point position of the correction value of the variable of the fracture, the linear difference non-intersection point position of each data point of the correction value of the variable.

8) according to each of the sets the correction value of the deviation of the data points, all new complete work area of the fracture in the variable time offset correction;

9) in accordance with step 3) re-calculate these new way of line through constant correction and variable correction after the remaining time of the deviation of the position of the intersection point, the intersection of the fracture position of the new residual deviation if the overall residual maximum time deviation is less than 5m, offset correction are performed, otherwise repeat steps 3)-step 8) until the meet the above-mentioned requirement;

10) after correcting output the deviation when intercalated bed bit data, after combining space correction of the fault data, usually adopt the structure diagram of the method.

Since the invention eliminates the static correction of seismic data processing is not accurate, the time error factors, and space later pursue deviation of the correction process, and prevent afterward human the structure distortion phenomenon for editing, the whole space correction result more accurate, reasonable, guarantee the correctness of the structure pattern, to correct interpretation of the underground structure.

The invention fully respects the authenticity of the original data, are protected to the greatest extent the original data, is equivalent to the original two-dimensional seismic data structure pattern-forming process of the Image-forming process of the increase in quality control, avoids the trivial afterwards for editing, the process of mapping is guaranteed scientificity and the stringency, the whole imaging result is more accurate, is reasonable.

Description of drawings

Figure 1. Work area folds the leaning level bit interpretation of data crossingpoint position mop chart time difference;

Figure 2. Work area reset the time variance of the layout display data;

Figure 2 the curved line indicated in Figure 1 the actual recherches deployment of the fracture in the underground of the representative of the reflection point connection;

Figure 3. Offset correction is not carried out directly after the reset for when intercalated bed bit data structure diagram motherland time;

Figure 4. The method of the invention provides that the constant correction method for correcting the deviation of position and time after the exhibition Bututs intersection point;

Figure 5. In the present invention after correcting the constant a variable correction deviation show layout;

Figure 6. This invention provides method for correcting the deviation of the offset correction to the structure diagram of the time.

Specific embodiment

In conjuction with the following detailed descriptions of the invention. The invention in particular implementation of the process is:

1) acquisition of two-dimensional seismic data in the work area, pickup when intercalated bed position data and plane combined fault, then interpolation on the plane, form a uniform time-level data, the initial structural model is reset;

Step 1 the interpolation is to be the plane of the horizon data is arranged into uniform mesh layer bit data.

2) model according to the initial structure, in accordance with the usual method of the time horizon and plane combined fault space correction, various sets of data points by each fault and reset after each breakpoint space position;

Step 2) the spatial location is the approximate location of the reflecting point.

3) data sets in accordance with the original combination mode of the reflection point position is, new-line, and calculating the new line in crossingpoint position for a period of time of the deviation;

Step 3) the original line is the actual recherches deployment of two-dimensional seismic line.

Step 3) the new line is an underground reflection point connection.

Step 3) the data points refer to the combination mode can only make one and the same line the underground reflection point connection, different line the underground reflection point can not be connected with each other.

Step 3) the combination of the data points is not repositioned in accordance with the order the data is connected with the reset of the reflection point.

Step 3) the new line through space homing of the underground reflection point connection.

Step 3) the new position of the point of intersection of the sets of the time deviation value is calculated is the process of:

According to the new line of the geodetic coordinates of each data point, calculate the new intersection sets the coordinates of the position, then according to the two intersection points each other and the position of the new sets of time information on-line, the intersection point position calculated new line on two mutually the respective time, achieve time deviation value.

4) according to the position of each intersection in cheng Tuqu time deviation value, computing each new line time constant deviation correction value;

Step 4) the each line time constant deviation correction value calculation process is:

New-line after a time constant deviation after correcting the position of the point deflection time remaining ε_i

ε_i = d_i-(x_l(i)-x_k(i))     (1)

d_i i is a section of the new intersection of the fracture in the constant deviation correction of the deviation of the time before, x_l(i) and x_k(i) are new l Criminalization k section and sets the new line time constant deviation, that is to be calculated in this step the line constant deviation correction value.

After correcting the constant deviation, each intersection point position overall residual deviation is the most under the condition of a small, that is, ε → 0 time, the formula (1) can be further written as:

x_l(i)-x_k(i) = d_i     (2)

The new cheng Tuqu of the number of the intersection points of the fracture M, the new test lines under the condition of N, M a can be obtained as the formula (2) shown by a linear equation.

Increasing the constraint equation:

Σi=1Nxi=0---(3)

Equation (3) in the Said new line correction amount in all cheng Tuqu algebraic and, x_i said new line constant deviation, said new N the number of sets.

Equations 2 and constraint equation 3 M + 1 of the joint by forming a linear equation of the equations, the equations of the least squares solution for each new line of the constant deviation correction value.

5) use of step 4) calculate the new line of the correction value of the constant deviation, the new line of constant deflection correction;

Step 5 the constant deviation correcting means: each new line each data points only one unified correction amount.

Correction formula is:T_ij = t_ij-x_i     (4)

In the formula: t_ij i section the strip measures the line section said j data points of the original time value, T_ij i section the strip measures the line section said j data points constant deviation of the time values of corrected, x_i expressed by the step 4) the calculated section i the deviation of the time constant of the fracture;

6) in accordance with step 3) re-calculating new way of line through the constant deviation after correcting the position of the point of intersection of the residual deviation;

7) according to the new position of the point of intersection of the lines of the remaining deviation calculation map each of the fracture in the region of each data point of the time variable correction value;

Step 7) the variable is corrected in the step 5) the constant correction remaining deviation more one-step correction.

Step 7) the calculation is:

(1) according to the constant deviation after correcting the position of each intersection point of the remaining deviation, computing each new line variable correction weight.

wi=kiΣl=1ki[xi(l)]2---(5)

Formula (5) in x_i^(l) section the strip measures the line l section i a time deviation values remaining at the intersection point of, K_i i the strip measures the line is the number of the intersection points with the remaining line, w_i i of lines to variable deflection of the correction weight.

(2) calculating two intersecting line of the new correction factor variable deflection of the m:

m=(wjwi)n,(n=1,2,3,4,5)---(6)

Formula (6) of the in w_i and w_j is through the formula (5) of the two calculated intersecting line variable offset correction weight. N is an integer, the value range of 1-5 between. cheng Tuqu specific is based on the determined line crossingpoint deviation distribution situation, if the map individual line and the remaining of the fracture value of the deviation is relatively large compared with large, otherwise the value is small; if all the weights of the relatively close to w of the fracture, is the n 1, under normal conditions, the value of 3, the maximum of not more than 5.

(3) calculate the strip measures the line i and after correcting the variable j, intersection point position of the time value of the fracture T_ij:

Tij=Ti+Tj*m1+m---(7)

Formula (7) in T_i and T_j respectively before correcting the variable section i and the strip measures the line the position of the point of intersection of the line j-time value.

(4) calculating the intersection point position section i the strip measures the line and j-line variable offset correction amount.

Δ T_i = T_ij-T_i     (8)

Δ T_j = T_ij-T_j     (9)

(5) repeat many times (2)-(4), the position of all the calculated correcting variable deflection of the intersection point.

(6) according to each of the new intersection point position of the correction value of the variable of the fracture, the linear difference non-intersection point position of each data point of the correction value of the variable.

8) according to each of the sets the correction value of the deviation of the data points, all new complete work area of the fracture in the variable time offset correction;

9) in accordance with step 3) re-calculate these new way of line through constant correction and variable correction after the remaining time of the deviation of the position of the intersection point, the intersection of the fracture position of the new residual deviation if the overall residual maximum time deviation is less than 5ms, offset correction are performed, otherwise repeat steps 3)-step 8) until the meet the above-mentioned requirement;

10) after correcting output the deviation when intercalated bed bit data, after combining space correction of the fault data, usually adopt the structure diagram of the method.

Figure 1 is the homing front folds the leaning level bit interpretation of data time difference spread Figure, in the picture plane position line straight line is spread, digital in the intersection point position of said large and small time difference (in order to with), from Figure 1 it can be seen in, the line intersects line crossingpoint position there is a large time of interpolation, this is because the case against folds the leaning level bit data, the intersection point position time is not from underground with a reflection point information, at the same time as a result of seismic data processing, such as in static correction process is the reason why the deviation will produce a certain period of time;

Fig. 2 is fig. 1 after space homing shows the level bit data after the exhibition of underground reflection point wiring plane layout, the time bias layout, Figure 2 the curved line indicated in Figure 1 the line in the underground of the representative of the reflection point connection, compare Figure 1 and Figure 2 can be seen, the pile lean towards time horizon after reset the space, the new (curved line) in the intersection of the fracture position is remarkably smaller the time difference, this is because the pile lean towards when intercalated bed bit data is obtained after homing space underground reflection point of the vertical time and position, therefore these underground reflecting point formed by the connection of the new line, in the new crossingpoint its reflection time is the representative of the underground with a reflection point information, without considering processing and space homing process under the condition of error generated in, the point of intersection of the sets in these new position for a period of time should be equal, that is, deviation is zero. However space homing not pre-treatment can be eliminated because the static correction is not correct, causes the time deviation, the space homing at the same time will produce the error also, the space for the position of the bullet is not capable of completely eliminating deflection of the data.

Figure 3. Directly after the reset for the when intercalated bed bit data structure diagram, in Figure 3 it can be seen in: the space not when intercalated bed bit data of the position of the offset correction, the final imaging result will be a very large structure distortion, even if the map by manually editing the result is also very difficult to accurately describe the true shape of the underground structure.

Figure 4 is constant provided by the method according to the invention after correcting method for correcting the deviation of the layout, some lines was also a time data of "the" time integral (correction amount is positive), some other seismic data sets up the overall "pull-down" (correction amount is negative), the deviation obtained after the remaining time for the spread pattern. Compare Figure 2 and Figure 4 can be seen, after correcting after a time constant, the overall time-offset is greatly improved, the most deflection 30ms within, in particular to structure the body part the effect is very obvious.

Figure 5 is in the present invention after provision of the constant correction provided by the invention after correcting the deviation of the remaining variable spread Figure. From Figure 5 it can be seen in the the invention provides a constant and variable deflection after correcting method for correcting the deviation greatly reducing the overall, most of the fracture cheng Tuqu intersection point position of the zero deviation value, the deviation of the bullet after correcting the data can be directly used in a structure.

Figure 6 is the Patent of the invention to space homing the time after the offset correction of the bullet formed after the structure diagram of the time, comparing Figure 6 and Figure 4 can be seen: the overall structure of the two basically the same shape, but after the present invention provides the method for correcting the deviation of the process, Figure 4 in the presence of distortion structure has been eliminated, at the same time very good very good to protect the structure form of the the, and Figure 6 the overall structure more clear the form, can be very clearly reflect the underground geological structure situation, the real Image imaged by the underground geological structure consistent with the situation. It is also more further note: this Patent offers method for correcting the deviation of the, fully respecting the authenticity of the original data, it not only can effectively eliminate the late and early stage of seismic data processing to correct the time of the space caused by the deviation of the bullet, can be effectively also at the same time to protect the whole structure form.

In space homing deviation in the correction process, the space of the first time data after correcting constant correction, some line of the time data on the whole at a time, to the other data line time of some of the overall pull-down, and in the region a on the overall of the fracture and the overall pull-down magnitude is equal to the value of a, can be in this way, not only the overall time after correcting the deviation of the space reaches a minimum, at the same time effectively protect the structure form.

On the basis of the constant deviation correction, and then a fine variable correction, the correction result, what is more important is that the variation in the correction process, fully consider the cheng Tuqu of deflection in each of the distribution characteristics of the line; each line in accordance with the different deviation deviation weight distribution, to the overall deviation is greater for relatively large line of the offset correction, the smaller the overall deviation of the sets of relatively small deflection correction, to do so fully respecting the authenticity of the original data, the original protected to the greatest extent the data, help to protect the structure form.

The present invention provides the deviation calculation and correction method, is also suitable for space depth layer is after correcting the data, use of the invention to provide the deviation calculation and correction step to the space after correcting the position data processing depth layers, can be directly used for depth map structure.

The invention Patent through the space homing of the offset correction level data when intercalated bed , since data processing is eliminated and not caused by inaccurate space homing late a horizon deflection of the data, in the process of mapping the distortion of the structure, in the conventional Image-forming process of the Image-forming process of the increase in quality control, avoids the trivial after the editing of the new error, the two-dimensional seismic data structure mapping result is more has scientificalness and rationality, effectively improves the precision of the two-dimensional imaging of the seismic data and mapping effect.