CN110488353B - A fault interpretation method based on the combination of profile interaction and tectonic style guidance - Google Patents

Abstract

The invention discloses a fault interpretation method based on combination of profile interaction and construction style guidance, which comprises the following steps of: 1) performing explanatory processing on the seismic data for fault interpretation; 2) making an attribute slice for explaining the vicinity of a target layer by using a variance body and ant body technology; 3) analyzing a construction stress field and a section typical construction pattern of the work area, and establishing a construction pattern library; 4) carrying out fault interpretation on a section perpendicular to the fault based on section interaction and section gridding technology; 5) carrying out fault interpretation quality control by using a three-dimensional visualization technology; 6) after the interpretation of the single fault is finished, the established construction pattern library is used as prior information, and the combination relation between the faults on the section is restrained and guided by a classical construction pattern template; 7) repeating the steps 4) to 6) until the explanation of all fault in the whole work area is completed; 8) and establishing a fault frame model of the work area to finish fault interpretation work.

Description

A fault interpretation method based on the combination of profile interaction and tectonic style guidance

technical field

The invention relates to a seismic fault interpretation method in the middle and late stages of oil and gas field development, in particular to a three-dimensional fault interpretation method for complex fault block oil and gas fields.

Background technique

Complex fault-block oil and gas fields have developed faults in multiple stages, and the fault system is complex. After such oilfields enter the middle and late stages of development, along with the demand for remaining oil distribution prediction and well location optimization, there are more stringent requirements for the accuracy of seismic structural interpretation. In recent years, with the advancement of 3D seismic data acquisition and processing technology, the full 3D interpretation technology with the automatic interpretation of 3D space as the core has developed rapidly. The technology sets spatial seed points according to geological knowledge, and realizes the interpretation of horizons and faults and the carving of the top and bottom of sand bodies through automatic tracking. However, in practical applications, because the applicable conditions are too ideal, when the quality of the data is poor or the geological conditions are complex, the technology is not effective and lacks practicability. Under this background, the seismic tectonic interpretation has returned to the track of 2D interpretation of 3D data, explaining section by section, and then seeking the closure of horizons and faults in space. The main survey line and tie line are used as the framework, and the survey line interpretation is gradually encrypted to realize the structural interpretation. For large-scale 3D data volumes, if using the 2D interpretation method for horizon tracking, fault interpretation, and fault plane combination, there will be problems such as horizons, non-closure of faults, and unreasonable combination of fault planes, which need to be revised repeatedly, which seriously affects work efficiency. Therefore, how to effectively mine the inherent information contained in the 3D data and improve the information utilization rate and work efficiency of the 3D data is an urgent problem to be solved in the current seismic structure interpretation work.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a fault interpretation method based on the combination of profile interaction and structural style guidance, which can provide a sufficiently high interpretation accuracy when carrying out fault interpretation in complex fault block oilfields, ensure the closure of the fault space, and improve the work efficiency.

In order to achieve the above object, the present invention adopts the following technical scheme, a fault interpretation method based on the combination of profile interaction and construction style guidance, which is characterized in that it includes the following steps:

1) Perform interpretive processing on the seismic data used for fault interpretation to obtain a seismic data body that can fully highlight the fault information;

2) Using variance body and ant body technology to optimize calculation parameters, make attribute slices near the interpretation target layer, as a plane navigation map for fault interpretation;

3) Analyze the tectonic stress field and typical tectonic styles of sections in the work area, establish a tectonic style library, and use them as faults to interpret prior information and constraints;

4) Carry out fault interpretation on the section perpendicular to the fault based on the interaction of sectioning and leveling and section grid technology;

5) Use 3D visualization technology to control the quality of fault interpretation and complete the closure of fault space;

6) After completing the interpretation of a single fault, use the structural style library established in step 3) as a priori information, and use the classical structural style template in the structural style library to constrain and guide the combination relationship between the faults on the section to confirm the faults in the work area. explain style;

7) Repeat the above steps 4) to 6) until the explanation of all faults in the whole work area is completed;

8) Establish the fault frame model of the work area and complete the fault interpretation work.

Further, in the above step 1), the interpretive processing includes resolution enhancement, noise suppression, and construction-guided structure filtering.

Further, in the above-mentioned step 2), the calculation parameters include time window length, operator radius, operator shape and seismic data volume; adopt the limit trial parameter method to carry out the optimization of calculation parameters, first cut with a preset total number of samples. Divide the range of parameters that can be selected, and experimentally calculate different values of the parameters to obtain the optimal variance body, so as to determine the optimal value of the calculation parameters.

Further, in the above-mentioned step 3), the specific process of establishing the construction style library is as follows:

First, analyze the tectonic stress field of the work area, study the tectonic stress background, main tectonic action, tectonic location and tectonic pattern of the basin where the work area is located, and determine the basic structural elements and structural keywords contained in the work area; then search according to the structural keywords of the work area. , determine the structural style of the work area, and compare it with the structural characteristics of other oilfields in the adjacent block to determine the typical structural style developed in the area, and establish a fault interpretation structural style library.

Further, in the above step 4), the fault interpretation is carried out on the section perpendicular to the fault based on the interaction of sectioning and leveling and the section grid technology, and the specific process is as follows:

In the first step, based on the plane navigation map formed in the above step 2), navigate to an area that can clearly describe the fault, and explain a fault on 2 to 3 adjacent attribute slices at a predetermined time interval;

The second step is to explain the fault on the section. In the first step, the fault interpretation result on the plane is projected on the seismic section, and the fault projection points will be formed on the seismic section. Connecting the projection points will complete the fault of the fault on the section. explain;

In the third step, the section grid technology is used to predict the fault interpretation result on the section in the second step, so as to refine the fault interpretation;

The section is further extracted along the direction perpendicular to the fault strike, and the fault grid is generated according to the fault interpretation results on the second step section, and the interpolative interpretation of the further extracted section along the direction perpendicular to the fault strike is performed to refine the fault interpretation. .

Further, in the first step above, the predetermined time interval is 50-80 milliseconds.

Further, in the step 5), using three-dimensional visualization technology to perform quality control of tomographic interpretation, the specific content includes:

① Generate a cross section based on the interpretation result of the fault layer in step 4), and in the three-dimensional view, follow the strike of the fault combination formed by the interpretation result of the first step on the plane and the interpretation result of the second step on the section in step 4), Check with the naked eye whether there is an abnormal interpretation line on the section and whether the section is smooth, so as to judge whether the fault interpretation is reasonable;

②If the section is not smooth, go back to step 4), correct the fault interpretation result on the section, reinterpret the non-smooth fault line, and regenerate the section;

③ Repeat the above steps ① and ② until the fault plane is smooth, and the fault space is closed.

Further, in the above-mentioned step 6), the construction style library established in the above-mentioned step 3) is used as a priori information, with the classical construction style template constraint in the construction style library and the combined relationship between the faults on the guidance section, the specific content includes :

The first step is to fix the vertical and horizontal ratios of the section display, compare the existing main section fault combination styles in the window with the classic styles in the structural style library, and select the classic style with the highest degree of matching as the desired style;

The second step is to correct the cutting and combination relationship of the main faults on the section based on the desired style;

According to the overlapping relationship and pattern shape of the expected fault patterns, adjust the actual interpreted fault pattern to minimize the difference between the actual interpreted fault pattern and the expected pattern, and complete the implementation of the profile fault combination.

The present invention adopts the above technical scheme, which has the following advantages: the present invention makes use of variance volume and ant volume technology to interpret the seismic data used for fault interpretation to make attribute slices near the interpretation target layer, analyze the tectonic stress field of the work area and The typical structural style of the profile is established, and a structural style library is established. The structural style library is used as the fault interpretation prior information and constraints, the plane attribute slice is used for navigation, the fault gridding and 3D visualization are used as the quality control, and the fault interpretation can be realized through the interaction of sectioning and leveling. When carrying out fault interpretation in complex fault block oilfields, it provides high enough interpretation accuracy to ensure the closure of fault space and improve work efficiency.

Description of drawings

Fig. 1 is the flow chart structure schematic diagram of the present invention;

Figure 2a is the seismic data before interpretive processing during fault interpretation in an oilfield, and Figure 2b is the seismic data after interpretation processing;

Figure 3 shows the plane navigation attributes extracted from the interpretatively processed seismic data during fault interpretation in this oilfield;

Fig. 4 is a structural style library established by structural style analysis during fault interpretation in this oilfield. Fig. 4a is a large shovel normal fault, Fig. 4b is an X-type conjugate normal fault, and Fig. 4c is a semi-fancy strike-slip fault (Y-shaped fault ), Fig. 4d is a fault-step positive fault, Fig. 4e is a negative fancy strike-slip fault, and Fig. 4f is a shovel half-flower fault;

Figure 5 is a fault explained by the interaction of sectioning and leveling in the fault interpretation of the oil field, Figure 5a is the plane fault interpretation, and Figure 5b is the section fault interpretation;

Fig. 6 is the explanation of the fault by using the fault grid technology;

Figure 7 is the quality control of fault interpretation using 3D visualization technology, Figure 7a is the original fault interpretation, Figure 7b is the corrected fault interpretation, Figure 7c is the original fault plane, and Figure 7d is the corrected cross section;

Fig. 8 is the combination of faults on the section under the constraint of prior information of the structural style library, Fig. 8A is the combination of shovel normal faults + negative flower-shaped faults, Fig. 8B is the combination of fault steps + half-flowered faults, and 8C is the combination of negative flower-shaped faults +X-type conjugate fault combination, Figure 8D is a shovel-type half-flower fault + fault step combination;

Fig. 9 is the fault frame model established after the interpretation of all faults in the work area is completed.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solutions of the present invention.

As shown in FIG. 1 , the present invention provides a fault interpretation method based on the combination of sectioning and leveling interaction and construction style guidance, which includes the following steps:

1) Perform interpretive processing on the seismic data used for fault interpretation to obtain a seismic data body that can fully highlight the fault information;

Interpretive processing includes resolution enhancement, noise suppression, and structural directional filtering to improve data quality, enhance the lateral continuity of seismic reflection events, highlight fault display, and obtain seismic data volumes that can fully highlight fault information.

2) Using variance body and ant body technology to optimize calculation parameters, make attribute slices near the interpretation target layer, and use it as a plane navigation map for fault interpretation;

The generation of the plane navigation map involves many important parameters, including the length of the time window, the radius of the operator, the shape of the operator, and the seismic data volume. The optimal value of the calculation parameter is optimized by the limit trial parameter method. First, the range of parameters available for selection is divided by the preset total number of samples, and the optimal variance body is obtained by experimenting with different values of the calculation parameter, so as to determine the calculation parameter. best value.

An example is given to illustrate the limit test parameter method: the total number of samples is preset as 4, and the optimal value of the time window length is selected. /4 = 40 milliseconds as the interval, experiment the effect of the plane navigation map under the time window length of 40ms, 80ms, 120ms and 160ms respectively, and choose the time window length value corresponding to the best effect of the plane navigation map. value; and then use the above method to complete the optimization of the best values of other parameters.

3) Analyze the tectonic stress field and typical tectonic styles of sections in the work area, establish a tectonic style library, and use them as faults to interpret prior information and constraints;

First, analyze the tectonic stress field of the work area, study the tectonic stress background, main tectonic action, tectonic location and tectonic pattern of the basin where the work area is located, and determine the basic structural elements and structural keywords contained in the work area; then search according to the structural keywords of the work area. , determine the structural style of the work area, and compare it with the structural characteristics of other oilfields in the adjacent block to determine the typical structural style developed in the area, and establish a fault interpretation structural style library.

4) Carry out fault interpretation on the section perpendicular to the fault strike direction based on section-level interaction (section-plane interaction) and section grid technology; specifically:

In the first step, based on the plane navigation map formed in step 2), navigate to the area that can clearly describe the fault, and explain a fault on 2 to 3 adjacent attribute slices at a predetermined time interval, that is, the fault interpretation on the plane is formed. Result; wherein, the predetermined time interval may be 50ms～80ms;

The second step is to explain the fault on the section. In the first step, the fault interpretation result on the plane is projected on the seismic section, and the fault projection points will be formed on the seismic section. Connecting the projection points will complete the fault of the fault on the section. explain;

In the third step, the section grid technology is used to predict the fault interpretation result on the section in the second step, so as to refine the fault interpretation;

The section is further extracted along the direction perpendicular to the fault strike, and the fault grid is generated according to the fault interpretation results on the second step section, and the interpolative interpretation of the further extracted section along the direction perpendicular to the fault strike is performed to refine the fault interpretation. .

5) Use 3D visualization technology to control the quality of fault interpretation and complete the closure of fault space;

① Generate a cross section based on the interpretation result of the fault layer in step 4), and in the three-dimensional view, follow the strike of the fault combination formed by the interpretation result of the first step on the plane and the interpretation result of the second step on the section in step 4), Check with the naked eye whether there are abnormal interpretation lines on the section and whether the section is smooth, so as to judge whether the fault interpretation is reasonable.

② If the section is not smooth, go back to step 4), correct the fault interpretation result on the section, reinterpret the non-smooth fault line, and regenerate the section.

③ Repeat the above steps ① and ② until the fault plane is smooth, and the fault space is closed.

6) After completing the interpretation of a single fault, use the structural style library established in step 3) as a priori information, and use the classical structural style template in the structural style library to constrain and guide the combination relationship between the faults on the section to confirm the faults in the work area. Interpretation styles; specifically include:

The first step is to fix the vertical and horizontal ratios of the section display, compare the existing main section fault combination styles in the window with the classic styles in the structural style library, and select the classic style with the highest degree of matching as the desired style;

The second step is to correct the cutting and combination relationship of the main faults on the section based on the desired style.

According to the overlapping relationship and pattern shape of the expected fault patterns, adjust the actual interpreted fault pattern to minimize the difference between the actual interpreted fault pattern and the expected pattern, and complete the implementation of the profile fault combination.

7) Repeat the above steps 4) to 6) until the explanation of all faults in the whole work area is completed;

8) Establish the fault frame model of the work area and complete the fault interpretation work.

The present invention is described below according to specific embodiment:

Complex fault-block oil and gas fields have developed faults in multiple stages, and the fault system is complex. The degree of structural implementation directly determines the effect of oilfield development and adjustment, and is the key to the prediction of remaining oil distribution and the implementation of adjustment well design. Taking the fault interpretation of a complex fault block oilfield in the middle and late stages of development as an example, the method of the present invention is used to carry out fault interpretation, including the following steps:

S1. Perform interpretive processing such as resolution enhancement, noise suppression, and structural directional structure filtering on the seismic data used for fault interpretation in the oilfield to improve the quality of the seismic data, enhance the lateral continuity of the seismic reflection event, and highlight the fault display. Seismic data volumes capable of sufficiently highlighting fault information. The comparison of seismic data before and after interpretive processing is shown in Figure 2, wherein Figure 2a is the seismic data before interpretation processing, and Figure 2b is the seismic data after interpretation processing.

S2. Combine variance volume and ant volume technology, optimize calculation parameters, including time window length, calculation radius, operator shape, seismic data volume and other influencing factors, create attribute slices near the interpretation target layer, as a plane navigation map for fault interpretation, such as shown in Figure 3.

S3. Study the fault background of the oil field, analyze the structural style of the section, establish a structural style library, and use it as the fault interpretation prior information and constraints;

The oilfield is located in the Bohai Bay Basin. The Bohai Bay Basin is a typical Cenozoic-dominated, Mesozoic-Cenozoic superimposed rifted basin, with an early extensional superimposed late strike-slip tectonic stress field. In addition, the structure of the oilfield is located at the boundary between the Yellow River Mouth Sag and the Bonan Low Uplift, with a structural pattern of "two mountains sandwiching a deep valley". The tectonic stress background of the early extension and the late strike-slip in the Bohai Bay Basin determines that the tectonic style contained in the oilfield is composed of four normal faults (non-rotating plane, rotating plane, shovel and slope-type normal faults) and two types of normal faults. Strike-slip faults (positive flower type and negative flower type strike-slip faults) are composed of basic structural elements. On this basis, the structural keywords of "Yellow River Mouth Sag", "Bonan Low Uplift" and "Two Mountains and One Deep Valley Pattern" were investigated, and it was determined that the oilfield has 6 typical structural styles (as shown in Figure 4). , Figure 4a is a large shovel normal fault, Figure 4b is an X-type conjugate normal fault, 4c is a semi-fancy strike-slip fault (Y-shaped fault), Figure 4d is a fault-step normal fault, and Figure 4e is a negative Fancy strike-slip fault, Fig. 4f is a shovel half-flower fault.

S4. Carry out true three-dimensional fault interpretation based on the interaction between section and plane (section-level interaction).

In the first step, based on the plane navigation map obtained in step S2, navigate to the area that can clearly describe the fault, and explain a fault F1 on 2 to 3 adjacent attribute slices at a time interval of 50ms to 80ms (as shown in Figure 5a). ).

The second step is to explain F1 on the section. The fault F1 explained in the first step is projected on the seismic section, and the fault projection points will be formed on the seismic section. Connecting the projection points will complete the fault interpretation of the fault F1 on the section (such as Figure 5b);

In the third step, the section grid technology is used to predict the fault interpretation result on the section in the second step, so as to refine the fault interpretation;

The section is further extracted along the direction perpendicular to the strike direction of the fault F1, and the fault grid is generated according to the fault interpretation results on the section in the second step, and the section further extracted along the direction perpendicular to the strike direction of the fault F1 is interpolated and interpreted, so as to refine Fault interpretation (shown in Figure 6).

S5. Use 3D visualization technology to perform quality control of tomographic interpretation.

Based on the fault interpretation result in step S4, the cross section of F1 is generated, and in the three-dimensional view, along the strike of the fault combination formed by the fault interpretation result of the first step on the plane and the interpretation result of the second step on the section in step 4), With naked eye inspection, it is found that there is an abnormal interpretation line and the section is not smooth, so as to judge that the interpretation of fault F1 is unreasonable. Return to step 4), correct the F1 interpretation result on the corresponding section until the fault plane of F1 is smooth. Figure 7a shows the original fault interpretation, Figure 7b shows the corrected fault interpretation under 3D visualization technology, Figure 7c shows the original fault plane, and Figure 7d shows the corrected fault plane.

S6. After completing the explanation of F1, use the prior information of the structural style library established in step S3 to constrain the specific 6 typical structural styles in the structural style library and guide the cutting and combination relationship between the faults on the section to implement The fault interpretation style in the work area (as shown in Figure 8) roughly includes the combination of shovel normal fault + negative flower type fault shown in Figure 8A, the combination of fault step + half flower type fault shown in Figure 8B, and the combination shown in Figure 8C , the combination of negative flower-type fault + X-type conjugate fault, and the combination of shovel-type half-flower fault + fault stage shown in Fig. 8D.

S7. Repeat steps S4 to S6 until the interpretation of all faults in the entire work area of the oil field is completed.

S8. Use the explained faults to build a high-precision fault frame model of the oilfield, as shown in Figure 9, to complete the fault interpretation work.

The present invention is only described by the above-mentioned embodiment, and the structure, arrangement position and connection of each component can be changed to some extent. On the basis of the technical solutions of the present invention, any improvement or equivalent transformation of individual components according to the principles of the present invention shall not be excluded from the protection scope of the present invention.

Claims (8)

1. A fault interpretation method based on combination of profile interaction and structural style guidance is characterized by comprising the following steps:

1) performing interpretative processing on the seismic data for fault interpretation to obtain a seismic data body capable of fully highlighting fault information;

2) utilizing a variance body and ant body technology, optimizing calculation parameters, and making attribute slices near an interpretation target layer to be used as a fault interpretation plane navigation chart;

3) analyzing a construction stress field and a profile typical construction pattern of a work area, establishing a construction pattern library, and using the construction pattern library as fault interpretation prior information and constraint;

4) carrying out fault interpretation on a section perpendicular to the fault based on section interaction and section gridding technology;

5) carrying out fault interpretation quality control by using a three-dimensional visualization technology to complete fault space closure;

6) after the interpretation of the single fault is finished, the construction pattern library established in the step 3) is used as prior information, and a fault interpretation pattern in a real area is implemented by using a classic construction pattern template in the construction pattern library to constrain and guide the combination relationship between faults on the section;

7) repeating the steps 4) to 6) until the explanation of all fault in the whole work area is completed;

8) and establishing a fault frame model of the work area to finish fault interpretation work.

2. The fault interpretation method based on the combination of the profile interaction and the construction style guidance as claimed in claim 1, wherein: in step 1) above, the explanatory processes include resolution enhancement, noise suppression, and structure-guided structure filtering.

3. The fault interpretation method based on the combination of the profile interaction and the construction style guidance as claimed in claim 1, wherein: in the step 2), the calculation parameters comprise time window length, operator radius, operator shape and seismic data volume; and (3) optimizing the calculation parameters by adopting a limit trial parameter method, firstly segmenting an optional parameter range by using a preset total sample number, and obtaining an optimal variance body by experimenting different values of the calculation parameters so as to determine the optimal value of the calculation parameters.

4. The fault interpretation method based on the combination of the profile interaction and the construction style guidance as claimed in claim 1, wherein in the step 3), the specific process of establishing the construction style library is as follows:

firstly, performing structural stress field analysis on a work area, researching a structural stress background, a main structural action, a structural position and a structural pattern of a basin where the work area is located, and determining basic structural elements and structural keywords contained in the work area; and searching according to the construction key words of the work area, determining the construction style of the work area, performing analogy with the construction characteristics of other oil fields in adjacent blocks, determining the typical construction style of the work area development, and establishing a fault interpretation construction style library.

5. The method for fault interpretation based on combination of profile interaction and structural style guidance as claimed in claim 1, wherein in the step 4), fault interpretation is performed on a section perpendicular to the fault based on profile interaction and section gridding technology, and the specific process is as follows:

firstly, navigating to a region capable of clearly depicting a fault layer based on the planar navigation map formed in the step 2), and interpreting a fault on 2-3 adjacent attribute slices at preset time intervals;

secondly, the fault is explained on the section, the fault explanation result on the middle plane is projected on the seismic section in the first step, fault projection points are formed on the seismic section, and the fault explanation of the fault on the section is completed by connecting the projection points;

thirdly, performing section gridding prediction on the fault interpretation result on the section in the second step by using a section gridding technology so as to refine fault interpretation;

and further extracting the section along the direction vertical to the fault trend, generating a fault grid according to the fault interpretation result on the second-step section, and performing interpolation interpretation on the section further extracted along the direction vertical to the fault trend so as to refine the fault interpretation.

6. The fault interpretation method based on the combination of dissection and leveling interaction and construction style guidance as claimed in claim 5, wherein: in the first step, the predetermined time interval is 50-80 milliseconds.

7. The fault interpretation method based on the combination of the dissection interaction and the construction style guidance as claimed in claim 5, wherein in the step 5), the fault interpretation quality control is performed by using a three-dimensional visualization technology, and the specific content includes:

generating a section based on the fault interpretation result in the step 4), and in a three-dimensional view, detecting whether an abnormal interpretation line exists on the section and whether the section is smooth by naked eyes along the trend of a fault combination formed by the fault interpretation result in the plane in the step 4) and the interpretation result in the section in the second step, so as to judge whether the fault interpretation is reasonable;

if the section is not smooth, returning to the step 4), correcting the fault interpretation result on the section, re-interpreting the non-smooth fault line, and then generating the section;

and thirdly, repeating the steps of the first step and the second step until the fault surface is smooth, and finishing the fault space closing.

8. The fault interpretation method based on the combination of profile interaction and construction pattern guidance as claimed in claim 1, wherein in the step 6), the construction pattern library established in the step 3) is used as prior information to construct a combination relationship between classical construction pattern template constraints in the pattern library and faults on the guidance profile, and the concrete contents include:

firstly, fixing the longitudinal and transverse proportion of section display, comparing the existing main section layer combination pattern in a window with the classic pattern in a construction pattern library window by window, and preferably selecting the classic pattern with the highest matching degree as an expected pattern;

secondly, correcting the cutting and combination relation of main faults on the section based on the expected pattern;

and adjusting the actually interpreted fault pattern according to the overlapping relation and the pattern form of the expected fault pattern, so that the difference between the actually interpreted fault pattern and the expected fault pattern is minimized, and the implementation of the section fault layer combination is completed.

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