CN114814941A - Method for pushing broken edge position of middle layer - Google Patents

Abstract

The present invention provides a method for shifting the position of the fault edge of an intermediate horizon, the method for shifting the position of the fault edge of the intermediate horizon includes: step 1, calculating the fault dip angle by using the position and depth of the stratigraphic fault edge of the upper and lower strata; step 2, according to the upper layer and the structural depth near the fault edge of the intermediate layer to calculate the formation thickness; step 3, shift the fault edge position of the intermediate horizon according to the fault dip angle and the formation thickness. The method of moving the position of the fault edge in the intermediate horizon solves the problem of low efficiency in accurately describing the position of the fault edge in the current geological map compilation process, and realizes the purpose of quickly and accurately depicting the fault edge position in the process of compiling oil and gas geological maps. It is clear and simple to apply, which greatly improves the accuracy of geological maps used in oil development, and has positive significance for the study of the distribution law of remaining oil in the later stage of oilfield development, the exploration of rolling exploration potential and the deployment of new wells in oilfield development.

Description

The method of shifting the position of the broken edge in the middle horizon

technical field

The invention relates to the technical field of oil and natural gas geological map compilation, in particular to a method for shifting the position of a fault edge in an intermediate horizon.

Background technique

In the late stage of oilfield development, the large structural pattern and outline have become relatively clear. The remaining oil in the reservoir is mainly controlled by the fault, and is enriched in the structural high parts along the fault line. The accuracy of the description of the fault edge position is very important for the potential exploitation of the remaining oil in the fault line. How to accurately describe the position of the fault edge and accurately describe the faults in the remaining oil-enriched areas has become the main problem to improve the accuracy of oil and gas geological maps. According to the previous work experience, the average position between the upper and lower layers is used to describe the position of the broken edge, which has low precision and cannot precisely describe the precise position of the broken edge. At present, the precise description of the fault edge position is carried out according to the following "three-step method": 1. Form a two-dimensional plane map of the seismic interpretation section through the three-dimensional seismic fault interpretation, and combine the breakpoints identified through the fine comparison and division of the strata, and use the breakpoint data and seismic Interpret the section constraint to form a section map; 2. Use the drilling well position layered data for fine layer calibration, interpret the generated sand group top structural map as the structural constraint surface, and apply the drilling depth correction of all target layers in the fault block area on this basis. , to form the top structure map of the sand group; 3. The intersection of the cross-sectional map and the top structure map of the sand group determines the precise position and shape of the fault edge plane. The above method can accurately describe the position of the fault edge on the map, but because the intersection of the cross-section map and the top structural map of the sand group needs to be done manually by geological researchers, the efficiency is low. Taking the second member of Shahejie Formation in the Xin109 fault block in Dongxin Oilfield as an example, the second member of the Shahejie Formation in the Xin109 fault block can be subdivided into 124 sub-layers of 18 sand layers, including Sha21- Sha2wen4, with 4 extending about 6000. It takes about 20 minutes to determine the position of a faulted edge by using the "three-step method" fault intersection. If all 124 small layers use the "three-step method" to accurately describe the position of the broken edge, it will take about 124*4*20=9920 minutes, which is very time-consuming and labor-intensive, and the efficiency is low. Therefore, it is necessary to adopt a new method to quickly and accurately characterize the position of broken edges, so as to improve the work efficiency of geological map compilation.

In the Chinese patent application with the application number: CN201410642991.3, it relates to a method for predicting the space homing of vertical well inclination in a complex fault block oil reservoir. The method for predicting the space homing of vertical well inclination in a complex fault block oil reservoir includes: Step 1, Through fine stratigraphic correlation, rationally divide and compare oil-bearing sublayers, and reasonably judge the oil-water relationship; step 2, carry out fine structural interpretation, compile top structural map and fault phylogenetic map, and judge whether there are abnormal fault shapes and structural trends. Well deviation problem; Step 3, use stratigraphic comparison results and seismic interpretation results to compile geological research maps; and Step 4, according to the found drilling vertical well deviation problem, propose a reasonable vertical well deviation spatial homing prediction method.

In the Chinese patent application with the application number: CN201410207293.0, it relates to a method for obtaining the true thickness of the Lower Paleozoic oblique strata, and the method for obtaining the true thickness of the Lower Paleozoic oblique strata includes: Step 1: Perform fine horizon interpretation of the reflection layer; step 2, on the basis of the fine interpretation of the standard reflection layer, perform depth conversion on the time horizon data, and make a plane contour map; step 3, calculate the parameters of formation thickness; and step 4, Calculate the true thickness of the formation.

In the Chinese patent application with the application number: CN201910427517.1, it relates to a method and device for determining the true thickness of the stratum in the stratum inclination area. According to the exploratory well data, the vertical direction apparent thickness of the destination layer encountered by the exploratory well is obtained; according to the seismic horizon data acquisition The strike direction of the destination layer; the stratigraphic dip angle of the destination layer is obtained according to the seismic horizon data and the strike direction; the real thickness of the destination layer is determined according to the vertical apparent thickness and the stratigraphic dip angle.

The above prior art is quite different from the present invention, and fails to solve the technical problem we want to solve. Therefore, we have invented a new method for shifting the position of the fracture edge of the intermediate layer.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for shifting the position of the middle layer by using the upper and lower layers to move the fractured edge in the process of drawing the fractured edge.

The object of the present invention can be realized by the following technical measures: the method for moving the position of the fault edge of the intermediate horizon, the method for moving the fault edge position of the intermediate horizon includes: Step 1, using the position and depth of the stratigraphic fault edge of the upper and lower strata to calculate the fault dip angle; step 2, calculate the stratum thickness according to the structural depth near the fault edge of the upper layer and the middle layer; step 3, shift the fault edge position of the intermediate horizon according to the fault dip angle and the stratum thickness.

The object of the present invention can also be realized through the following technical measures:

In step 1, the positions of the stratigraphic fault edges of the upper and lower strata are determined according to the structural interpretation, stratigraphic comparison results and the analysis results of drilling and drilling encounters in the basic petroleum geological research process.

In step 1, on this basis, put the position of the broken edge of the upper and lower layers into a drawing, and calculate the distance difference between the broken edges of the upper and lower layers by measuring or drawing software, which is recorded as ab; and then according to the upper layer system The depth of the fault edge of the lower layer is subtracted from the depth of the fault edge of the lower layer, and the difference of the fault edge depth of the upper and lower layers is calculated, which is recorded as AB; then the fault dip angle α is calculated by the trigonometric function method, and the fault dip angle α is the angle between the fault and the stratum.

In step 1, the formula for calculating the fault dip angle α is:

α=arctan(AB/ab)

In the formula: α is the fault dip angle, AB is the depth difference of the fault edge of the upper and lower strata, and ab is the position difference of the fault edge of the upper and lower strata. According to this formula, the direct fault dip angle of the upper and lower strata is calculated.

In step 2, the structural depth near the upper stratum fault ridge is first determined by counting the stratum depths drilled by adjacent wells near the upper strata fault ridge.

In step 2, the stratum depths drilled by adjacent wells near the fault edge of the middle strata are counted to determine the structural depth near the fault edge of the upper strata.

In step 2, finally subtract the structural depth near the fault edge of the upper layer and the structural depth near the fault edge of the middle layer to calculate the depth difference between the fault edge of the upper layer and the middle layer, and this depth difference is the difference between the upper layer and the middle layer. The formation thickness of the system, denoted as AC.

In step 3, according to the fault dip angle α calculated in step 1 and the formation thickness AC of the upper and middle strata in step 2, the distance difference between the upper and middle strata can be derived by using trigonometric functions, which is recorded as ac.

In step 3, the calculation formula of the depth difference ac between the upper layer and the middle layer is:

ac=AC*tanα

where α is the dip angle of the fault, ac is the depth difference between the upper and middle strata, and AC is the stratum thickness of the upper and middle strata.

In step 3, according to the distance difference between the upper layer and the middle layer, the position of the broken edge of the middle layer is determined by manual measurement or by drawing software calculation.

The method for shifting the position of the fault edge in the middle horizon in the present invention solves the problem of low efficiency of finely describing the position of the fault edge in the current geological map compilation process, and realizes the rapid and accurate description of the fault edge position in the process of compiling the oil and natural gas geological map. the goal of. The invention has clear thinking and simple application, and provides a feasible method for quickly and accurately characterizing the position of broken edges in the process of compiling oil and natural gas geological maps. It fills the technical gap of high-speed, high-efficiency and precise description of the position of broken edges in the process of compiling geological maps by petroleum geologists. It greatly improves the accuracy of geological maps used in oil development, and has positive significance for the study of the distribution law of remaining oil in the later stage of oilfield development, the exploration of rolling exploration potential and the deployment of new wells in oilfield development.

Description of drawings

Fig. 1 is a flow chart of a specific embodiment of the method for shifting the position of the fracture edge of the intermediate horizon of the present invention;

2 is a schematic diagram of the principle of calculating the dip angle of a fault by utilizing the position and depth of the fault edge of the upper and lower layers in the present invention;

3 is a schematic diagram of the principle of calculating formation thickness according to the structural depth near the fault edge of the upper layer and the middle layer in the present invention;

4 is a schematic diagram of the principle of shifting the position of the fault edge in the middle horizon according to the fault dip angle and the formation thickness in the present invention;

Fig. 5 is a schematic diagram of the position and depth of the fault edges of the Sha Er 1 (1) and Sha Er 2 (1) sublayers in the Xin 109 fault block of Dongxin Oilfield in accordance with a specific embodiment of the present invention;

6 is a schematic diagram of the position of the fault edge of the middle layer Sha Er 1 (5+6) sub-layer according to the fault dip angle and formation thickness of the Xin 109 fault block in Dongxin Oilfield according to a specific embodiment of the present invention;

7 is a schematic diagram showing the positions of the fault edges of the middle layer Sha Er 2, Sha Er 3, Sha Er 4 and Sha Er 5 according to the fault dip angle and formation thickness of Xin 1 fault block in Dongxin Oilfield according to a specific embodiment of the present invention;

FIG. 8 is a schematic diagram of the position of the fault edge position of the middle layer Sha Er 6 moving according to the fault dip angle and formation thickness of the Xin 15 fault block of Dongxin Oilfield according to a specific embodiment of the present invention.

Detailed ways

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, and/or combinations thereof.

As shown in FIG. 1 , FIG. 1 is a flow chart of the method for shifting the position of the fractured edge of the intermediate horizon according to the present invention.

Step 101, calculating the dip angle of the fault by using the position and depth of the stratigraphic fault edge of the upper and lower strata;

According to the structural interpretation, stratigraphic comparison results and drilling encounter analysis results in the process of basic petroleum geological research, the positions of the stratigraphic fault edges of the upper and lower strata are determined; on this basis, as shown in Fig. Put it in a drawing, calculate the distance difference between the upper and lower layers of the broken edge by measuring or drawing software, and record it as ab; then subtract the depth of the broken edge of the upper layer and the depth of the lower layer to calculate the upper and lower layers. The depth difference of the fault edge of the stratum is recorded as AB; then the fault dip angle α is calculated by the trigonometric function method, and the fault dip angle α is the angle between the fault and the stratum, and the calculation formula is:

α=arctan(AB/ab)

In the formula: α is the dip angle of the fault, AB is the depth difference between the upper and lower strata, and ab is the position difference between the upper and lower strata. According to this formula, the direct fault dip angle of the upper and lower strata is calculated.

Step 102: Calculate the formation thickness according to the structural depth near the fault edge of the upper layer and the middle layer;

In order to push out the position of the fault edge of the middle strata, as shown in Fig. 3, firstly, by counting the stratum depths drilled by adjacent wells near the fault edge of the upper strata, the structural depth near the fault edge of the upper strata is determined; The stratum depth near the fault edge of the stratum series encountered by adjacent wells is used to determine the structural depth near the fault edge of the upper strata; the structural depth near the fault edge of the upper strata is subtracted from the structural depth near the fault edge of the middle strata to calculate The depth difference between the upper layer and the middle layer is the depth difference between the upper layer and the middle layer. This depth difference is the thickness of the upper layer and the middle layer, which is recorded as AC.

Step 103 , shifting the position of the fault edge of the intermediate horizon according to the fault dip angle and the formation thickness.

As shown in Fig. 4, according to the fault dip angle α calculated in step 1 and the formation thickness AC of the upper and middle strata in step 2, the distance difference between the upper and middle strata can be derived by using trigonometric functions, which is denoted as ac , the calculation formula is:

ac=AC*tanα

where α is the dip angle of the fault, ac is the depth difference between the upper and middle strata, and AC is the stratum thickness of the upper and middle strata.

By knowing the distance difference between the upper layer and the middle layer, the position of the broken edge of the middle layer can be determined by manual measurement or by drawing software, so as to achieve the purpose of high-speed, high-efficiency and precise description of the position of the middle layer.

Example 1:

In a specific embodiment 1 of the application of the present invention, the following steps are included:

In step 1, the fault dip angle is calculated using the position and depth of the stratigraphic fault edge of the upper and lower strata.

In the Xin 109 fault block in Dongxin Oilfield, the fault edge positions of the Sha Er 1(1) and Sha Er 2(1) sublayers have been accurately determined through fine structural interpretation and drilling data analysis. However, the position of the broken edge in the middle position cannot be accurately determined.

As shown in Figure 5, put Sha Er 1 (1) and Sha Er 2 (1) small layer fractured edges in one drawing at the same time, measure Sha Er 1 (1) and Sha Er 2 (1) The distance difference between the fault edges of the layers is 50 meters; the depth difference between the Sha 2 1 (1) and the Sha 2 2 (1) sublayers is calculated through the calculation: The depth of the faulted edge of the group is -1950 meters, and the depth of the faulted edge is 45 meters. According to the distance difference and depth difference between the fault edges of Sha Er 1 (1) and Sha Er 2 (1), the fault dip angle α is calculated by trigonometric functions. α=arctan(45/50)=42.0°. The flow goes to step 2.

In step 2, the formation thickness is calculated according to the structural depth near the fault edge of the upper layer and the middle layer.

The stratigraphic thickness was calculated by statistic data on the neighbors' depths near the fault edge of the upper Sha 2 1(1) and the middle Sha 2 1(5+6).

As shown in Table 1, according to the statistical analysis of the depth data of 4 adjacent wells near the fault, the structural depth near the fault edge of the Sha Er 1(1) sublayer is -1931 meters; The structural depth near the edge is -1954 meters, and the difference between the structural depths is the formation thickness. The calculated formation thickness is: 1954-1931=23 meters. The flow goes to step 3.

Table 1 Depth statistics of Sha Er 1(1) and Sha Er 1(5+6) sublayers in the adjacent wells of Xin 109 fault block

In step 3, the position of the fault edge of the intermediate horizon is shifted according to the fault dip angle and the formation thickness.

As shown in FIG. 6 , according to the fault dip angle α of the Sha Er 1(1)-Sha 2(1) sub-layer in step 101 and the formation thickness of the Sha 2 1(1)-Sha 2(1) sub-layer in step 102, Calculate the distance difference between the fault edges and push out the fault edge position of the middle layer Sha Er 1(5+6): the fault dip angle α is 42.0°, the formation thickness is 25 meters, and the fault edge distance difference: formation thickness*tanα=23*tan42. 0 = 20.7 meters. The exact position of the broken edge of sand 2 1(5+6) in the middle layer is obtained by automatic calculation of the map-editing software. Process ends.

Example 2:

In the specific embodiment 2 of the application of the present invention, in the Xin 1 fault block of Dongxin Oilfield, because the Xin 1 fault block has a relatively simple structure, there is only one boundary fault, and through the analysis of seismic data and drilling data, the fault dip angle is relatively consistent, According to this method, it is only necessary to determine the position of the top and bottom two horizons of fault edges in the whole area to accurately describe the fault edge positions of all the horizons in the middle. As shown in Fig. 7, firstly, through structural interpretation and drilling data analysis, the two sand layers of Sha 2 1 on the top surface and Sha 2 6 on the bottom surface were finely described, and the distance difference between the plane faults and the vertical faults was calculated. Then, the fault dip angle is calculated; secondly, the stratigraphic thickness of the four sand layers in the middle layer, such as Sha'er 2, Sha'er 3, Sha'er 4, and Sha'er 5, is calculated based on the structural depth of the adjacent well of the fault edge. Finally, according to the fault dip angle and The stratum thickness is calculated to calculate the distance difference between the fault edge of the four sand layers in the middle Sha 2, Sha 3, Sha 4, and Sha 5 and the top Sha 2 1, so that the middle Sha 2, 2 and 2 can be pushed out quickly and accurately. The exact positions of the fault edges of the 4 sand layers, including Sha 2 3, Sha 2 4, and Sha 2 5.

Example 3:

In the specific embodiment 3 of the application of the present invention, in the complex fault block Xin 15 in Dongxin Oilfield, because the Xin 15 fault block is located in the structural fault transition zone, the structure is extremely complex, and a single well may be different from multiple The faults are adjacent, and according to this method, the position of multiple broken edges can be shifted in the middle layer at the same time to determine the precise position of the broken edges. As shown in Fig. 8, Well Xin 15-1 is adjacent to the NW-trending F1 fault and the NEE-trending F2 fault, and it is necessary to finely describe the fault edge positions of the two faults F1 and F2 in the Shaer 7 sand formation. First, through structural interpretation and drilling data analysis, the two sand layers of Sha 2 6 on the top surface and Sha 2 8 on the bottom surface are finely described, and the specific positions of faults F1 and F2 on the fault edges of Sha 2 6 and Sha 2 8 are determined, respectively. The distance difference between the F1 and F2 faults on the plane and the depth difference between the faults in the vertical direction are obtained, so as to calculate the dip angle of the F1 fault and the F2 fault respectively; secondly, the stratigraphic thickness of the middle layer Sha 2 7 is calculated by the structural depth of Well Xin 15-1. Finally, according to the fault dip angle and formation thickness, the distance difference between the fault edge of the F1 and F2 faults in the middle Sha 2 7 sand group and the top Sha 2 6 is calculated respectively, so that the middle Sha 2 7 sand group can be pushed out quickly and accurately. The exact location of the fracture edges of the F1 and F2 faults.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features therein. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Except for the technical features described in the specification, they are all known technologies by those skilled in the art.

Claims (10)

1. the method for pushing the position of the broken edge of the middle horizon, it is characterized in that, the method of this pushing the position of the broken edge of the middle horizon comprises: Step 1: Calculate the dip angle of the fault by using the position and depth of the stratigraphic fault edge of the upper and lower strata; Step 2: Calculate the formation thickness according to the structural depth near the fault edge of the upper layer and the middle layer; Step 3, according to the fault dip angle and the stratum thickness, the position of the fault edge of the intermediate horizon is shifted. 2. the method for moving intermediate horizon fault edge position according to claim 1, is characterized in that, in step 1, according to structural interpretation in basic petroleum geological research process, stratigraphic comparison result and drilling encounter analysis result determine upper layer The position of stratigraphic fault edges of the system and the lower system. 3. The method for shifting the position of the broken edge of the middle layer according to claim 2, it is characterized in that, in step 1, on this basis, the position of the upper and lower layers of the broken edge is placed in a drawing, and the amount of Take or draw the software to calculate the distance difference between the upper and lower layers of the broken edge, denoted as ab; and then subtract the depth of the upper and lower layers of the broken edge according to the depth of the broken edge of the lower layer to calculate the depth difference between the upper and lower layers, denoted as AB ; Then, the fault dip angle α is calculated by the trigonometric function method, and the fault dip angle α is the angle between the fault and the formation. 4. The method for shifting the position of the fault edge of the intermediate horizon according to claim 3, wherein in step 1, the formula for calculating the fault dip angle α is: α=arctan(AB/ab) In the formula: α is the fault dip angle, AB is the depth difference of the fault edge of the upper and lower strata, and ab is the position difference of the fault edge of the upper and lower strata. According to this formula, the direct fault dip angle of the upper and lower strata is calculated. 5. The method for shifting the position of the fault edge of the intermediate horizon according to claim 1, it is characterized in that, in step 2, first by counting the stratum depths drilled by adjacent wells near the fault edge of the upper horizon, to determine the upper horizon Structural depth near the fault edge. 6. The method for shifting the position of the fault edge of the intermediate horizon according to claim 5, wherein in step 2, the stratum depths drilled by adjacent wells near the fault edge of the intermediate horizon are counted to determine the upper horizon Structural depth near the fault edge. 7. The method for shifting the position of an intermediate layer fault edge according to claim 6, characterized in that, in step 2, the structure depth near the upper layer system fault edge and the structure depth near the intermediate layer system fault edge are finally subtracted, Calculate the depth difference between the upper layer and the middle layer. This depth difference is the stratum thickness between the upper layer and the middle layer. 8. The method according to claim 1, characterized in that, in step 3, according to the fault dip angle α calculated in step 1 and the stratum thickness of upper and middle layers in step 2 AC, the distance difference between the upper layer and the middle layer can be obtained by using the trigonometric function, which is recorded as ac. 9. the method for moving the position of the broken edge of the middle layer according to claim 8, is characterized in that, in step 3, the calculation formula of the depth difference ac of the broken edge of the upper layer system and the middle layer system is: ac=AC*tanα where α is the dip angle of the fault, ac is the depth difference between the upper and middle strata, and AC is the stratum thickness of the upper and middle strata. 10. The method for shifting the position of the broken edge of the intermediate horizon according to claim 8, wherein in step 3, according to the distance difference between the upper horizon and the intermediate horizon, the intermediate horizon is determined by manual measurement or by drawing software calculation. the fracture edge position.

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