CN109086324A - A kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A - Google Patents
A kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A Download PDFInfo
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Abstract
The invention discloses a kind of Oil/gas Geochemical Anomalies extracting methods for dividing shape based on S-A, comprising the following steps: A, chooses target area, grid spacing is arranged, by sample point data gridding；B, interpolation index and interpolation method are chosen, carries out interpolation calculation, and save as raster map layer R1；C, raster file is imported into figure layer, carries out Fourier transformation calculating, GEOCHEMICAL DATA is changed into frequency domain from transform of spatial domain, and save raster map layer F1；D, it is based on figure layer F1, log-log graph is generated using " energy spectral density-area " fractal model；E, according to log-log graph, fitting a straight line number, the straight line of piecewise fitting Different Slope are selected；F, two class filters are defined；G, to figure layer FF inverse Fourier transform after filtering；The present invention does not need to carry out extra-high value processing to original hydrocarbon geochemical exploration data, simplifies flow chart of data processing, has compacting variation background influence, and the function of prominent local anomaly improves complicated abnormal, weak anomaly extraction efficiency.
Description
Technical field
The present invention relates to Oil/gas Geochemical Anomalies to draw a circle to approve technical field, specially a kind of to divide the hydrocarbon geochemical exploration of shape different based on S-A
Normal extracting method.
Background technique
Hydrocarbon geochemical exploration is with geochemistry method system to detect from the media such as soil, rock, water sample, atmosphere and plant
Hydrocarbon and its accompaniment and alteration product, predict the oil-gas bearing prospect in basin, it is indicated that containing for block is evaluated in rich accumulation of oil and gas area (band)
Oil gas is a kind of cheap, efficiently direct Petroleum Exploration Methods.Oil/gas Geochemical Anomalies extraction is in geochemical to pass
Important core content, can directly affect correctly extract ore information and geochemical exploration prospecting effect.Traditional hydrocarbon geochemical exploration is different
Often evaluation mainly uses average statistical to add the method for K times of standard deviation, isoline method, iterative method, gradient method and different with extracting
Normal probability method.In recent years, and by the methods of trend surface or Kriging method, filter method and point shape commenting for Oil/gas Geochemical Anomalies is introduced
Valence.
Generally only use Normal Distribution Theory in hydrocarbon geochemical exploration and come research background and exception, i.e., background and it is abnormal be not Tongfang
The background distributions and spatial abnormal feature sample set of difference and mean value.The threshold value determined with average value standard deviation method is higher and preceding
Proposing condition is data Normal Distribution.Case figure scalping method is not necessarily to consider the distribution of initial data, can weaken the influence of special datum,
It is more reasonable to acquire threshold.Trend surface analysis protrusion weak anomaly weakens high Anomalies of Backgrounds, but in its meeting weakening part,
Intense anomaly leads to abnormal dispersion.Krieger and Spatial factor analysis etc., although effectively by the probability distribution of geochemical elements
And correlation and sample space correlation and variability comprehensively consider, but are decomposing complex background and superimposed anomaly, weak anomaly mention
Take etc. still has certain limitation.This patent divides shape mould using " energy spectral density-area " (S-A) of multi-fractal field
Type by Conversion of Spatial Data to frequency domain and can be divided by measurement self-similarity or the statistical self-similarity regularity of distribution
Solution, then then returns to spatial domain, has compacting variation background influence, and the function of prominent local anomaly has and realizes that separation is different
The effect of normal field and background mode
Summary of the invention
The purpose of the present invention is to provide one kind, to solve the problems mentioned in the above background technology.
To achieve the above object, the invention provides the following technical scheme: a kind of Oil/gas Geochemical Anomalies based on S-A points of shape mention
Take method, it is characterised in that: the following steps are included:
A, target area is chosen, grid spacing is set, by sample point data gridding；
B, interpolation index and interpolation method are chosen, carries out interpolation calculation, and save as raster map layer R1；
C, raster file is imported into figure layer, carries out Fourier transformation calculating, GEOCHEMICAL DATA is changed into frequency from transform of spatial domain
Domain, and save raster map layer F1；
D, it is based on figure layer F1, log-log graph is generated using " energy spectral density-area " fractal model, wherein horizontal axis is log
(A), the longitudinal axis is log (S)；
E, according to log-log graph, fitting a straight line number, the straight line of piecewise fitting Different Slope, different straightway generations are selected
Table it is different divide shape relationship, abscissa value corresponding to the intersection point of two straight lines can be used to determine the threshold of Fractal Filtering device
Value；
F, define two class filters, high frequency low energy spectrum density filter and the high power spectrum metric density filter of low frequency, respectively into
Row filtering processing；
G, to figure layer FF inverse Fourier transform after filtering.
Preferably, it is described according to each sampled point of step A within a grid, the sampled point in grid should not be too many, include 1
~3 point sampling points.
Preferably, described according to the anti-distance weighting interpolation of step B, anti-distance is sampled under conditions of sampled point is relatively uniform
Interpolation, interpolation.
Preferably, described according to step B Ordinary Kriging Interpolation interpolation, kriging method considers the point of observation and is estimated a little
Positional relationship, and also consider the relative positional relationship between each observation point, the kriging analysis effect in sampled point rareness
It is better than anti-distance weighting method.
Preferably, described that GEOCHEMICAL DATA is changed to from transform of spatial domain by frequency domain according to step C, and save raster map layer F1.
Preferably, the pass between the area A according to the wave number set of step D energy spectral density S and energy spectral density greater than S
System can be described with formula (1):
A(≥S)∝S-α
(1) wherein, A (>=S) indicates that energy spectral density is greater than the region area of a certain value S, and α is fractal dimension, and ∝ is expressed as just
Than.With the raising of S value, for A (>=S) always corresponding reduce, A (>=S) depends on the size of index α, formula with the rule that S changes
Sub- both sides take logarithm, generate the log-log graph of logA (>=S) and ogS, and X-axis ties up log (A), Y-axis is log (S).
Preferably, two straight lines for checking that rectilinear configuration selects adjacent slope variation bigger according to step E are handed over
The corresponding abscissa value of point, for determining the threshold value of Fractal Filtering device.
Preferably, described according to step F such as formula 2,3, GAIt is a high frequency low energy spectrum density filter, and GBIt is then low frequency
High power spectrum metric density filter, usual GAReferred to as abnormal filter, GBReferred to as background filter utilizes the two filters
And value is filtered GEOCHEMICAL DATA frequency domain figure layer F1 respectively, generates filtered figure layer FF.
Preferably, data of the hydrocarbon geochemical exploration data exception extracted according to step G in spatial domain, by oil gas
The abnormal data in spatial domain of GEOCHEMICAL DATA make isogram, extract hydrocarbon geochemical exploration exceptional value.
Compared with prior art, the beneficial effects of the present invention are:
(1) it does not need to carry out extra-high value processing to original hydrocarbon geochemical exploration data, simplifies flow chart of data processing；
(2) there is compacting variation background influence, the function of prominent local anomaly improves complicated abnormal, weak anomaly mention
Take efficiency.
Detailed description of the invention
Fig. 1 is cutting machine body construction schematic diagram of the present invention.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other
Embodiment shall fall within the protection scope of the present invention.
Referring to Fig. 1, the present invention provides a kind of technical solution: a kind of Oil/gas Geochemical Anomalies extraction side based on S-A points of shape
Method, it is characterised in that: the following steps are included:
A, target area is chosen, grid spacing is set, by sample point data gridding；
B, interpolation index and interpolation method are chosen, carries out interpolation calculation, and save as raster map layer R1；
C, raster file is imported into figure layer, carries out Fourier transformation calculating, GEOCHEMICAL DATA is changed into frequency from transform of spatial domain
Domain, and save raster map layer F1；
D, it is based on figure layer F1, log-log graph is generated using " energy spectral density-area " fractal model, wherein horizontal axis is log
(A), the longitudinal axis is log (S)；
E, according to log-log graph, fitting a straight line number, the straight line of piecewise fitting Different Slope, different straightway generations are selected
Table it is different divide shape relationship, abscissa value corresponding to the intersection point of two straight lines can be used to determine the threshold of Fractal Filtering device
Value；
F, define two class filters, high frequency low energy spectrum density filter and the high power spectrum metric density filter of low frequency, respectively into
Row filtering processing；
G, to figure layer FF inverse Fourier transform after filtering
Preferably, it is described according to each sampled point of step A within a grid, the sampled point in grid should not be too many, include 1
~3 point sampling points.
Preferably, described according to the anti-distance weighting interpolation of step B, anti-distance is sampled under conditions of sampled point is relatively uniform
Interpolation, interpolation.
Preferably, described according to step B Ordinary Kriging Interpolation interpolation, kriging method considers the point of observation and is estimated a little
Positional relationship, and also consider the relative positional relationship between each observation point, the kriging analysis effect in sampled point rareness
It is better than anti-distance weighting method.
Preferably, described that GEOCHEMICAL DATA is changed to from transform of spatial domain by frequency domain according to step C, and save raster map layer F1.
Preferably, the pass between the area A according to the wave number set of step D energy spectral density S and energy spectral density greater than S
System can be described with formula (1):
A(≥S)∝S-α
(1)
Wherein, A (>=S) indicates that energy spectral density is greater than the region area of a certain value S, and α is fractal dimension, indicates directly proportional.With
The raising of S value, A (>=S) always corresponding reduce, size of the rule that A (>=S) change with S depending on index α, formula two
While taking logarithm, the log-log graph of logA (>=S) and ogS are generated, X-axis ties up log (S), Y-axis is log (A).
Preferably, two straight lines for checking that rectilinear configuration selects adjacent slope variation bigger according to step E are handed over
The corresponding abscissa value of point, for determining the threshold value of Fractal Filtering device.
Preferably, described according to step F such as formula 2,3, GAIt is a high frequency low energy spectrum density filter, and GBIt is then low frequency
High power spectrum metric density filter, usual GAReferred to as abnormal filter, GBReferred to as background filter utilizes the two filters
And value is filtered GEOCHEMICAL DATA frequency domain figure layer F1 respectively, generates filtered figure layer FF.
Preferably, data of the hydrocarbon geochemical exploration data exception extracted according to step G in spatial domain, by oil gas
The abnormal data in spatial domain of GEOCHEMICAL DATA make isogram, extract hydrocarbon geochemical exploration exceptional value.
The beneficial effects of the present invention are:
(1) it does not need to carry out extra-high value processing to original hydrocarbon geochemical exploration data, simplifies flow chart of data processing；
Change background influence with compacting, the function of prominent local anomaly improves complicated abnormal, weak anomaly extraction effect
Rate.
It although an embodiment of the present invention has been shown and described, for the ordinary skill in the art, can be with
A variety of variations, modification, replacement can be carried out to these embodiments without departing from the principles and spirit of the present invention by understanding
And modification, the scope of the present invention is defined by the appended.
Claims (9)
1. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A, it is characterised in that: the following steps are included:
A, target area is chosen, grid spacing is set, by sample point data gridding；
B, interpolation index and interpolation method are chosen, carries out interpolation calculation, and save as raster map layer R1；
C, raster file is imported into figure layer, carries out Fourier transformation calculating, GEOCHEMICAL DATA is changed into frequency domain from transform of spatial domain, and
Save raster map layer F1；
D, it is based on figure layer F1, log-log graph is generated using " energy spectral density-area " fractal model, wherein horizontal axis is log (A), indulges
Axis is log (S)；
E, according to log-log graph, fitting a straight line number, the straight line of piecewise fitting Different Slope are selected, different straightways represents
Different divides shape relationship, and abscissa value corresponding to the intersection point of two straight lines can be used to determine the threshold value of Fractal Filtering device；
F, two class filters, high frequency low energy spectrum density filter and the high power spectrum metric density filter of low frequency are defined, is filtered respectively
Wave processing；
G, to figure layer FF inverse Fourier transform after filtering.
2. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1, it is characterised in that: institute
It states according to each sampled point of step A within a grid, the sampled point in grid should not be too many, includes 1~3 point sampling point.
3. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1, it is characterised in that: institute
It states according to the anti-distance weighting interpolation of step B, interpolation, interpolation is sampled under conditions of sampled point is relatively uniform.
4. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1, it is characterised in that: institute
It states according to step B Ordinary Kriging Interpolation interpolation, kriging method considers the point of observation and is estimated positional relationship a little, and
Consider the relative positional relationship between each observation point, kriging analysis effect is than anti-distance weighting method in sampled point rareness
It is good.
5. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1: it is characterized by: institute
It states and GEOCHEMICAL DATA is changed to from transform of spatial domain by frequency domain according to step C, and save raster map layer F1.
6. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1: it is characterized by: institute
Stating can be retouched according to the relationship between the area A of the wave number set of step D energy spectral density S and energy spectral density greater than S with formula (1)
It states:
A(≥S)∝S-α
(1)
Wherein, A (>=S) indicates that energy spectral density is greater than the region area of a certain value S, and α is fractal dimension, and ∝ indicates directly proportional.With S
The raising of value, A (>=S) is always corresponding reduce, and A (>=S) depends on the size of index α with the rule that S changes, and formula both sides take
Logarithm generates the log-log graph of logA (>=S) and ogS, and X-axis ties up log (S), Y-axis is log (A).
7. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1: it is characterized by: institute
It states and two straight lines that rectilinear configuration selects adjacent slope variation bigger, abscissa corresponding to intersection point is checked according to step E
Value, for determining the threshold value of Fractal Filtering device.
8. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1: it is characterized by: institute
It states according to step F such as formula 2,3, GAIt is a high frequency low energy spectrum density filter, and GBIt is then the high power spectrum metric density filtering of low frequency
Device, usual GAReferred to as abnormal filter, GBReferred to as background filter, using the two filters and value to GEOCHEMICAL DATA frequency
Rate domain figure layer F1 is filtered respectively, generates filtered figure layer FF.
。
9. a kind of Oil/gas Geochemical Anomalies extracting method for dividing shape based on S-A according to claim 1: it is characterized by: institute
Data of the hydrocarbon geochemical exploration data exception extracted according to step G in spatial domain are stated, by hydrocarbon geochemical exploration data exception in sky
Between data on domain make isogram, extract hydrocarbon geochemical exploration exceptional value.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110264405A (en) * | 2019-06-17 | 2019-09-20 | 深圳飞马机器人科技有限公司 | Image processing method, device, server and storage medium based on interpolation algorithm |
| CN110347969A (en) * | 2019-07-17 | 2019-10-18 | 大港油田集团有限责任公司 | A kind of soil surface relief feature fractal date based on DFT is according to generating algorithm |
| CN112348644A (en) * | 2020-11-16 | 2021-02-09 | 上海品见智能科技有限公司 | Abnormal logistics order detection method by establishing monotonous positive correlation filter screen |
| CN113407797A (en) * | 2021-08-18 | 2021-09-17 | 成都千嘉科技有限公司 | Data mining method for gas stealing behavior by utilizing fractal calculation |
| CN114841586A (en) * | 2022-05-12 | 2022-08-02 | 广州海洋地质调查局 | Oil gas scenic spot delineation method and system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101504659A (en) * | 2009-03-03 | 2009-08-12 | 成秋明 | Method for extracting geoscience spatial information based on generalized self-similarity principle |
| CN101726761A (en) * | 2008-10-15 | 2010-06-09 | 中国石油天然气股份有限公司 | Risk-constrained oil and gas resource spatial distribution forecasting method |
-
2018
- 2018-07-04 CN CN201810713214.1A patent/CN109086324B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101726761A (en) * | 2008-10-15 | 2010-06-09 | 中国石油天然气股份有限公司 | Risk-constrained oil and gas resource spatial distribution forecasting method |
| CN101504659A (en) * | 2009-03-03 | 2009-08-12 | 成秋明 | Method for extracting geoscience spatial information based on generalized self-similarity principle |
Non-Patent Citations (4)
| Title |
|---|
| 成秋明 等: "多重分形滤波方法和地球化学信息提取技术研究与进展", 《地学前缘》 * |
| 第3期: "基于反距离加权和克里格插值的S-A多重分形滤波对比研究", 《测绘科学》 * |
| 辛存林 等: "新疆喀拉尕依沙地区地球化学异常信息的提取", 《西北大学学报(自然科学版)》 * |
| 郭学飞: "基于分形理论的遥感蚀变异常提取方法研究", 《中国优秀硕士学位论文全文数据库 基础科学辑》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110264405A (en) * | 2019-06-17 | 2019-09-20 | 深圳飞马机器人科技有限公司 | Image processing method, device, server and storage medium based on interpolation algorithm |
| CN110264405B (en) * | 2019-06-17 | 2023-05-09 | 深圳飞马机器人科技有限公司 | Image processing method, device, server and storage medium based on interpolation algorithm |
| CN110347969A (en) * | 2019-07-17 | 2019-10-18 | 大港油田集团有限责任公司 | A kind of soil surface relief feature fractal date based on DFT is according to generating algorithm |
| CN112348644A (en) * | 2020-11-16 | 2021-02-09 | 上海品见智能科技有限公司 | Abnormal logistics order detection method by establishing monotonous positive correlation filter screen |
| CN112348644B (en) * | 2020-11-16 | 2024-04-02 | 上海品见智能科技有限公司 | Abnormal logistics order detection method by establishing monotonic positive correlation filter screen |
| CN113407797A (en) * | 2021-08-18 | 2021-09-17 | 成都千嘉科技有限公司 | Data mining method for gas stealing behavior by utilizing fractal calculation |
| CN113407797B (en) * | 2021-08-18 | 2021-10-29 | 成都千嘉科技有限公司 | Data mining method for gas stealing behavior by utilizing fractal calculation |
| CN114841586A (en) * | 2022-05-12 | 2022-08-02 | 广州海洋地质调查局 | Oil gas scenic spot delineation method and system |
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Effective date of registration: 20230530 Address after: 100101 Beijing city Chaoyang District Datun Road No. 11 Patentee after: Institute of Geographic Sciences and Natural Resources Research, CAS Patentee after: CHINA PETROLEUM & CHEMICAL Corp. Patentee after: CHINA PETROLEUM & CHEMICAL CORPORATION EXPLORATION & PRODUCTION Research Institute Address before: 100020 No.11, Datun Road, Chaoyang District, Beijing Patentee before: Institute of Geographic Sciences and Natural Resources Research, CAS |