CN103278851B - State testing method buried by a kind of submarine pipeline - Google Patents

Abstract

The invention discloses a kind of submarine pipeline and bury state testing method, described method comprises: utilize the grouping voice data after Fast Fourier Transform (FFT) to make the spectrogram of subset of array; The statistic histogram of spectrum distribution is made by spectrogram; The comparison interval of setting grouping voice data, by subscript difference for histogram vectors that the grouping voice data of Δ l is corresponding subtract each other and ask its mould square, obtain difference data sequence; Obtain fitting result function by described difference data sequence and burying pipeline transition section voice data sampling number, and carry out peakvalue's checking; The statistic histogram corresponding with peak value is judged, so identify pipeline bury situation.This method shortens sense cycle, reduce detection difficulty and cost, and provide pipeline comparatively accurately and bury the criterion with naked leakage state completely, workmen can find the naked leakage of pipeline timely, avoid loss economically, meet the multiple needs in practical application.

Description

State testing method buried by a kind of submarine pipeline

Technical field

The present invention relates to pipe detection field, particularly state testing method buried by a kind of submarine pipeline.

Background technology

Along with the expansion of China's marine petroleum exploitation scale, sea-bottom oil-gas pipeline construction progresses into peak, and the major companies such as CNOOC, PetroChina Company Limited., China Petrochemical Industry have only reached hundreds of km at the submarine pipeline in Bohai Sea Gulf.Submarine pipeline is the Offshore Engineering that investment is high, have a big risk, and it plays vital effect to the production of offshore oil and gas field.The potential safety hazards such as the marine environment residing for submarine pipeline is very complicated, is subject to the effect of natural environments such as stormy waves, ocean current, storm tide, and ubiquity is exposed, unsettled.Submarine pipeline is long-term unsettled exposed, impacted by stormy waves, ocean current and very easily produces fatigue break; Meanwhile, due to the destruction of the human factors such as offshore engineering construction, fishing operation and anchorage regardless, submarine pipeline breakage event also happens occasionally.Sea-bottom oil-gas pipeline is once occur leaking, and offshore oil and gas field will be caused to stop production, and pollution of marine environment, causes ecocatas-trophe, not only rushes to repair costly, even causes offshore platform to explode, and brings huge economic loss to enterprise and country.So detecting the science of submarine pipeline state is the task of top priority, is also the most important thing of marine oil safe operation work.

The primary acoustic method of at present both at home and abroad conventional Technique of Subsea Pipeline Inspection comprises: multibeam echosounder, side sweep sonar, sub-bottom profiler, Underwater Camera, marine magnetometer etc., completes under water and the following pipeline in mud face, seabed buries situation and Routing Area submarine geology status investigation.Wherein, multibeam echosounder and other sonar of sweeping are by reaching the investigation exposure position of Aerial Submarine Pipeline and the object of flying height to the detection of the depth of water and sea-bed topography; Sub-bottom profiler can obtain high and low frequency two kinds of shallow seismic profile data, realize the buried depth to embedded pipe, the type of overlying sediments thing and the investigation of thickness, multibeam echosounding can not show the state of complete buried pipes, needs to coordinate sub-bottom profiler to determine overlying sediments thing thickness.Underwater camera machine testing submarine pipeline intuitive is strong, but visibility is very low.Whether marine magnetometer can be used for testing pipes exists, but can not the spatiality of pipelines.

Inventor is realizing in process of the present invention, finds at least to leave following shortcoming and defect in prior art:

Said method has respective deficiency, needs comprehensive utilization, Conjoint Analysis, and along with the increase of the submarine pipeline degree of depth, detection difficulty sharply rises.This will cause the problem that Detection task is complicated, difficulty is large, cost is high, the cycle is long.

Summary of the invention

The invention provides a kind of submarine pipeline and bury state testing method, this method shortens sense cycle, reduces detection difficulty and cost, described below:

State testing method buried by a kind of submarine pipeline, and described method comprises:

Utilize the grouping voice data X after Fast Fourier Transform (FFT) _lk () makes the spectrogram of subset of array; The statistic histogram of spectrum distribution is made by spectrogram;

The comparison interval of setting grouping voice data, by subscript difference for histogram vectors that the grouping voice data of Δ l is corresponding subtract each other and ask its mould square, obtain difference data sequence;

Obtain fitting result function by described difference data sequence and burying pipeline transition section voice data sampling number, and carry out peakvalue's checking;

The statistic histogram corresponding with peak value is judged, so identify pipeline bury situation.

Described utilize Fast Fourier Transform (FFT) after grouping voice data X _lk () makes the step of the spectrogram of subset of array before, described method also comprises:

Sound transducer is fixed on the optional position in in-pipeline detector, obtains ducted voice data, and by data transmission in network telephony to host computer; Fast Fourier Transform (FFT) (FFT) conversion is done to each grouping voice data, obtains X _l(k).

Wherein, the step being made the statistic histogram of spectrum distribution by spectrogram is specially:

[0, f/2] interval of spectrogram is divided into M section; For the abscissa value f in each piecewise interval _c, calculate its corresponding ordinate value add and; Acquisition statistic histogram vector.

Wherein, be specially by the step of described difference data sequence and burying pipeline transition section voice data sampling number acquisition fitting result function:

Maximal value in retrieval difference data sequence, composes maximal value as G _max, setting threshold coefficient ε, if there are continuous print data to be greater than threshold epsilon G _max, then continuous data being compiled is a subset of array.

Separately, the statistic histogram corresponding with peak value is judged, and then the step of the situation of burying of identification pipeline is specially:

1) determine corresponding statistic histogram vector H ₁, to the discrete data { h in this vector ₁, h ₂..., h _mcarry out the least square fitting of quadratic polynomial and detection peak, record peak value place abscissa value l ';

2) when a peak value detected and l ' < γ M time, γ is low frequency threshold coefficient, shows that pipeline enters complete buried state;

3) when two peak values being detected and l ₁' < γ M, l ₂' > δ M time, δ is high frequency threshold coefficient, and δ > γ, shows that pipeline enters naked state.

The beneficial effect of technical scheme provided by the invention is: relative to the outer detection method of other pipelines, the method depends on interior detection system and carries out pipeline detection.Interior detection system weight only several kilograms to tens of kilograms, cheap, compact size, sense cycle is only a few hours; This interior detection system is freely advanced in the duct under the promotion of pumped (conveying) medium, does not affect pipeline and normally transports, and has nothing to do with the submarine pipeline degree of depth and residing outside marine environment; And this method shortens sense cycle, reduce detection difficulty and cost, and provide pipeline comparatively accurately and bury the criterion with naked leakage state completely, workmen can find the naked leakage of pipeline timely, avoid loss economically, meet the multiple needs in practical application.

Accompanying drawing explanation

Fig. 1 is voice signal spectrogram;

Fig. 2 is the schematic diagram of sound spectrum integrated distribution at low frequency region;

Fig. 3 is that sound spectrum has the schematic diagram of distribution in low frequency range and high frequency region;

Fig. 4 is the process flow diagram that state testing method buried by a kind of submarine pipeline.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.

101: sound transducer is fixed on the optional position in in-pipeline detector, obtain ducted voice data, and by data transmission in network telephony to host computer;

Being operating as in detail of this step: sound transducer is fixed on the optional position in in-pipeline detector, internal detector is thrown pipe patrol and examine, voice data in measuring channel, patrol and examine complete, the voice data of internal detector record is downloaded to host computer, carries out data processing.

Wherein, the model of the embodiment of the present invention to sound transducer and in-pipeline detector does not limit, as long as can complete the device of above-mentioned functions, such as: in-pipeline detector can be cylindricality internal detector or spherical internal detector etc.

102: the voice data obtained is split in groups by host computer, obtain grouping voice data { D _j} _l;

Being operating as in detail of this step: the voice data that host computer obtains is { D _i| i=1,2,3 ... N}, N are always counting of voice data.With N ₃for step-length, voice data is divided into groups, counts less than N ₃last group cast out, obtain grouping voice data { D _j| j=0,1,2 ... N ₃-1} _l, l=1,2 ..., N N ₃, wherein symbol " " represent divide exactly.

$N_1=\frac{L}{v}f$

N ₃=αN ₁

Wherein, L is burying pipeline transition section length, can obtain from construction information, and v is the average detected speed of internal detector, and f is sound transducer sample frequency, N ₁for burying pipeline transition section voice data sampling number.α gets 0.2, suitably can change according to actual conditions, but unsuitable excessive.Such as: N gets 100, N ₃when being 6, the grouping voice data obtained is:

{D ₀,D ₁,D ₂,D ₃,D ₄,D ₅} ₁,{D ₀,D ₁,D ₂,D ₃,D ₄,D ₅} ₂,…,{D ₀,D ₁,D ₂,D ₃,D ₄,D ₅} ₁₆。

103: Fast Fourier Transform (FFT) (FFT) conversion is done to each grouping voice data, obtains X _l(k).

$X_l\left(k\right)=\mathrm{DFT}\left[{\left\{D_j\right\}}_l\right]=\underset{j=0}{\overset{N_3-1}{\mathrm{\&Sigma;}}}{D}_j{\left(W_{N_3}\right)}^{\mathrm{kj}},0\&le;k\&le;N_3-1$

$W_{N_3}=e^{-j(2\mathrm{\&pi;}/N_3)}$

Due to the difference that discrete Fourier transformation (DFT) and Fast Fourier Transform (FFT) (FFT) are only arithmetic speeds, operation result is identical, therefore replaces the result after FFT expression transformation with DFT formula.Subscript l represents and processes l subset.

104: utilize Fast Fourier Transform (FFT) X _lk () makes the spectrogram of subset of array;

This step is specially:

1) horizontal ordinate is got symbol representative rounds downwards;

2) getting corresponding ordinate is y _c=| X _l(c) |, c=k, symbol " || " represents X _lc the mould of () is long, if X _l(c)=a+bj,

Then $\left|X_l\left(c\right)\right|=\sqrt{a^2+b^2};$

3) (f _c, y _c) form a coordinate pair;

Such as: if X _l(1)=3+4j, | X _l(1) |=5, then horizontal ordinate $f_1=\frac{f}{N_3}\&CenterDot;1,$ Ordinate $y_1=\left|X_l\left(1\right)\right|=\sqrt{3^2+4^2}=5.$

105: utilize spectrogram to make the statistic histogram of spectrum distribution;

This step is specially: [0, f/2] interval of spectrogram is divided into M section (value of M can be selected according to actual conditions, and the embodiment of the present invention is described for 10); For the abscissa value f in each piecewise interval _c, calculate its corresponding ordinate value add and, i.e. h _m=∑ y _c; Obtain statistic histogram vector H _l=(h ₁, h ₂..., h _m..., h _m).

106: the comparison interval N of setting grouping voice data ₂=β N ₁, β gets 2, suitably can change according to actual conditions, then the interval of corresponding grouping voice data subscript l by subscript difference for histogram vectors that the grouping voice data of Δ l is corresponding subtract each other and ask its mould square, obtain difference data sequence { G _p;

The specific implementation process of this step is: calculate G _p=| H _{p+ Δ l}-H _p| ², p=1,2 ..., N N ₃-Δ l, such as: when grouping voice data has 16 groups, namely l maximal value is 16, when Δ l is 10,

Calculate G ₁=| H ₁₁-H ₁| ², G ₂=| H ₁₂-H ₂| ²..., G ₆=| H ₁₆-H ₆| ², difference data sequence is { G ₁, G ₂..., G ₆.

107: by difference data sequence { G _pand burying pipeline transition section voice data sampling number N ₁obtain fitting result function, and carry out peakvalue's checking;

This step is specially: retrieval difference data sequence { G _pin maximal value, maximal value is composed as G _max, setting threshold coefficient ε (value of ε can be selected according to actual conditions, and the embodiment of the present invention is described for 0.5).If there is continuous print data G _pbe greater than threshold epsilon G _max, then continuous data being compiled is a subset of array { G _p} _q, q=1,2,3 ..., be less than ε G _maxdata omit and do not consider.Namely this operation is passed through by difference data sequence { G _pdivide into some sections and be greater than threshold epsilon G _maxcontinuous data set, the value of q is by difference data sequence { G _pand threshold epsilon G _maxdetermine, being commonly referred to as continuously in the embodiment of the present invention is more than or equal to 3 data becomes continuous data.

Such as: difference data sequence is that { 0,0.5,2.3,5.1,7.9,6.4,3.2,1.1,0.9,1.5,5.8,7.6,9.3,10.0,6.2,1.6,0.8}, if maximal value G _max=10.0, then judgment threshold ε G _maxbe 5.0, difference data sequence is divided into following 2 sections of subset of array:

{G _p} ₁={5.1,7.9,6.4}，{G _p} ₂={5.8,7.6,9.3,10.0,6.2}。Separately,

Such as: difference data sequence is that { 0,0.5,2.3,5.1,4.9,6.4,3.2,1.1,0.9,1.5,5.8,7.6,9.3,10.0,6.2,1.6,0.8}, if maximal value G _max=10.0, then judgment threshold ε G _maxbe 5.0, difference data sequence is divided into following 1 section of subset of array:

{G _p} ₁={5.8,7.6,9.3,10.0,6.2}。

To difference data sequence { G _pq subset of array { G _p} _qdo the least square fitting of Gaussian function, obtain fitting result function wherein undetermined coefficient a, b, c are obtained by following Algebraic Equation set:

$f\left(x\right)=\underset{p=1}{\overset{N_q}{\mathrm{\&Sigma;}}}{({\mathrm{ae}}^{-{(x_p-b)}^2/c^2}-y_p)}^2$

$\frac{\&PartialD;f}{\&PartialD;a}=2\underset{p=1}{\overset{N_q}{\mathrm{\&Sigma;}}}({\mathrm{ae}}^{-{(x_p-b)}^2/c^2}-y_p)e^{-{(x_p-b)}^2/c^2}=0$

$\frac{\&PartialD;f}{\&PartialD;b}=2a\underset{p=1}{\overset{N_q}{\mathrm{\&Sigma;}}}({\mathrm{ae}}^{-{(x_p-b)}^2/c^2}-y_p)e^{-{(x_p-b)}^2/c^2}\&times;\frac{2(x_p-b)}{c^2}=0$

$\frac{\&PartialD;f}{\&PartialD;c}=2a\underset{p=1}{\overset{N_q}{\mathrm{\&Sigma;}}}({\mathrm{ae}}^{-{(x_p-b)}^2/c^2}-y_p)e^{-{(x_p-b)}^2/c^2}\&times;\frac{2{(x_p-b)}^2}{c^3}=0$

In formula, N _qfor the element number of subset of array, x _p=p, y _p=G _p.From the character of Gaussian function, a peak value detected at t=b place.

108: the statistic histogram corresponding with peak value is judged, so identify pipeline bury situation.

The ultimate principle that this step judges is: when pipeline is buried completely by soil, the sound that interior detection bodies is collided with pipeline is more overcast, and namely sound spectrum concentrates on the relatively low region of frequency, has a peak value in the case in the low frequency range of spectrogram; When pipeline is exposed, the sound that interior detection bodies is collided with pipeline is clearer and more melodious, and namely sound spectrum concentrates on the relatively high region of frequency, all has peak value in the case in the low frequency range of spectrogram and high frequency region.Therefore, by judging the distribution situation of sound spectrum, the buried state of pipeline can be judged, and the spectrum distribution information of sound can obtain from statistic histogram.When burying pipeline situation is constant, sound spectrum signal stabilization, difference data sequence { G _pstable and numerical value is little; When burying pipeline changed condition, sound spectrum signal changes thereupon, difference data sequence { G _pnumerical value also can increase.Therefore, in upper step, namely peak value place represents that pipeline conditions changes.See Fig. 1,1. place represents that significantly change occurs voice signal frequency spectrum, and burying pipeline situation changes; 2. place represents that sound spectrum is comparatively steady, and burying pipeline state is constant, and then this step is specially:

1) determine corresponding statistic histogram vector H ₁, to the discrete data { h in this vector ₁, h ₂..., h _mcarrying out the least square fitting of quadratic polynomial equally and detection peak, record peak value place abscissa value l ', method is as shown in step 107.

2) when a peak value detected and l ' < γ M time, γ is low frequency threshold coefficient (value of γ can be chosen flexibly according to actual conditions, and the embodiment of the present invention is described for 0.4).As shown in Figure 2, show that sound spectrum integrated distribution is at low frequency region, pipeline enters complete buried state;

3) when two peak values being detected and l ₁' < γ M, l ₂' > δ M time, δ is high frequency threshold coefficient, and δ > γ (value of δ can be chosen flexibly according to actual conditions, and the embodiment of the present invention is described for 0.6).As shown in Figure 3, show that sound spectrum has distribution in low frequency range and high frequency region, pipeline enters naked state.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (4)

1. a state testing method buried by submarine pipeline, it is characterized in that, described method comprises:

Utilize the grouping voice data X after Fast Fourier Transform (FFT) _lk () makes the spectrogram of subset of array; The statistic histogram of spectrum distribution is made by spectrogram;

The comparison interval of setting grouping voice data, by subscript difference for histogram vectors that the grouping voice data of Δ l is corresponding subtract each other and ask its mould square, obtain difference data sequence;

Obtain fitting result function by described difference data sequence and burying pipeline transition section voice data sampling number, and carry out peakvalue's checking;

The statistic histogram corresponding with peak value is judged, so identify pipeline bury situation;

Wherein, the described step by described difference data sequence and burying pipeline transition section voice data sampling number acquisition fitting result function is specially:

Maximal value in retrieval difference data sequence, composes maximal value as G _max, setting threshold coefficient ε, if there are continuous print data to be greater than threshold epsilon G _max, then continuous data being compiled is a subset of array; To difference data sequence { G _pq subset of array { G _p} _qdo the least square fitting of Gaussian function, obtain fitting result function.

2. state testing method buried by a kind of submarine pipeline according to claim 1, it is characterized in that, described utilize Fast Fourier Transform (FFT) after grouping voice data X _lk () makes the step of the spectrogram of subset of array before, described method also comprises:

Sound transducer is fixed on the optional position in in-pipeline detector, obtains ducted voice data, and by data transmission in network telephony to host computer; Fast Fourier Transform (FFT) is done to each grouping voice data, obtains X _l(k).

3. state testing method buried by a kind of submarine pipeline according to claim 1, it is characterized in that, the described step being made the statistic histogram of spectrum distribution by spectrogram is specially:

[0, f/2] interval of spectrogram is divided into M section; For the abscissa value f in each piecewise interval _c, calculate its corresponding ordinate value add and; Acquisition statistic histogram vector; Wherein, f is sound transducer sample frequency.

4. state testing method buried by a kind of submarine pipeline according to claim 1, it is characterized in that, describedly judges the statistic histogram corresponding with peak value, and then identifies that the step of situation of burying of pipeline is specially:

1) determine corresponding statistic histogram vector H _l, to the discrete data { h in this vector ₁, h ₂..., h _mcarry out the least square fitting of quadratic polynomial and detection peak, record peak value place abscissa value l '; Wherein, representative rounds downwards;

2) when a peak value detected and l ' < γ M time, γ is low frequency threshold coefficient, shows that pipeline enters complete buried state;

3) when two peak values being detected and l ₁' < γ M, l ₂' > δ M time, δ is high frequency threshold coefficient, and δ > γ, shows that pipeline enters naked state.