CN203688488U - Pipe external measurement device for water content of raw oil - Google Patents

Abstract

The utility model provides a pipe external measurement device for the water content of raw oil. The device is characterized by comprising a microprocessor, a DDS (direct digital synthesis) signal generation module, a power amplification module, an electromagnetic conductivity sensor, an amplification circuit, a filter circuit, a phase-sensitive detection circuit and an A/D (analog/digital) conversion module, wherein the microprocessor is connected with the DDS signal generation module; the DDS signal generation module is connected with the power amplification module; the power amplification module is connected with the electromagnetic conductivity sensor; the electromagnetic conductivity sensor is connected with the amplification circuit; the amplification circuit is connected with the filter circuit; the filter circuit is connected with the phase-sensitive detection circuit; the phase-sensitive detection circuit is connected with the A/D conversion module. According to a method, the measurement position is not limited, the cost is low, the safety is high, and the requirements of existing field conditions are well met.

Description

Crude oil water content pipe external pelivimetry device

Technical field:

The utility model belongs to multiphase flow measurement field, multiphase flow measurement refers to that the ratio of the potpourri of the formation to gas, solid, liquid measures, application comprises the measurement such as pulverized coal flow measurement, air quantity of fuel-burning power plant, crude oil water content in oil field, the output metering of oil, the proportioning measurements of asphalt etc., the measurement of the utility model crude oil water content relates to a kind of matching device of the measurement potpourri from the pipeline of transport potpourri

Background technology: in Petroleum Production, the detection method of crude oil water content comprises the way of distillation, the de-method of electricity, vibration tube densimeter method, radio frequency method, x-ray method, capacitance method and microwave method etc. at present.Because the measurement of crude oil water content is subject to the impact of many factors, and have complicated nonlinear relationship with its influence factor, therefore the method for various measurement crude oil water contents all has certain limitation.The way of distillation refers to that traditional timing sampling distills the manual analysis method of chemically examining and carries out the measurement of crude oil water content.Because the method can not be measured the water percentage of crude oil online in time, therefore how to detect online quickly and accurately the water percentage of crude oil, be oil field urgent problem always.Although x-ray method can adapt to larger measurement of water ratio scope, due to the feared state of mind of site operation personnel to radioelement, be difficult to promote.Microwave method principle complexity, instrument cost is higher, and operation and maintenance difficulty.Vibration tube densimeter measurement precision is higher, but is subject to the impact of the factor such as fouling, fluid gassiness.So, also do not have at present a kind of can safety and environmental protection, with low cost, the gauging instrument of accurately and reliably measuring water percentage.

For the measurement of pipeline crude oil water content, due to the closure of metallic conduit, especially the strong electromagnetic screen effect of metallic conduit, is limited by very large the application of existing most of measuring methods.To this, mainly containing at present two kinds of methods solves, a kind of is to adopt special shunt conduit, place sensor at pipe interior, the method measuring accuracy is high, can directly adopt theoretical ripe moisture content detecting method, just the place of application is restricted, and its stochastic error is larger, can not the overall water percentage of large-area representative, owing to containing many stickums in crude oil, these stickums are easy to be attached to the surface of sensor, cause very large error, and the method for placing sensor at pipe interior can only be measured at ducted some point of fixity, another kind method is to adopt the strong gamma-rays of transmittance to measure, and the method can solve the problem in above-mentioned place, but its security and cost become again topmost problem.

Utility model content

Utility model object: the utility model provides a kind of crude oil water content pipe external pelivimetry device, its objective is the problems such as solve that current measuring method exists expensive, potential safety hazard.

Technical scheme: the utility model is achieved through the following technical solutions:

A kind of crude oil water content pipe external pelivimetry device, is characterized in that: this device comprises microprocessor, DDS signal generation module, power amplifier module, electromagnetism conductivity sensor, amplifying circuit, filtering circuit, phase-sensitive detection circuit and A/D modular converter; Microprocessor connects DDS signal generation module, DDS signal generation module connects power amplifier module, power amplifier module connects electromagnetism conductivity sensor, electromagnetism conductivity sensor connects amplifying circuit, amplifying circuit connects filtering circuit, filtering circuit connects phase-sensitive detection circuit, and phase-sensitive detection circuit connects A/D modular converter.

Electromagnetism conductivity sensor is that crude oil water content pipe external pelivimetry sensor is made up of three-coil array, comprises transmitting coil, potted coil and receiving coil, and wherein potted coil is arranged between transmitting coil and receiving coil, and meets N _p=-α ³n _trelation, "-" represents transmitting coil and potted coil coiling opposite direction, α is that scale-up factor meets L _pR=α L _tR, L _tRfor the distance between transmitting coil and receiving coil, L _pRfor the distance between potted coil and receiving coil, N _tfor the number of turn of transmitting coil, N _pfor the number of turn of potted coil.

Electromagnetism conductivity sensor is placed in outside tested pipeline, adjust the position of potted coil between transmitting coil and receiving coil to obtain maximum transducer sensitivity, in the time that the useful signal on receiving coil is maximum, the position of potted coil is best, and the distance between potted coil and receiving coil is optimal distance.

Electromagnetism conductivity sensor is placed in outside tested pipeline, when parameter arranges when following: the internal diameter r of metallic conduit ₁for 0.1m, the external diameter r of metallic conduit ₂for 0.104m, metallic conduit thickness is 0.004m, the relative permeability μ of metallic conduit _rbeing 5000, is 1 with the relative permeability of the outer material of pipe in pipe, and the resistivity of the crude oil in pipeline and the potpourri of moisture is 0.01, the electricalresistivityρ of pipeline ₂for 2.00e-5, pipeline outer air electricalresistivityρ ₃for 1.00e+5.The parameter of sensor is that the diameter of sub-thread copper conductor is 0.001m, thickness of insulating layer 0.00007m, and 20 DEG C time, its resistivity is 0.284 Ω/in ³, the number of turn is 534 circles per square inch.The relative permeability of copper cash is also 1, and resistivity is 3.00e-8.The number of turn of transmitting coil is 20 circles, and the number of turn of potted coil is 10 circles, and the number of turn of receiving coil is 50 circles.The driving source optimal parameter of transmitting coil is that frequency is 39Hz, the high power low-frequency signal that electric current is 2.108A.Optimal distance under above-mentioned parameter condition between potted coil and receiving coil is 0.6m.

The crude oil water content pipe external pelivimetry method that above-mentioned crude oil water content pipe external pelivimetry device is implemented, is characterized in that: the method utilizes triple coil electromagnetism conductivity sensor to measure at tube wall outward, and the step of the method is as follows:

Transmitting coil, potted coil and receiving coil are enclosed within to the periphery of tested pipeline wall; Potted coil is placed between transmitting coil and receiving coil, makes the coiling opposite direction of potted coil and transmitting coil:

If the number of turn of transmitting coil T is N _t, the number of turn of potted coil P is N _p, the number of turn of receiving coil R is N _r, in the time using three-coil array, the induction electromotive force producing at receiving coil is:

V＝V _TR+V _PR

$V_{\mathrm{TR}}=\frac{{\mathrm{fI}}_T{S}_T{N}_T{S}_R{N}_{R}i}{L_{\mathrm{TR}}^3}[1-(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{TR}}]e^{(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{TR}}}$

$V_{\mathrm{PR}}=\frac{{\mathrm{fI}}_T{S}_P{N}_P{S}_R{N}_{R}i}{L_{\mathrm{PR}}^3}[1-(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{PR}}]e^{(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{PR}}}$

The once direct induction electromotive force producing at receiving coil is:

$V_{\mathrm{gr}}=\frac{S_T{N}_T{S}_R{N}_R}{L_{\mathrm{TR}}^3}{\mathrm{fI}}_{T}i+\frac{S_P{N}_P{S}_R{N}_R}{L_{\mathrm{PR}}^3}{\mathrm{fI}}_{T}i$

Wherein: L _tRfor the distance of transmitting coil and receiving coil;

L _pRfor the distance of potted coil and receiving coil;

F is the frequency transmitting;

I _tfor the strength of current transmitting;

N _tfor the number of turn of transmitting coil;

N _rfor the number of turn of receiving coil;

S _tfor the area of transmitting coil;

S _rfor the area of receiving coil;

S _t=S _r=π r ², r is the long-pending radius of coil section;

σ is the conductivity of wet oil;

L is the distance of transmitting coil and receiving coil;

μ is the magnetic permeability of medium

Useful signal on receiving coil is that secondary induction electromotive force is:

ΔV＝V-V _gr

This signal is transferred to microprocessor by amplifying circuit, filtering circuit, phase-sensitive detection circuit and A/D modular converter.

Advantage and effect: the utility model provides a kind of crude oil water content pipe external pelivimetry device, and it has special advantage to the measurement of crude oil water content under metallic conduit external environment condition.Major advantage shows following four aspects:

(1) non-cpntact measurement.Its measuring principle has determined that electromagnetism conductance measurement technology is and the non-cpntact measurement of crude oil, thereby can fundamentally eliminate the impact of oil water mixture on sensor itself.Owing to being non-cpntact measurement, the installation and maintenance cost of equipment will significantly reduce again.

(2) better to metallic conduit penetrability.Metallic conduit has strong shielding action to high-frequency electromagnetic signal, but the signal of electromagnetism conductivity sensor belongs to low-frequency range, can penetrating metal pipeline.

(3) the better precision of stability is higher.The measured scope of traditional crude oil water content measuring method is all the region between sensor, is that the mode of employing " fanning out from point to area " is measured substantially.But electromagnetism conductivity sensor is taking whole pipeline space as basis, what measure is interior on a large scale crude oil water content, the precision of its measurement will improve like this, be very different with other the metering system of " fanning out from point to area ", the result that uses electromagnetism conductance method to measure can represent the ratio of whole ducted former water content in oil.And by sensor through optimization after, also can measure at any time the crude oil water content flowing through in a certain region, at any time measurement result is carried out the correction of precision.

(4) cost of manufacture of electromagnetism conductivity sensor is lower.Electromagnetism conductivity sensor does not need complicated circuit design, the radiationless safety precautions that does not yet need special tectonic.

The method measuring position is not limited, and cost is low, safe, has well met the needs of current field working conditions.

Brief description of the drawings:

Fig. 1 is electromagnetism conductivity sensor theoretical analysis model;

Fig. 2 is sensor construction schematic diagram;

The electromagnetic field that Fig. 3 low frequency signal produces;

Figure 43 0Hz and 39Hz frequency comparison diagram;

Fig. 5 .1 is the measurement result figure of air dielectric;

Fig. 5 .2 is the measurement result figure of certain salinity;

Fig. 5 .3 is that crude oil water content is 8.3% measurement result figure;

Fig. 6 plot of water cut;

The structured flowchart of Fig. 7 device of the present utility model.

Embodiment: the utility model is further described below in conjunction with accompanying drawing:

As shown in Figure 7, the utility model provides a kind of crude oil water content pipe external pelivimetry device, and this device comprises microprocessor, DDS signal generation module, power amplifier module, electromagnetism conductivity sensor, amplifying circuit, filtering circuit, phase-sensitive detection circuit and A/D modular converter; Microprocessor connects DDS signal generation module, DDS signal generation module connects power amplifier module, power amplifier module connects electromagnetism conductivity sensor, electromagnetism conductivity sensor connects amplifying circuit, amplifying circuit connects filtering circuit, filtering circuit connects phase-sensitive detection circuit, and phase-sensitive detection circuit connects A/D modular converter.

As shown in Figure 2, electromagnetism conductivity sensor is made up of transmitting coil, potted coil and receiving coil, three-coil array sensor is placed in outside tested pipeline, be analyzed by the excitation frequency to different and electric current, frequency can obtain optimum magnetic field intensity in the scope interior conduit of 20Hz to 40Hz, in the time that frequency is greater than 1kHz, the magnetic field intensity of pipe interior is very faint, as shown in Figures 3 and 4.Finally determine that frequency of utilization is 39Hz, the high power low-frequency signal that electric current is 2.108A is as the driving source of transmitting coil.Adjust the position of potted coil between transmitting coil and receiving coil to obtain maximum transducer sensitivity, in the time that the useful signal on receiving coil is maximum, the position of potted coil is best, distance between potted coil and receiving coil is optimal distance, and the many factors such as number of turn of the diameter of this distance and tested pipeline, material, driving source frequency, exciting current, power, coil is relevant.When parameter arranges as follows: the internal diameter r of metallic conduit ₁for 0.1m, the external diameter r of metallic conduit ₂for 0.104m, metallic conduit thickness is 0.004m, the relative permeability μ of metallic conduit _rbeing 5000, is 1 with the relative permeability of the outer material of pipe in pipe, and the resistivity of the crude oil in pipeline and the potpourri of moisture is 0.01, the electricalresistivityρ of pipeline ₂for 2.00e-5, pipeline outer air electricalresistivityρ ₃for 1.00e+5.The parameter of sensor is that the diameter of sub-thread copper conductor is 0.001m, thickness of insulating layer 0.00007m, and 20 DEG C time, its resistivity is 0.284 Ω/in ³, the number of turn is 534 circles per square inch.The relative permeability of copper cash is also 1, and resistivity is 3.00e-8.The number of turn of transmitting coil is 20 circles, and the number of turn of potted coil is 10 circles, and the number of turn of receiving coil is 50 circles.The frequency of driving source is 39Hz, and strength of current is 2.108A.Optimal distance in the time that this arranges between potted coil and receiving coil is 0.6m, as shown in Fig. 5 .1-5.3.

Implementation method of the present utility model is to utilize triple coil to measure at tube wall outward, and the step of the method is as follows:

Transmitting coil, potted coil and receiving coil are enclosed within to the periphery of tested pipeline wall; As shown in Figure 2, between transmitting coil T and receiving coil R, add potted coil P, make the coiling opposite direction of potted coil and transmitting coil, wherein the number of turn of transmitting coil T is N _t, the number of turn of potted coil P is N _p, the number of turn of receiving coil R is N _r.If there is no potted coil, the secondary induction electromotive force that the direct induction electromotive force producing on receiving coil will produce wet oil on receiving coil covers, very unfavorable for measuring.So added potted coil P between transmitting coil and receiving coil, object is exactly the direct induction electromotive force producing on receiving coil in order to eliminate transmitting coil.

In the time using three-coil array, the induction electromotive force producing at receiving coil is:

V＝V _TR+V _PR (1)

$V_{\mathrm{TR}}=\frac{{\mathrm{fI}}_T{S}_T{N}_T{S}_R{N}_{R}i}{L_{\mathrm{TR}}^3}[1-(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{TR}}]e^{(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{TR}}}---\left(2\right)$

$V_{\mathrm{PR}}=\frac{{\mathrm{fI}}_T{S}_P{N}_P{S}_R{N}_{R}i}{L_{\mathrm{PR}}^3}[1-(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{PR}}]e^{(i-1)\sqrt{\mathrm{\πf\μ\σ}}{L}_{\mathrm{PR}}}---\left(3\right)$

The once direct induction electromotive force producing at receiving coil is:

$V_{\mathrm{gr}}=\frac{S_T{N}_T{S}_R{N}_R}{L_{\mathrm{TR}}^3}{\mathrm{fI}}_{T}i+\frac{S_P{N}_P{S}_R{N}_R}{L_{\mathrm{PR}}^3}{\mathrm{fI}}_{T}i---\left(4\right)$

Wherein: L _tRfor the distance of transmitting coil and receiving coil;

L _pRfor the distance of potted coil and receiving coil;

F is the frequency transmitting;

I _tfor the strength of current transmitting;

N _tfor the number of turn of transmitting coil;

N _rfor the number of turn of receiving coil;

S _tfor the area of transmitting coil;

S _rfor the area of receiving coil;

S _t=S _r=π r ², r is the long-pending radius of coil section;

σ is the conductivity of wet oil;

L is the distance of transmitting coil and receiving coil;

μ is the magnetic permeability of medium

Useful signal (secondary induction electromotive force) on receiving coil is:

ΔV＝V-V _gr (5)

This signal is transferred to microprocessor by amplifying circuit, filtering circuit, phase-sensitive detection circuit and A/D modular converter.

By adding potted coil, can make the garbage signal on receiving coil, directly induction electromotive force significantly reduces, relative raising the shared ratio of useful signal, very favourable to follow-up measurement.Because transmitting coil, potted coil and receiving coil are all wound on above same pipeline, so can establish: L _tR=L, L _pR=α L, wherein α is scale-up factor.:

$V_{\mathrm{gr}}=(\frac{S_T{N}_T{S}_R{N}_R}{L^3}+\frac{S_R{N}_R{S}_P{N}_P}{\mathrm{\α}{L}^3}){\mathrm{fI}}_{T}i---\left(6\right)$

Making undesired signal is 0, must have:

$\frac{S_T{N}_T{S}_R{N}_R}{L^3}+\frac{S_R{N}_R{S}_P{N}_P}{\mathrm{\α}{L}^3}=0---\left(7\right)$

Have:

N _P＝-α ³N _T (8)

Can be found out by (8) formula, want to eliminate the direct induction electromotive force that transmitting coil produces completely, between transmitting coil and potted coil, must meet the relation between formula (8)."-" wherein represents transmitting coil and potted coil coiling opposite direction.

Pass to the electric current of high power low-frequency to transmitting coil, the electromagnetic field that transmitting coil forms can part pass metallic conduit, enter the inside of metallic conduit, in negative ions in oil water mixture, form current vortex, the electromagnetic field that this current vortex forms produces secondary induction electromotive force on receiving coil, how much relevant the size of secondary induction electromotive force is with current vortex, the number of current vortex is relevant with the content of moisture in oil water mixture, so the secondary induction electromotive force on receiving coil is corresponding relevant to crude oil water content, the secondary induction electromotive force of measuring on receiving coil just can obtain crude oil water content.

In the distribution situation of low frequency magnetic field under ferromagnetic conduit environment of having utilized ANSYS emulation and the computational analysis of MATLAB data, draw using the compound system of triple coil to carry out crude oil water content while measuring, the relation that signal frequency is poor with the signal amplitude detecting.Be increased to the μ V level of multi-coil system by the nV level of two coil systems (referring to transmitting coil and receiving coil).And by actual pipeline experiment measuring the size of the secondary induction voltage water percentage from 0% to 100% receiving coil, the variable quantity of its useful signal is positioned at μ V level.In actual duct survey, total variable quantity of Δ V is for to be increased to 0.01545V from 0V.But still contain some noises in useful signal now, the Main Function that adds potted coil in two coil systems is that the signal to noise ratio (S/N ratio) of signal has significantly been improved, final useful signal shared ratio in Δ V is increased.Also can find out by actual experiment, along with increasing of former water content in oil, its useful signal Δ V also increases thereupon simultaneously, and what between crude oil water content and the rate of change of useful signal, substantially present is linear relationship, as shown in Figure 6.

The utility model is measured for crude oil water content parameter, and the wet oil of carrying for pipeline, utilizes low frequency electromagnetic conductance method from pipeline, to realize measurement, have and do not destroy pipeline, Non-Destructive Testing, infield is any, safe, feature cheaply, the method also has following features:

1., the outer sensor installation of pipe

Lead ultimate principle based on eddy current principle and electromagnetism electricity, sensor is positioned over to pipeline and has realized the measurement of water percentage outward, solved the shielding problem of metallic conduit to driving source, solved extraction and the test problems of feeble signal.The method measuring position is not limited, and cost is low, safe, is applicable to measuring height moisture, meets current field working conditions needs.

2., electric vortex method

Electromagnetism conductivity sensor to design has carried out MATLAB numerical simulation calculation, carries out quantitative test for sensor.Numerical simulation calculation has also shown that electromagnetism conductivity sensor after optimizing can be by useful signal from using the nV level of traditional electromagnetism conductivity sensor or nV level is increased to μ V level below or more than μ V level.

3., ultralow frequency electromagnetism conductance method

By ANSYS finite element software, the electromagnetism conductivity sensor after optimizing is carried out to emulation, shown that while using the electromagnetism conductivity sensor after optimizing, the sinusoidal wave optimal frequency using is 39Hz.And in electromagnetism conductivity sensor after optimization, the optimal distance between potted coil and receiving coil is 0.6m.

4., sensor construction

Based on electromagnetism electricity a kind of novel electromagnetism conductivity sensor of having led principle design, novel electromagnetism conductivity sensor is made up of three parts, is respectively transmitting coil, potted coil and receiving coil.The effect that wherein adds potted coil is to eliminate the direct induction electromotive force that transmitting coil produces on receiving coil, has improved the signal to noise ratio (S/N ratio) of useful signal on receiving coil.

5., measurement mechanism

Design whole measuring system.Comprise the design of driving source, the design of signal amplification circuit, design, the design of phase-sensitive detection circuit and the design of A/D change-over circuit of filtering circuit, and write corresponding program.By the measurement on actual metallic conduit, prove that this sensor has good detection effect.

Claims (5)

1. a crude oil water content pipe external pelivimetry device, is characterized in that: this device comprises microprocessor, DDS signal generation module, power amplifier module, electromagnetism conductivity sensor, amplifying circuit, filtering circuit, phase-sensitive detection circuit and A/D modular converter; Microprocessor connects DDS signal generation module, DDS signal generation module connects power amplifier module, power amplifier module connects electromagnetism conductivity sensor, electromagnetism conductivity sensor connects amplifying circuit, amplifying circuit connects filtering circuit, filtering circuit connects phase-sensitive detection circuit, and phase-sensitive detection circuit connects A/D modular converter.

2. crude oil water content pipe external pelivimetry device according to claim 1, it is characterized in that: electromagnetism conductivity sensor is that crude oil water content pipe external pelivimetry sensor is made up of three-coil array, comprise transmitting coil, potted coil and receiving coil, wherein potted coil is arranged between transmitting coil and receiving coil.

3. crude oil water content pipe external pelivimetry device according to claim 2, is characterized in that: transmitting coil, potted coil and receiving coil meet N _p=-α ³n _trelation, "-" represents transmitting coil and potted coil coiling opposite direction, α is that scale-up factor meets L _pR=α L _tR, L _tRfor the distance between transmitting coil and receiving coil, L _pRfor the distance between potted coil and receiving coil, N _tfor the number of turn of transmitting coil, N _pfor the number of turn of potted coil.

4. crude oil water content pipe external pelivimetry device according to claim 3, is characterized in that: electromagnetism conductivity sensor is placed in outside tested pipeline.

5. crude oil water content pipe external pelivimetry device according to claim 4, is characterized in that: electromagnetism conductivity sensor is placed in outside tested pipeline, when parameter arranges when following: the internal diameter r of metallic conduit ₁for 0.1m, the external diameter r of metallic conduit ₂for 0.104m, metallic conduit thickness is 0.004m, the relative permeability μ of metallic conduit _rbeing 5000, is 1 with the relative permeability of the outer material of pipe in pipe, and the resistivity of the crude oil in pipeline and the potpourri of moisture is 0.01, the electricalresistivityρ of pipeline ₂for 2.00e-5, pipeline outer air electricalresistivityρ ₃for 1.00e+5, the parameter of sensor is that the diameter of sub-thread copper conductor is 0.001m, thickness of insulating layer 0.00007m, and 20 DEG C time, its resistivity is 0.284 Ω/in ³, the number of turn is 534 circles per square inch, and the relative permeability of copper cash is also 1, and resistivity is 3.00e-8, and the number of turn of transmitting coil is 20 circles, and the number of turn of potted coil is 10 circles, and the number of turn of receiving coil is 50 circles; The driving source optimal parameter of transmitting coil is that frequency is 39Hz, the high power low-frequency signal that electric current is 2.108A, and the distance under above-mentioned parameter condition between potted coil and receiving coil is 0.6m.

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