CN106761699A - A kind of leakage real-time detecting system for controlled pressure drilling - Google Patents

Abstract

Collect pretreatment module, signal intelligent discrimination module and drop ply and indicate and warning module the present invention relates to a kind of leakage real-time detecting system for controlled pressure drilling, including signal, it is characterised in that：The signal collects pretreatment module includes flow sensor, preamplifier a, shaping amplifier, converter a, standpipe pressure sensor, preamplifier b, bandpass filter, converter b, the signal intelligent discrimination module includes single-chip microcomputer, and the drop ply indicates to include power amplifier, sound and light signal device and computer with warning module.System of the invention can be monitored in controlled pressure drilling work progress automatically at the scene, fast reaction, timely early warning leakage real-time condition, and Well leakage position can be accurately shown, the accident treatment time is saved as much as possible, for live drilling engineer provides valuable down-hole information, the economic loss that the complex situations such as leakage are brought is reduced to greatest extent.

Description

A kind of leakage real-time detecting system for controlled pressure drilling

Technical field

The present invention relates to petroleum gas field, a kind of system and method for real-time monitoring leakage in controlled pressure drilling, Automatic alarm when realizing leakage, and predict the purpose of leakage layer position.

Background technology

Leakage is a kind of drilling fluid leakage in drilling process to the phenomenon in stratum.On the one hand it be in drilling process often One of down hole problem seen, while being also presence but also insoluble technical problem for a long time in drilling process.In drilling well Scene, the generation of leakage can waste substantial amounts of effective drilling time, even result in well and scrap, and cause huge economic loss.

Leakage not only needs timely early warning, fast reaction, in addition it is also necessary to carry out plugging operations once occurring.Although current Leakage stopping technology constantly develops and improves, but plugging operations still suffer from risk higher, there is larger probability of failure.Study carefully Its reason, mainly leakage determining layer be inaccurate etc., and factor causes.Therefore, it is necessary to invent one kind can real-time monitoring, in time It was found that leakage and early warning, additionally it is possible to be accurately judged to the leakage monitoring system and method for specific leakage layer position, be that situ of drilling well is carried For supporting.

Now widely used method is that hydrodynamics is surveyed and downhole instrument method of testing.The certainty of measurement of hydrodynamics method Influenceed by many kinds of parameters such as hole diameter, drilling tool, mud flow rates, there is certain error, it is as a result inaccurate, can only determine one compared with Big scope.Instrument test method is presently mainly to be measured using the various physical characteristics of borehole fluid, such as flow velocity, temperature Deng.This kind of measuring method is relatively accurate, but measurement well section is long, and time-consuming, and efficiency is low, and different geology are easily received in single method application The limitation of condition.Current drop ply position e measurement technology lacks ground and the comprehensive of underground method, systematization research and application, Lack the integral method that multiple technologies are mutually combined, are complementary to one another.

Such as the Chinese patent of Application No. CN201520899414.2, there is provided a kind of well kick leakage monitoring device, it is related to Drilling parameter detection technique field, including data acquisition device, change-over circuit and data processor, the data acquisition device bag Include the drilling fluid inlet flow rate sensor on suction line, the drilling fluid outlet stream on drilling fluid outlet pipeline Quantity sensor and drilling parameter measuring instrument, drilling fluid inlet flow rate sensor and drilling fluids outlet flow sensor with change-over circuit phase Even, change-over circuit and drilling parameter measuring instrument are connected with data processor.The patent drains the pond to get all the fish brill drilling fluid gateway flow The information such as well depth, weight on hook, the standpipe pressure that well Parameters Instrument is provided are combined and carry out comprehensive descision, although can be in drilling process The situation of middle forecast overflow leakage, but presence cannot be accurately judged to the defect of specific leakage layer position.For another example Application No. 201410501685.8 Chinese patent, there is provided a kind of overflow and leakage monitoring system and its monitoring method, including monitoring tank, Liquid level gauge, regulating valve, stop valve, pump rush sensor, grouting pump, drilling fluid pot and Monitoring and Controlling warning device.Monitoring tank passes through Dividing plate is divided into major and minor chamber, and sets liquid level gauge and the different mouths of pipe and wellhead assembly, grouting pump, drilling fluid pot thereon Connection is set up, liquid level gauge, pump rush sensor and regulating valve are connected with Monitoring and Controlling warning device, control to adjust the switch of valve, fill The start and stop of stock pump simultaneously leak into row real-time monitoring and early warning to overflow well.The invention passes through during circulation of drilling fluid in pit shaft The speed of liquid level pace of change in secondary cavity, by judging that the situation of change that outflow is returned in pit shaft predicts overflow and leakage, receives Pit shaft liquid level and the very sectional area influence of monitoring tank are larger during making a trip, and complex operation, accuracy is relatively low, and can not accurately sentence Break and specific leakage layer position.

The content of the invention

The technical problem to be solved in the present invention is directed to the bottleneck of prior art presence, there is provided a kind of controlled pressure drilling at the scene Can be monitored automatically in work progress, fast reaction, the leakage real-time monitoring system of timely early warning and method, save as much as possible The accident treatment time, for live drilling engineer provides valuable down-hole information, the complex situations such as leakage is reduced to greatest extent The economic loss brought.

To achieve the above object, the present invention uses following technical scheme：

A kind of leakage real-time detecting system for controlled pressure drilling, including signal is collected pretreatment module, signal intelligent and is sentenced Other module and drop ply are indicated and warning module, the signal collect pretreatment module include flow sensor, preamplifier a, Shaping amplifier, converter a, standpipe pressure sensor, preamplifier b, bandpass filter, converter b, the signal Intelligent distinguishing module includes single-chip microcomputer, and the drop ply indicates to include power amplifier, sound and light signal device and electricity with warning module Brain.

Preferably, the signal collection pretreatment module is divided into two branch roads, branch road one, and flow sensor is arranged on and bores Well liquid returns out pipeline, and is connected with preamplifier a, and preamplifier a is connected with shaping amplifier, and shaping amplifier turns with AD Parallel operation a is connected；Branch road two, standpipe pressure sensor is arranged at standpipe, is connected with preamplifier b, preamplifier b and band Bandpass filter is connected, and bandpass filter is connected with converter b.

Any of the above-described scheme is preferably, and the converter a and converter b passes through input port and single-chip microcomputer respectively Connection.

Any of the above-described scheme is preferably, and a branch of the single-chip microcomputer output mouthful is connected with computer, exports drop ply meter Result and instant playback are calculated, another branch is connected with power amplifier, after power amplifier is by signal enhancing, is transferred to acousto-optic Recoil simulator sends leakage early warning.

Any of the above-described scheme is preferably, and the flow sensor includes that turbine flow transducer, restrictive flow are sensed Device, rotor flow sensor, ultrasonic flow sensor, for measuring drilling fluid return flow, produce flow signal.

Any of the above-described scheme is preferably, and the preamplifier a is used to receive flow monitoring signals and carry out gain to put Greatly.

Any of the above-described scheme is preferably, and the shaping amplifier is used to carry out flow signal shaping pretreatment, and will Signal waveform is further amplified.

Any of the above-described scheme is preferably, and the analog signal of flow signal can be converted to numeral by the converter a Signal.

Any of the above-described scheme is preferably, the standpipe pressure sensor can with real-time monitoring standpipe pressure situation of change, Produce standpipe pressure signal.

Any of the above-described scheme is preferably, and pressure signal can be carried out gain amplification by the preamplifier b, improve letter External interference is made an uproar than and reduced, then sends bandpass filter to.

Any of the above-described scheme is preferably, and the bandpass filter can be filtered pretreatment, noise reduction to pressure signal Signal afterwards is further transmitted to converter b.

Any of the above-described scheme is preferably, and the analog signal of pressure signal can be converted into data signal by converter b.

Any of the above-described scheme is preferably, and the single-chip microcomputer can be processed data signal, writes MCU programs to well Leakage signal carries out intelligence computation with analysis.

Any of the above-described scheme is preferably, and under normal circumstances, the single-chip microcomputer is carried out to flow signal and pressure signal Real-time monitoring is simultaneously recorded, in storing data in computer；In the case of generation leakage, flow is significantly reduced, and the single-chip microcomputer sends Early warning signal, after amplifying by power amplifier, passes to sound and light signal device, sends alarm, meanwhile, single-chip microcomputer is to record Flow signal and pressure signal be analyzed, extract and the characteristic point of leakage occur in two kinds of signals, according to two characteristic points The corresponding moment asks for the time difference, finally provides leakage depth according to leakage layer position prediction model, and show immediately by computer Show.

Any of the above-described scheme is preferably, described pressure signal and flow signal, the data type bag of its store files Include time point, pressure value, flow value.

A kind of leakage layer position prediction model, including fluid in annular space on return Time Calculation, standpipe pressure response time Calculate, drop ply position is calculated.

1) fluid in annular space on return the time

Leakage front entrance and rate of discharge are Q, and rate of discharge is reduced to Q after leakage₁, mineshaft annulus sectional area is A, ring Empty upward velocity meets：

Fluid in the annular space on return the time and be：

Wherein, h is the well depth of drop ply position；

2) the standpipe pressure response time

Once occurring, the pressure reduction in shaft bottom ultimately results in standpipe pressure decline, it is assumed that pressure drop is in annular space and brill to leakage Respectively with v in bar_p1And v_p2Speed propagate, then after leakage standpipe pressure response time meet：

Wherein, H is to have bored total well depth；

3) drop ply position is calculated

After occurring due to leakage, the time of being returned on standpipe pressure response time and fluid has differences, therefore according to the two Time difference Δ t determine drop ply depth；

The calculating formula of time difference is：

Drop ply position is represented by：

Preferably, pressure drop spread speed measuring method step is as follows：

1. in a certain normal drilling process opened time, when well depth reaches H₁During place, using the back pressure of controlled pressure drilling device Pump artificially applies wellhead back pressure Δ p, and starts timing, after standpipe pressure is increased to stable state, stops timing, meets with a response Time Δ t₁；

2. continue to creep into, when well depth respectively reaches H₂And H₃During place, respectively repeat steps and 1. operate, try to achieve response time Δ t₂With Δ t₃, obtain：

Simultaneous formula (6) and formula (7), obtain first group of pressure drop spread speedWithSimultaneous formula (7) and formula (8), obtain To second group of pressure drop spread speedWithWhen the error between two groups of measuring speeds is less than 10%, it is believed that measured value Accurately, i.e.,：

Wherein e₁、e₂It is error amount；If measured value is unsatisfactory for formula (9) and (10), repeat step behaviour 1. with step 2. Make, continue to measure.

The advantage of technical solution of the present invention is that comprehensive, the systematization monitoring combined as a kind of ground and underground are System, down-hole information is gathered using various kinds of sensors, and time and standpipe pressure response time etc. are returned on fluid, is set by ground It is standby to calculate drop ply position, data processing and analysis are automatically performed, real-time monitoring leakage situation provides drop ply depth, especially immediately That can measure drop ply position not in shaft bottom, with intelligence, efficiently, it is reliable the characteristics of, than those can only monitoring well bottom miss System it is even better.

Brief description of the drawings

Fig. 1 is the structural representation according to the preferred embodiment of leakage real-time detecting system one of controlled pressure drilling of the invention；

Fig. 2 is well before occurring according to the leakage of the preferred embodiment of leakage real-time detecting system one of controlled pressure drilling of the invention Cylinder changes in flow rate schematic diagram；

Fig. 3 is well after occurring according to the leakage of the preferred embodiment of leakage real-time detecting system one of controlled pressure drilling of the invention Cylinder changes in flow rate schematic diagram；

Fig. 4 is excellent according to the leakage real-time detecting system pressure drop spread speed measuring method one of controlled pressure drilling of the invention Select the flow chart of embodiment.

Illustrate：

1- flow sensors, 2- preamplifier a, 3- shaping amplifier, 4-AD converter a, 5- standpipe pressures sensor, 6- preamplifier b, 7- bandpass filter, 8-AD converter b, 9- single-chip microcomputer, 10- power amplifiers, 11- sound and light signals dress Put, 12- computers.

Specific embodiment

In order to be further understood that the content of the invention of the invention, more detailed is made to the present invention below in conjunction with specific embodiment Thin description, embodiment only has exemplary effect to the present invention, without any restricted effect；Any this area skill The insubstantial modifications that art personnel make on the basis of of the invention, should all belong to the scope of protection of the invention.

Embodiment 1

As shown in figure 1, a kind of leakage real-time detecting system for controlled pressure drilling, including signal collection pretreatment module, Signal intelligent discrimination module and drop ply are indicated and warning module, and the signal collects pretreatment module includes flow sensor 1, preceding Put amplifier a2, shaping amplifier 3, converter a4, standpipe pressure sensor 5, preamplifier b6, bandpass filter 7, AD Converter b8, the signal intelligent discrimination module includes single-chip microcomputer 9, and the drop ply indicates to include power amplifier with warning module 10th, sound and light signal device 11 and computer 12.

In the present embodiment, the signal collection pretreatment module is divided into two branch roads, and branch road one, flow sensor 1 is pacified Pipeline is returned out mounted in drilling fluid, and is connected with preamplifier a2, preamplifier a2 is connected with shaping amplifier 3, and shaping is put Big device 3 is connected with converter a4；Branch road two, standpipe pressure sensor 5 is arranged at standpipe, is connected with preamplifier b6, Preamplifier b6 is connected with bandpass filter 7, and bandpass filter 7 is connected with converter b8.

In the present embodiment, the converter a4 and converter b8 are connected by input port with single-chip microcomputer 9 respectively.

In the present embodiment, 9 output port of the single-chip microcomputer, one branch is connected with computer 12, exports drop ply result of calculation And instant playback, another branch is connected with power amplifier 10, after power amplifier 10 is by signal enhancing, is transferred to acousto-optic letter Number device 11 sends leakage early warning.

In the present embodiment, the preferred ultrasonic flow sensor of the flow sensor, returns out for measuring drilling fluid Flow, produces flow signal.

In the present embodiment, the preamplifier a2 is used to receive flow monitoring signals and carries out gain amplification.

In the present embodiment, the shaping amplifier 3 is used to carry out flow signal shaping pretreatment, and by signal waveform Further amplify.

In the present embodiment, the analog signal of flow signal can be converted to data signal by the converter a4.

In the present embodiment, the standpipe pressure sensor 5 can produce standpipe with real-time monitoring standpipe pressure situation of change Pressure signal.

In the present embodiment, pressure signal can be carried out gain amplification by the preamplifier b6, improve signal to noise ratio simultaneously External interference is reduced, then sends bandpass filter 7 to.

In the present embodiment, the bandpass filter 7 can be filtered pretreatment, the letter after noise reduction to pressure signal Number it is further transmitted to converter b8.

In the present embodiment, the analog signal of pressure signal can be converted into data signal by converter b8.

In the present embodiment, the single-chip microcomputer 9 can be processed data signal, write MCU programs to leakage signal Intelligence computation is carried out with analysis.

In the present embodiment, described pressure signal and flow signal, the data type of its store files include time point, Pressure value, flow value.

As shown in Fig. 2 in the present embodiment, the inlet flow rate of well head is Q, and the normal drilling situation of leakage is not occurring Under, rate of discharge is also Q.

As shown in figure 3, in the present embodiment, once there is leakage, the leakage flow of drop ply is Q₂, rate of discharge is reduced to Q₁, meet Q=Q₁+Q₂.At the same time bottom pressure reduction, standpipe pressure is also decreased.

In the present embodiment, standpipe pressure is measured in real time by standpipe pressure sensor 5, and pressure signal is by preamplifier b6 Carry out gain amplification, improve signal to noise ratio and simultaneously reduce external interference, then send bandpass filter 7 to be filtered treatment, noise reduction it Signal afterwards is further transmitted to converter b8, and analog signal is converted into data signal, is finally transmitted by input interface end It is analyzed to single-chip microcomputer 9.

In the present embodiment, the real-time monitoring drilling fluid return flow of flow sensor 1, flow monitoring signal is by preceding storing After big device a2 gains are amplified, pass to shaping amplifier 3 carries out shaping pretreatment to signal, and signal waveform is further put Greatly, analog signal is converted into by data signal by converter a4, single-chip microcomputer 9 is passed to by input interface end.

In the present embodiment, when there is no leakage, preferred single-chip microcomputer 9 is supervised in real time to flow signal and pressure signal Survey and record, in storing data in computer 12.When leakage occurs, once finding that flow is significantly reduced, single-chip microcomputer 9 sends early warning Signal, after amplifying by power amplifier 10, passes to sound and light signal device 11, sends alarm.Meanwhile, 9 pairs of notes of single-chip microcomputer The flow signal and pressure signal of record are analyzed, and the characteristic point of generation leakage in two kinds of signals are extracted, according to two features The point corresponding moment asks for time difference Δ t, finally provides leakage depth according to leakage layer position prediction model, and by computer 12 Instant playback.

As shown in figure 4, a kind of implementation steps of pressure drop spread speed measuring method are：Normal drilling arrives certain well depth H_i During (i=1,2,3 ... ...) place, keep operating mode constant, adjust the throttle valve opening of backpressure pump, it is extra to apply wellhead back pressure Δ p, And must ensure not pressing Lou barefoot interval weak formation after applying back pressure Δ p.Back pressure applies the moment after finishing when being recorded as starting Between.Monitoring standpipe pressure sensor 5, record pressure value and correspondence time.After standpipe pressure is increased to stable state, stop meter When, pressure is recorded as the end time from the time flex point for being increased to stabilization.According to initial time and end time, the time difference is calculated Δt_i(i=1,2,3 ... ...).After measuring the data at three groups of different well depths, according to formula：

Simultaneous formula (6) and formula (7), obtain first group of pressure drop spread speedWithSimultaneous formula (7) and formula (8), obtain To second group of pressure drop spread speedWithWhen the error between two groups of measuring speeds is less than 10%, it is believed that measured value Accurately, i.e.,：

CalculateAnd e_iIf error is unsatisfactory for requiring, repeats aforesaid operations and continue to measure, until error amount meets.

The present embodiment gathers down-hole information using various kinds of sensors, is automatically performed data processing and analysis, real-time monitoring well Leakage situation, provides drop ply depth immediately, can particularly measure drop ply position not in shaft bottom, with intelligence, efficient, reliable spy Point, than those can only monitoring well bottom miss system it is even better.

Although the present invention has shown and described referring particularly to its preferred embodiment, those skilled in the art can be with Understand, the various changes in form and details can be made without deviating from the model of the invention described in appended claims Enclose.It is described in detail above in association with specific embodiment of the invention, but is not limitation of the present invention.It is every according to this hair Bright technical spirit still falls within the scope of technical solution of the present invention to any simple modification made for any of the above embodiments.

Claims (10)

1. a kind of leakage real-time detecting system for controlled pressure drilling, including signal is collected pretreatment module, signal intelligent and is differentiated Module and drop ply are indicated and warning module, it is characterised in that：The signal collect pretreatment module include flow sensor (1), Preamplifier a (2), shaping amplifier (3), converter a (4), standpipe pressure sensor (5), preamplifier b (6), band Bandpass filter (7), converter b (8), the signal intelligent discrimination module include single-chip microcomputer (9), and the drop ply is indicated and early warning Module includes power amplifier (10), sound and light signal device (11) and computer (12).

2. the leakage real-time detecting system of controlled pressure drilling is used for as claimed in claim 1, it is characterised in that：The signal is collected Pretreatment module is divided into two branch roads, branch road one, and flow sensor (1) returns out pipeline installed in drilling fluid, and with preposition amplification Device a (2) is connected, and preamplifier a (2) is connected with shaping amplifier (3), and shaping amplifier (3) is connected with converter a (4)； Branch road two, standpipe pressure sensor (5) is connected at standpipe with preamplifier b (6), preamplifier b (6) and band Bandpass filter (7) is connected, and bandpass filter (7) is connected with converter b (8).

3. the leakage real-time detecting system of controlled pressure drilling is used for as claimed in claim 1, it is characterised in that：The converter A (4) and converter b (8) are connected by input port with single-chip microcomputer (9) respectively.

4. the leakage real-time detecting system of controlled pressure drilling is used for as claimed in claim 1, it is characterised in that：The single-chip microcomputer (9) one branch of output port is connected with computer (12), and output drop ply result of calculation simultaneously instant playback, another branch puts with power Big device (10) connection, after power amplifier (10) is by signal enhancing, is transferred to sound and light signal device (11) and sends leakage early warning.

5. the leakage real-time detecting system of controlled pressure drilling is used for as claimed in claim 2, it is characterised in that：The flow sensing Device (1) includes turbine flow transducer, throttle-type flow sensor, rotor flow sensor, ultrasonic flow sensor, is used for Measurement drilling fluid return flow, produces flow signal.

6. the leakage real-time detecting system of controlled pressure drilling is used for as claimed in claim 2, it is characterised in that：The standpipe pressure Sensor (5) can produce standpipe pressure signal with real-time monitoring standpipe pressure situation of change.

7. the leakage real-time detecting system for controlled pressure drilling as described in claim 1~6 any one, it is characterised in that： Under normal circumstances, the single-chip microcomputer (9) carries out real-time monitoring and records to flow signal and pressure signal, stores data in In computer (12)；In the case of generation leakage, flow is significantly reduced, and the single-chip microcomputer (9) sends early warning signal, by power amplification After device (10) amplifies, sound and light signal device (11) is passed to, send alarm, meanwhile, flow signal of the single-chip microcomputer (9) to record Be analyzed with pressure signal, extract and the characteristic point of leakage occurs in two kinds of signals, according to corresponding to two characteristic points when Quarter asks for the time difference, finally provides leakage depth according to leakage layer position prediction model, and by computer (12) instant playback.

8. the leakage real-time detecting system for controlled pressure drilling as described in claim 5 or 6, it is characterised in that：Described pressure Force signal and flow signal, the data type of its store files include time point, pressure value, flow value.

9. a kind of leakage layer position prediction model, including fluid in annular space on return Time Calculation, standpipe pressure response time meter Calculate, drop ply position is calculated, it is characterised in that：

1) fluid in annular space on return the time

Leakage front entrance and rate of discharge are Q, and rate of discharge is reduced to Q after leakage₁, mineshaft annulus sectional area is A, on annular space Return speed satisfaction：

$v_a=\frac{Q_1}{A}---\left(1\right)$

Fluid in the annular space on return the time and be：

$t_1=\frac{h}{v_a}=\frac{hA}{Q_1}---\left(2\right)$

Wherein, h is the well depth of drop ply position；

2) the standpipe pressure response time

Once occurring, the pressure reduction in shaft bottom ultimately results in standpipe pressure decline, it is assumed that pressure drop is in annular space and drilling rod to leakage Respectively with v_p1And v_p2Speed propagate, then after leakage standpipe pressure response time meet：

$t_2=\frac{H-h}{v_{p1}}+\frac{h}{v_{p2}}---\left(3\right)$

Wherein, H is to have bored total well depth；

3) drop ply position is calculated

Due to leakage occur after, the time of being returned on standpipe pressure response time and fluid has differences, thus according to the two when Between difference Δ t determine drop ply depth；

The calculating formula of time difference is：

$\mathrm{\Δ}t=t_2-t_1=\frac{hA}{Q_1}-(\frac{H-h}{v_{p1}}+\frac{h}{v_{p2}})---\left(4\right)$

Drop ply position is represented by：

$h=\frac{v_{p2}(v_{p1}\mathrm{\Δ}t+H)Q_1}{{\mathrm{Av}}_{p1}{v}_{p2}+Q_1(v_{p2}-v_{p1})}---\left(5\right).$

10. leakage as claimed in claim 8 layer position prediction model, it is characterised in that：Pressure drop spread speed measuring method is walked It is rapid as follows：

1. in a certain normal drilling process opened time, when well depth reaches H₁During place, the backpressure pump using controlled pressure drilling device is artificial Apply wellhead back pressure Δ p, and start timing, after standpipe pressure is increased to stable state, stop timing, meet with a response time Δ t₁；

2. continue to creep into, when well depth respectively reaches H₂And H₃During place, respectively repeat steps and 1. operate, try to achieve response time Δ t₂With Δt₃, obtain：

${\mathrm{\Δt}}_1=\frac{H_1}{v_{p1}}+\frac{H_1}{v_{p2}}---\left(6\right)$

${\mathrm{\Δt}}_2=\frac{H_2}{v_{p1}}+\frac{H_2}{v_{p2}}---\left(7\right)$

${\mathrm{\Δt}}_3=\frac{H_3}{v_{p1}}+\frac{H_3}{v_{p2}}---\left(8\right)$

Simultaneous formula (6) and formula (7), obtain first group of pressure drop spread speedWithSimultaneous formula (7) and formula (8), obtain Two groups of pressure drop spread speedsWithWhen the error between two groups of measuring speeds is less than 10%, it is believed that measured value is accurate, I.e.：

$e_1=\frac{|v_{p1}^{\left(2\right)}-v_{p1}^{\left(1\right)}|}{v_{p1}^{\left(1\right)}}\≤10\%---\left(9\right)$

$e_2=\frac{|v_{p2}^{\left(2\right)}-v_{p2}^{\left(1\right)}|}{v_{p2}^{\left(1\right)}}\≤10\%---\left(10\right)$

Wherein e₁、e₂It is error amount；If measured value is unsatisfactory for formula (9) and (10), repeat step operation 1. with step 2., after Continuous measurement.