CN106351645A - Method and device for continuously measuring working fluid level of rod-pumped well - Google Patents

Abstract

The invention discloses a method for continuously measuring the working fluid level of a rod-pumped well, which can be used for greatly improving the measurement accuracy. The method comprises the following steps: (1) analyzing dynamic characteristics of a pumping rod, establishing a vibration model of the pumping rod, and establishing a one-dimensional second-order partial differential equation for describing motion of the pumping rod; (2) iteratively calculating a damping coefficient by applying a ground dynamometer card; (3) calculating a polished rod load value with the accelerated speed being zero; (4) calculating the working fluid level H of an oil well; (5) eliminating accidental errors, and optimizing the calculation result; and (6) calibrating the data of the working fluid level of the oil well. The invention further provides a device for continuously measuring the working fluid level of a rod-pumped well.

Description

A kind of rod-pumped well hydrodynamic face method for continuous measuring and device

Technical field

The invention belongs to the technical field that automatization recovers the oil, more particularly, to a kind of rod-pumped well hydrodynamic face method for continuous measuring And device.

Background technology

The hydrodynamic face of rod-pumped well is the fluid supply capacity of reaction oil well and guarantees that pumping well system safety joint is fertile Important parameter.At present well fluid level e measurement technology relies primarily on Acoustic Reflection Method, the method be primarily present problems with (1) if Using artificial periodic measurement it is impossible to realize continuous measurement.(2) on-line continuous measuring apparatus high cost, and need external driving source, Energy expenditure is big.(3) due to situation complexity in pit shaft, when dynamic oil level is excessive, interference factor is excessive, and certainty of measurement is poor.

In recent years due to the fast development of sensor technology, polished rod indicator card e measurement technology is increasingly popular and precision is higher, The practical application that indicator card calculates well fluid level technology is made to become reality.Go to solve the dynamic of oil well by the upper and lower dead load of oil well Liquid level, more difficult in actual applications, once and oil well condition change, also need to re-start dead load measurement.

Content of the invention

The technical problem to be solved in the present invention is the defect overcoming prior art, provides a kind of rod-pumped well hydrodynamic face continuous Measuring method, it can greatly improve certainty of measurement.

The technical scheme solving the above problems is: this rod-pumped well hydrodynamic face method for continuous measuring it is characterised in that: its Comprise the following steps:

(1) dynamicss of analysis sucker rod and the model of vibration setting up rod string, sets up description rod string fortune Dynamic one-dimensional partial differential equation of second order；

(2) to iterate to calculate damped coefficient with surface dynamometer card；

(3) asking for acceleration is polished rod load value at zero；

(4) solve well fluid level h；

(5) reject incidental error, optimize result of calculation；

(6) carry out well fluid level data scaling.

Realizing well fluid level, calculating, is optimized the present invention to result simultaneously in real time, reduces measurement error, outer having In the case of boundary's data, demarcated by extraneous dynamic fluid level data, improved well fluid level certainty of measurement further.

Additionally provide a kind of rod-pumped well hydrodynamic face continuous measuring device, comprising: work(figure collecting unit, pressure acquisition list Unit, data processing unit；Work(figure collecting unit comprises load transducer and angular displacement sensor；Pressure acquisition unit comprises back pressure Measurement sensor and casing pressure measurement sensor.

Brief description

Fig. 1 is the structural representation of the rod-pumped well hydrodynamic face continuous measuring device according to the present invention.

Fig. 2 is the flow chart of the rod-pumped well hydrodynamic face method for continuous measuring according to the present invention.

Specific embodiment

As shown in Fig. 2 this rod-pumped well hydrodynamic face method for continuous measuring it is characterised in that: it comprises the following steps:

(1) dynamicss of analysis sucker rod and the model of vibration setting up rod string, sets up description rod string fortune Dynamic one-dimensional partial differential equation of second order；

(2) to iterate to calculate damped coefficient with surface dynamometer card；

(3) asking for acceleration is polished rod load value at zero；

(4) solve well fluid level h；

(5) reject incidental error, optimize result of calculation；

(6) carry out well fluid level data scaling.

Realizing well fluid level, calculating, is optimized the present invention to result simultaneously in real time, reduces measurement error, outer having In the case of boundary's data, demarcated by extraneous dynamic fluid level data, improved well fluid level certainty of measurement further.

In addition, one-dimensional partial differential equation of second order is formula (1-3) in described step (1)

$\frac{{\∂}^{2}u}{\∂t^2}=a^2\frac{{\∂}^{2}u}{\∂x^2}-c\frac{\∂u}{\∂t}---(1-3)$

WhereinFor the damped coefficient to sucker rod for the liquid in well, unit is s^-1；

For spread speed in sucker rod for the stress wave, unit is m/s.

In addition, sucker rod emulation vibration maths model comprises in described step (1): wave equation, boundary condition, initial strip Part and the condition of continuity.

In addition, the specific formula for calculation of damped coefficient is formula (1-16) in described step (2):

$c=\frac{t\[(1-\mathrm{\α})({\stackrel{\&overbar;}{f}}_{pd}-{\stackrel{\&overbar;}{f}}_{od})-\mathrm{\α}({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{ou})\]}{s_o(1+s_p/s_o)\·\underset{i=1}{\overset{n}{\σ}}{\mathrm{\ρ}}_i{a}_i{x}_i}---(1-16)$

WhereinObtained divided by the length of stroke of polished rod according to the area integral of the upper and lower stroke of polished rod indicator card respectively Arrive；Obtained divided by pump stroke according to the area integral of the upper and lower stroke of pump dynagraoph respectively, α is Pumping Unit coefficient, t For the cycle；

The condition of convergence of formula (1-16) is:

$\left|\frac{k_1-f_o}{k_1-({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{pd})}-1\right|<\mathrm{\&epsiv;}---(1-17)$

Wherein ε is allowable error；

In addition, described step (3) inclusion is following step by step:

(3.1) the abscissa meansigma methodss of the arbitrary discrete point of pump dynagraoph are sought using 5 points of averaging method

$\stackrel{\&overbar;}{x_i}=\frac{x_{i-2}+x_{i-1}+x_i+x_{i+1}+x_{i+2}}{5}---(1-18);$

(3.2) by the maximum of transverse and longitudinal coordinate and the minima of discrete point on displacement data:

x_max,y_max；

(3.3) pump dynagraoph displacement is normalized；

${\mathrm{\&delta;x}}_i=\frac{\stackrel{\&overbar;}{x_i}-x_{min}}{x_{\max }-x_{min}}---(1-19);$

(3.4) slope value k of each discrete point on pump dynagraoph is calculated according to formula (1-20)_i

$k_i=\frac{2(x_{i+1}-2x_i+x_{i-1})}{{\mathrm{\&delta;t}}^2}---(1-20);$

(3.5) meansigma methodss of Curvature varying amount are sought using five-spot

${k_i}^{\&prime;}=\frac{k_{i-2}+k_{i-1}+k_i+k_{i+1}+k_{i+2}}{5};$

(3.6) ask for k in up-down stroke respectively_iThe value of corresponding i at=0, if k_i＞ 0, k_i+1＜ 0 or k_i+1＞ 0, k_i ＜ 0

ThenSolve f_dAnd f_u.

In addition, described step (4) inclusion is following step by step:

(4.1) solve fluid column load w in the full ram area of dynamic oil level in oil well_l

w_l=f_u-f_d-(p_t-p_c)×a_p(1-21)

Wherein p_tFor wellhead back pressure, pa；p_cFor casing pressure, pa；a_pFor ram area, m²；

(4.3) solve hydrodynamic face h

In addition, described step (5) inclusion is following step by step:

(5.1) meansigma methodss of nearest five calculating hydrodynamic face h are solved

$\stackrel{\&overbar;}{h}=\frac{h_i+h_{i-1}+h_{i-2}+h_{i-3}+h_{i-4}}{5}---(1-23);$

(5.4) reject the point that result of calculation is more than 20% with meansigma methodss relative error

$\mathrm{\&epsiv;}=\frac{\stackrel{\&overbar;}{h}-h_i}{\stackrel{\&overbar;}{h}}---(1-24);$

(5.5) surplus value is asked for average and as currently move fluid level data h, if total data relative error is all higher than 20%, then calculate unsuccessfully, the current production status of oil well are unstable, wait 5 full stroke after after calculated again；

For the time point hydrodynamic face h calculating failure_i, carry out supplement calculation according to formula (1-25),

$h_i=h_{i-1}+\frac{1}{k}(h_{i+k}-h_{i-1})---(1-25).$

In addition, the demarcation that in described step (6), hydrodynamic face calculates measures well fluid level data h using combining reality_iEnter Rower is fixed

h_bi=μ h_i(1 26)

$\mathrm{\&mu;}=\frac{h_i}{h_i}---(1-27).$

As shown in figure 1, additionally providing a kind of rod-pumped well hydrodynamic face continuous measuring device, comprising: work(figure collecting unit, Pressure acquisition unit, data processing unit；Work(figure collecting unit comprises load transducer and angular displacement sensor；Pressure acquisition list Unit comprises back pressure measurement sensor and casing pressure measurement sensor.

First pass through each stroke current load of sensor acquisition oil well, angular displacement data and corresponding back pressure and set Pressure.Load data and displacement data are formed the polished rod indicator card of oil well.

The present invention described further below.

The embodiment of the present invention provides a kind of continuous survey calculation flow process in rod-pumped well hydrodynamic face to include:

[1] dynamicss of analysis sucker rod and the model of vibration setting up rod string, sets up description rod string fortune Dynamic one-dimensional partial differential equation of second order, i.e. wave equation, and further solving wave equations,

$\frac{{\&part;}^{2}u}{\&part;t^2}=a^2\frac{{\&part;}^{2}u}{\&part;x^2}-c\frac{\&part;u}{\&part;t}---(1-3)$

In formulaFor the damped coefficient to sucker rod for the liquid in well, s^-1；For stress wave in oil pumping Spread speed in bar, m/s.

Sucker rod emulation vibration maths model comprises following four aspect: wave equation, boundary condition, initial condition and company Continuous property condition.

(1) boundary condition

Determine boundary condition according to pumping unit hanging point laws of motion, can be asked by the geometry motion characteristic of oil pumper Go out.

u(x,t)|_X=0=u (t) (1-4)

(2) initial condition

If initial time, oil pump piston is located at bottom dead centre, prepares to start to move upwards from bottom dead centre, and actual measurement ground shows work( Load on figure and displacement are initial condition.

$\left\{\begin{array}{c}u(x,t){|}_{x=0}=u\left(t\right)\\ f(i,j){|}_{x=0}=d\left(t\right)-w_r\end{array}\right.---(1-5)$

In formula, u (t) is the displacement of actual measurement surface dynamometer card；D (t) is the load of actual measurement surface dynamometer card；w_rFor sucker rod Gravity in well liquid for the post.

(3) condition of continuity

The multistage sucker rod forming for different-diameter, different materials, the load of two-stage roofbolt intersection and displacement are continuous Property condition is:

$\left\{\begin{array}{c}f{(i,j)}_1=f{(i,j)}_2\\ u{(i,j)}_1=u{(i,j)}_2\end{array}\right.---(1-6)$

Vibration of sucker-rod string simulation mathematical model is drawn by formula (1-3), (1-4), (1-5), (1-6):

$\left\{\begin{array}{c}\frac{{\&part;}^{2}u}{\&part;t^2}=a^2\frac{{\&part;}^{2}u}{\&part;x^2}-c\frac{\&part;u}{\&part;t}\\ \begin{array}{cc}u(x,t){|}_{x=0}=u\left(t\right)& f(i,j){|}_{x=0}=d\left(t\right)-w_r\\ f{(i,j)}_1=f{(i,j)}_2& u{(i,j)}_1=u{(i,j)}_2\end{array}\end{array}\right.---(1-7)$

5. determine whether afterbody sucker rod, if it is, calculated displacement load relation is pump dynagraoph, calculate Terminate；Otherwise, then the principle of continuity according to power, to calculate second level roofbolt end u₂(x_i, t) and f₂(x_i, calculate t) and successively Until the end of afterbody bar, you can obtain corresponding pump dynamometers.

To solve the mathematical model wave equation of vibration of sucker-rod string using the method for fourier series:

If dynamic load function is d (t), polished rod displacement function u (t), as boundary condition, d (t) and u (t) is distinguished It is launched into fourier series:

$\left\{\begin{array}{c}d\left(t\right)=\frac{{\mathrm{\&sigma;}}_o}{2}+\underset{n=1}{\overset{n}{\&sigma;}}\left({\mathrm{\&sigma;}}_{n}cos\right(nwt)+{\mathrm{\&tau;}}_{n}sin(nwt\left)\right)\\ u\left(t\right)=\frac{{\mathrm{\&gamma;}}_o}{2}+\underset{n=1}{\overset{n}{\&sigma;}}\left(v_{n}cos\right(nwt)+{\mathrm{\&delta;}}_{n}sin(nwt\left)\right)\end{array}\right.---(1-8)$

Wherein n represents fourier series item number；σ_o,γ_o,σ_n,τ_n,v_n,δ_n(n=1,2, n) represent Fourier leaf system Number, w is crank angular velocity.

The Fu Shi coefficient of sucker rod dynamic load and change in displacement is obtained by the d (t) surveying and u (t) curve numerical integration:

$\left\{\begin{array}{c}{\mathrm{\&sigma;}}_n=\frac{2}{k}\underset{p=1}{\overset{k}{\&sigma;}}d\left(p\right)cos\left(\frac{2n\mathrm{\&pi;}}{k}p\right)\\ {\mathrm{\&tau;}}_n=\frac{2}{k}\underset{p=1}{\overset{k}{\&sigma;}}d\left(p\right)\sin \left(\frac{2n\mathrm{\&pi;}}{k}p\right)\end{array}\right.---(1-9)$

$\left\{\begin{array}{c}{v}_n=\frac{2}{k}\underset{p=1}{\overset{k}{\&sigma;}}u\left(p\right)cos\left(\frac{2n\mathrm{\&pi;}}{k}p\right)\\ {\mathrm{\&delta;}}_n=\frac{2}{k}\underset{p=1}{\overset{k}{\&sigma;}}u\left(p\right)sin\left(\frac{2n\mathrm{\&pi;}}{k}p\right)\end{array}\right.---(1-10)$

N=0 in formula, 1,2 ..., n, d (p) and u (p) are respectively the load of discrete point and the displacement of indicator card.

With (1-7) as boundary condition, with separation of variable solving equation (1-8), any of rod string can be obtained The displacement of depth change over time:

$u(x,t)=\frac{{\mathrm{\&sigma;}}_o}{2e_r{a}_r}\&centerdot;x+\frac{v_o}{2}+\underset{n=1}{\overset{n}{\&sigma;}}\left(o_n\left(x\right)\cos \left(nwt\right)+p_n\left(x\right)\sin \left(nwt\right)\right)---(1-11)$

Can be obtained according to Hooke's law:

$f(x,t)=e_r{a}_r\frac{\&part;u(x,t)}{\&part;x}---(1-12)$

Then dynamic load change over time can be obtained according to formula (1-12) to turn to:

$f(x,t)=\frac{{\mathrm{\&sigma;}}_o}{2}+e_{r}a\underset{n=1}{\overset{n}{\&sigma;}}\&lsqb;\frac{\&part;o_n\left(x\right)}{\&part;x}cos\left(nwt\right)+\frac{\&part;p_n\left(x\right)}{\&part;x}sin\left(nwt\right)\&rsqb;---(1-13)$

Full payload f (x, t) in t, x section is the weight plus the following rod string of x section.

In formula (1-12) (1-13):

$\left\{\begin{array}{c}{o}_n\left(x\right)=(k_n{\mathrm{ch\&beta;}}_{n}x+{\mathrm{\&delta;}}_n{\mathrm{sh\&beta;}}_{n}x){\mathrm{sin\&alpha;}}_{n}x+({\mathrm{\&mu;}}_n{\mathrm{sh\&beta;}}_{n}x+v_n{\mathrm{ch\&beta;}}_{n}x){\mathrm{cos\&alpha;}}_{n}x\\ p_n\left(x\right)=(k_n{\mathrm{sh\&beta;}}_{n}x+{\mathrm{\&delta;}}_n{\mathrm{ch\&beta;}}_{n}x){\mathrm{cos\&alpha;}}_{n}x-({\mathrm{\&mu;}}_n{\mathrm{ch\&beta;}}_{n}x+v_n{\mathrm{sh\&beta;}}_{n}x){\mathrm{sin\&alpha;}}_{n}x\\ \frac{\&part;o_n\left(x\right)}{\&part;x}=({\mathrm{\&beta;}}_n{c}_n-{\mathrm{\&alpha;}}_n{d}_n)v_n+({\mathrm{\&beta;}}_n{d}_n+{\mathrm{\&alpha;}}_n{c}_n){\mathrm{\&delta;}}_n+({\mathrm{\&beta;}}_n{\mathrm{\&alpha;}}_n-{\mathrm{\&alpha;}}_n{b}_n){\mathrm{\&mu;}}_n+({\mathrm{\&beta;}}_n{b}_n+{\mathrm{\&alpha;}}_n{a}_n)k_n\\ \frac{\&part;p_n\left(x\right)}{\&part;x}=-({\mathrm{\&beta;}}_n{d}_n+{\mathrm{\&alpha;}}_n{c}_n)v_n+({\mathrm{\&beta;}}_n{c}_n-{\mathrm{\&alpha;}}_n{d}_n){\mathrm{\&delta;}}_n-({\mathrm{\&beta;}}_n{b}_n+{\mathrm{\&alpha;}}_n{a}_n){\mathrm{\&mu;}}_n+({\mathrm{\&beta;}}_n{a}_n-{\mathrm{\&alpha;}}_n{b}_n)k_n\end{array}\right.---(1-14)$

Wherein α_n,β_n,k_n,μ_n,a_n,b_n,c_n,d_nIt is special constant:

$\left\{\begin{array}{cc}\begin{array}{c}{\mathrm{\&alpha;}}_n=\frac{n\mathrm{\&omega;}}{\mathrm{\&alpha;}\sqrt{2}}\sqrt{1+\sqrt{1+{\left(\frac{c}{n\mathrm{\&omega;}}\right)}^2}}\\ k_n=\frac{{\mathrm{\&sigma;}}_n{\mathrm{\&alpha;}}_n+{\mathrm{\&tau;}}_n{\mathrm{\&beta;}}_n}{e_r{a}_r({\mathrm{\&alpha;}}_n^2+{\mathrm{\&beta;}}_n^2)}\\ a_n={\mathrm{ch\&beta;}}_{n}x{\mathrm{cos\&alpha;}}_{n}x\\ c_n={\mathrm{sh\&beta;}}_{n}x{\mathrm{cos\&alpha;}}_{n}x\end{array}& \begin{array}{c}{\mathrm{\&beta;}}_n=\frac{n\mathrm{\&omega;}}{\mathrm{\&alpha;}\sqrt{2}}\sqrt{-1+\sqrt{1+{\left(\frac{c}{n\mathrm{\&omega;}}\right)}^2}}\\ {\mathrm{\&mu;}}_n=\frac{{\mathrm{\&sigma;}}_n{\mathrm{\&beta;}}_n-{\mathrm{\&tau;}}_n{\mathrm{\&beta;}}_n}{e_r{a}_r({\mathrm{\&alpha;}}_n^2+{\mathrm{\&beta;}}_n^2)}\\ b_n={\mathrm{sh\&beta;}}_{n}x{\mathrm{sin\&alpha;}}_{n}x\\ d_n={\mathrm{ch\&beta;}}_{n}x{\mathrm{sin\&alpha;}}_{n}x\end{array}\end{array}\right.---(1-15)$

[2] pass through tentative calculation, have selected the method to iterate to calculate damped coefficient with surface dynamometer card.

The specific formula for calculation of its damped coefficient is:

$c=\frac{t\&lsqb;(1-\mathrm{\&alpha;})({\stackrel{\&overbar;}{f}}_{pd}-{\stackrel{\&overbar;}{f}}_{od})-\mathrm{\&alpha;}({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{ou})\&rsqb;}{s_o(1+s_p/s_o)\&centerdot;\underset{i=1}{\overset{n}{\&sigma;}}{\mathrm{\&rho;}}_i{a}_i{x}_i}---(1-16)$

In formula,Can respectively the area integral according to the upper and lower stroke of polished rod indicator card divided by the length of stroke of polished rod Obtain；Can be obtained divided by pump stroke according to the area integral of the upper and lower stroke of pump dynagraoph respectively, α is Pumping Unit system Number, t is the cycle.

Solve during damped coefficient it is necessary to first know pump dynamometers with formula (1-16), but if it is known that pump dynamometers, must First damped coefficient must be known, so using after initialization, to solve using iterative method.

The condition of convergence of formula (1-16) is:

$\left|\frac{k_1-f_o}{k_1-({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{pd})}-1\right|<\mathrm{\&epsiv;}---(1-17)$

In formula, ε is allowable error；

[3] asking for acceleration is polished rod load value at zero.

(1) the abscissa meansigma methodss of the arbitrary discrete point of pump dynagraoph are sought using 5 points of averaging method；

$\stackrel{\&overbar;}{x_i}=\frac{x_{i-2}+x_{i-1}+x_i+x_{i+1}+x_{i+2}}{5}---(1-18)$

(2) pass through the maximum of transverse and longitudinal coordinate of discrete point and minima: x on displacement data_max,y_max；

(3) pump dynagraoph displacement is normalized；

${\mathrm{\&delta;x}}_i=\frac{\stackrel{\&overbar;}{x_i}-x_{min}}{x_{\max }-x_{min}}---(1-19)$

(4) slope value k of each discrete point on pump dynagraoph is calculated according to formula (1-20)_i；

$k_i=\frac{2(x_{i+1}-2x_i+x_{i-1})}{{\mathrm{\&delta;t}}^2}---(1-20)$

(5) meansigma methodss of Curvature varying amount are sought using five-spotTo improve algorithm Accuracy.

(6) ask for k in up-down stroke respectively_iThe value of corresponding i at=0, if k_i＞ 0, k_i+1＜ 0 or k_i+1＞ 0, k_i＜ 0

ThenSolve f_dAnd f_u.

[4] solve well fluid level h.

(1) solve fluid column load w in the full ram area of dynamic oil level in oil well_l

w_l=f_u-f_d-(p_t-p_c)×a_p(1 21)

Wherein p_tFor wellhead back pressure, pa；p_cFor casing pressure, pa；a_pFor ram area, m²；

(2) solve hydrodynamic face h.

[5] reject incidental error, optimize result of calculation.

(1) meansigma methodss of nearest five calculating hydrodynamic face h are solved

$\stackrel{\&overbar;}{h}=\frac{h_i+h_{i-1}+h_{i-2}+h_{i-3}+h_{i-4}}{5}---(1-23)$

(2) reject the point that result of calculation is more than 20% with meansigma methodss relative error.

$\mathrm{\&epsiv;}=\frac{\stackrel{\&overbar;}{h}-h_i}{\stackrel{\&overbar;}{h}}---(1-24)$

(3) surplus value is asked for average and as currently move fluid level data h, if total data relative error is all higher than 20%, Then calculate unsuccessfully, the current production status of oil well are unstable, wait 5 full stroke after after calculated again.

For the time point hydrodynamic face h calculating failure_i, carry out supplement calculation according to formula (1-25),

$h_i=h_{i-1}+\frac{1}{k}(h_{i+k}-h_{i-1})---(1-25)$

[6] well fluid level data scaling；

The demarcation that hydrodynamic face calculates measures well fluid level data h using combining reality_iDemarcated.

h_bi=μ h_i(1 26)

$\mathrm{\&mu;}=\frac{h_i}{h_i}---(1-27).$

The above, be only presently preferred embodiments of the present invention, and not the present invention is made with any pro forma restriction.This area Those of ordinary skill it should be understood that every technical spirit according to the present invention any simply repairing that above example is made Change, equivalent variations and modification, all still belong to the protection domain of technical solution of the present invention.

Claims (9)

1. a kind of rod-pumped well hydrodynamic face method for continuous measuring it is characterised in that: it comprises the following steps:

(1) dynamicss of analysis sucker rod and the model of vibration setting up rod string, sets up description rod string motion One-dimensional partial differential equation of second order；

(2) to iterate to calculate damped coefficient with surface dynamometer card；

(3) asking for acceleration is polished rod load value at zero；

(4) solve well fluid level h；

(5) reject incidental error, optimize result of calculation；

(6) carry out well fluid level data scaling.

2. rod-pumped well hydrodynamic face method for continuous measuring according to claim 1 it is characterised in that: in described step (1) One-dimensional partial differential equation of second order is formula (1-3)

$\frac{{\&part;}^{2}u}{\&part;t^2}=a^2\frac{{\&part;}^{2}u}{\&part;x^2}-c\frac{\&part;u}{\&part;t}---(1-3)$

WhereinFor the damped coefficient to sucker rod for the liquid in well, unit is s^-1；Taking out for stress wave Spread speed in beam hanger, unit is m/s.

3. rod-pumped well hydrodynamic face method for continuous measuring according to claim 2 it is characterised in that: in described step (1) Sucker rod emulation vibration maths model comprises: wave equation, boundary condition, initial condition and the condition of continuity.

4. rod-pumped well hydrodynamic face method for continuous measuring according to claim 3 it is characterised in that: in described step (2) The specific formula for calculation of damped coefficient is formula (1-16):

$c=\frac{t\&lsqb;(1-\mathrm{\&alpha;})({\stackrel{\&overbar;}{f}}_{pd}-{\stackrel{\&overbar;}{f}}_{od})-\mathrm{\&alpha;}({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{ou})\&rsqb;}{s_o(1+s_p/s_o)\&centerdot;\underset{i=1}{\overset{n}{\mathrm{\&sigma;}}}{\mathrm{\&rho;}}_i{a}_i{x}_i}---\left(1-16\right)$

WhereinObtained divided by the length of stroke of polished rod according to the area integral of the upper and lower stroke of polished rod indicator card respectively；Obtained divided by pump stroke according to the area integral of the upper and lower stroke of pump dynagraoph respectively, α is Pumping Unit coefficient, t is Cycle；

The condition of convergence of formula (1-16) is:

$|\frac{k_1-f_o}{k_1-\left({\stackrel{\&overbar;}{f}}_{pu}-{\stackrel{\&overbar;}{f}}_{pd}\right)}-1|<\mathrm{\&epsiv;}---(1-17)$

Wherein ε is allowable error；

5. rod-pumped well hydrodynamic face method for continuous measuring according to claim 4 it is characterised in that: described step (3) bag Include following step by step:

(3.1) the abscissa meansigma methodss of the arbitrary discrete point of pump dynagraoph are sought using 5 points of averaging method

$\stackrel{\&overbar;}{x_i}=\frac{x_{i-2}+x_{i-1}+x_i+x_{i+1}+x_{i+2}}{5}---(1-18);$

(3.2) pass through the maximum of transverse and longitudinal coordinate of discrete point and minima: x on displacement data_max,y_max；

(3.3) pump dynagraoph displacement is normalized；

${\mathrm{\&delta;x}}_i=\frac{\stackrel{\&overbar;}{x_i}-x_{min}}{x_{\max }-x_{min}}---(1-19);$

(3.4) slope value k of each discrete point on pump dynagraoph is calculated according to formula (1-20)_i

$k_i=\frac{2(x_{i+1}-2x_i+x_{i-1})}{{\mathrm{\&delta;t}}^2}---(1-20);$

(3.5) meansigma methodss of Curvature varying amount are sought using five-spot

${k_i}^{\&prime;}=\frac{k_{i-2}+k_{i-1}+k_i+k_{i+1}+k_{i+2}}{5};$

(3.6) ask for k in up-down stroke respectively_iThe value of corresponding i at=0, if k_i＞ 0, k_i+1＜ 0 or k_i+1＞ 0, k_i＜ 0

ThenSolve f_dAnd f_u.

6. rod-pumped well hydrodynamic face method for continuous measuring according to claim 5 it is characterised in that: described step (4) bag Include following step by step:

(4.1) solve fluid column load w in the full ram area of dynamic oil level in oil well_l

w_l=f_u-f_d-(p_t-p_c)×a_p(1—21)

Wherein p_tFor wellhead back pressure, pa；p_cFor casing pressure, pa；a_pFor ram area, m²；

(4.2) solve hydrodynamic face h

7. rod-pumped well hydrodynamic face method for continuous measuring according to claim 6 it is characterised in that: described step (5) bag Include following step by step:

(5.1) meansigma methodss of nearest five calculating hydrodynamic face h are solved

$\stackrel{\&overbar;}{h}=\frac{h_i+h_{i-1}+h_{i-2}+h_{i-3}+h_{i-4}}{5}---(1-23);$

(5.2) reject the point that result of calculation is more than 20% with meansigma methodss relative error

$\mathrm{\&epsiv;}=\frac{\stackrel{\&overbar;}{h}-h_i}{\stackrel{\&overbar;}{h}}---(1-24);$

(5.3) surplus value is asked for average and as currently move fluid level data h, if total data relative error is all higher than 20%, Then calculate unsuccessfully, the current production status of oil well are unstable, wait 5 full stroke after after calculated again；

For the time point hydrodynamic face h calculating failure_i, carry out supplement calculation according to formula (1-25),

$h_i=h_{i-1}+\frac{1}{k}(h_{i+k}-h_{i-1})---(1-25).$

8. rod-pumped well hydrodynamic face method for continuous measuring according to claim 7 it is characterised in that: in described step (6) The demarcation that hydrodynamic face calculates measures well fluid level data h using combining reality_iDemarcated

h_bi=μ h_i(1—26)

$\mathrm{\&mu;}=\frac{h_i}{h_i}---(1-27).$

9. a kind of rod-pumped well hydrodynamic face continuous measuring device it is characterised in that: comprising: work(figure collecting unit, pressure acquisition Unit, data processing unit；Work(figure collecting unit comprises load transducer and angular displacement sensor；Pressure acquisition unit comprises back Pressure measurement sensor and casing pressure measurement sensor.