1. The utility model provides an oil field reinjection water oil content on-line measuring device which characterized in that: including detecting pipeline (1), relief valve (2), internal thread over-and-under type check valve (3), flange ball valve (4) and detection portion (5), detecting pipeline (1) one end is followed the other receipts of the pipe wall upper shed of reinjection water pipeline and is come out, and the other end returns the reinjection water pipeline in some place in the low reaches along the reinjection water direction again, and detecting pipeline (1) is the form of falling U, and detecting pipeline (1) one side pipe is equipped with relief valve (2) and flange ball valve (4) from top to bottom in proper order, and detecting pipeline (1) another side pipe is equipped with internal thread over-and-under type check valve (3) and flange ball valve (4) from top to bottom in proper order, and detecting pipeline (5) middle part is equipped with detection portion (5).

2. The oil field reinjection water oil content on-line measuring device of claim 1, characterized in that: detection portion (5) include laser emitter (6), quartz window (7), laser receiver (8), photoelectric processor (9), data transmission center (10), display screen (11) and control switch (12), detection pipeline (1) middle part is located in quartz window (7), and quartz window (7) both sides are equipped with laser generator (6) and laser receiver (8) respectively relatively, and laser emitter (6) are connected with photoelectric processor (9) through the wire, and photoelectric processor (9) are connected with laser receiver (8), data transmission center (10), display screen (11) and control switch (12) respectively through the wire.

3. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the laser emitter (6) emits light with the wavelength of 400 nm-460 nm.

4. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the thickness of the quartz window (7) is 20mm as same as that of the detection pipeline (1), the quartz window (7) is arc-shaped, the curvature is the same as that of the detection pipeline (1), and the number of the quartz window is two.

5. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the photoelectric processor (9) controls the light emitted by the laser emitter (6).

6. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the photoelectric processor (9) transmits the analysis result to a display screen (11) in the form of an electric signal through a lead, and the oil content is displayed locally.

7. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the data transmission center (10) transmits the electric signals converted by the photoelectric processor (9) to a remote control center.

8. The oil field reinjection water oil content on-line measuring device of claim 2, characterized in that: the control switch (12) realizes the on or off of the photoelectric processor (9).

9. The oil field reinjection water oil content on-line measuring device of claim 1, characterized in that: the detection part (5) and the detection pipeline (1) are connected in a flange mode.

Background art:

the exploitation of oil fields in China basically enters a high water content stage, and a large amount of oil field sewage is generated in the exploitation process of the high water content oil fields. The oil field sewage is treated to reach the standard and then reinjected, and the oil field water injection is used for maintaining the formation pressure, improving the oil reservoir recovery ratio and ensuring the efficient development of the oil reservoir. The oil content is one of important indexes concerned by the reinjection water, the reinjection water with high oil content can cause pollution of a water injection stratum, on the other hand, the possibility of corrosion of equipment facilities can be increased, and finally, the high-efficiency exploitation of an oil field can be influenced, so that a rapid and accurate detection device for the oil content is urgently needed.

At present, the detection method of the oil content of the reinjection water is mainly a spectrophotometry method, and the method is that an oil-containing sample is extracted to obtain standard oil, and then the absorbance of the standard oil with different concentrations is measured, so that a standard curve is drawn. And then extracting the oil in the reinjection water, measuring the absorbance by using an ultraviolet or infrared spectrophotometry, and checking the oil content by using a standard curve. The detection process is complex and the oil content of the reinjection water cannot be detected in real time.

The invention content is as follows:

the invention aims to overcome the defects of the prior art and provides the oil field reinjection water oil content online detection device which is based on the Lambert beer law and realizes online quantitative detection of the oil content of the reinjection water. The method can solve the problems that the existing method for detecting the oil content of the reinjection water is complex in operation, low in detection efficiency, incapable of displaying the change of the oil content in time, high in labor intensity, difficult to realize automatic management of a sewage treatment station and the like.

In order to solve the problems existing in the background technology, the invention adopts the following technical scheme: including detection pipeline, relief valve, internal thread over-and-under type check valve, flange ball valve and detection portion, detection pipeline one end is followed the other connecing of pipe wall upper shed of reinjection water pipeline and is come out, and the other end returns the reinjection water pipeline in certain place of low reaches along the reinjection water direction again, and the detection pipeline is the form of falling U, and a detection pipeline side pipe is equipped with relief valve and flange ball valve from top to bottom in proper order, and a detection pipeline opposite side pipe is equipped with internal thread over-and-under type check valve and flange ball valve from top to bottom in proper order, and the detection pipeline middle part is equipped with the detection portion.

The detection part comprises a laser transmitter, a quartz window, a laser receiver, a photoelectric processor, a data transmission center, a display screen and a control switch, the middle part of the detection pipeline is arranged on the quartz window, the laser generator and the laser receiver are respectively arranged on two opposite sides of the quartz window, the laser transmitter is connected with the photoelectric processor through a wire, and the photoelectric processor is respectively connected with the laser receiver, the data transmission center, the display screen and the control switch through wires.

The laser emitter emits light with the wavelength of 400 nm-460 nm.

The thickness of the quartz window is 20mm as same as that of the detection pipeline, the quartz window is arc-shaped, the curvature of the quartz window is the same as that of the detection pipeline, and the number of the quartz window is two.

The photoelectric processor controls the light emitted by the laser emitter.

And the photoelectric processor transmits the analysis result to a display screen in an electric signal form through a lead, and the oil content is displayed locally.

The data transmission center transmits the electrical signal converted by the photoelectric processor to a remote control center.

The control switch realizes the on or off of the photoelectric processor.

The detection part and the detection pipeline are connected by a flange.

The invention has the beneficial effects that:

1) the structure design is reasonable, the equipment layout is flexible and simple, the automation degree of microcomputer control is high, and the labor intensity of workers is reduced;

2) the whole device adopts an optical detection method, realizes the on-line monitoring of the reinjection water from the sewage treatment station to the water injection well, can reflect the oil content change trend of the reinjection water in time, and is convenient for technicians to adjust the water treatment process in time;

3) the detection part of the device is connected to the reinjection water main pipe, and secondary pollution can not be caused by adopting an optical detection method;

4) the optimum wavelength for analyzing the oil content of the reinjection water is obtained by using a partial least square regression modeling method, and the oil content of the reinjection water is analyzed by using the optimum wavelength, so that the reliability of a detection result is improved.

Description of the drawings:

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a view showing the structure of the detecting part of the present invention.

The specific implementation mode is as follows:

referring to the drawings, the present invention specifically adopts the following embodiments: including detection pipeline 1, relief valve 2, internal thread over-and-under type check valve 3, flange ball valve 4 and detection portion 5, 1 one end of detection pipeline is followed other the connecing of the pipe wall upper shed of reinjection water pipeline, and the other end returns the reinjection water pipeline in some place of low reaches along the reinjection water direction again, and detection pipeline 1 is the form of falling U, and 1 one side pipe of detection pipeline is equipped with relief valve 2 and flange ball valve 4 from top to bottom in proper order, and 1 other side pipe of detection pipeline is equipped with internal thread over-and-under type check valve 3 and flange ball valve 4 from top to bottom in proper order, and detection pipeline 5 middle part is equipped. The detection part 5 comprises a laser transmitter 6, a quartz window 7, a laser receiver 8, a photoelectric processor 9, a data transmission center 10, a display screen 11 and a control switch 12, the quartz window 7 is arranged in the middle of the detection pipeline 1, the laser generator 6 and the laser receiver 8 are respectively arranged on two opposite sides of the quartz window 7, the laser transmitter 6 is connected with the photoelectric processor 9 through a wire, and the photoelectric processor 9 is respectively connected with the laser receiver 8, the data transmission center 10, the display screen 11 and the control switch 12 through wires. The laser emitter 6 emits light with a wavelength of 400nm to 460 nm. The thickness of the quartz window 7 is 20mm as same as that of the detection pipeline 1, the quartz window 7 is arc-shaped, the curvature is the same as that of the detection pipeline 1, and the number of the quartz windows is two. The photoelectric processor 9 controls the light emitted by the laser emitter 6. The photoelectric processor 9 transmits the analysis result to the display screen 11 in the form of an electric signal through a wire, and the oil content is displayed locally. The data transmission center 10 transmits the electrical signal converted by the photoelectric processor 9 to a remote control center, so that technicians can conveniently monitor the quality of the reinjection water in real time. The control switch 12 realizes the on or off of the photoelectric processor 9, and further controls the on or off of the whole detection part. The detection part 5 and the detection pipeline 1 are connected in a flange mode, so that the detection part can be conveniently mounted and dismounted.

The model 2 of the pressure reducing valve is Y₁₃W_₈T, internal thread lifting type check valve 3 type H₁₁T_₁₆K, the flange ball valve 4 is Q47F.

The laser wavelength of the laser emitter 6 of the detection part 5 is 430 nm. Selecting the wavelength: the method comprises the steps of firstly obtaining transmittance data of the oily water standard liquid in a laboratory, and then carrying out interval partial least squares regression modeling (IPLS) on the basis of the transmittance data, wherein the result shows that an IPLS model has good prediction precision in a 420-440nm waveband, so that light with the wavelength of 430nm is selected.

The quartz window 7 for the light path incidence and emergence of the detection part 5 is made of quartz glass, is directly arranged in the middle of the detection pipeline 1, and is sealed.

The tail end of the detection pipeline 1 is provided with H₁₁T_₁₆K's internal thread over-and-under type check valve 3 ensures that the reinjection water flows in the detection pipeline one-way.

The working principle is as follows, the relation between the absorbance or transmittance and the concentration of the substance to be detected is established according to the Lambert beer law, namely when a beam of parallel light vertically irradiates a water sample to be detected, the water sample absorbs light with specific wavelength, the absorbance A of the component to be detected, the concentration c, and the light absorption thickness l, are in a direct proportion relation, the transmittance T, the c and the l are in an inverse proportion relation, and the expression is as follows:

in the formula: a (lambda) -absorbance of the solution to be detected;

I₀-the intensity of the incident light;

I_t-the intensity of the transmitted light;

T_t-transmittance, i.e. the ratio of It to I0;

c, the concentration of the component to be detected;

l-the thickness of the absorption;

ε -molar absorptivity.

When the solution to be detected contains a plurality of components which do not influence each other, the total absorbance of the solution is equal to the sum of the absorbance of each component in the solution at the same wavelength. The total absorbance calculation formula is as follows:

in the formula: a. the₁，A₂，A₃，...，A_n-absorbance of each component;

ε_i-the absorption coefficient of each component;

c_i-the concentration of each component;

A-Total Absorbance of Mixed Components.

The design is based on the chemometrics principle to obtain the relation between the spectral information of a sample to be measured and the sample to be measured with different concentrations, establish a database, rapidly detect the sample to be measured by using a single-wavelength ultraviolet laser transmitter on a measurement site, and substitute the transmittance information into the database to obtain the oil content information of the reinjection water on the measurement site. The chemometric modeling method employed in the present invention is partial least squares regression.

Partial least squares regression modeling principle

The Partial Least Squares Regression (PLSR) is a method that by establishing the correlation between a dependent variable and an independent variable, the numerical value of the dependent variable is predicted by the known independent variable numerical value, and is applicable when the data volume is small and the linear relationship between data is large, and the Partial Least Squares Regression model is modeled as follows:

recording an independent variable group n times of standardized observation data matrix as A, a dependent variable group as B:

the first pair of components (U1, V1) of the two variable groups is extracted and its correlation is maximized.

Converting the conditional extremum problem into a mathematical conditional extremum problem:

the regression model is assumed to be:

then the least squares estimate of the regression coefficient vector is as follows:

using residual error matrix A for A and B₁And B₁Instead, the above calculation process is repeated.

The residual is calculated as:

if the absolute value of the element in the residual matrix B1 is approximately 0, the accuracy is considered to have reached the requirement of the regression formula established for the first component, and the extraction of the component may be stopped. Otherwise, continuously repeating the calculation steps:

α⁽²⁾＝[α₂₁,...,α_2m]^T,β⁽²⁾＝[β₂₁,…,β_2p]^T

andis the score vector for the second pair of components, then the following holds:

will U_k＝α_k1x₁+···+α_kmx_m(k-1, 2, …, r) into Y-U₁τ⁽¹⁾+…+U_rτ^(r)A partial least squares regression of p dependent variables can be obtained:

y_j＝c_j1x₁+…+c_jmx_m,(j＝1,2,…,p)

regression model evaluation indexes: coefficient of correlation R or coefficient of determination R²The larger the value of the error is, the smaller the values of the correction set cross validation root mean square error RMSECV, the validation set external validation root mean square error RMSEP and the system deviation Bias are, the higher the prediction accuracy of the established regression model is, and the better the prediction effect is. If the RMSECV is much smaller than the RMSEP, this means that the representative of the correction set samples is poor. If RMSEP is much smaller than RMSECV, it indicates poor representation of the prediction set samples.

In the formula:-a spectral modeling prediction value;

-an arithmetic mean of the spectral modeling predictors;

-arithmetic mean of the values determined by the standard method.

In the formula:-a spectral modeling prediction value;

-arithmetic mean of the values determined by the standard method.

The relation database of the content of the sample to be measured and the spectral information established by the partial least square method is stored in the photoelectric processor 9 and is convenient to call during measurement.

The detection process was performed every 2 hours.

1) First, the control switch 12 is turned on to put the detection unit 5 into an operating state. And (3) injecting a sample into the detection pipeline, when the oil content of the reinjection water is detected, opening the pressure reduction valve 2 to enable the reinjection water to enter a working position, enabling the reinjection water to enter the detection pipeline 1 in a low-pressure state, and keeping the flowing state for 5 minutes to enable the water quality in the detection pipeline 1 to be stable.

2) And (3) detecting the oil content of the reinjection water: the laser transmitter 6 emits a light beam with the wavelength of 430nm and reaches the laser receiver 8 through three media of an incidence window, a reinjection water and an exit window. The laser receiver 8 converts the transmittance data into an electric signal and transmits to the photoelectric processor 9. After receiving the electrical signal, the photoelectric processor 9 brings the electrical signal into a database of a model established by a partial least squares regression method, thereby obtaining the oil content of the reinjection water sample.

3) Analysis results representation and transmission: the photoelectric processor 9 sends the modeling analysis results to the data transmission center 10 in the form of electric signals, and the data transmission center transmits the result signals to a remote control center located at the reinjection water treatment station. In addition, the photoelectric processor 9 will also send the result signal to the display screen 11 to locally display the oil content of the reinjection water.

The invention adopts the transmittance data under the 430nm wave band to characterize the oil content of the reinjection water, and can accurately and efficiently detect the oil content of the reinjection water. The whole device is simple, the stability is strong, and the long-term high-efficiency operation of the system can be realized.

In conclusion, the oil content online detection device for the oilfield reinjection water has the advantages of reasonable structural design, flexible and simple equipment layout, high automation degree of microcomputer control and reduction of labor intensity; the whole device adopts an optical detection method, realizes the on-line monitoring of the reinjection water from the sewage treatment station to the water injection well, can reflect the oil content change trend of the reinjection water in time, and is convenient for technicians to adjust the water treatment process in time; the detection part of the device is connected to the reinjection water main pipe, and secondary pollution can not be caused by adopting an optical detection method; the optimum wavelength for analyzing the oil content of the reinjection water is obtained by using a partial least square regression modeling method, and the oil content of the reinjection water is analyzed by using the optimum wavelength, so that the reliability of a detection result is improved.