CN101344764B - Level automatic measurement and control method of oil-water separation automatic measurement and control device based on combined station free water remover - Google Patents

Abstract

An automatic oil-water separation measurement and control system for free water dehydrators in joint stations relates to an oil-water separation measurement device and a measurement control method for free water dehydrators used in oil fields to solve the problems of difficult operation, poor accuracy and low reliability in liquid level measurement. A liquid level measurement module transmits signals to a main control module by a liquid level signal modulation module, an interface switching module and a USB interface module; the main control module transmits control signals to a valve open-close driving module by the USB interface module and the interface switching module. The method comprises the following steps of: acquiring conductivity of all detecting heads; computing the liquid level height by means of singularity detection; closing the oil inlet pipe and opening the oil discharge pipe according to the liquid level height value; closing the oil discharge pipe and opening the water discharge pipe according to the air-oil surface height value; closing the water discharge pipe and opening the liquid discharge pipe of the transition layer according to the transition layer-water layer height value; and opening the oil discharge pipe according to the oil-transition layer surface height value. The device and the method of the invention have the advantages of high accuracy and reliability.

Description

Automatically measure and automatic measurement of the liquid level of control device and control method based on the oil and water separation of multi-purpose station free water knockout (FWKO)

Technical field

The present invention relates to a kind of oil field measures and control method automatically with the liquid level of the oil and water separation measurement mechanism of free water knockout (FWKO).

Background technology

Free water knockout (FWKO) interface level measurement value is the crucial process control parameter during oil field gathering and transportation is produced.Because there are the higher shortcomings of impurity content such as the polymkeric substance, sulfide of extraction liquid medium in the poly-technology of driving of tertiary oil recovery, detect and forbidden to cause the problem that oil-containing exceeds standard in the unbalance and water of electrical dewatering control thereby make multi-purpose station gathering and transportation technology system the free water interface occur.Therefore, whether interface level measurement and control accurately influences water cut in purified, sewage with oil index and technology and equipment work system stability.At present, there be inaccurate, the not strong problem of operation automation measured in the detection of the free water knockout (FWKO) liquid level of the multi-purpose station in most of oil fields.For example, what use was detected at free water and electrical dewatering interface is radio frequency admittance water-oil interface instrument, control system is the DCS collective and distributive type control system, operation is more steady since putting into operation, but since receiving poly-driving after the station comes liquid to contain the above concentration of 50mg/L and processed medium to change, fluctuation often occurs, detection is difficult to control automatically.The principle of work of the DE table of design and installation mainly is to utilize different these character with the specific inductive capacity of water of oil to detect water-oil interface, because this transition bed is very sticking and conductance is high, changed the specific inductive capacity of contact bed oil-water media, so DE table accuracy in detection is not high.If change manual control into, then increased post operation personnel's labour intensity, make the more difficult control of process management again.

Table 1

	Advantage	Limitation
			The radio frequency admittance interface-measuring device	Gamut detects, and two-wire system, accuracy of detection are 0.5 grade	The strictness of installation mode, mounting process requires high, can not detect transition bed
The EJK interface-measuring device	Gamut detects, and accuracy of detection is 1.0 grades	Non-two-wire system, subsidiary transmitter, mounting process requires high, can not detect transition bed
			Gamma-rays type interface-measuring device	Gamut detects, and accuracy of detection is 0.1 grade, does not need perforate, and non-contact measurement is not influenced by dielectric property and external environment.	Non-two-wire system, subsidiary transmitter has radioactive source, uses and there is safety problem in recovery, can not detect transition bed
The shortwave water-oil interface	Easy to maintenance, can be with and press dismounting	Point position formula detects, and scope is little, and is linear poor, can not
			Measurement mechanism		Detect transition bed

Table 1 is several liquid surface measuring devices at present commonly used.As can be seen, present measurement mechanism is energy measurement transition bed liquid level not, and transition bed is when thickening, along with entering electricity, takes off by tank deck oil, take off the water-oil interface place that the middle sulfide that produces is blended in electrical dewatering with electricity, the electric field that influences electrical dewatering because of conductance is high is stable, will cause electricity to take off the electric field that collapses when accumulation is thicker, causes the collapse of hydroextractor system.

Summary of the invention

The present invention solves the operation of existing liquid surface measuring device existence difficulty, accuracy and the relatively poor problem of reliability, provides automatic the measurement with the liquid level of control device is automatic of a kind of oil and water separation based on the multi-purpose station free water knockout (FWKO) to measure and control method.

Liquid level method for automatic measurement of the present invention based on the oil and water separation of multi-purpose station free water knockout (FWKO) automatically measure with control device by the liquid level gauging module, the liquid level signal modulation module, interface modular converter, usb interface module, main control module and valve opening and closing driver module are formed, the measuring-signal output terminal of liquid level gauging module is connected with the measuring-signal input end of liquid level signal modulation module, the modulation signal output terminal of liquid level signal modulation module is connected with the modulation signal input end of interface modular converter, the control signal output ends of interface modular converter is connected with the signal input end of valve opening and closing driver module, the data input/output terminal of interface modular converter is connected with the data input/output terminal of usb interface module, and the control signal input/output terminal of usb interface module is connected with the control signal input/output terminal of main control module.

The oil and water separation of multi-purpose station free water knockout (FWKO) of the present invention is measured automatically with the liquid level method for automatic measurement of control device and is realized by following steps:

Steps A 1, by the sequence number of popping one's head in the sequential definition liquid level gauging module from bottom to up for from 1 to n, nethermost probe is the 1st probe, initialization makes n=0;

Steps A 2, n=n+1;

Steps A 3, the conductivity signal that n probe gathered are converted to real-time conductivity value corresponding voltage value by A/D;

Whether the magnitude of voltage that steps A 4, determining step A3 obtain is greater than threshold value, and judged result then enters steps A 5 for being, judged result then enters steps A 6 for not;

Steps A 5, demonstration conductivity value overrun error return steps A 3;

The real-time conductivity that steps A 6, n probe of calculating record;

Steps A 7, judge whether the value of n equals N, N represents the probe number summation of sensor array, and judged result then enters steps A 8 for being, judged result is then returned steps A 2 for not;

Steps A 8, calculate the value of the real-time conductivity of each probe measurement by the singular point detection method;

The value of steps A 9, the conductivity that obtains according to steps A 8 is calculated the height of liquid level.

Autocontrol method based on liquid level method for automatic measurement of the present invention is realized by following steps:

Step B1, open oil inlet pipe;

Step B2, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the liquid level that step B3, determining step B2 obtain reaches threshold value, and judged result then enters step B4 for being, judged result is then returned step B2 for not;

Step B4, close oil inlet pipe, treat to open draw-off pipe after the oil tank precipitation finishes;

Step B5, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B6, air that determining step B5 obtains and pasta reaches threshold value, and judged result then enters step B7 for being, judged result for otherwise return step B5;

Step B7, close draw-off pipe, open drainpipe;

Step B8, employing sensor array are measured the height value of the laminated fluid level of transition bed and water layer, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B9, transition bed that determining step B8 obtains and water layer satisfies threshold value, and judged result then enters step B10 for being, judged result is then returned step B8 for not;

Step B10, close drainpipe, open the liquid delivery pipe of transition bed;

Step B11, employing sensor array are measured the height value of the laminated fluid level of oil reservoir and transition bed, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B12, oil reservoir that determining step B11 obtains and transition bed satisfies threshold value, and judged result is then returned step B1 for being, judged result is then returned step B11 for not.

Beneficial effect: measurement of the present invention mainly is the different principle of conductivity of utilizing the liquid of oil reservoir, transition bed and water layer with control device, adopt the voltage signal of method for scanning collection different liquids conductivity one by one, determine the position of liquid level to have all higher characteristics of accuracy and reliability by all acquired signal of analyte sensors array; The conductivity of method of the present invention by measuring three liquid levels to be obtaining the height value of each liquid level, and according to the switching of measurement result control oil fuel tube, draw-off pipe and drainpipe, have

Following formula can be noted by abridging and is:

WT _ax(t)＝x(t)*ψ _a(t)

Wherein, ${\mathrm{\ψ}}_a\left(t\right)=\frac{1}{a}\mathrm{\ψ}\left(\frac{t}{a}\right)$ Be basic small echo ψ (t) stretching on yardstick, a is a scale factor, and * is a convolution.

Therefore if signal x (t) at a time undergos mutation, near the wavelet transformation value this moment on each yardstick all can produce a local maximum point so, can utilize the wavelet transformation modulus maximum to detect all catastrophe points on the signal x (t).Signal has reflected the size of this singularity at certain any lipschitz exponent, and the maximum point position correspondence behind the wavelet transformation singular point.Since there is such relation,, just can find the position of sign mutation then by judgement to wavelet transformation maximum value.

Embodiment six: referring to Fig. 4 and Fig. 6, the oil and water separation autocontrol method of the multi-purpose station free water knockout (FWKO) of present embodiment is realized by following steps:

Step B1, open oil inlet pipe;

Step B2, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the liquid level that step B3, determining step B2 obtain reaches threshold value, and judged result then enters step B4 for being, judged result is then returned step B2 for not;

Step B4, close oil inlet pipe, treat to open draw-off pipe after the oil tank precipitation finishes;

Step B5, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B6, air that determining step B5 obtains and pasta reaches threshold value, and judged result then enters step B7 for being, judged result for otherwise return step B5;

Step B7, close draw-off pipe, open drainpipe;

Step B8, employing sensor array are measured the height value of the laminated fluid level of transition bed and water layer, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B9, transition bed that determining step B8 obtains and water layer satisfies threshold value, and judged result then enters step B10 for being, judged result is then returned step B8 for not;

Step B10, close drainpipe, open the liquid delivery pipe of transition bed;

Step B11, employing sensor array are measured the height value of the laminated fluid level of oil reservoir and transition bed, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B12, oil reservoir that determining step B11 obtains and transition bed satisfies threshold value, and judged result is then returned step B1 for being, judged result is then returned step B11 for not.

Claims (3)

1. based on the liquid level method for automatic measurement of the automatic measurement of the oil and water separation of multi-purpose station free water knockout (FWKO) with control device, automatic measurement of the oil and water separation of described multi-purpose station free water knockout (FWKO) and control device are by liquid level gauging module (1), liquid level signal modulation module (2), interface modular converter (3), usb interface module (4), main control module (5) and valve opening and closing driver module (6) are formed, the measuring-signal output terminal of liquid level gauging module (1) is connected with the measuring-signal input end of liquid level signal modulation module (2), the modulation signal output terminal of liquid level signal modulation module (2) is connected with the modulation signal input end of interface modular converter (3), the control signal output ends of interface modular converter (3) is connected with the signal input end of valve opening and closing driver module (6), the data input/output terminal of interface modular converter (3) is connected with the data input/output terminal of usb interface module (4), and the control signal input/output terminal of usb interface module (4) is connected with the control signal input/output terminal of main control module (5); Described liquid level gauging module (1) comprises a plurality of probes (1-1), and a plurality of probes (1-1) are formed a controlled sensor array, and the measuring-signal output terminal of each probe (1-1) all is connected with the measuring-signal input end of liquid level signal modulation module (2);

It is characterized in that it is realized by following steps:

Steps A 1, by the sequence number of popping one's head in the sequential definition liquid level gauging module from bottom to up for from 1 to n, nethermost probe is the 1st probe, initialization makes n=0;

Steps A 2, n=n+1;

Steps A 3, the conductivity signal that n probe gathered are converted to real-time conductivity value corresponding voltage value by A/D;

Whether the magnitude of voltage that steps A 4, determining step A3 obtain is greater than threshold value, and judged result then enters steps A 5 for being, judged result then enters steps A 6 for not;

Steps A 5, demonstration conductivity value overrun error return steps A 3;

The real-time conductivity that steps A 6, n probe of calculating record;

Steps A 7, judge whether the value of n equals N, N represents the probe number summation of sensor array, and judged result then enters steps A 8 for being, judged result is then returned steps A 2 for not;

Steps A 8, calculate the value of the real-time conductivity of each probe measurement by the singular point detection method;

The value of steps A 9, the conductivity that obtains according to steps A 8 is calculated the height of liquid level.

2. the oil and water separation method for automatic measurement of multi-purpose station free water knockout (FWKO) according to claim 1 is characterized in that the singular point detection method described in the steps A 8 is a wavelet analysis method.

3. autocontrol method with the liquid level method for automatic measurement of control device is measured in described oil and water separation based on the multi-purpose station free water knockout (FWKO) automatically based on claim 1, it is characterized in that it is realized by following steps:

Step B1, open oil inlet pipe;

Step B2, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the liquid level that step B3, determining step B2 obtain reaches threshold value, and judged result then enters step B4 for being, judged result is then returned step B2 for not;

Step B4, close oil inlet pipe, treat to open draw-off pipe after the oil tank precipitation finishes;

Step B5, employing sensor array are measured the height value of the laminated fluid level of air and pasta, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B6, air that determining step B5 obtains and pasta reaches threshold value, and judged result then enters step B7 for being, judged result for otherwise return step B5;

Step B7, close draw-off pipe, open drainpipe;

Step B8, employing sensor array are measured the height value of the laminated fluid level of transition bed and water layer, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B9, transition bed that determining step B8 obtains and water layer satisfies threshold value, and judged result then enters step B10 for being, judged result is then returned step B8 for not;

Step B10, close drainpipe, open the liquid delivery pipe of transition bed;

Step B11, employing sensor array are measured the height value of the laminated fluid level of oil reservoir and transition bed, and described sensor array is made up of N probe;

Whether the height value of the laminated fluid level of step B12, oil reservoir that determining step B11 obtains and transition bed satisfies threshold value, and judged result is then returned step B1 for being, judged result is then returned step B11 for not.

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