* Yao Danya Sun Yong Zhong Shuo-ping Zhang Baofen
100084 * Tsinghua University, Liaohe Oilfield

Abstract:

Thermal Recovery Act is the most effective method of recovery of heavy oil. Heavy oil output by two-phase soft drinks into the stem of the flow and quality impact. This paper presents a set of single-hole plate can be used to stem flow of soft drinks and two-parameter mass flow measurement instruments at the same time, the measuring method based on soft drinks flow orifice differential noise study to come to the measurement of soft drink Two-phase stem the flow and quality based on the theoretical model, a full set of instruments successfully applied to the Liaohe Oilfield heavy oil thermal recovery process.

Keywords : Orifice noise, two-phase, mass flow, the stem of

Thermal Recovery Act is the most effective method of recovery of heavy oil, heavy oil thermal recovery process, the quality of steam injection wells and flow of dry, to a large extent affect the heavy oil output, which makes the steam injection wells parameters of measurement Very important, this is the issue of soft drinks two-phase flow measurements.
In the industrial process and scientific research, the two-phase testing has been a focus of scientific research testing. Murdock orifice, such as the establishment of a separate model, James, such as the establishment of the improved orifice homogeneous flow model. These two models with two-phase density than the amendment, further improve the accuracy of the model, and to expand the scope of application.
Two-phase flow is a random process, the flow of the phase distribution in space and time are random. This randomness in the process of measuring the noise, such as orifice differential pulse, is the two-phase testing in the practice of well-known physical phenomena. However, according to the traditional measurement theory, this is just noise detection system of signal interference. According to modern detection theory point of view, noise is also a process of information system output. Through the noise of the analysis, the statistical noise filtering model, can be detected with the variables related to quantitative information, thus establishing the two-phase noise testing practical theoretical model.

1, orifice differential noise measuring flow of soft drinks theoretical model
Assumptions: vapor-liquid two-phase flow orifice, respectively; free-and momentum exchange; without phase transition process; meet the conditions of insulation.
Obtained from an idealized model for Orifice:




Is, the greater the differential noise.
Will be-(3) on both sides were divided by type (2) the two sides, available:


- (5), (6) is the use of orifice differential pressure measuring noise vapor-liquid two-phase two-parameter (such as mass flow and dry degrees) the theoretical model. Its physical meaning clear, the form is very simple, do not have to be directly applied to transform computer instrument.
Orifice soft drinks flow measured the relative differential Fanggen statistical variance (R), are up by dozens of large and small are also a few per cent, the stem of a sensitive response to changes.

2, soft drinks two-phase two-parameter measuring instrument

According to the model, the author successfully developed and single-hole plate supporting the measuring instruments. Instrumentation is the core of the Intel 8098 CPU, targeting 32 K ROM and 8 K RAM, also includes eight LED, 8 keys and micro-printer. A switching regulator power to provide electricity meters and the transmitter.
Pressure from the pressure transmitter and the transmitter 4 to 20 mA DC signal I / V converted into a voltage signal to 5 volts, and then the A / D conversion to digital. Digital filtering and Statistics estimated in the mathematical model for calculating the P, and. P and pressure from the corresponding subroutine calculated density and enthalpy, thereby stem the flow of soft drink calculated, the mass flow and carry the heat, and heat flow and a cumulative operation. LED constant for the keyboard and set-up and results showed that micro-playing regularly or can print the results immediately. D / A output interface of the dry signal, RS232 interfaces can communicate with the PC. Block diagram of instruments as shown in Figure 1.

Figure 1 instrumentation diagram



3, meters in the field of
Orifice use of soft drinks two-phase experiment measuring the 78 sets of data to determine the value of proportion. Following the experimental data from the Liaohe Oilfield, the two wells. Table 1 shows the use of the instruments and traditional sampling method of data stem from the difference. Table 2 shows the use of the instruments and traditional orifice flowmeter measured the difference between the flow of data.

[Table 1]

[table 2]

From the above data shows that the instrument measured the mass flow of water and boiler orifice flow, compared to less than 5% error; stem of error is less than 10 percent.

4, conclusions

(1) in soft drinks flow in the orifice differential in the two-phase noise is due to the uneven distribution of the density of the orifice and the effects arising from the separation. Pressure its noise variance compared to contain the flow and quality of the information. Orifice noise measurements using stem flow of soft drinks flow and quality of the theoretical models, the experiment proved that in line with the actual fundamental. To achieve a single orifice of the soft drinks at the same time measuring two-phase two parameters (of dry and traffic).
(2) soft drinks two-phase two-parameter measuring instruments compared with traditional instrumentation, measurement error is basically the same, but the simple structure, but also have a stronger performance.

References
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1, Lin Zonghu, etc.Two-phase flow measurements with sharp-edged orifice, International Journal of Multiphase Flow, 1962,8 (6):683-693
2 Tong Yun Gazette, in the orifice in the two-phase separation of the two-phase and humidity measurements. Journal of Tsinghua University,Vol. 31, No. 3, 1991:12-16
3 Tong Yun Gazette, noise measuring devices used to cut expenditure flow of theoretical models. Journal of Tsinghua University,Vol. 32, No. 6, 1992: 13-17
4 Wang Ran, use of noise measuring orifice flow and dry in the study. Journal of Tsinghua University,Vol. 32, No. S3, 1993: 117-123
5 SIN Schomburg equality, single-hole plate measuring soft drinks two-phase two parameters. China's nuclear science and technology reportsCNIC-00671, TSHUNE-0051
6 SIN Schomburg equality, orifice differential noise measuring two parameters of soft drinks two-phase theory and practice. Electronic ?instrumentation users, 1995 by Issue,111-115
7, Yao Danya, and so on, The Application of Double Measurement of Steam-water in Oil Field. The second session of the International Multiphase Flow testing technology conference proceedings,1998:140-145