# The method of measuring water content in oil-water emulsions

Usage: in the automation of the extraction and refining of oil. The inventive method is based on the selection of oil-water emulsion in the vessel constant level, the measurement of the differential pressure created by the column of oil emulsion in the vessel constant level, measuring the density of oil and water, forming an emulsion. After substituting the known parameters in the formula

P=N_{in}XP_{in}+(H_{e}-N_{in})p_{n}, (1)

whereP is the differential pressure of a column of water-oil emulsion in the vessel constant level, kg/m^{2}; p_{in}and R_{n}- the density of water and oil density (density of liquid media, forming an emulsion), kg/m^{3}; N_{e}and H_{in}- the level of oil-water emulsion in the vessel constant level (H_{e}=const) and the water level is incorporated into the emulsion, m; optionally substituted in the formula (1) level values of H_{in}sequentially starting with the lowest values of water level, with pre-selected interval, is calculated at each value of the level H_{in}the differential pressure values, and the calculation stops when calculated by the formula (1) is the differential pressure becomes equal to izmerenie differential pressure becomes equal to the measured differential pressure gauge differential pressure, use when determining the required water content (W,%) in water-oil emulsions according to the formula

where N_{in}- the value of the water level in the vessel constant level, which is calculated by the formula (1) is the differential pressure becomes equal to the measured differential pressure gauge differential pressure. The technical result - the simplification of the hardware and design of the devices implementing the proposed method of measurement. 1 Il.

The invention relates to the measurement technique is to measure the water content in oil-water emulsions and can be used in automation of processes of extraction and refining, as well as during metering operations.

Known devices intended for measuring water content in oil-water emulsion in the range from 0 to 100% (see, for example, technical description and operating instructions of the instrument of the American firm “Agar”, 1999), implementing the measurement method, based on the relationship between water content and intensity of high-frequency electromagnetic radiation, does not perform satisfactorily in the range of change of volumetric water content in oil-water A in oil”, and Vice versa, as a consequence, there is a sharp change (1-3) physico-chemical properties VNE associated functionally with the measured electrical parameters.

The change of physico-chemical properties VNE depends on many factors, the effect of which is almost impossible to consider, and this is the reason for the large errors of measurement devices-analogues in the above measurement range of the water content in the VNE.

The closest in technical essence to the claimed technical solution is the measurement method presented in the patent of the Russian Federation 2170925 (published. 20.07.2001), based on the selection of oil-water emulsion in the vessel, measuring the pressure created by the column of oil emulsion in the vessel, measuring the density of oil and water, forming an emulsion, the definition of the interface between oil and water in a vessel and calculating the desired water content according to the appropriate formula.

The disadvantage of this method is the complexity of the hardware and design of the devices when implementing it directly to the stream for measuring the water content in the VNE in a production environment.

The technical result of the invention is the simplification of the devices, the value of water content in oil-water emulsion, based on the selection of the VNE in the vessel constant level, the measurement of the differential pressure created by the column VNE in the vessel constant level, measuring the density of oil and water, forming an emulsion, in contrast to the prototype after substituting the known parameters (density of oil and water level water-oil emulsion in the vessel constant level) in the formula

P=N_{in}XP_{in}+(H_{e}-N_{in})p_{n}, (1)

whereP is the differential pressure of a column of water-oil emulsion in the vessel constant level, kg/m^{2}; p_{in}and R_{n}- the density of water and oil density (density of liquid media, forming an emulsion), kg/m^{3}; N_{e}and H_{in}- the level of oil-water emulsion in the vessel constant level (H_{e}=const) and the water level is incorporated into the emulsion, m;

optionally substituted in the formula (1) level values of H_{in}sequentially, starting with the minimum values of water level, for example with N_{in}=0.04 m, with a pre-selected interval, for example 0.01 m, is calculated at each value of the level H_{in}the differential pressure values, and the calculation stops when calculated by the formula (1) is the differential pressure becomes equal to the measured di is (1) the value of the differential pressure becomes equal to the measured differential pressure gauge (actual) pressure drop, use when determining the required water content (W,%) in water-oil emulsions according to the formula

where N_{in}- the value of the water level in the vessel constant level, which is calculated by the formula (1) is the differential pressure becomes equal to the measured differential pressure gauge (actual) pressure drop.

The simplification of the hardware and design is achieved due to the fact that is excluded from the measurement process, the level meter section of liquid media “oil-water”.

Example. The drawing shows a block diagram of the device for implementing the proposed method of measurement. In the drawing: 1 - vessel constant level, in which a constant level of oil-water emulsion is provided by the excess of the emulsion in the other coaxially located the vessel of larger diameter; 2 - differential pressure gauge with two pulse tubes (application of a differential pressure gauge due to the need to compensate the pressure when the gauge pressure); 3 - electronic computing unit (microprocessor controller with display unit and registration); 4, 6 - sensors density of water and oil, respectively; 5, 7 - a measure of the density of water and oil, respectively.

In every the of eritera differential pressure 2 (differential pressure gauge), water density 5 density oil 7 enters the electronic computing unit, where it is processed according to the algorithm given in this description.

Health check method and evaluation of its actual metrological characteristics produced in the following sequence.

Transparent vessel (glass tube) was filled with the investigated liquid (oil-water emulsion with different percentages of water and oil) and was determined using a sensor and an electronic functional computational units according to formulas given in this description.

To assess the measurement error used calibration fluid with a water content of 0% oil and 100%, with a water content of 10% oil and 90%, with a water content of 20% oil and 80%, with a water content of 30% oil and 70%, with a water content of 40% oil and 60%, with a water content of 50% oil and 50%, with a water content of 60% oil and 40%, with a water content of 70% oil and 30%, with a water content of 80% oil and 20%, with a water content of 90% oil and 10%, with a water content of 100% oil 0%.

In the preparation of calibration fluids used oil, having a density of p=855 kg/m^{3}and water with a given content of chloride salts in oil=25 g/L. Prepared calibration fluids have been certified by prodcost at a temperature of 20With produced in 11 dimensions. The main limit of the absolute measurement error did not exceed 1.0%, which is quite acceptable product control wells directly in the flow field.

The implementation of the method will improve the accuracy of measuring the water content in oil-water emulsion, thus simplifying the hardware and design of instrument technology, which, in turn, will allow more precision to produce control over the number of production wells directly in the flow field conditions. In addition, within one field density of oil and the density of produced water varies over a long period of time is very small, and can be introduced in the form of constant parameters that will allow to solve measurement tasks more simple and cheap means.

The proposed method can find application in different industries.

Claims

The method of measuring water content in oil-water emulsion, based on the selection of oil-water emulsion in the vessel constant level, the measurement of the differential pressure created by the column of oil emulsion in woodstove known parameters (density of oil and water, the level of water-oil emulsion in the vessel constant level) in the formula

P=N_{in}_{}XP_{in}+(H_{e}-N_{in})p_{n}, (1)

whereP is the differential pressure of a column of water-oil emulsion in the vessel constant level, kg/m^{2};

p_{in}and R_{n}- the density of water and oil density (density of liquid media, forming an emulsion), kg/m^{3};

H_{e}and H_{in}- the level of oil-water emulsion in the vessel constant level (H_{e}=nst) and the water level is incorporated into the emulsion, m;

optionally substituted in the formula (1) level values of H_{in}sequentially, starting with the minimum values of water level, for example, with N_{in}=0.04 m, with a pre-selected interval, for example, 0.01 m, is calculated at each value of the level H_{in}the differential pressure values, and the calculation stops when calculated by the formula (1) is the differential pressure becomes equal to the measured differential pressure gauge (actual) pressure drop, and the value of the level H_{in}where calculated by formula (1) is the differential pressure becomes equal to the measured differential pressure gauge (actual) pressure drop, used for definition wide-angle>the- the value of the water level in the vessel constant level, which is calculated by the formula (1) is the differential pressure becomes equal to the measured differential pressure gauge (actual) pressure drop.

**Same patents:**