RU2815063C1 - Device for separating production fluid - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention concerns a unit for separating production fluid, which consists of a horizontally located pipe, in the upper part of which pipes for oil and gas extraction are installed, with pipes for water drainage in the lower part. Inside the housing there is a device for adhesive initialization of coalescence of water droplets, made in the form of hydrophilic plates installed at a negative angle to the horizontal direction of flow.

EFFECT: increase in efficiency by reducing the dispersion of the aqueous phase, i.e., improvement of phase separation conditions in reverse emulsions.

3 cl, 1 dwg, 1 tbl

Description

The invention relates to the oil production industry, in particular to installations for separating an oil-water emulsion into oil and water phases.

There is a known method of water separation in so-called reverse emulsions (the dispersion medium is hydrocarbon, for example, oil, and the dispersed medium is water) in the so-called pipe water separators (TWO) (Tronov V.P. Field oil preparation. - Kazan, FEN. - 2000, 416 pp., Author's certificate of the USSR No. 1404464, 06/23/1988, Bulletin No. 23).

A device for separating a mixture of the “water in oil” type is known, consisting of a horizontally located pipe, in the upper part of which there are pipes for extracting oil and gas, in the bottom there are pipes for draining water, and inside there are dividing transverse partitions, each of which is hinged a vertical wall is attached, connected to a mechanism for regulating the extraction of oil and water (Author's certificate No. 488595, MKI B01D 17/02, C10G 33/06, 10.25.75)

The disadvantage of the known device is the difficulty of collecting precipitated water without capturing oil, in the lower part of which there is an insignificant layer of water along the entire length of a horizontal pipe.

The principal obstacle to increasing the efficiency of any HME is the dependence on the initial dispersion of inclusions (water droplets in oil).

The technical problem of the claimed invention is the development of a device for separating well products with the achievement of the following technical result: increasing the efficiency of water extraction by initializing a decrease in the dispersion of the aqueous (hydrophilic) phase, i.e. improving the conditions for sedimentation of the aqueous phase in a gravitational field by increasing the sedimentation rate with increasing droplet diameter (Gimatudinov Sh.K., Shirkovsky A.I. Physics of oil and gas reservoirs. 3rd ed. - M.: Nedra, 1982. - 311 With).

The technical result is achieved by the fact that in a device for separating well products, containing a housing in the form of a horizontally located pipe, in the upper part of which pipes for oil and gas extraction are installed, in the lower part there are pipes for draining water, according to the invention, a device for adhesion initialization is located inside the housing coalescence of water droplets, made in the form of hydrophilic plates installed at a negative angle of 5-9 degrees to the horizontal direction of flow. In this case, the length of the hydrophobic plates (in meters) increases from bottom to top according to the law:

Where - liquid flow, m ³ /s;

- cross-sectional area, ^m2 ;

- distance between plates, m;

- experimental coefficient, 1.7-3.8 (selected depending on the nature of the contaminants: dispersion, wetting angle);

- minimum diameter of extracted (sedimented) particles, m (usually more than 10 microns).

The drawing shows a device for separating well products.

The device contains a housing 1 in the form of a pipe, with a gas outlet pipe 2 located in the upper part of the pipe, a flow calming zone 3, a water extraction pipe 4 located in the lower part of the pipe, with a gas-water-oil emulsion input pipe 5, a dehydrated oil extraction pipe 6, inside The housing contains a device for coalescence of water droplets, made in the form of hydrophilic (wetting angle no more than 30 degrees) plates 7, installed at a negative angle to the horizontal direction of flow (5-9 degrees).

The device works as follows.

Gas-water-oil inverse emulsion 8 is fed through pipe 5 into a device for separating well products, enters flow calming zone 3, in which the flow is distributed along the height of the pipe, passes through a system of hydrophilic plates 7. In this case, water drops 9 (aqueous phase in inverse emulsion) , finding themselves in the flow between the plates 7, coalesce under the action of surface forces as a result of adhesion interaction on the upper surface of the plates 7. This leads to an increase in their diameters, and therefore to an increase in the rate of sedimentation under the influence of gravity due to the difference in densities, because the settling velocity _vc , according to Stokes' law, is a function of the particle diameter:

Where - velocity of sedimentation of a spherical particle, m/s;

- drop diameter, m;

- density of water, kg/ ^m3 ;

- density of the dispersion medium (oil), kg/m ³ ;

- dynamic viscosity of the dispersion medium (oil), Pa*s;

- free fall acceleration, m/s ² .

As a result, water droplets accumulate on the upper surfaces of the hydrophilic plates 7, their enlargement (coalescence) and separation from the edge of the plates occurs, and the diameter depends on the length of the plates and is defined as:

,

Where - experimental coefficient.

Plate length determined from the inequality

Where - respectively, the time of vertical deposition and horizontal movement along the plate, m;

- vertical distance between the plates;

- velocity of sedimentation of a spherical particle, m/s;

- horizontal flow velocity, m/s;

Where - liquid flow, m ³ /s;

- cross-sectional area, ^m2 .

Moreover, the time of horizontal movement along a plate of length L; sufficient for sedimentation of particles with a diameter d _min .

Thus, in the space between the plates, hydrophilic particles enlarge to a size d _max , sufficient for hydrophilic particles in the main volume of the settling tank to sediment at a speed V _max (see drawing) into the lower part of housing 1. As a result, through the nozzles 2 and 6, the gas and oil phase with reduced water content are removed, respectively.

In the lower part of the settling tank, water with oil concentration reduced to acceptable values is removed through pipe 4.

The table presents the results of purification of gas-oil inverse emulsion with the comparative effect of using hydrophilic plates.

From Table 1 it follows that the efficiency of water separation for reverse emulsions increases significantly even without the use of coagulants, and averages (2.33/2.55) * 100% = 91% (without the use of hydrophilic plates no more than 15%).

Thus, the technical result of the invention is to increase the efficiency of separation of well products by reducing the dispersion of the hydrophilic phase in the initial section of sedimentation of water droplets.

Claims (10)

a in the form of hydrophilic plates installed at a negative angle to the horizontal direction of flow. 2. The device according to claim 1, characterized in that the hydrophilic plates are installed at an angle of 5-9 degrees. 3. The device according to claim 1, characterized in that the length of the hydrophilic plates increases from bottom to top according to the law: Where - liquid flow, m ³ /s; - cross-sectional area, ^m2 ; - distance between plates, m; - experimental coefficient; -minimum diameter of extracted particles, m.

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