End phase pipe divider (KDFT) are designed for separation of well production and preparation of formation water to the required standards. Used in water pre-discharge units, formation pressure maintenance systems, or as an inlet stage of oil treatment units.
Advantages of KDFT over the classical preparation scheme
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combining several devices in one unit,
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parallel rather than sequential flow of the phase separation processes,
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exclusion of some of the equipment by using mixers and coalescers, as well as the use of the tube separation method.
Thus, installation of KDFT will reduce capital costs by reducing the metal intensity up to three times and the building area up to 1.5 times.
Main components and equipment of KDFT
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process unit, which is a cylindrical device with outer and inner corrosion-resistant coating, with elliptical bottoms, with internal devices for separation of water from oil, as well as for purification of water from mechanical impurities and oil;
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gas pre-sampling unit (UPOG) designed to extract the separated free gas in the supply header;
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pipelines of the process unit piping with shut-off and control valves;
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supports for process piping and the device;
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ladders and service platforms;
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water quantity measurement system (SIKV);
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safety valve block with switching device;
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control valve to maintain the level of the "oil-water" phase interface in the apparatus.
Operating principle of KDFT
KDFT-1400-60-4 is four cylindrical devices inclined at an angle of 6° to the horizon with ladders and service platforms, bundled with pipelines for raw materials, treated water, oil, and gas with shutoff and control valves, and equipped with instrumentation and control equipment which is necessary for the process.
The unit uses the principles of hydrodynamic and hydrostatic separation of the incoming gas-liquid mixture. Degassing, dewatering, and water purification processes take place simultaneously. For this purpose, pre-selection devices for gas extraction are used at the inlet, and multi-shelf coalescers-desiccators for post-treatment of water from mechanical impurities and oil are used in the lower part of the unit section. The dimensions and volume of the devices are selected for a given liquid capacity, physical, and chemical properties of oil, foundation water, and quality requirements for the final product.
The oil and gas-water emulsion, after passing through the gas pre-sampling unit, enters the four devices through the inlet nozzles, where additional separation of liquid and gas phases occurs. The water is directed to the lower part of the device, where it passes through narrow channels by means of coalescence sections, changing the direction of water movement and freeing it from oil. After the coalescence sections, the water enters the collection compartment and exits the units through the water outlet manifold. The emulsion separation process is carried out with the addition of a demulsifier prior to installation.
Due to its lower density, the oil emulsion rises to the upper level of the units, is freed from the gas and flows into the oil emulsion collection section.
The gas is exhausted from the top of the devices combining with the gas from the UPOG and then combining with the dewatered oil stream.