RU2557627C1 - Method of separation of emulsion - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: initial emulsion is fed for separation, then the light phase after separation is injected and subjected to hydrodynamic cavitation, and then mixed with the initial emulsion which is heated by the heat of removed heavy and light phases.

EFFECT: invention enables to intensify the process of separation of emulsions and to reduce energy costs for its implementation.

1 ex, 1 dwg

Description

The invention relates to methods for the separation of emulsions (in particular, highly viscous persistent oil), consisting mainly of hydrocarbons and water. It can be used in the oil and gas industry, namely in systems for the collection, preparation and processing of hydrocarbons.

A known method of processing viscous persistent oil emulsions (AS USSR No. 1761187, MKI ⁵ B01D 17/04), comprising supplying a demulsifier and washing liquid; emulsion heating; its separation into light and heavy liquid phases, as well as the separation of solids and salts; recirculation of the heated heavy phase.

Common features of the known and proposed methods are:

- supply of the original emulsion for separation;

- heating the emulsion;

- recirculation of the heated phase;

- separation of the heavy phase from the light;

- their separate removal.

The disadvantages of this method are:

- the complexity of the process;

- the need for the use of demulsifiers and flushing fluid;

- the need for chemical decontamination after application of demulsifiers;

- significant energy consumption for heating the emulsion, recirculation of the heavy liquid phase, for high-speed input of the emulsion into the heavy liquid phase;

- a significant number of blowers for the selection and supply of intermediate emulsion layers, the supply of flushing water and emulsifiers.

The closest in technical essence and the achieved result to the proposed one is the known method of separation of emulsions (RU 2286194, IPC B01D 17/038, publ. 10/27/2006), including the jet feed of the original emulsion, the impact of the jet and the selection of phases, characterized in that the jet feed emulsions are carried out in the form of a swirling vortex stream, in the central zone of which a centrifugal force creates a reduced pressure equal to the saturated vapor pressure of a low-boiling liquid, and in its peripheral zone a pressure that ensures low-boiling pressure fluid in the central zone of the jet flow swirling emulsion selected peripheral part stream is recycled to the starting emulsion, the emulsion is heated to a vortex flow of the saturated vapor temperature by impact deceleration and output the heated central and peripheral streams after shock braking recirculated to the starting emulsion.

Common features of the known and proposed methods are:

- supply of the original emulsion for separation;

- fluid injection followed by its hydrodynamic cavitation;

- heating the emulsion by mixing with a circulating fluid subjected to cavitation;

- separation of the heavy phase from the light;

- their separate removal.

The disadvantages of this method are:

- injection of the entire stream of the original emulsion by the pump, which increases energy consumption;

- the supply of the heated central and peripheral flows after shock braking in a vortex flow for recirculation into the original emulsion leads to repeated mixing of the heavy and light phases (liquids) and the deterioration of their separation;

- Loss of thermal energy with discharged light and heavy phases. The technical task of the invention is to increase the efficiency of the process of separation of emulsions. The technical result is the intensification of the process of separation of emulsions and the reduction of energy costs for its implementation.

The problem is achieved in that in a method for separating emulsions, including feeding the original emulsion for separation, pumping a liquid followed by its hydrodynamic cavitation, heating the emulsion by mixing with a circulating liquid that has undergone cavitation, separating the heavy phase from the light, separate removal of them is new, that the light phase after separation is pumped up, subjected to hydrodynamic cavitation and mixed with the original emulsion, the original emulsion is heated with heat removed heavy and light phases, mixing soft phases and produce an emulsion of the initial ejection.

The technique, which consists in pumping the light phase and its subsequent hydrodynamic cavitation, allows it to be heated under the influence of cavitation, to break the intermolecular bonds of large hydrocarbon molecules (for example, highly viscous oil) that make up the light phase, and as a result, to reduce the density and viscosity of the latter and intensify the process of separation of the emulsion.

The technique, which consists in mixing the cavitated light phase with the initial emulsion, allows the transfer of thermal energy from the first to the second, thereby reducing the energy cost of heating it and intensifying the process of separation of the emulsion.

The technique, which consists in heating the initial emulsions with heat, removing the heavy and light phases, allows the recovery of thermal energy, thereby reducing its costs for the overall heating of the emulsion.

The technical method is that the light phase and the initial emulsion are mixed by ejection, which makes it possible to increase the pressure of the low-potential phase and thereby use the potential energy (pressure) of the high-pressure phase.

The authors are not aware of the current level of technology to increase the efficiency of the process of separation of emulsions, which consists in intensifying the process and reducing energy costs in a similar way.

The figure shows a schematic diagram of the installation, illustrating the technological and technical aspects of the implementation of the proposed method for the separation of emulsions.

The installation of the proposed method is as follows.

The product emulsion 1 is fed with the initial emulsion for separation into the separator 2, then the light phase after separation is fed via line 3 to the pump 4, which is injected into the Venturi nozzle 5 and, in the latter, subjected to hydrodynamic cavitation, after which it is mixed in the mixer 6 with the initial emulsion, the initial emulsion heated by heat removed through lines 7 of the heavy and light 8 phases in recuperative heat exchangers 9 and 10, respectively.

In addition, the mixing of the light phase and the original emulsion in the mixer 6 is performed by ejection.

In the separator 2, the amount of the light phase is regulated by a regulator 11, the temperature by a temperature regulator 12, and the overpressure by a safety valve 13.

The implementation of the method is illustrated by an example.

EXAMPLE

In the oil field through product pipeline 1, the initial emulsion, consisting of 60% oil and 40% water, and having a temperature of 20 ° C and a density of 0.85 kg / m ³ , is fed under pressure of 0.3 MPa for separation into the separator 2. Before this the initial emulsion is heated to a temperature of 35 ° C by heat removed along the lines of heavy 7 and light 8 phases in recuperative heat exchangers 9 and 10, respectively.

The easy phase - the oil after separation is fed for recycling in an amount of 30% of the initial amount of the emulsion through line 3 to pump 4, which is pumped to a pressure of 10 MPa into the Venturi nozzle 5. In the Venturi nozzle 5, the oil is subjected to hydrodynamic cavitation. After which the light phase - oil acquires an elevated temperature of 70 ° C, while its density decreases to 0.75 kg / m ³ , after which it is mixed in the mixer 6 with the original emulsion. After mixing, the emulsion acquires a temperature of 47-48 ° C. At this temperature, the process of emulsion separation is intensified by 1.3-1.33 times.

The mixture of the light phase and the initial emulsion in the mixer 6 is produced by ejection, while the pressure of the light phase exceeds the pressure of the original emulsion by 0.7 MPa. After ejection mixing, the emulsion pressure becomes equal to 0.35-0.4 MPa. Such pressure is sufficient for separate removal of the heavy and light phases in the field pipelines.

Claims (1)

A method of separating emulsions, including feeding the original emulsion for separation, pumping a liquid followed by its hydrodynamic cavitation, heating the emulsion by mixing with a circulating liquid subjected to cavitation, separating the heavy phase from the light, separately removing them, characterized in that the light phase is pumped after separation and subjected to hydrodynamic cavitation and mixed with the original emulsion, the original emulsion is heated with heat of the removed heavy and light phases, the light phase and the original emulsion are mixed ktsiey.