RU2622931C1 - Way to manage the process of intrauterine separation of oil-water emulsion by acoustic impact - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: way is to select the frequency of the oscillation ƒ₁ from first source of ultrasound exposure with the direction of wave propagation, matching the flow direction, so that a plot of L is equal to the distance between the sources, run fading condition

and

Wherein A_l(0)=A₂(L), where A₁(0) and A₂(L)-amplitude acoustic oscillations in emulsion directly near sources, A₁(L) and A₂(0)-amplitude acoustic oscillations at a distance L from sources, measure flow rate and create frequency fluctuations of ƒ₂, less than ƒ₁, and the direction of wave propagation, opposite to the direction of traffic flow, so that

where c is the speed of sound w-emulsion flow rate.

EFFECT: enables to increase the degree of flocculation of oil globule.

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Description

The invention relates to the oil industry, and in particular to methods for dehydration of oil.

A known method of controlling the process of dissolution of sylvinite ores (RF Patent 2398620 C1, B01F 1/00, C01D 3/08, G05D 27/00, 2009), namely, that the ore supply is regulated depending on the content of the useful component in the input streams, In this case, the weighing batcher is controlled by setting the following dependence in the control system:

where ± G _ore is the _ore flow rate, allowing to adjust its main flow, G _got.r-p is the flow rate of the clarified solution, t, С _{KClгClCl.r-p} is the content of calcium chloride in the clarified solution,%, С _{KCl ore} is the content of potassium chloride in sylvinite ore,%, α _{KClгCl.р-р} - degree of saturation of the clarified solution with potassium chloride.

The disadvantage of this method can be considered that the process of dissolution of calcium chloride in a saturated solution slows down, and therefore accurate determination of the content of KCl in the ore is difficult.

, контролируют давление газа в каждом шлейфе, проверяя выполнение условия

, а также контролируют работу клапана-регулятора в запорной арматуре каждого шлейфа через обратную связь, определяя разность

.A known method of controlling the technological processes of a gas field (RF Patent 2344339 C1, F17D 3/00, 2007), which consists in creating an interfield reservoir from the plumes of cluster wells, from where gas is sent to a complex gas treatment unit (UKPG). At the same time, pressure and gas flow are monitored along its entire path from the well exit to the gas treatment facility in order to optimize the development of the gas field. At the same time, the gas flow rate for each of the process gas treatment units is maintained within the specified values

, control the gas pressure in each loop, checking the condition

, and also control the operation of the valve regulator in the shutoff valves of each loop through feedback, determining the difference

.

Known methods can not be used for in-line separation of oil-water emulsion, because there is no need to dose any reagents, as well as to measure and control the pressure in the loop of the well.

The process of oil production from oil reservoirs is accompanied by continuous mixing of oil with water and the formation of oil-water emulsions (VNE). The mixing of oil with water and the formation of VE often occurs even in reservoir conditions during the displacement of oil by water. This process also occurs when the watered oil rises from the bottom of the wells to its mouth and further in the field communications. The presence of water in oil leads to a rise in the cost of transport due to increasing volumes of transported liquid and an increase in its viscosity. The presence of aggressive aqueous solutions of mineral salts leads to rapid deterioration of both oil pumping and oil refining equipment. Highly watered products overload field pipelines and also increase their capital intensity in view of the costs of corrosion control and oil emulsification. In this regard, it is advisable to separate oil and water directly near the wellhead.

The task of the invention is to develop a method for optimal control of the process of separation of oil-water emulsions.

The technical result is an increase in the degree of flocculation of oil globules.

и

, причем A₁(0)=А₂(L), где A₁(0) и A₂(L) - амплитуда акустических колебаний в эмульсии непосредственно вблизи источников, А₁(L) и A₂(0) - амплитуда акустических колебаний на расстоянии L от источников, измеряют скорость потока и создают частоту колебаний ƒ₂, меньшую ƒ₁, и направлением распространения волны, противоположным направлению движения потока, таким образом, чтобы

, где с - скорость звука, w - скорость потока эмульсии.The technical result is achieved by the fact that in the method for controlling the in-line separation of the oil-water emulsion by acoustic exposure, the vibration frequency ƒ ₁ from the first source of ultrasonic treatment is selected with the wave propagation direction coinciding with the direction of flow, so that in the section L equal to the distance between the sources, the damping condition was satisfied

and

moreover, A ₁ (0) = A ₂ (L), where A ₁ (0) and A ₂ (L) are the amplitude of acoustic vibrations in the emulsion directly near the sources, A ₁ (L) and A ₂ (0) are the amplitude of acoustic oscillations at a distance L from the sources, measure the flow velocity and create an oscillation frequency ƒ ₂ less than ƒ ₁ and the direction of wave propagation opposite to the direction of flow, so that

where c is the speed of sound, w is the flow rate of the emulsion.

из-за обратного дробления глобул скоагулировавшей эмульсии.The technical result is achieved due to the simultaneous existence of two wave motions in the flow medium. Their superposition leads to the fact that the interference pattern is established in the flow, consisting of nodes - where the amplitude of oscillations is the smallest, and antinodes - where the amplitude of oscillations is the largest and moving at a speed equal to the speed of the stream. The relative velocity of the flow and the interference pattern, therefore, is zero, and therefore the particles of the emulsion are in nodes (where their concentration is greatest), sufficient time for their coagulation. Experiments show that with increasing frequency, the efficiency of flocculation increases, but the absorption of ultrasound in the stream also increases, which imposes a restriction on the length L and frequency, and the intensity of ultrasound in the stream is also limited by the value

due to the reverse fragmentation of globules of a coagulated emulsion.

To implement the method directly into the loop of the well at a distance L from each other, sources of acoustic effects are installed. A wave source with a greater frequency ƒ ₁ is located at the beginning of the flow, and with a smaller ƒ ₂ at the end. The vibration frequencies ƒ ₁ and ƒ _{2 are} selected depending on the flow rate and the value of L.

At nodes, the total amplitude of oscillations is the smallest, and at antinodes the largest. It is necessary to ensure the movement of nodes along with the flow at the same speed. In this case, the nodes with respect to the flow will be stationary, and the time spent by the particles in the nodes will be maximum and is determined by the length L and the flow velocity w. The vibration frequencies ƒ ₁ and ƒ _{2 are} selected so that several (more than 100) nodes of the interference pattern fit along the length L. Oscillations of waves with a frequency of ƒ ₁ and ƒ ₂ should have the same amplitude.

It can be shown that the planes of the nodes move in the direction of flow, if ƒ ₁ > ƒ ₂ . The amplitude of the longitudinal vibrations of the emulsion, if it extend towards each other wave with a frequency ƒ ₁ and amplitude A and the frequency ƒ _{1 2} and amplitude A ₂ is determined by superposition of these two oscillations.

;Wave along the stream:

;

,upstream:

,

where x is the coordinate of the nodal plane along the pipe,

s is the speed of sound,

t is the duration of the time from the beginning of exposure to ultrasound.

The amplitude A ₁ = A (x) is the largest at the source location A ₁ = (0) and damps along the pipe due to dissipation of vibrational energy and becomes equal to A ₁ = A ₁ (L) at the end of the working section. Similarly, A ₂ = A ₂ (L) is greatest at L and decreases to A ₂ = 0.

Adding the expressions, making the transformations, we obtain for A _x = A ₂ :

.

.

It can be seen that under these conditions a wave propagates in the emulsion with a frequency (ƒ ₁ + ƒ ₂ ), while its amplitude varies along the pipe according to the law determined by

,

,

, где n - 0, 1, 2, 3 … ∞, а скорость движения узловых плоскостей определяется формулой:

.position of nodal planes:

, where n - 0, 1, 2, 3 ... ∞, and the speed of the nodal planes is determined by the formula:

.

In FIG. 1 is a diagram illustrating the effect of the total amplitude of oscillations on the concentration of oil globules in a stream; 1 - source of acoustic vibrations with a frequency of ƒ ₁ ; 2 - a source of acoustic vibrations with a frequency of ƒ ₂ ; total amplitude of oscillations.

, и поскольку скорость частиц в пучностях V₁ больше скорости частиц в узлах V₂, то и С₂ больше С₁. Так как концентрация глобул нефти в плоскости узлов возрастает, расстояние между ними уменьшается, глобулы слипаются (концентрационная коагуляция) и эмульсия теряет свою устойчивость.We show that the concentration of oil globules in nodes is greater than in antinodes. We choose some plane Z (Fig. 1) located between the antinode and the node and moving together with the flow, and consider zone 1 and zone 2 (in zone 1, the amplitude of oscillations is greater than in zone 2). Accordingly, the concentration of the oil globules C ₁ and C ₂ , their speed due to the effects of the fluctuations of the emulsion flow V ₁ and V ₂ . Because the flow of globules from the antinode to the node is equal to their reverse flow in the steady state: С ₁ ⋅V ₁ = С ₂ ⋅V ₂ , therefore

, and since the velocity of particles in antinodes V _{1 is} greater than the velocity of particles in nodes V ₂ , then C _{2 is} greater than C ₁ . As the concentration of oil globules in the plane of the nodes increases, the distance between them decreases, the globules stick together (concentration coagulation) and the emulsion loses its stability.

и

причем А₁(0)=А₂(L).The flocculation efficiency increases with an increase in the number of nodal planes, which is proportional to the frequencies ƒ ₁ and ƒ ₂ . However, it is known that with an increase in ƒ ₁ and ƒ ₂ the damping of the oscillations increases, and for the formation of nodal surfaces during the interference of the oscillations it is necessary that their amplitudes A ₁ and A ₂ be close in magnitude throughout the entire working section L. The value of ƒ ₁ depends on the damping fluctuations in the emulsion and is selected maximum when taking into account the ratios:

and

where A ₁ (0) = A ₂ (L).

The implementation of the method is illustrated by an example.

EXAMPLE

и

выполняется на 10-ти метрах. На расстоянии L=10 м друг от друга устанавливают источники ультразвуковых колебаний 1 и 2, в поток устанавливают также датчик скорости потока 3. Скорость потока эмульсии в трубе w=1 м/с, скорость звука с=1000 м/с. Сигнал от датчика скорости потока 3 проходит на генератор колебаний 4, вырабатывающий колебания с частотами ƒ₁ и ƒ₂. В состав генератора 4 входит средство обработки информации, например компьютер, работающий по заданной программе и связанный с датчиком скорости потока. T.к. ƒ₁=50000 Гц, то

. Далее колебания частотой ƒ₁ и ƒ₂ проходят на усилители мощности, входящих в генератор 4 и далее на источники акустических колебаний 1 и 2, генерирующих колебательный процесс уже в среде движущегося потока эмульсии и представляющие собой магнитострикционные преобразователи. При реализации данного способа степень флокуляции глобул нефти увеличивается на 30%.In the pipe 5 (Fig. 2) the emulsion flow moves. For a frequency of 50,000 Hz, the attenuation condition

and

runs at 10 meters. At a distance of L = 10 m from each other, sources of ultrasonic vibrations 1 and 2 are installed, a flow velocity sensor 3 is also installed in the flow. The emulsion flow velocity in the pipe is w = 1 m / s, the sound velocity is c = 1000 m / s. The signal from the flow rate sensor 3 passes to the oscillation generator 4, generating oscillations with frequencies ƒ ₁ and ƒ ₂ . The composition of the generator 4 includes a means of processing information, for example, a computer that runs on a given program and is associated with a flow rate sensor. T.k. ƒ ₁ = 50,000 Hz, then

. Further, the oscillations with a frequency of ƒ ₁ and ƒ ₂ pass to the power amplifiers included in the generator 4 and then to the sources of acoustic vibrations 1 and 2, which generate the oscillatory process already in the medium of the moving emulsion flow and are magnetostrictive converters. When implementing this method, the degree of flocculation of oil globules increases by 30%.

Claims (1)

A method for controlling the in-tube separation of a water-oil emulsion by an acoustic effect, which consists in selecting a vibration frequency

from the first source of ultrasonic exposure with the direction of wave propagation coinciding with the direction of flow, so that in the area L equal to the distance between the sources, the damping condition is satisfied

and

moreover, A _l (0) = A ₂ (L), where A ₁ (0) and A ₂ (L) are the amplitude of acoustic vibrations in the emulsion directly near the sources, A ₁ (L) and A ₂ (0) are the amplitude of acoustic oscillations at a distance L from the sources, measure the flow velocity and create the oscillation frequency

less

, and the direction of wave propagation, opposite to the direction of flow, so that

where c is the speed of sound, w is the flow rate of the emulsion.

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