CN105334247A - Multi-polar-plate sample pool and emulsion characteristic meter - Google Patents

Abstract

The invention relates to a multi-polar-plate sample pool and an emulsion characteristic meter. The multi-polar-plate sample pool comprises a cuboid insulation pool body with an opening in the top and two or more polar plates. Insulation plates are adopted for the four side walls and the bottom of the cuboid insulation pool body. The two or more polar plates are correspondingly pasted to any two parallel inner walls of the cuboid insulation pool body at equal intervals, a connecting strip is arranged at the outer end of each polar plate, and all the connecting strips extend out of the cuboid insulation pool body. The emulsion characteristic meter with the multi-polar-plate sample pool has quite good sensitivity and quite good stability. By means of the emulsion characteristic meter, the internal liquid ball distribution, the change process and the emulsion stability of a stable W/O and O/W type emulsion system can be accurately measured; as for instable W/O and O/W type emulsion, the oil-water distribution states of different layers inside the emulsion, the aggregation process and the settlement process of water drops inside the emulsion, the oil-water layered process and stability can be measured.

Description

A multi-plate sample cell and emulsion characteristic instrument

technical field

The invention relates to the field of oilfield chemistry, in particular to a multi-plate sample pool and an emulsion characteristic instrument.

Background technique

Emulsion is an important type of dispersion system. People have done a lot of research on its stability. However, due to the difference in the type, composition, and number of phases of the oil and water phase substances in the emulsion, and the difference in emulsifiers, the stability of the emulsion cannot be guaranteed. The difference is very large, so there is no unified method for the determination of emulsion stability. The crude oil emulsions formed in the oil recovery process include W/O type, O/W type and multiple emulsions. Since the crude oil emulsion is dark brown, it is difficult to investigate the flocculation and coalescence process of the droplets, and even the stratification of the crude oil and the emulsion cannot be distinguished. The general evaluation method of emulsion stability has large errors. Therefore, in order to study the stability, type, droplet distribution and phase inversion of emulsion in depth, it is necessary to study and establish a new evaluation method for emulsion type and stability, and to investigate the conditions for phase inversion of emulsion.

The dielectric properties of crude oil emulsion are very important for judging the type and stability of the emulsion, and selecting the demulsification method. At room temperature, the relative dielectric constant of pure crude oil is 2.0-2.7, and that of pure water is 80. When water droplets are dispersed in crude oil to form a W/O emulsion or oil droplets are dispersed in water to form an O/W emulsion, the relative dielectric constant of the emulsion varies with the volume of the dispersed phase, the size and number of water droplets will change. Kubo and Nakamura considered the dielectric properties of a dispersed system theoretically. This system is composed of small balls with a dielectric constant of ε ₁ dispersed in a medium with a dielectric constant of ε _0. They made the following assumptions: 1 ) The particles of the dispersed phase are all spherical; 2) There is no net charge on the particles; 3) Compared with the size of the whole multi-phase system, the radius of the ball is extremely small; 4) Compared with the molecule, the radius of the ball is is very large, so both the dispersed phase and the dispersion medium can be regarded as uniform objects, and their properties are only determined by their dielectric constants. According to these assumptions, the two derived the dielectric constant ε of the dispersed system and the volume fraction of the dispersed phase relationship, but the result is a very complicated relationship, which has not been verified by experiments. Most of the work related to the dielectric constant of emulsions is based on the formula derived from theoretical assumptions, lacking systematic and complete experimental results to verify.

Contents of the invention

In view of the above problems, one object of the present invention is to provide a multi-plate sample cell; another object of the present invention is to provide an emulsion characteristic instrument with sensitivity and stability.

In order to achieve the above object, the present invention adopts the following technical solutions: a multi-plate sample cell, which is characterized in that the multi-plate sample cell includes a cuboid insulating cell with an open top and more than two polar plates, and the cuboid insulator The four side walls and the bottom of the pool are all made of insulating plates, and two or more of the pole plates are pasted at equal intervals on any two parallel inner walls of the cuboid insulating pool, and the outer end of each pole plate is A connecting bar is arranged on each part, and each connecting bar extends to the outside of the cuboid insulating pool.

Preferably, the insulating board is made of glass sheet.

Preferably, copper sheets are used for each of the pole plates and connecting bars.

An emulsion characteristic instrument is characterized in that the emulsion characteristic instrument comprises a power supply, an oscillating circuit, an amplifier, a detector, a computer and a multi-plate sample cell, and the multi-plate sample cell is provided with The emulsion is used as a dielectric; two corresponding plates on the two parallel inner walls of the cuboid insulating pool form a capacitor, and the oscillation circuit is connected to the capacitor by wires to form an oscillator, and the output terminal of the oscillator is connected to the The input terminal of the amplifier, the output terminal of the amplifier is connected to the detector, the detector sends the detected oscillation frequency signal to the computer, and the power supply is used to supply power for the oscillator, amplifier and detector .

Preferably, the emulsion is a water-in-oil emulsion, an oil-in-water emulsion or a crude oil emulsion.

Because the present invention adopts the above technical scheme, it has the following advantages: 1. The emulsion characteristic instrument equipped with multi-plate sample cell of the present invention has good sensitivity and stability, and can accurately measure stable W/O emulsion The distribution and change process of liquid droplets inside the liquid system and the stability of the emulsion are used to determine the settling velocity of the liquid droplets. 2. The present invention uses a multi-plate sample cell to measure the distribution state of oil and water in different layers inside the unstable W/O emulsion, and to investigate the aggregation, sedimentation process and oil-water stratification process of water droplets inside the emulsion. The invention can be widely used in the property measurement of the emulsion.

Description of drawings

Fig. 1 is the structural representation of polar plate of the present invention;

Fig. 2 is a schematic diagram of pole plate arrangement in the multi-plate sample pool of the present invention;

Fig. 3 is the schematic diagram of the principle of the emulsion characteristic instrument of the present invention;

Fig. 4 is a schematic diagram of the F value of deionized water of the present invention changing with time;

Fig. 5 is the schematic diagram of the time-varying curve of simulated water F value of the present invention;

Fig. 6 is a schematic diagram of the characteristic curve of the emulsion with a water content of 10% according to the present invention;

Fig. 7 is a schematic diagram of the characteristic curve of the emulsion with a water content of 90% according to the present invention;

Fig. 8 is a schematic diagram of the F value of the crude oil/formation simulated water emulsion changing with time according to the present invention.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings. However, it should be understood that the accompanying drawings are provided only for better understanding of the present invention, and they should not be construed as limiting the present invention.

As shown in Fig. 1 and Fig. 2, the multi-plate sample cell provided by the present invention comprises a cuboid insulating cell with an open top and more than two pole plates, and the four side walls and the bottom of the cuboid insulating cell all adopt insulating plates, On any two parallel inner walls of the cuboid insulating pool, more than two pole plates 1 are respectively pasted at equal intervals, and a connecting strip 2 is arranged on the outer end of each pole plate 1, and each connecting strip 2 extends to the cuboid The outside of the insulating pool is connected with wires when used.

In a preferred embodiment, the insulating plate can be a glass sheet with a thickness of 2 mm.

In a preferred embodiment, the bottom of the cuboid insulating pool can be a square with a side length of 28 mm, and the height of the cuboid insulating pool can be 124 mm.

In a preferred embodiment, both the pole plate 1 and the connection bar 2 can be copper sheets with a thickness of 0.5 mm.

In a preferred embodiment, the two parallel inner walls of the cuboid insulating pool are respectively pasted with six pole plates 1 at equal intervals, and each pole plate 1 can be pasted on the inner wall of the cuboid insulating pool with 504 glue.

The manufacturing process of the multi-plate sample cell of the present invention is described in detail below through specific embodiments. In the present embodiment, the manufacturing materials are: the polar plate adopts a 0.5mm thick copper sheet and the insulating plate adopts a 2mm thick glass sheet, and the specific manufacturing process is:

1) According to the shape in Figure 1, use scissors to cut out 12 pieces of copper sheets with a length of 22mm and a width of 16mm. The copper sheets have a connecting strip 2 with a length of 20mm as a test point connector.

2) Use a glass cutter to cut out a glass piece with a length of 124mm and a width of 28mm and two pieces of glass with a length of 124mm and a width of 22mm.

3) Glue 6 copper sheets to a glass sheet with a width of 28mm with 504 evenly at a distance of 2mm each, and apply a layer of 504 glue on the other side of the copper sheet; glue the other 6 copper sheets on the On another glass sheet with a width of 28mm, and coat the other side of the copper sheet with a layer of 504 glue, the thickness of the 504 glue can be 0.5mm to 2mm.

4) Glue the two glass sheets with copper sheets and the other two glass sheets with a width of 22mm to form a cuboid insulating pool with 504, and use another piece of glass to seal the bottom of the rectangular parallelepiped insulating pool as the bottom of the rectangular parallelepiped insulating pool. As shown in Figure 2, the numbers from the bottom of the rectangular parallelepiped insulating cell to the lower and upper plates are 1-6, and the total volume of the multi-plate sample cell obtained at this time is about 40mL.

As shown in Figure 3, based on the multi-plate sample cell of the present invention, the present invention also provides an emulsion characteristic instrument, comprises a power supply 3, an oscillation circuit 4, an amplifier 5, a detector 6 and a computer 7, The emulsion is placed in the multi-plate sample cell as a dielectric, and the two corresponding plates 1 arranged on the two parallel inner walls of the cuboid insulating cell form a capacitor. The power supply 3 is used to supply power to all electrical devices. The corresponding two ends of the wires passing through the two parallel inner walls of the cuboid insulation pool (i.e. the two input ends of the oscillating circuit are respectively connected to capacitors made of polar plates) constitute an oscillator, and the output end of the oscillator is connected to the input end of the amplifier 5 to carry out the oscillation frequency signal Amplify, the amplifier 5 sends the amplified signal to the detector 6, and the detector 6 sends the detected oscillation frequency signal to the computer 7 for data processing to obtain the emulsion characteristic parameters, wherein the emulsion can be a water-in-oil emulsion or a water-in-oil emulsion. Oil emulsion or crude oil emulsion.

The F value is measured by the emulsion characteristic instrument, and its physical meaning is "frequency". The basic principle of the emulsion characteristic instrument is that changing the capacitance of the capacitor can change the oscillation frequency, and the oil-water ratio of the emulsion in the multi-plate sample cell , Changes in the size of liquid droplets, etc. will change the capacitance. Generally, the frequency of the oscillator can be changed by adjusting the capacitance of the capacitor. When the capacitance of the capacitor changes slightly, the frequency of the oscillator will change greatly, and the characteristics of the circuit will change sensitively. The oscillation frequency of the oscillator can be detected and recorded by a frequency meter, and the detected data can be processed by a computer to output characteristic parameters. The multi-plate sample cell containing the emulsion is made into a capacitor, and the emulsion is used as the dielectric. When the size and distribution of the droplets in the emulsion change, or when the oil and water phase separation occurs, the dielectric properties of the emulsion will change. Changes occur, and further lead to changes in capacitance and circuit characteristics. According to changes in circuit characteristics, the stability, type, and droplet distribution of the emulsion can be determined, and the phase inversion conditions of the emulsion can be investigated.

The method for measuring the emulsion characteristic properties by the emulsion characteristic instrument of the present invention is described in detail below by each embodiment, specifically:

Embodiment 1: Sensitivity determination of emulsion characteristic instrument containing multi-plate sample cell

1) Experimental conditions

Oil phase: 15# white oil; kerosene; Gudong crude oil; model oil (dilute Gudong crude oil 5 times with kerosene to become a model oil); water phase: deionized water; simulated water; temperature: room temperature; Table 1:

Table 1 Simulated water ion composition (mg/L)

Ionic composition Cl ^- HCO ₃ ^- Na ⁺ +K ⁺ Mg ²⁺ Ca ²⁺ Salinity concentration 2885.49 818.89 2064.55 20.88 66.85 5856.66

2) Operation method of the emulsion characteristic instrument

Measure 40mL of various water phases and oil phases, inject them into a clean multi-plate sample cell, let it stand for 5 minutes, connect the emulsion characteristic instrument containing the multi-plate sample cell, and start timing. The measurement time is 60 minutes, record the F values of the 6 plates at 0, 10 minutes, 20 minutes, 30 minutes, 40 minutes and 60 minutes, take time as the X axis, and the F values of different plates at different times on the Y axis drawing.

It can be seen from Table 2 and Table 3 that although the dielectric constant only changes by dozens of units from oil to water, the F value measured by each plate changes by more than 3000 units, indicating that the multi-plate The sensitivity of the emulsion characterization instrument is quite high.

Table 2 deionized water, white oil measurement results

plate 1 2 3 4 5 6 F _{deionized water} 11942 11842 12149 11911 11812 11886 F _{white oil} 15230 15189 15232 15226 15237 15245 F _{white oil} -F _{deionized water} 3288 3347 3083 3315 3425 3359

Note: The F value is measured at 60 minutes.

Table 3 Determination results of simulated water, simulated oil and crude oil

Note: The F value is measured at 60 minutes.

Embodiment 2: Stability and repeatability determination of the emulsion characteristic instrument containing the multi-plate sample cell

Under the same experimental conditions as in Example 1, the F value of deionized water and simulated water was measured as a function of time. The results are shown in Fig. 4 and Fig. 5, and Table 4 is the comparison of two measurement results of deionized water:

Comparison of the two measurement results of table 4 deionized water

plate 1 2 3 4 5 6 F value for the first time 11942 11842 12149 11911 11812 11886 Second F value 12013 11884 12196 12023 11880 11958 difference 71 42 47 112 68 72 Relative rate of change/% 0.60 0.35 0.38 0.94 0.57 0.60

Note: The F value in the table is the F value measured at 60 minutes.

From the above results, it can be seen that the emulsion characteristic instrument with multi-plate sample cell has good stability and repeatability.

Embodiment 3: Determination of the characteristics of water-in-oil emulsion by the emulsion characteristic instrument containing the multi-plate sample cell

1) Experimental conditions

Oil phase: 15# white oil; water phase: deionized water; surfactant: Span80, chemically pure; absolute ethanol: analytically pure; German X120 emulsifier; temperature: room temperature.

2) Experiment method: Span80 white oil solution/water emulsion system

(1) Prepare 400 mL of white oil solutions with mass concentrations of Span80 of 0.3%, 0.1%, and 0.05% each as the oil phase.

(2) Deionized water was used as the water phase, and the experiment was carried out on the oil phase with a mass concentration of Span80 of 0.3%. The total volume of the oil-water two-phase is 70mL. According to different volume ratios, measure the water phase and the oil phase with a graduated cylinder, add the water phase first, and then put the oil phase into a small 80mL beaker.

(3) Fully immerse the emulsifying head of the emulsifier under the liquid surface, open the emulsifier at the same time, and emulsify at a speed of 10000rpm for 2 minutes.

(4) Take 10 mL of the prepared emulsion and inject it into a graduated test tube, then pour the emulsion into the multi-plate sample cell, fill the multi-plate sample cell, and then inject the remaining emulsion into the test tube, and observe Its state, and use the dilution method to determine the type of emulsion.

(5) Connect the multi-plate sample cell with the emulsion characteristic instrument, and start timing, and record the characteristic parameter F data of each plate at 0 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes and 60 minutes and Emulsion changes in test tubes.

(6) After the measurement, the multi-plate sample cell was washed with washing powder, then rinsed with deionized water, then rinsed with absolute ethanol, and dried with a hair dryer.

(7) Measure the emulsion prepared by the next oil-water volume ratio in the same way. The order of determination was measured in the order of the volume content of water from 10%, 20%, 30%, ... 90%, and then the above experimental steps were repeated in the order of Span80 mass concentration of 0.1%, 0.05% white oil solution.

Taking the characteristic curve of the emulsion with a water content of 10% as an example (see Figure 6), the concentration of the Span80 oil phase is 0.3%.

As shown in Figure 6, at 0 minutes, the F value of each plate has little difference. As time increases, the F value of 6 plates gradually increases, while the F values of the other plates gradually decrease. This phenomenon shows that, as time changes, for emulsions with relatively uniform dispersion of water droplets, the size distribution of water droplets inside the system will change, and the water droplets in the emulsion will settle downward, resulting in liquid droplets in the upper part of the emulsion system Smaller in diameter and less in number, and larger in size and in more numbers in the lower part. This phenomenon cannot be observed by the naked eye, and it is difficult to accurately measure this change process with other instruments or methods for measuring the stability of emulsions. At 60 minutes, the F value of each plate of the emulsion characteristic instrument decreases from 6 plates to 1 plate, which is consistent with the distribution law that the number of water droplets inside the emulsion increases from top to bottom.

Embodiment 4: Determination of the characteristics of oil-in-water emulsion by the emulsion characteristic instrument containing the multi-plate sample cell

1) Experimental materials and conditions

Oil phase: 15# white oil; water phase: deionized water; surfactant: sodium oleate, chemically pure; absolute ethanol: analytically pure; German X120 emulsifier; temperature: room temperature.

2) Experiment method: white oil/sodium oleate aqueous emulsification system

(1) Prepare 400 mL of deionized aqueous solutions with sodium oleate concentrations of 0.3%, 0.1%, and 0.03%, respectively, as the water phase.

(2) Using white oil as the oil phase, the experiment was carried out on the water phase with a sodium oleate concentration of 0.3%. The total volume of the two phases of oil and water is 70mL, and according to the volume ratio of the two phases, take the water phase and the oil phase with a measuring cylinder respectively, add the water phase first, and then put the oil phase into a small 80mL beaker.

(3) Fully immerse the emulsifying head of the emulsifier under the liquid surface, open the emulsifier at the same time, and emulsify at a speed of 10000rpm for 2 minutes.

(4) Take 10 mL of the prepared emulsion and inject it into a graduated test tube, then pour the emulsion into the multi-plate sample cell, fill the multi-plate sample cell, and then inject the remaining emulsion into the test tube, and observe Its state, and use the dilution method to determine the type of emulsion.

(5) Connect the multi-plate sample cell with the emulsion characteristic instrument, and start timing, and record the characteristic parameter F data of each plate at 0 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes and 60 minutes and Emulsion changes in test tubes.

(6) After the measurement, the multi-plate sample cell was washed with washing powder, then rinsed with deionized water, then rinsed with absolute ethanol, and dried with a hair dryer. Then use the same method to measure the emulsion prepared in the next ratio. The order of measurement was measured in the order of 90%, 80%, 70%...10% of the volume content of water, and then the above experimental steps were repeated in the order that the aqueous phase concentration of sodium oleate was 0.1%, 0.03%.

As shown in Figure 7, when the aqueous phase concentration of sodium oleate is 0.1%, the emulsion characteristic curve when the water content is 90%. Visual observation and detection experiments show that when the water content is 90%, the system forms an oil-in-water emulsion, which is relatively stable. It can be seen from Figure 7 that the F value of each plate measured by the system at 0 minutes is less than 12000, and changes little with time, which shows that the type and milky state of the emulsion can be judged by the F value of each plate. liquid stability.

Embodiment 5: Determination of properties of crude oil emulsion by an emulsion characteristic instrument containing a multi-plate sample cell

1) Experimental materials and conditions

Gudong crude oil; MgCl ₂ 6H ₂ O, analytically pure; sodium bicarbonate, analytically pure; calcium chloride, analytically pure; potassium chloride, analytically pure; sodium sulfate, analytically pure; absolute ethanol, analytically pure; deionized Water: X120 emulsifier made in Germany; temperature: room temperature; see Table 1 for the composition of formation simulated water.

2) Experimental method

(1) Crude oil is used for the oil phase, and formation simulation water is used for the water phase. The total volume of the oil and water phases is 70mL. According to different volume ratios of the two phases, the water phase and the oil phase are respectively taken with a measuring cylinder, and the water phase is added first, and then the oil phase is added to 80mL in a small beaker.

(2) Fully immerse the emulsifying head of the emulsifier under the liquid surface, and at the same time turn on the emulsifier, and emulsify at 10000rpm for 2 minutes.

(3) Take 10 mL of the prepared emulsion and inject it into a graduated test tube, then pour the emulsion into the multi-plate sample cell, fill the multi-plate sample cell, and then inject the remaining emulsion into the test tube, and observe Its state, and use the dilution method to determine the type of emulsion.

(4) Connect the multi-plate sample cell with the emulsion characteristic instrument, and start timing, and record the characteristic parameter F data of each plate at 0 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes and 60 minutes respectively and Emulsion changes in test tubes.

(5) After the measurement, the multi-plate sample cell was washed with washing powder, then rinsed with deionized water, then rinsed with absolute ethanol, and dried with a hair dryer. Use the same method to prepare the emulsion prepared by measuring the next oil-water volume ratio. The order of determination is determined in sequence from 10%, 20%, 30%...70% of the volume content of water.

Figure 8 is the curve of the F value of the crude oil/formation simulated water emulsion versus time, where the water cut is 70%. Visual observation and detection experiments show that the whole system is a water-in-oil emulsion and is very stable, and the system is paste-like and unevenly dispersed. It can be seen from Figure 8 that the F value of the 2 pole plates is the smallest at 0 minutes, and the F values of the other plates are close. With the increase of time, the F value of each polar plate increased, and the F value of the 2 polar plate increased the most. At 60 minutes, the F value of the 2 polar plate was still the smallest. This shows that the water droplet content of the emulsion at the 2 pole plate is relatively high, and it decreases with time, but it is still higher than the water droplet content of the emulsion at other plate parts. This phenomenon shows that for some emulsions, even if they are stable Strong resistance, but the distribution of water droplets inside the system is uneven.

The above-mentioned embodiments are only used to illustrate the present invention, wherein the structure, connection mode and manufacturing process of each component can be changed to some extent, and any equivalent transformation and improvement carried out on the basis of the technical solution of the present invention should not excluded from the protection scope of the present invention.

Claims (5)

1. a multipolar plate sample cell, it is characterized in that, this multipolar plate sample cell comprises a cuboid insulating pool with an open top and more than two pole plates, and four side walls and the bottom of the cuboid insulating pool all adopt Insulating plates, on any two parallel inner walls of the cuboid insulating pool, more than two plates are correspondingly pasted at equal intervals, and a connecting strip is arranged at the outer end of each of the plates, and each The connecting bars all extend to the outside of the cuboid insulating pool. 2. A kind of multipolar plate sample cell as claimed in claim 1, is characterized in that, described insulating plate adopts glass sheet. 3. A kind of multi-plate sample cell as claimed in claim 1 or 2, is characterized in that, each described pole plate and connecting bar all adopt copper sheet. 4. An emulsion characteristic instrument, it is characterized in that, this emulsion characteristic instrument comprises a power supply, an oscillating circuit, an amplifier, a detector, a computer and a multiplex as described in any one of claims 1 to 3 Plate sample cell, the multi-plate sample cell is provided with an emulsion as a dielectric; two corresponding plates on the two parallel inner walls of the cuboid insulating pool form a capacitor, and the oscillation circuit is formed by connecting the capacitor with a wire An oscillator, the output end of the oscillator is connected to the input end of the amplifier, the output end of the amplifier is connected to the detector, and the detector sends the detected oscillation frequency signal to the computer, the A power supply is used to power the oscillators, amplifiers and detectors. 5. A kind of emulsion characteristic instrument as claimed in claim 4, is characterized in that, described emulsion is water-in-oil emulsion, oil-in-water emulsion or crude oil emulsion.