CN105319246A - Emulsion characteristic detecting instrument - Google Patents

Abstract

The invention relates to an emulsion property detector, which is characterized in that it comprises: a capacitor, a wire, an oscillating circuit, an amplifier, a detector, a computer and a power supply; the capacitor is connected to the oscillating circuit through the wire to form an oscillator, and the The output terminal of the oscillator is connected to the detector through the amplifier, and the detector transmits the detected oscillation frequency signal to the computer; the power supply supplies power for the oscillation circuit, the amplifier and the detector. The emulsion characteristic instrument of the present invention has good sensitivity and stability, and can measure the stability of the emulsion, the type of the emulsion and the phase inversion process, the aggregation, sedimentation or floating of liquid droplets in the emulsion, and the phase change of the emulsion. Demulsification process.

Description

An emulsion characteristic detector

technical field

The invention relates to an emulsion property detection device, in particular to an emulsion property detection instrument used in the field of oil field chemistry.

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 quantity of oil and water phase substances in the emulsion, as well as the difference in emulsifiers, the stability of the emulsion cannot be guaranteed. The difference is very large, so there is no unified and universal 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. The paper by Kubo and Nakamura theoretically considers the dielectric properties of a dispersed system. This system is composed of small balls with _a dielectric constant of ε1 dispersed in a medium with a dielectric constant of _ε0 . 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 multiphase system, the radius of the small ball is extremely small; 4. In comparison, the radius of the sphere is very large, so both the dispersed phase and the dispersed medium can be regarded as uniform objects, and their properties are only determined by their dielectric constants. Based on these assumptions, the two derived the relationship between the dielectric constant ε of the dispersed system and the volume fraction φ of the dispersed phase, but the result is a very complicated relationship that 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

At the problems referred to above, the object of the present invention is to provide a kind of emulsion property detector, it utilizes the dielectric property of emulsion to evaluate the property of emulsion, and can measure the stability of emulsion quantitatively, measure the type of emulsion (W/ O type, O/W type) and phase inversion process, investigate the coalescence, sedimentation (floating) of liquid beads and the demulsification process of emulsion.

In order to achieve the above object, the present invention adopts the following technical solutions: an emulsion characteristic detector, which is characterized in that it includes: a capacitor, a lead, an oscillating circuit, an amplifier, a detector, a computer and a power supply; The oscillation circuit is connected to form an oscillator, and the output terminal of the oscillator is connected to the detector through the amplifier, and the detector transmits the detected oscillation frequency signal to the computer; the power supply is the oscillation circuit , amplifier and detector power supply.

Further, the sample cell includes an insulating box with an upper opening and two electrode plates, one electrode plate is respectively arranged on both sides of the inner wall of the insulating box, the two electrode plates are arranged parallel and symmetrical, and the The two electrode plates are respectively connected to the oscillation circuit through the wires.

Further, insulating glue is coated on the outer surfaces of the two electrode plates.

Further, the thickness of the insulating glue is 0.5mm-2mm, and the insulating glue is epoxy resin or 504 glue.

Further, the insulating box is made of plastic or glass material.

Further, the insulating box adopts a rectangular parallelepiped structure or a cylindrical structure.

Further, the emulsion characteristic detector also includes a rectangular aluminum box and a thermostatic jacket, the thermostatic jacket is arranged outside the sample pool, the sample pool with the thermostatic jacket and the The oscillating circuit, the amplifier and the detector are all arranged in the aluminum box, and the aluminum box is grounded.

Further, a heat transfer medium is also arranged in the constant temperature jacket.

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

Based on the above-mentioned embodiments, the emulsion characteristic detector is used to detect the stability of the emulsion, the type of the emulsion and the phase inversion process, the aggregation, sedimentation or floating of liquid droplets in the emulsion and the demulsification process of the emulsion .

The present invention has the following advantages due to taking the above technical scheme: the emulsion characteristic instrument of the present invention has good sensitivity and stability, and can measure the stability of the emulsion, the type of the emulsion (W/O type, O/ W type) and phase inversion process, the aggregation, sedimentation (floating) of liquid droplets in the emulsion and the demulsification process of the emulsion. Simultaneously, the present invention provides a new method for the determination of emulsion stability.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is the structural representation when the sample cell of the present invention adopts a cuboid;

Fig. 3 is the structural representation when the sample cell of the present invention adopts a cylinder;

Fig. 4 is the emulsion characteristic curve when Span-80 oil phase concentration is 0.6%;

Fig. 5 is the emulsion characteristic curve (measurement value of 20 minutes) when different sodium oleate concentrations.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in FIGS. 1 to 3 , the present invention provides an emulsion characteristic detector, which includes a capacitor 1 , a wire 2 , an oscillation circuit 3 , an amplifier 4 , a detector 5 , a computer 6 and a power supply 7 . The capacitor 1 is connected to the oscillation circuit 3 through the wire 2 to form an oscillator, the output terminal of the oscillator is connected to the detector 5 through the amplifier 4, and the detector 5 transmits the detected oscillation frequency signal to the computer 6, and the computer 6 pairs the received After the oscillation frequency signal is processed, the characteristic parameter F value is output. The power supply 7 supplies power to the oscillation circuit 3 , the amplifier 4 and the detector 5 . When the capacitance of the capacitor 1 changes slightly, the output frequency of the oscillator can be changed to cause a large change in the frequency, and the frequency is amplified by the amplifier 4 and then transmitted to the detector 5 for detection, After recording, transmit to computer 6.

Wherein, the capacitor 1 is composed of a sample cell filled with emulsion, and the emulsion is used as a dielectric. When the size and distribution of liquid droplets in the emulsion change, or when oil and water phase separation occurs, the dielectric properties of the emulsion will change, and further lead to changes in capacitance and oscillation frequency, which can be measured according to the change in oscillation frequency Stability, type, droplet distribution and other characteristics of the emulsion, investigate the phase inversion conditions of the emulsion, etc.

In the foregoing embodiment, as shown in Fig. 2 and Fig. 3, the sample cell includes an insulating box body 8 with an upper opening and two electrode plates 9, and an electrode plate 9 is respectively arranged on both sides of the inner wall of the insulating box body 8, and the two electrode plates 9 are parallel and symmetrically arranged, and the two electrode plates 9 are respectively connected to the oscillation circuit 3 through wires 2 . Insulating glue can also be coated on the outer surfaces of the two electrode plates 9, and the thickness of the insulating glue is 0.5mm-2mm, preferably 0.5mm or 2mm; the insulating glue can be epoxy resin or 504 glue.

Wherein, the insulating box body 8 can be made of plastic or glass material, and the insulating box body 8 can adopt a cuboid, for example: as shown in Fig. Made of a 0.1mm thick red copper sheet with a width of 10mm, it is attached to the inner wall of a 10×10×40mm plastic dish in parallel with epoxy resin, and the outer surface of the electrode plate 9 is coated with epoxy resin for insulation, epoxy resin The thickness of the resin is 0.5mm. Insulating box body 8 can also adopt cylinder, for example: as shown in Figure 3, two electrode plates 9 that are set in the insulating box body 8 of cylinder are all made of high 40mm, 0.1mm thick red copper sheet of wide 16mm, use 504 glue is pasted on the inner wall of the glass cylinder of φ 12 × 50mm to form a pair of semicircular electrodes. The outer surface of the electrode plate 9 is coated with 504 glue for insulation, and the thickness of the 504 glue is 2mm.

In each of the above-mentioned embodiments, the emulsion characteristic detector also includes a rectangular aluminum box and a constant temperature jacket, the constant temperature jacket is arranged outside the sample cell, and the sample cell with the constant temperature jacket and the oscillation circuit 3, amplifier 4 and detection The devices 5 are all arranged in the aluminum box, and the aluminum box is grounded to shield the interference of the external electromagnetic field. Wherein, a heat transfer medium, such as white oil, is also arranged in the thermostatic jacket.

When the present invention is in use, it is used to detect the stability of the emulsion, the type of the emulsion (oil-in-water (O/W) emulsion, water-in-oil (W/O) emulsion) and phase inversion process, the emulsion The process of merging, settling (floating) and emulsion breaking of liquid droplets in the liquid comprises the following steps:

(1) Use a measuring cylinder to measure 18mL of the oil sample prepared for the experiment and pour it into a beaker, then pipette 2mL of twice distilled water into the same beaker. Use a T18 emulsifier to emulsify at a speed of 6000 rpm for 30s to prepare a W/O emulsion. When emulsifying, fully immerse the emulsifying head of the emulsifier under the liquid level, open the emulsifier at the same time, and emulsify for 3 minutes.

(2) Set the constant temperature oil bath of the external jacket to 30°C.

(3) Quickly put the emulsion into the sample cell along the wall of the sample cell, place it in a fixed measurement position in the measurement shielding box, cover the shielding box, and connect the sample cell to the emulsion characteristic instrument.

(4) Start the measurement program of the emulsion characteristic instrument to determine the F value. The measurement time is 1 hour, and the measurement is completed.

(5) Pour out the mixed solution in the sample cell, rinse the sample cell with absolute ethanol, then dry it with a hair dryer, and set it aside.

Embodiment 1: when carrying out the sensitivity detection of emulsion characteristic instrument, its steps are as follows:

(1) After cleaning and drying the sample cell, first measure the characteristic parameters of the air;

(2) Then use a pipette to pipette 4.3mL of double distilled water into the sample cell, connect the emulsion

The characteristic measuring instrument measures its characteristic parameters;

(3) Wash and dry the sample pool again, pipette 4.3mL of kerosene in the sample pool, connect the emulsion property tester to measure its characteristic parameters;

(4) Record the characteristic parameter data after stabilization, and the results are shown in Table 1; in the table, sample cell 1# is a cuboid plastic insulating box, and sample cell 2# is a cylindrical glass insulating box. Use sample cell 1# and sample cell respectively 2# detection, the detection temperature is room temperature 27 ℃.

Table 1 Determination results of sample pool 1# and sample pool 2#

Cell samples Air double distilled water kerosene F _kerosene -F _{double distilled water} F value of sample cell 1# 15217 8584 15225 6641 F value of sample cell 2# 15085 7284 14939 7655

From the results in Table 1, it can be known that the F value difference between kerosene and double distilled water measured in sample pool 1# is 6641, while the corresponding F value measured in sample pool 2# is 7655. It can be seen that the emulsion characteristic instrument has high sensitivity.

Embodiment 2: when carrying out emulsion stability detection, its method is as follows:

Under the same experimental conditions as in Example 1, the characteristic parameter F of twice distilled water has been measured as a function of time with sample pool 1# and sample pool 2# respectively, and the F value when comparing the beginning and measuring 20 minutes, investigate its stability. The measurement results show that the relative change rates of the F value of sample pool 1# and sample pool 2# at 20 minutes and the F value at the beginning are 0.89% and 0.045%. It can be seen that the emulsion characteristic instrument has good stability.

Embodiment 3: when carrying out the characteristic detection of water-in-oil emulsion, its steps are as follows:

(1) Setting experimental conditions: the oil phase is kerosene, the water phase is double distilled water, surfactant: Span-80, and the mass percentage concentration in the oil phase is respectively 0.6%, 0.3%, 0.1%, and 0.05%; temperature: 15-17°C.

The sample cell is sample cell 2#, the volume between the plates is 4.5mL, and the entire sample cell is placed in a grounded aluminum box to shield the interference of external electric and magnetic fields.

(2) Prepare 200 mL of kerosene solutions with mass concentrations of 0.6%, 0.3%, 0.1%, and 0.05% respectively for Span-80;

(3) Clean the sample cell with n-pentane and dry it;

(4) The experiment was carried out with the oil phase whose mass concentration of Span-80 was 0.6%. The total volume of the oil-water two-phase is 20mL, according to different volume ratios, use a pipette to add the water phase first, and then put the oil phase into a 25mL small beaker;

(5) Fully immerse the emulsifying head of the emulsifier under the liquid surface, open the emulsifier at the same time, and emulsify at the second speed (13300-16000rpm) for 5 minutes;

(6) Use a pipette to pipette 4.5mL of emulsion into the sample pool;

(7) The sample pool is connected to the emulsion characteristic instrument, timed from the beginning of the measurement, measured for 20 minutes, and recorded the characteristic parameter F data at each moment;

(8) After the measurement, the sample cell was washed with n-pentane and dried. Use the same method to prepare the emulsion prepared by measuring the next oil-water volume ratio. The measurement sequence is measured sequentially according to the volume content of water from 10%, 20%, 30%, ... 100%.

Result analysis: For a system with a mass concentration of Span-80 oil phase of 0.6%, do the following data processing, take the test results as the X-axis, and the characteristic parameter F at different times as the Y-axis, and make emulsions with different volume contents of the water phase The liquid stability curve is shown in Fig. 4. It can be seen from Figure 4 that when the volume content of the water phase is less than 74%, the characteristic curves of the emulsion formed by different oil-water ratios are all horizontal straight lines as time changes, and the characteristic parameter F value is almost unchanged, indicating that the emulsion has better stability. When the volume of the water phase is greater than 74%, as time changes, within the first 10 minutes, the characteristic curve has obvious changes, showing an upward or downward trend respectively; it is speculated that this change of the characteristic curve may be related to the floating and accumulation of oil droplets. and related.

Embodiment 4: when carrying out oil-in-water emulsion characteristic detection, its steps are as follows:

(1) set experimental conditions: oil phase: kerosene; water phase: twice distilled water; surfactant: sodium oleate, the concentration in water phase is respectively 0.6%, 0.3%, 0.1%, 0.05%; temperature: 18 ℃;

The sample cell is sample cell 2#, the volume between the plates is 4.5mL, and the entire sample cell is placed in a grounded square aluminum box to shield the interference of external electric and magnetic fields.

(2) Prepare 200 mL of twice-distilled aqueous solutions with sodium oleate concentrations of 0.6%, 0.3%, 0.1%, and 0.05%, respectively.

(3) Clean the sample cell with n-pentane and dry it.

(4) The experiment was carried out in the aqueous phase with a sodium oleate concentration of 0.6%. The total volume of the oil-water two-phase is 20mL, and according to different two-phase volume ratios, use a pipette to add the water phase first, and then the oil phase into a 25mL small beaker.

(5) Fully immerse the emulsifying head of the emulsifier under the liquid surface, open the emulsifier at the same time, and emulsify at the second speed (13300-16000rpm) for 2 minutes.

(6) Use a pipette to pipette 4.5mL of emulsion into the sample pool;

(7) Connect the sample cell to the emulsion characteristic instrument, count the time from the beginning of the measurement, measure for 20 minutes, record the characteristic parameter F data at each moment and the situation of the emulsion in the test tube.

(8) After the measurement, the sample cell was washed with n-pentane and dried. Use the same method to prepare the emulsion prepared by measuring the next oil-water volume ratio. The measurement sequence is measured sequentially according to the volume content of water from 0, 10%, 20%, 30%...100%.

(9) Repeat the above experimental steps in the order that the concentration of sodium oleate is 0.6%, 0.3%, 0.1%, and 0.05%, respectively.

Result analysis: The F value of the system with different emulsifier concentrations at 20 minutes was plotted against the water content, and made together with the standard curve to investigate the effect of emulsifier concentration on the stability of the emulsion, as shown in Figure 5. The results in Figure 5 show that with the decrease of the concentration of sodium oleate in the aqueous phase, the closer the emulsion characteristic curve is to the standard curve, the worse the stability of the emulsion is.

Along with the decline of sodium oleate concentration, the scope of internal phase (being oil phase) volume content expands gradually when phase inversion occurs, when concentration is 0.6%, when emulsion occurs phase inversion, internal volume content is at 78%-80% and when the concentration of sodium oleate drops to 0.6%, the volume content of the internal phase expands to 70%-80% when the emulsion phase inversion occurs. This phenomenon shows that the phase inversion of the emulsion is not only closely related to the ratio of oil and water, but also the strength of the interfacial film plays an important role. As the concentration of emulsifier sodium oleate decreases, the strength of the oil-water interface film decreases, and the stability of the emulsion also decreases, resulting in a phase inversion at a lower volume content of the water phase.

The results in Fig. 5 also show that with the decrease of the concentration of sodium oleate, the stability of the emulsion decreases, and the characteristic curve of the emulsion is closer to the standard curve. separated from the liquid.

The above-mentioned embodiments are only used to illustrate the present invention, and the structure, size, location and shape of each component can be changed. On the basis of the technical solution of the present invention, all improvements to individual components according to the principles of the present invention and equivalent transformations shall not be excluded from the protection scope of the present invention.

Claims (10)

1. an emulsion fluid Characteristics Detection instrument, is characterized in that comprising: capacitor, wire, oscillatory circuit, amplifier, detecting device, computing machine and power supply; Described capacitor connects and composes oscillator through described wire and described oscillatory circuit, and described oscillator output end is connected with described detecting device through described amplifier, and the oscillation frequency signal detected is transferred to described computing machine by described detecting device; Described power supply is that described oscillatory circuit, amplifier and detecting device are powered.

2. a kind of emulsion fluid Characteristics Detection instrument as claimed in claim 1, it is characterized in that: described sample cell comprises insulation box body and two battery lead plates of a upper opening, the internal face both sides of described insulation box body arrange battery lead plate described in respectively, described two battery lead plates are that Parallel Symmetric is arranged, and described two battery lead plates are connected with described oscillatory circuit respectively by described wire again.

3. a kind of emulsion fluid Characteristics Detection instrument as claimed in claim 2, is characterized in that: described two battery lead plate outside surfaces are coated with insulating gel.

4. a kind of emulsion fluid Characteristics Detection instrument as claimed in claim 3, is characterized in that: the thickness of described insulating gel is 0.5mm ~ 2mm, and described insulating gel adopts epoxy resin or 504 glue.

5. a kind of emulsion fluid Characteristics Detection instrument as described in any one of claim 2 to 4, is characterized in that: described insulation box body adopts plastics or glass material to make.

6. a kind of emulsion fluid Characteristics Detection instrument as described in any one of claim 2 to 4, is characterized in that: described insulation box body adopts rectangular structure or cylindrical structure.

7. a kind of emulsion fluid Characteristics Detection instrument as described in any one of Claims 1-4, it is characterized in that: described emulsion fluid Characteristics Detection instrument also comprises a rectangular aluminium box and constant temperature jacket, it is outside that described constant temperature jacket is arranged on described sample cell, the described sample cell and described oscillatory circuit, amplifier and the detecting device that are arranged with described constant temperature jacket are all arranged in described aluminium box, described aluminium box ground connection.

8. a kind of emulsion fluid Characteristics Detection instrument as claimed in claim 7, is characterized in that: be also provided with heat transfer medium in described constant temperature jacket.

9. a kind of emulsion fluid Characteristics Detection instrument as described in any one of Claims 1-4, is characterized in that: described emulsion fluid is oil-in-water emulsion or Water in Oil emulsion.

10. a kind of emulsion fluid Characteristics Detection instrument as described in any one of Claims 1-4, it is characterized in that: described emulsion fluid Characteristics Detection instrument for detecting the stability of emulsion fluid, the type of emulsion fluid and phase inversion process, the breakdown of emulsion process of the coalescence of liquid pearl in emulsion fluid, sedimentation or floating and emulsion fluid.