DE2212185B2 - METHOD AND DEVICE FOR TESTING DEMULGATERS FOR AQUATIC CRUDE OIL EMULSIONS - Google Patents

Description

The emulsifier closed the sample vessel at the top 15 by means of suitable preliminary tests the optimal splitter type un <i can be found in such a circular motion. In addition, the subsidies have also set that one is in a phase of the circulatory conditions or the type of processing plant send movement of the part of the top located (flow conditions, dwell times, throughput, Sample vessel in the opposite phase of the cleavage temperature, etc.) decisive influence on the circular movement at the bottom and vice versa. 20 Stability of the emulsions. Both from temporal reverses and that the sample is in either of the two reasons as well as ongoing production

In order not to disturb the processing plants, the preliminary tests must be carried out on a laboratory scale _; taking into account the aging of raw

Move phases under the effect of gravity from the upper to the lower end of the sample vessel can.

2. Device for carrying out the process oil (stabilization of the interfacial equilibria, rens according to claim 1 with graduated sample oxidative influences) the tests preferably directly on the vessels and a thermostated liquid bath, characterized by a mechanical
driven, ringwheel-like roller (1) to
their central axis (2) at a 60 ° angle to one another 30
and at equidistant intervals from this axis

six mounting strips (3) each with eight circular holes (3 a) to accommodate the graduated Lower parts (4 a) of the sample vessels (4) and eight each

35 attached the two principles to these circular holes:

oil field should be done with fresh wet oil. With regard to a targeted selection of splitters, the results of the laboratory test should be transferable to practical use as well as possible. However, this is only possible if the laboratory test method allows a practical assessment of the effectiveness of demulsifiers.
The known test methods work according to the following

Spiral springs (6) are arranged for fixing the sample vessels, with these receiving strips (3) six additional mounting strips (7) with Ω-shaped recesses in the radial direction outwards (8) for receiving and fixing the head part of the sample vessels (4 ft) face each other and further said roller being in said roller with its axis parallel to the surface of the liquid Liquid bath (16) is located, the liquid level through an overflow pipe (12) in height adjustable with a cooling circuit (9) and a contact thermometer (10) adjustable two-stage heating (11) and is equipped with a circulating pump (17).

3. Apparatus according to claim 2, characterized in that the roller (1) with its wheel-like formed lateral boundary surfaces (13) rests on four rotatable rubber rollers (14), two of these rubber rollers each arranged on one parallel to the roller axis (2) Axle (17) sit and one of these last-mentioned axes is driven by an electric motor (15) will.

The invention relates to a method for spraying demulsifiers for aqueous crude oil emulsions : according to the preamble of claim 1 as well as a device for carrying out the test procedure.

Crude oils are usually sold together with storage

a) The wet oil samples spiked with defined amounts of splitter are used immediately after mixing of the demulsifier treated in an ultracentrifuge at 30,000 rpm or 150,000 g and after preselected running times the separation of free water is measured (see tensides, 1965, p. 365). This method has the following disadvantage: It will be the crucial one in the end Detected ability of a breaker to destroy the natural emulsifier films, however there is no statement about the influence of the splitter on flocculation and flocculation, which is important in practice Coalescence processes (problems of spontaneous separation or the separation of small Residual water).

b) The wet oil samples spiked with defined amounts of splitter are mixed in with the The demulsifier was placed in a thermostated water bath and kept there in complete rest. After certain time intervals, the amount of separated water is read off (cf. e.g. Oil and Gas Journal, 50 [1950], No. 9, p. 64; US-PS 32 02 615, DT-OS 15 95 320). Besides can still be used for assessment: color and appearance of the pure oil after treatment, content of bottom sediments and residual water as well as residual emulsion content in the dehydrated pure oil (obtained by centrifugation), Re-emulsification properties of the pure oil.

The disadvantage associated with the known processes is that the wet oil / demulsifier system or at an advanced stage of the test that

solid pure oil / residual emulsion / free water / demulsification systems heating of the tanks and systems,

tor during the entire splitting process, in which the splitting is to take place, is provided.

Quiet is kept while in practice, temperatures above + 8O ⁰ C- at least

this phase, in some cases considerable mechanical damage in field preparation systems - already from economic

play movement processes (e.g. not common when flowing through economic considerations

of pipelines, sedimentation tanks and Trea- is the partial pressure at such high temperatures

tern). The lack of an intimate mixing of the water vapor so high that even without use

entire system prevents both a quantitative and a chemical aid at least partially

Breaking the emulsion as well as a splitting by the mere evaporation of water

quantitative separation of the split-out emulsion enters the emulsion and thus from the laboratory test

sion water. no clear assessment of the effectiveness of a

By using a very high and in practice un- demulsifier, this would be possible. Preferably working

customary cleavage concentrations or by means of practical cleavage tests in the

Increase of the gap temperature to values that are in the temperature range from + 30 to + 60 ° C.

In practice, for economic reasons, hardly any 15 The number of revolutions that the specimens make in

be eligible (80 ° C and higher), this circular movement is primarily

Effect can be largely compensated, but depending on the viscosity of the crude oil at the

is even then the deposition of the entire gap temperature. It must be set so

split emulsion water only in rare cases the fact that with each revolution the entire liquid

within a reasonable sedimentation for laboratory tests from one end of the test vessel to the other

tation times (max. 5 to 6 hours), since it can flow off in order to achieve the desired

neither flocculation, d. H. to ensure the approximation of the water mixing effect. This is especially

droplets, still coalescing, d. H. to pay attention to the special at the beginning of the experiment, since the

flow from smaller droplets to larger sedi- viscosity of the intact emulsion at the same tempe-

mentable units, due to the static system 25 temperature conditions are always significantly higher than the

be favored. Viscosity of the decomposition products pure oil and water, the

Thus, the present invention was not an object in the advanced stage of the splitting process

based on developing a test method that will be available to the remaining residual emulsion. The for

corresponds better to practical conditions. the tests that usually occur in practice

The invention relates to a method for selecting the most favorable speed is in the range from 0.2 to

Testing of demulsifiers for aqueous crude oil 10 revolutions per minute of the sample around the

sions, in which a crude oil emulsion sample with an axis of the roller. The one for the respective experiment

appropriate amount of demulsifier added and optimal speed is expedient in a pre

determined in a thermostated medium during the experiment. It usually stays during

Demulsification process mixed by mechanical means 35 of the entire test run the same, can be used for special

and then changed once or several times after a further handling purpose

process at predetermined times that will be.

deposited amount of water is determined, the da- The invention also relates to a device for is characterized in that the implementation of the method according to the invention with for the mixture Crude oil emulsion sample with the demulsifier, the 40 graduated sample vessels and a thermostati sample vessel closed at the top and in such a liquid bath, which is characterized by circular motion is displaced that a mechanically driven, ringwheel-like a phase of the circular movement above roller 1, about its central axis 2 at a 60 ° angle Licher part of the sample vessel in the opposite direction to each other and at equidistant distances from this 45th phase of the circular movement is located at the bottom 45 axis six mounting strips 3 each with eight circular and vice versa and that the sample in each of the round holes 3 α to accommodate the graduated two phases under the action of gravity lower parts 4a of the sample vessels 4 and eight each Spiral paths attached from the upper to the lower end of the sample vessel using these circular bores can. springs 6 arranged to fix the sample vessels

The actual cleavage process is followed by 50, with these receiving strips 3 in a radial direction, while cooling the system to 20 ° C., a one-hour outward direction, followed by six additional recording periods of rest, in the course of which the sedimentation strips 7 are Ω-shaped Recesses 8 for the portion of the split emulsion water that can be applied and the fixation of the head part of the sample can be deposited and then read off. Facing under vessels Ab and with the requirement that minimal splitter concentration 55 roller was used with parallel to the liquid surface, takes place during this lying axis in the liquid bath 16, standing time at 20 ° C no further emulsion splitting of its liquid level by a Overflow pipe 12 more instead. On the other hand, it is also possible to adjust the height by cooling the actual splitting process by means of a direct circuit 9 and centrifuging the sample using a contact thermometer 10 or by means of 60 controllable two-stage heating II as well as centrifuging for an additional 1 hour at 20 ° C ge circulation pump 17 is equipped.
The above numbers refer to the nem water to be determined. Designations in FIGS. 1 to 3.

The temperature of the water bath should be in the range. This arrangement ensures that the

adjustable from +20 to + 80 ° C. Lower tempe- 65 sample vessels during the test duration in radialei

Temperatures of + 20 ° C are unusual in practice, direction is fixed and neither changes its position

since mostly the crude oil can fall out even at higher temperatures,

np.raturen or in the processing. The dimensioning of the roller is dependent on

correspond to the size and number of samples to be recorded, in laboratory tests an approximately quantitative

vessels. The emulsion water is equipped with 6X8 intake points.

for sample vessels has proven to be practical for d. H. in other words, the entire course of the

Carrying out the search has proven to be useful, with a sedimentation curve for the assessment of a crevice

The experiment can also be used with any number of samples for 5 days,

under 48 can be carried out. As samples, another advantage of the new method is to-

Vessels are particularly suitable for graduated centrifuges - the fact that the splitting process takes place in the

pears of the shape as shown in Fig. 3 and given by practice, sometimes very low

which take place a thread with screw cap 5 on the head conditions conveying temperatures and yet one

of the vessel. However, there are also other almost quantitative cleavage and separation

Shapes of sample vessels possible (cf. for both emulsion water can be achieved, whereby

play Zerbe »mineral oils and related products«, the informative value of the laboratory test with regard to it

Springer-Verlag, 1969, p. 126) without significantly improving the transferability to practice

Is left within the scope of the invention. The volume will.

of the sample vessels is expediently between 50 and 15 The time required for a measurement is included

200 ml. Low amounts of demulsifier used and low

The thermostatted liquid bath contains gap temperatures in comparison to the familiar, homely water; other liquids for special procedures are considerably shorter, with measurement purposes being conceivable. The level of the liquid is then to be regarded as finished when the bath is expediently set so that the head of ao percent of the known total water expressed from the straight vertical sample vessels protrudes asymptotically from the separated amounts of water from the bath. This makes it possible to approach the 100% limit. If the gap temperatures and the roller are sufficiently high in a simple and quick manner in the immersed demulsifier concentrations, the state must be charged and samples can also be taken during the 100%> limit in the conventional tests. The drive of the 25 drive would be even close to that, roller can in principle be done in any way, depending on the crude oil used, for example the 2- to z. B. via V-belts, chains, etc., but this is necessary in 5 times the time, so to give preference to the method described below, according to the method. Normally, this results in the possibility of using the roller in the method according to the invention for a test duration, for. B. for cleaning purposes by simply removing them for 4 to 6 hours,
remove from the water bath without the need for an additional separation from the drive unit of the experiment tightly closed. From this resui boundary surfaces 13 without additional fastenings, the advantage is that even with the use of high supply devices on four rotatable rubber rollers, gap temperatures (above 50 ° C.) do not result in evaporation. Two of the total of four rubber rollers, which can occur in pairs of water and low-boiling constituent losses on one part of the crude oil that is parallel to the roller axis. The use of an ordered axis can be driven by means of a continuously variable electric motor 15 and 40 for the splitting test, which has proven itself to be driven by centrifugal pears, because after the actual splitting process, the roller resting on the rollers works on one and the same sample without the rotary movement offset. To open the cap or even have to decant

In Fig. 1 and 2 is the basic structure of a sen, is possible, both through sedimentation free

Embodiment of the pre-separated amount of water according to the invention as well as by subsequent

Direction shown: F i g. 1 shows a cross section 45 following centrifugation in a centrifuge the

and F i g. 2 shows a longitudinal section with the above-described total amount of split-out emulsion water

benen preferred type of drive. F i g. 1 a is a determine and conclusions can be drawn from the measured values

Top view of the described receiving strips 3 showing the gap or flocculation and coalescence

and7. to close a product. As a result

By using the dynamic 5 ° according to the invention, the test method according to the invention is not suitable mix the test method in which it is carried out exclusively for the selection of a suitable demulration Specially suitable technical device for gators for a certain oil, but also for eenepraxis-related Testing of demulsifiers for real comparative assessment of new developing water Crude oil emulsions can be compared to manufacturing products.

Conventional test methods according to the prior art. The method according to the invention is also suitable

Technology can achieve some significant advantages. in a special way for the assessment of splitter

The fact that the samples to be tested during the direct on the oil field, since the equipment required for the entire splitting process is continuously mixed through devices in a simple manner in a measuring mix, whereby the speed of rotation can be installed,
speed of the roller carrying the test vessels optionally 60

according to the mechanical examples occurring in practice
Movement processes or, depending on the viscosity of the splitter, the task was set for a crude oil with wet oil, the actual average of 42% emulsion water can find optimal movement processes in processing plants. The required residual water at least approximately in the laboratory to simulate advertising 65 content in the crude oil was max. 1 ° / _0th In the existing den. This has the effect that, with the use of the processing plant, comparatively small amounts of breaker could be maintained at a dwell time, the concentrations used in practice in about 20 hours of oil temperatures of about 35 ° C. The laboratory tests were

carried out both by a method known from the literature and by the process according to the invention.

Procedure for a test method according to the prior art: For each 400 g of crude oil, the content of emulsion water of which has been determined beforehand using one of the known methods, the desired amounts of demulsifier are expediently in the form of a 500 ml beaker at room temperature while gently stirring of dilute solutions are pipetted in and distributed evenly over the entire volume of oil by further stirring. Then four graduated test vessels (measuring cylinders) are filled up to the 100 ml mark for each batch, slightly closed with a cork stopper and placed in a thermostated water bath. After certain time intervals, the separated amounts of free water are read off in all vessels and the mean value from the four individual samples of the same type is noted in each case. The test vessels are then returned to the water bath. To determine the residual content of emulsified water, one of the four parallel samples can be taken at any point in time, the contents poured into a graduated centrifugal glass and then spun in a centrifuge at 3000 rpm for 5 minutes. The content of residual emulsion water RE _{Z is} calculated from the difference between total water and centrifuged water. The water separation is usually followed over a period of 20 hours, with any number of individual readings being taken.

The test method according to the present invention is carried out as follows:

Introduction of the demulsifier and homogenization with the crude oil takes place in the manner described above Way. Then each batch is distributed over a total of 6 graduated centrifugal pears, with each 50.0 g of the demulsifier-containing crude oil must be weighed into the test vessel. After carefully closing the test vessels by means of a screw cap, these are inserted into the roller and thermostatically controlled Water bath set in rotary motion. Overall, the test apparatus described can include Blank sample take up 8 different batches in one operation. After certain time intervals a centrifugal glass is used from each batch, i. H. at the same time a maximum of 8 samples from the apparatus removed and left to stand motionless for 1 hour at 20 ° C. Those in that period The sedimented amounts of water are noted and then the still closed centrifugal pears placed in a centrifuge, spun at 350OUpM for 5 minutes and again the deposited Read the amount of water. Once centrifuged samples are no longer in the Bringing back the splitting device. Since each of the 8 approaches 6 samples of the same type are put into the apparatus can be recorded, thus a total of 2 times 6 measuring points are available for each approach of sedimentation curves are available. The time required for an attempt is normally max. 4 to 6 hours.

Attempt 1

4 different commercially available demulsifiers A to D were used in a comparative manner State-of-the-art test methods investigated.

Water content of the crude oil 41.0%

Use amount of splitter 20 ppm

Gap temperature 35 ° C

° / o water separation after lh 2h 3h 4h KE _Z 6h 20 h 30 ' after 4 h 2 18th 27 29 26th 31 36 A. 1 4th 8th 12th 23 19th 40 B. 1 8th 21 40 48 16 50 56 C. - 63 70 71 73 11th 74 76 D. 5 40 Blank value

The test shows that product D is the only demulsifier which is reasonably satisfactory for the given oil splits, but under the given conditions, even after a residence time of 20 hours, Far from any attempt to observe even approximately quantitative separation of the water obtained 2

The same 4 demulsifiers A to D w
tested in experiment 1, but the invention
appropriate test procedure was used.

Water content of the crude oil 41.4 ⁰ zo

Use amount of splitter 20 ppm

Gap temperature 35 ° C

Roller speed 1 rpm

ίο

° / o water separation after

10 '30' lh 2 h 3 h 4 h

A. 2 2 17th 27 65 80 (7) (63) (82) (89) (94) (94) B. , 19th 29 48 72 85 (70) (87) (87) (92) (96) (94) C. 2 34 80 82 84 90 (72) (82) (89) (89) (94) (96) D. 60 68 92 92 92 94 (82) (89) (94) (94) (96) (97) Blank value 2 (1) (1) (1) (2) (2) (2)

In contrast to experiment 1, this shows that 20 when comparing the values removed by sedimentation

all tested products under the given conditions with the water quantities in the table above

In a relatively short period of time, the values given in brackets for the

Emulsion are largely able to split, trifuging separated water results, dai

whereby, in actuation of the above experiment, products B and C are also the present one

duct D appears to be optimally effective. The unier ver 25 crude oil emulsion is able to break very quickly, e <

A degree of separation of 92% achieved using D can only be achieved using product D.

Water after 1 hour or from 94% water after the split water to sediment very quickly

4 hours can be expected during practical mentoring.

The knowledge gained through experiment 2 in the processing plant

separation of at least 99% water is achieved. 30 have now been fully confirmed in practice.

For this purpose 2 sheets of drawings

Claims (1)

Patent claims: 1. Method for testing demuigators for aqueous crude oil emulsions, in which one Crude oil emulsion sample mixed with a corresponding amount of demulsifier and in one thermostated medium mixed mechanically during the demulsification process and then after a further treatment process at predetermined times the deposited amount of water is determined, characterized in that for the Mixture of the crude oil emulsion sample with the site water in the form of more or less stable Emulsions (mostly water-in-oil emulsions, but sometimes also oil-in-water and double emulsions) promoted and have to face another Processing can be dewatered or desalinated with the exception of small residues. The splitting of the emulsions in pure oil and free water is preferably carried out by adding small amounts of surface-active substances Substances, the so-called splitters or demulsifiers o gates. After crude oils are in their chemical composition as well as in the type and amount of contained natural emulsifiers, depending on the conditions in which they are formed, are very different from one another must be able to differentiate for every oil