US3264204A - Process for resolving gas-containing emulsions - Google Patents

Description

Aug. 2, 1966 H. R. JARVIS ETAL 3,254,204

PROCESS FOR RESOLVING GAS-CONTAINING EMULSIONS 2 Sheets-Sheet 1 Original Filed March '7, 1962 'L/n/w 1091.5

INVENTORS.

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a A BY mew ,dzmvmsvs. HARE/9, alscH, IPusssu. 8; KER/v Unite States 3,264,204 PROCESS FOR RESOLVIN G GAS-CONTAINING EMULSIONS Howell R. Jarvis and William L. Shirley, Houston, Tex., assignors to National Tank Company, a corporation of Nevada Original application Mar. 7, 1962, Ser. No. 178,091, now Patent No. 3,207,286, dated Sept. 21, 1965. Divided and this application Apr. 16, 1965, Ser. No. 448,808

21 Claims. (Cl. 204188) This application is a division of our earlier application Serial No. 178,091, filed March 7, 1962, now US. Patent 3,207,286, entitled Electric Dehydrator.

Our invention relates to the electric treatment of emulsions of the water-in-oil type ranging from somewhat temporary dispersions to tight emulsions that will not settle on long standing. The continuous phase of such emulsions may be crude oil or other oils of relatively high resistivity. The dispersed phase of such emulsions is usually aqueous and when separated is referred to herein merely as water irrespective of purity or salt content, it being understood that the term is inclusive of the brine found in crude oils and the aqueous material of other emulsions. The emulsions with which the invention is concerned may be naturally occurring or may be the result of prior processing of oils. The invention will be exemplified with reference to the electric resolution of crude oil emulsions with or without the aid of chemicals added thereto to facilitate such electric resolution.

There is an increasing need for an inexpensive electric dehydrator of simple construction that can operate for long periods of time without supervision. It is an object of the invention to provide such a dehydrator that is well adapted to the electric resolution of crude oil emulsions as produced from the ground or after preliminary settling in storage tanks.

Many emulsions contain dissolved or entrained gases which are desirably separated therefrom before subjecttion to the action of an electric field. It is an object of the invention to provide an improved electric dehydrator in which gas separation is effected within the dehydration unit itself.

It is also an object of the invention to provide an improved structure by which a complete separation of the water is achieved in a simple and economical way without application of excessive heat. This is in contradistinction to existing non-electric separators which heat the emulsion to facilitate its resolution and which thereby remove and waste valuable lighter fractions of the oil. It is an object of the invention to reduce or minimize the usual demulsifying heat requirements and to conserve the lighter fractions or light ends of the oil so that the gravity of the oil is maintained during dehydration and volume losses due to vaporization are avoided. The resulting oil can thus often be sold at a higher price, Minimization or elimination of heat also reduces problems arising from scale and corrosion of the treating equipment.

Some of the dispersed material of many emulsions can be initially coalesced and/or extracted and separated by gravity separation or a water-washing step. It is an object of the invention to provide space within the electric dehydrator separate from the main treating chamber therein to water-wash the incoming emulsion. A further object is to water-wash the emulsion by upward passage thereof through a body of wash-water in an upright passage in such way that any impurities or dispersed-phase material thus extracted will leave the top of the upright passage for subsequent separation in a later zone.

The invention is further characterized by a process and apparatus in which the emulsion flows downward in an oil-continuous environment, then upward in a water-con- 3,264,204 Patented August 2, 1966 tinuous environment, e.g. through the aforesaid body of Wash water, and then into an electric field. Water-in-oil type emulsions are often encountered which contain also some emulsion of the reverse or oil-in-water type. Downward flow through an oil-continuous environment helps to break the oil-in-water type emulsion that is present. Upward flow through a water-continuous environment helps to break the water-in-oil type emulsion and particularly so if the steps are performed in this sequence. In addition, water-wet solids in the emulsion break out during the upward flow in the water-continuous environment and drop to the bottom to be trapped out of the system and thus make subsequent electric treatment of the emulsion easier. Heat applied to the water-continuous environment facilitates such removal of water-wet solids. It is an object of the invention to provide such a process and a compact electric treater in which such steps can be performed.

Further objects and advantages of the invention reside in the internal partitioning of a container to provide zones for sequential preliminary treatment of the emulsion before entry into the electric field. Other objects and advantages reside in the manner in which the preliminary treated emulsion is distributed in the main treating chamber preparatory to subjection to the action of a highvoltage electrostatic field. Still further objects and advantages will be apparent to those skilled in the art from the following description of an exemplary embodiment of the invention described as used in the resolution of crude oil emulsions.

Referring to the drawings:

FIG. 1 is a vertical sectional view of one embodiment of the improved electric dehydrator of the invention, FIG. 2 being a transverse sectional view taken along corresponding lines of FIG. 1.

FIG. 3 is a sectional plan view taken along the line 3-3 of FIG. 1; and

FIG. 4 is a transverse sectional view taken along the line 4-4 of FIG. 1.

The invention can be incorporated in any suitable upright or horizontal container but is exemplified as including a container 10 much longer in axial length than width mounted on supports 11 in substantially horizontal position, the container being closed by heads 12 and 13. Emulsion from one or more wells or storage tanks can be pumped through lines 14 to a manifold 15 and thence to the dehydrator. Although not essential in all instances, it is usually desirable to introduce a small amount of a chemical demulsifying agent into the emulsion ahead of the dehydrator. This agent may be of any known type and will be selected with reference to its ability to aid the electric resolution to be described. It can be pumped from storage 16 into a line 17 by a metering pump 18.

The interior of the container 10 is partitioned to provide an entrance section or chamber 20, a waterwash and/or heater section 21, a gas-separating section 22, an emulsion-delivery or pre-separation section 23 and a main treating section or chamber 24. The entrance chamber 20 is formed between an end partition 26 and the head- 12 and provides a gas space 27 and an emulsion space 28. The incoming emulsion may be discharged at any position in the entrance chamber 20 but preferably discharges in-to the gas space 27 through a laterally-orificed distributor 29 so that initial gas separation takes place in the entrance chamber. The gas space 27 is in open communication with the gas-separating section 22 as through an opening 30.

An upstanding partition 32 separates the sections 21 and 23. It is spaced from the end partition 26 to define an upright passage 33 constituting an important part of the water-wash and/or heater section 21. The upstanding partition 32 is separated from a transverse partition 35 to form therebetween a delivery chamber or well 36 acting as a settling space. At the upper end of the upstand ing partition 32 and preferably near the midsection of the container is a weir which may comprise merely the top edge of the partition 32 !but which is illustrated as comprising a deck 38 traversing the width of the container and attached to such top edge of the partition. This deck provides an upstream edge 39 near the top of the upright passage 33 forming with the end partition 26 an entrance passage 40 for the gas-separating section 22. The deck 38 provides also a discharge lip 41 above the well 36.

The lower end of the emulsion space 28 is in open communication with the lower end of the upright passage 33. In the preferred arrangement the end partition 26 terminates short of the bottom of the container to provide a passage means 42 for this purpose. The end partition 26 may provide a sloping bafile 43 having a lip 44 spaced from the upright partition 32 to provide an opening on the opposite side of the upright passage 33 from the passage 40 so that emulsion rising in the passage will flow diagonally and across the heat-transfer surfaces of a heater 45 to be described. Alternatively the baifie 43 may provide metering orifices to evenly distribute the emulsion across the upright passage 33.

A body of wash water 47 is maintained in the upright passage 33. -Its upper boundary will be within the entrance passage 40 during operation of the device. The lower portion of this body continues leftward into the emulsion space 28 forming an emulsion-water interface 48 determined by the position of the lip 44. The column of wash water in the upright passage 33 hydrostatically balances the column of emulsion in the emulsion space 28. As the emulsion is of lower specific gravity than the wash water it follows that the emulsion-gas interface 49 in the entrance chamber 20 will be slightly above the deck 38.

\From the structure thus far described it will be apparent that the emulsion flows downward in the emulsion space 28, through the emulsion-water interface 48 and the passage means 42 to rise as emulsion masses through the body of Wash Water 47 in the upright passage 33. The heater 45 can be used to control the temperature of the body of wash water and thus the temperature of the washed emulsion rising in the entrance passage 40, heating being largely by heat transfer from the :water to the emulsion. Some of the water masses of the emulsion may be washed out or released during rise in the upright passage 33 but it is preferable that the excess water thus added to the .body of wash water 47 should flow upwardly through the passage 40 along with the washed emulsion. Any water wet solids settling in the passage 33 can be periodically flushed out through a valved pipe 49a. This or a similar pipe can also be used to introduce a chemical treating agent that is partly or completely water soluble into the body of wash water 47 if this is desired. At the top of the passage 33 the mixture spreads over and flows along the top surface of the deck 38. Gas separation is facilitated by thus flowing a thin stream of the washed emulsion along the deck, the separated gas rising in a gas space 50 of the gas-separating section 22. In addition some water settles to the top surface of the deck to form an underlying water layer or film. This promotes coalescence of the water droplets in the remainder of the emulsion as it flows as a thin upper layer above and in contact with the underlying water layer or film. This is a mechanical coalescing action and supplements the previous mechanical coalescing actions in a manner to prepare the emulsion stream for better separation in the well 36 and better electric treatment in the main treating chamber 24. The emulsion stream drops from the discharge lip 41 into the well 36 to an emulsion-igas interface 51 and separates to some extent therebelow to form an emulsion-water interface 52 within the well.

The transverse partition 35 terminates in a lower edge 52' and provides a passage means interconnecting the lower interiors of the well 36 and the main treating chamber 24. This passage means is exemplified as comprising two cutouts or notches 53 cut in the partition upwardly from the lower edge 52' thereof. Each notch has a top wall 54 disposed at a level above the emulsionwater interface 52 and spaced side walls 55 extending to the lower edge 52'. The Washed emulsion lwhich separates in the well 36 above the interface 52 thus flows rightward through the upper portions of the notches 53, as indicated by the arrow 56, into the upper interior of a distributor 5-8 to be described. The water masses settling from the emulsion in the well 36 drop to the interface 52 and move rightward at a lower level, as indicated by the arrow 59, through lower portions of the notches 53 or the space below the lower edge 52' to join a body of separated water '60 in the main treating chamber 24. It is a feature of the invention that a portion of this body of separated water extends into the lower end of the well 36 and that the emulsion-Water interface 52 continues at the same level into the distributor 58 as an interface 52a therein. The number of notches '53 and distributors 58 will depend on such [factors as size of the container, the characteristics of the emulsion undergoing treatment and the type of electrodes employed to establish the electric field into which the emulsion will flow upon discharge from the distributors, etc. One or more of such distributors can be used.

While various types of distributors 58 can be employed, the one illustrated is particularly effective in uniformly exuding streams of the washed emulsion at a large number of horizontally-spaced positions in the lower interior of the main treating chamber 24. It has the further feature that the areas of all of the exudation orifices can be uniformly increased or decreased by a drop or rise of the interface 52a. As illustrated, each distributor is of the inverted-pan type providing a top wall 64 and depending side walls 65 connected to the transverse partition 35 near the top and respective side walls of the cutout or notch 53. The distributor thus provides a downwardlyopen distributor chamber 66. The side walls 65 depend below the interface 52a and provide downwardly-diverging exudation orifices 68 on the three closed sides of the distributor. These exudation orifices have narrow upper apex portions in an upper horizontal plane above the interface 52a and wider lower portions in a lower horizontal plane below such interface. As a consequence the emulsion will exude through those upper portions of the orifices above the interface 52a, the emulsiondischarge portions of the orifices being bounded downwardly by a heavier liquid, here the separated water. A gravity-flow equal-distribution and equal-discharge of the washed emulsion is thus effected at a plurality of points in a pattern determined by the location of the exudation orifices 68.

In normal operation an oil-'water interface 70 is present in the main treating chamber 24. If this interface is maintained at a level above the interface 52a, as is usually preferable, the emulsion issuing from the exudation orifices 68 will be further washed during rise through the 'body of separated water. The position of the interface 70 is maintained substantially constant by a level-control means of known type, shown as including a float 71 actuating a valve 72 controlling the flow of a gas through a line 73. The gas pressure in turn controls the setting of a valve 74 in a line 75 which withdraws water from the body of separated water 60.

Any suitable electrode system can be employed for establishing a high-voltage electrostatic field in that portion of the main treating chamber 24 above the interface 70 to treat the rising emulsion. Such an electric field will coalesce the dispersed water particles of an emulsion into masses of sufiicient size to gravitate to the body 60. As shown, upper and lower foraminous electrodes and 81 define two treating spaces comprising a main treating space 82 between the electrodes and an auxiliary treating space 83 between the lower electrode 81 and the body of separated water 60. Each electrode may comprise a sheet of metallic screen 85 (FIG. 3) supported by a suitable framework 86. Hangers 87 suspend the upper electrode 80 from the container to maintain this electrode at ground potential. The lower electrode 81 is suspended from the container by insulators 88 and is energized by a high-voltage transformer 90. The AC. potential applied to the primary of this transformer is suitably controlled as by a choke coil 91. The highvoltage terminal of the secondary winding is connected through an inlet bushing 94 to a conductor 95 which is in turn connected to a post 96 rising from the electrode 81 through an opening 96' (FIG. 3) of the upper electrode 80.

A low-level safety device is provided to short-circuit the electrodes should the main treating chamber 24 not remain filled with liquid. This includes a float 97 pivoted at 98 to drop if an oil-gas interface should develop. To the pivot arm of this float is attached an arm 99 carrying a contact 100 which engages the post 96 to ground it through the float arm upon lowering of the float, thus short-circuiting the electrodes.

The treated oil largely free of dispersed Water is suitably withdrawn from the upper end of the main treating chamber 24. Such withdrawal is preferably through a multi-orifice pipe network 102 comprising two longitudinal pipes centrally connected to a riser pipe 103 extending to a position outside the container. The longitudinal pipes preferably have upwardly-facing orifices distributed throughout the upper interior of a main treating chamber 24 to aid in establishing a uniform-flow rising mass of emulsion and treated oil in this chamber.

The treated oil eflluent is preferably increased and decreased respectively upon rise and fall of the emulsiongas interface 51 in the well 36. Stated in other words the treated oil eflluent is controlled to keep this interface substantially constant in position. To accomplish this the transverse partition 35 supports a housing 104 depending below the interface near one side wall of the container and shielding a float 106 from the stream dropping from the discharge lip 41. The housing is open at the bottom and at one side as best shown in FIGS. 1 and 3 so that the emulsion-gas interface therein corresponds in position to the interface in the remainder of the well. The up and down motion of the float 106 is transmitted by a link 107 (FIG. 3) outside the container to a valve 108 is the treated-oil effluent line 103. FIG. 1 shows the valve 108 diagrammatically, the dotted line 109 indicating the operative connection between the valve and the float 106. Actuation of the valve 108 indirectly controls the gas withdrawal, as Will be described.

' While any suitable gas-withdrawal means can be employed for removing the separated gas from the gas space 50, the preferred structure includes an upright pipe 111 suspended with its upper end a slight distance below the top of the container to provide an orifice means 112 and with its open lower end below the interface 51. A smaller-diameter pipe 113 depends a short distance into the pipe 111 and communicates with an effluent pipe 114 through which the flow is controlled by an adjustable pressure-release valve 115 which is set to maintain a desired back pressure on the dehydrator. As the interface 51 drops and the flow of treated oil is restricted by the valve 108 this restriction causes the pressure inside the container to increase. The increased pressure in the gas space 50 rises above the value at which the adjustable valve 115 is set thereby starting or increasing the gas etfluent through the pipe 114. The gas discharging therethrough is free of suspended particles of oil or light fractions thereof, such particles separating from the gas either in the gas space 50 or within the pipe 111. The latter provides a confined space which with the reverse flow of the gas, indicated by the arrows, induces separation of such particles. The separated particles can drop from the open lower end of the pipe 111 to become a part of the treated-oil eflluent of the dehydrator.

The electric treater of the invention will desirably be operated at temperatures substantially below those possible when treating the emulsion by chemical or electric action alone and at temperatures very substantially below those required to resolve the emulsion in the older heater-settling equipment. Crude oil emusions are preferably resolved in the dehydrator of the invention while at or near ambient temperature. In many instances the heater 45 is employed only during cold seasons when the ambient temperature is abnormally low. In other instances and where diflicult emulsions are encountered the heater may be used to maintain the temperature in the range of about 60l20 F. with higher temperatures being seldom if ever required, the treating temperature being typically about 30-100" F. lower than when attempting to resolve the emulsion by the older heater-settling equipment. The dehydrator is at all times operated at relatively low temperatures to avoid loss of lighter fractions.

During periods when heating is desired, this heat is preferably applied to the water and emulsion in the upright passage 33. The heater illustrated is particularly effective in this regard and comprises a burner housing extending laterally into the container. A burner 121 and a pilot 122 produce products of combustion which move toward the closed inner end of the housing 120 to an internal flue passage means comprising a pair of pipes 124 which communicate with an external stack 125 rising to a level substantially above the top of the container 10. The burner 121 may be manually controlled but is preferably thermostatically controlled by means of a heat-responsive element 126 (FIGS. 3 and 4) connected by a suitable control, shown diagrammatically by the dotted line 127, to the burner 121 in controlling relationship and in such manner as to maintain substantially uniform the temperature of the emulsion entering the main treating space 24.

As an example of the operation of the invention and its efficacy as compared with-a conventional thermochemical dehydrator, in which the emulsion was broken by heat and pressure aided 'by chemical action but without the use of any electric field, the following data are presented comparing such electric and non-electric units of equal diameter, respectively designated as treaters A and B.

The amounts of chemical added into the two treaters were virtually the same but it will be observed that the electrical dehydrator of the invention was able to treat more than twice the amount of emulsion at a temperature 85 F. lower as compared with the thermochemical dehydrator, all while producing a higher-gravity and more valuable oil of far less BS & W content.

As another example, the operation of one treater of the invention (container 6' x 12') was compared with the operation of two dehydrators of the heater-settling type (each container 6 x 22') between which the stream of emulsion was divided, the amounts of chemical'employed being virtually the same. The treating rate for the single treater of the invention was 947.6 bbls./day as compared with 904 bbls./day for the two Older-type and much larger treaters (452 bbls./day per treater). The temperature of treatment was 60 F., as compared with 145 F., a reduction of 95 F. resulting in a saving in gas for heating of $12.70/day. The average gravity of the treated oil was 34.7 A.P.I. as compared with 33.6, the increased value from the gravity increase being $18.95/ day and the increase due to a 1.8% volume savings being an additional $48.11/ day, resulting in a total daily saving of $79.76.

In another example the operation of one treater of the invention (container 8' x 12') was similarly compared with the operation of two dehydrators of the heatersettling type (each container 6 x 22') on a difficult emulsion. The treating rate of the single electric treater was 936 bbls./day as compared with 548 bbls./day for the two older and larger treaters. Operating temperature was lower by 42 F. (118 F. as compared with 160 F.), resulting in a saving in heating gas of $23.40/ day. Savings or augmented value due to increased gravity (25.5 A.P.I. as compared with 24.05) was $46.80/day and from increased volume (15.16 bbls./day) was $44.26, making a total savings $114.46/day in favor of the electric treater of the invention.

For purpose of simplicity in description the foregoing material refers to various liquid-liquid interfaces. In all instances and particularly as concerns the interfaces 52 and 70 these interfaces may be zones of transition between water-continuous and oil-continuous systems, often being shallow zones containing sludge or components undergoing separation, all as distinct from a planar junction of bodies of oil and water. This is well understood in the art.

Similarly the liquid bodies in the several zones have usually been designated by the simpler terms emulsion, water and oil. It is to be understood that the material in the emulsion space 28 below the interface 49 is predominately oil-continuous, as is also the material in the upper portion of the well 36. The material around the heater in the upright passage 33 and in the bottom of this passage and the entrance chamber 20 is predominately water-continuous. The oil in and above the electrode system is oil-continuous and is in the process of separation. correspondingly the above-quoted terms are not to be construed as referring to pure systems free of contaminating substances but to the predominately oil-continuous or water-continuous systems mentioned above.

Various changes and modifications can be made without departing from the spirit of the invention as defined in the appended claims.

We claim: a

1. A process for the resolution of a gas containing water-in-oil type emulsion in a closed container having gas-separating and treating zones therein spaced from each other, which process includes the steps of:

(a) establishing an electric field in a horizontal stratum of said treating zone throughput substantially the entire horizontal cross-section of such treating zone;

(b) maintaining bodies of gas and liquid in said gasseparating zone contacting at a gas-liquid interface;

(c) discharging a stream of said emulsion into said gas-separating zone while containing gas;

(d) separating gas from said emulsion while in said gas-separating zone, the separated gas joining said body of gas leaving a degasified emulsion continuously augmenting the volume of said liquid body;

(e) withdrawing gas and degasified emulsion respectively from said gas and liquid bodies in said gasseparating zone at a rate to maintain substantially constant the level of said gas-liquid interface therein;

(f) dividing the thus-withdrawn degasified emulsion between a plurality of discharge passages all in the same horizontal plane below said horizontal stratum and exuding the emulsion into said treating zone through such discharge passages to move upward in said treating zone to said electric field, said electric field coalescing the dispersed material of said emulsion to produce coalesced masses of the dispersed material settling through the upwardly moving emulsion to the bottom of said treating zone and leaving a treated oil in the top of said treating zone, said discharge passages being openings of significant vertical dimension;

(g) maintaining in the lower portion of said treating zone a body of the separated dispersed phase material having one portion thereof contacting said degasified emulsion at an interface;

(h) maintaining such interface relative to the discharge passages while said distributed and degasified emulsion exudes into said horizontal plane preparatory to said upward movement in said treating zone to said electric field;

(i) withdrawing dispersed phase material from the bottom of said treating zone;

(j) and Withdrawing electrically treated oil from the top of said treating zone.

2. A process as defined in claim 1 in which said body of separated dispersed material has another portion having an upper surface exposed to said settling coalesced masses to receive same, and including the step of maintaining such surface at a level above the level of said interface between said degasified emulsion and said one portion of said separated dispersed material, the degasified emulsion exuding from said discharge passages into said other portion of said body of separated dispersed material to be washed thereby during upward movement to said surface.

3. A process for the resolution of a water-in-oil type emulsion, which process includes the steps of:

(a) washing the emulsion by flowing same upwardly in a water-continuous environment within a wash passage, some of the water of the emulsion joining the water in such water-continuous environment;

(b) removing from the top of said wash passage a washed emulsion stream containing a part of the water of said water-continuous environment;

(c) discharging such removed stream of washed emulsion into a settling zone for separation of some of the water therein, leaving a washed and settled emulsion;

((1) subjecting said washed and settled emulsion to the action of a high-voltage electrostatic field to coalesce the water remaining therein into masses of sufiicient size to gravitate from the oil of the emulsion; and

(e) separating such coalesced masses from the oil.

4. A process as defined in claim 3 including the additional steps of:

(a) flowing said washed emulsion stream along a surface as a thin stream before discharging same into said settling zone; and

(b) separating gas from such washed emulsion as it flows as said thin stream.

5. A process as defined in claim 4 in which said surface is substantially horizontal and including the steps of:

(a) separating some of the water from said washed emulsion stream during flow along said substantially horizontal surface to form a film of such separated water on said surface;

I (b) flowing additional washed emulsion as a thin layer I overlying said water film to a discharge position; and

(c) flowing from said discharge position into said settling zone the emulsion from said thin layer and water from said film.

v 6. A process as defined in claim 3 in which said waterin-oil type emulsion contains water-wet solids, and including the steps of:

(a) applying heat to said water-continuous environment during rise of said emulsion therein to remove such water-wet solids from such emulsion;

(b) settling such water-wet solids in said wash passage to a lower portion thereof during the rise of said emulsion in such passage; and

(c) removing such separated solids from said lower portion of said upright passage.

7. A process as defined in claim 3 including the step of subjecting said emulsion prior to entry into said electrostatic field to the action of a chemical treating agent.

8. A process as defined in claim 3 including the step of flowing the water-in-oil type emulsion downward in an oil-continuous environment before washing the emulsion by said upward flow in said wash passage.

9. A process for the resolution of a gas-containing water-in-oil type emulsion in a closed horizontally-elongated container having gas-separating and treating zones therein spaced from each other, which process includes the steps of:

(a) establishing an oil-filled electric field in a horizontal stratum of said treating zone throughout substantially the entire horizontal cross section of such treating zone;

(b) flowing said emulsion downwardly in said container and then upwardly in said gas-separating zone;

() withdrawing from the top of said gas-separating zone gas separating from said emulson therein;

(d) flowing degasified emulsion from an upper position in said gas-separating zone downwardly in a settling space to a lower position therein, said lower position being below said horizontal stratum, and withdrawing from the lower end of said settling space any dispersed-phase material separating from the degasified emulsion therein;

(e) withdrawing a stream of the settled emulsion from such lower position and delivering same to said treating zone while dividing such stream in said treating zone between a plurality of discharge passages all in the same horizontal plane below said horizontal stratum and exuding the emulsion into said treating zone to rise therein to said oil-filled electric fiield, said electric field coalescing the dispersed-phase material of said emulsion to produce coalesced masses of the dispersed-phase material settling to the bottom of said treating zone and leaving a treated oil in the top of said treating zone;

(f) withdrawing separated dispersed-phase material from the bottom of said treating zone; and

(g) withdrawing treated oil from the top of said treating zone.

10. A process as defined in claim 9 including the step of heating said emulsion during upward flow in said gasseparating zone.

11. A process for the resolution of water-in-oil type emulsion containing gas and dispersed water in connected internal zones of a closed container, the first such zone being a gas-separating zone containing a body of gas, some of said dispersed water being present as free water, which process includes the steps of:

(a) discharging the emulsion into the gas of said first zone and then flowing the emulsion downwardly and upwardly in said first zone of said container while subjecting same to the action of gravity to separate free water therefrom, said free water collecting as a body in said first zone;

(b) separating gas from said emulsion in said first zone and collecting same in the upper end of said first zone to form said body of gas;

(c) flowing degasified emulsion from said first zone downwardly in a second zone within said container and thence upwardly in a third zone therein;

((1) establishig a high-voltage electric field in said third zone and subjecting the rising emulsion in such third zone to the action of such electric field;

(e) withdrawing separated water from the bottom of said third zone; and

(f) withdrawing treated oil from an upper portion of said third zone above said electric field.

12. A process as defined in claim 11 including the step of separating additional free water from said emulsion in said second zone and withdrawing such separated water from said container along with the water separating in said third zone.

13. A process as defined in claim 11 including the step of collecting free water in the bottom of said first zone and withdrawing such free water from said container separate from the withdrawal of said separated water from said third zone.

14. A process as defined in claim 11 including the'step of maintaining a gas-emulsion interface in said first zone between said body of separated gas and the emulsion rising therein, and skimming emulsion from said first zone at a position just below said gas-emulsion interface and dropping the emulsion thus skimmed into said second zone.

15. A process as defined in claim 14 including the step of maintaining a second gas-emulsion interface in said second zone at a level below the gas-emulsion interface in said first zone, and dropping the emulsion skimmed from said first zone through the gas in said second zone to said second gas-emulsion interface preparatory to further downward movement of said degasified emulsion in said second zone.

16. A process as defined in claim 15 including the step of controlling the rate of flow of treated oil from said third zone to maintain said second gas-emulsion interface at a substantially constant level.

17. A process as defined in claim 11 including the additional steps of flowing the emulsion toward said second zone along a surface as a thin film preparatory to downward flow in said second zone, and separating gas from such emulsion as it flows as said thin stream.

18. A process as defined in claim 17 in which said surface is substantially horizontal, and including the steps of separating some of the water from the emulsion during flow along said substantially horizontal surface to form a film of such separated water on such surface, flowing additional emulsion as a thin layer overlying said water film to a discharge position, and flowing from said discharge position into said second zone the emulsion from said thin layer and water from said film.

19. A process as defined in claim 11 in which said water-in-oil type emulsion contains water-wet solids, and including the steps of applying heat to said emulsion during upward flow in said one zone, settling such water-wet solids in said first zone to said body of free water therein, and removing such separated solids from said one zone along with free water from said body thereof.

20. A process for the resolution of water-in-oil type emulsion, which process includes the steps of:

(a) flowing said emulsion downwardly in an oil-continuous environment into contact with wash-water to wash the emulsion, some of the water of the emulsion joining the wash water;

(b) flowing the resulting emulsion upwardly in an upright passage;

(0) removing a stream of emulsion from the top of said upright passage and discharging such removed stream into a settling zone for separation of some of the water therein;

(d) subjecting the resulting washed and settled emulsion to the action of a high-voltage electrostatic field to coalesce the water remaining therein into masses of sufiicient size to gravitate from the oil of the emulsion; and

(e) separating such coalesced masses from the oil.

21. A process for the resolution of water-in-oil type emulsion containing gas and dispersed water in a closed system, some of said dispersed water being present as free water, which process includes the steps of:

1 1 1 2 (a) flowing the emulsion successively through two (f) withdrawing treated oil from the top of said other zones while separating gas and free water from the zone.

emulsion in both zones;

(b) mingling the gases separated in both zones and References cued by the Exammer withdrawing the mingled gases from the system; 5 UNITED STATES PATENTS (c) flowing the resulting degasified emulsion down- 1,299,589 4/ 1919 McKibben 204188 w-ardly and then upwardly in another zone; 3,073,775 1/ 1963 Waterman 204-188 X (d) subjecting the emulsion during such upward flow 3,121,055 2/1964 C'arswell 204-302 to the action of a high-voltage electric field acting to i coalesce dispersed water in the degasified emulsion 10 References Cited by the Apphcant into masses of sufficient size to gravitate to the bot- UNITED STATES- PATENTS tom of said other zone and form a body of separated 2,894,895 7 /1959 Turner water therein; (e) withdrawing water from said body of separated 15 JOHN K U Exammerwater; and R. MIHALEK, Assistant Examiner.

Claims (1)

1. A PROCESS FOR THE RESOLUTION OF A GAS-CONTAINING WATER-IN-OIL TYPE EMULSION IN A CLOSED CONTAINER HAVING GAS-SEPARATING AND TREATING ZONES THEREIN SPACED FROM EACH OTHER, WHICH PROCESS INCLUDES THE STEPS OF: (A) ESTABLISHING AN ELECTRIC FIELD IN A HORIZONTAL STRATUM OF SAID TREATING ZONE THROUGHPUT SUBSTANTIALLY THE ENTIRE HORIZONTAL CROSS-SECTION OF SUCH TREATING ZONE; (B) MAINTAINING BODIES OF GAS AND LIQUID IN SAID GASSEPARATING ZONE CONTACTING AT A GAS-LIQUID INTERFACE; (C) DISCHARGING A STREAM OF SAID EMULSION INTO SAID GAS-SEPARATING ZONE WHILE CONTAINING GAS; (D) SEPARATING GAS FROM SAID EMULSION WHILE IN SAID GAS-SEPARATING ZONE, THE SEPARATED GAS JOINING SAID BODY OF GAS LEAVING A DEGASIFIED EMULSION CONTINOUSLY AUGMENTING THE VOLUME OF SAID LIQUID BODY; (E) WITHDRAWING GAS AND DEGASIFIED EMULSION RESPECTIVELY FROM SAID GAS AND LIQUID BODIES IN SAID GASSEPARATING ZONE AT A RATE TO MAINTAIN SUBSTANTIALLY CONSTANT THE LEVEL OF SAID GAS-LIQUID INTERFACE THEREIN; (F) DIVIDING THE THUS-WITHDRAWN DEGASIFIED EMULSION BETWEEN A PLURALITY OF DISCHARGE PASSAGES ALL IN THE SAME HORIZONTAL PLANE BELOW SAID HORIZONTAL STRATRUM AND EXUDING THE EMULSION INTO SAID TREATING ZONE THROUGH SUCH DISCHARGE PASSAGES TO MOVE UPWARD IN SAID TREATING ZONE TO SAID ELECTRIC FIELD, SAID ELECTRIC FIELD COALESCING THE DISPERSED MATERIAL OF SAID EMULSION TO PRODUCE COALESCED MASSES OF THE DISPERSED MATERIAL SETTLING THROUGH THE UPWARDLY MOVING EMULSION TO THE BOTTOM OF SAID TREATING ZONE AND LEAVING A TREATED OIL IN THE TOP OF SAID TREATING ZONE, SAID DISCHARGE PASSAGES BEING OPENINGS OF SIGNIFICANT VERTICAL DIMENSION; (G) MAINTAINING IN THE LOWER PORTION OF SAID TREATING ZONE A BODY OF THE SEPARATED DISPERSED PHASE MATERIAL HAVING ONE PORTION THEREOF CONTACTING SAID DEGASIFIED EMULSION AT AN INTERFACE;; (H) MAINTAINING SUCH INTERFACE RELATIVE TO THE DISCHARGE PASSAGE WHILE SAID DISTRIBUTED AND DEGASIFIED EMULSION EXUDES INTO SAID HORIZONTAL PLANE PREPARATORY TO SAID UPWARD MOVEMENT IN SAID TREATING ZONE TO SAID ELECTRIC FIELD; (I) WITHDRAWING DISPERSED PHASE MATERIAL FROM THE BOTTOM OF SAID TREATING ZONE; (J) AND WITHDRAWING ELECTRICALLY TREATED OIL FROM THE TOP OF SAID TREATINGG ZONE.

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