US2400713A - Process and apparatus for the demulsification of hydrocarbons - Google Patents

Description

May 21, 1946. w. ant-155s 2,400,713 PROCESS AND APPARATUS FOR THE DEMULSIFIC EATION 0F HYDROCABBONS Filed-Feb. 15, 1943 2 Sheets-Shae 1 Y IINVENTOR.

yam/lam $2M May 21, 1946. w. B. RHEES 2,400,713 PROCESS AND APPARATUS FOR THE DEMULSIFICATION OF HYDROCARBONS Fiied Feb. '15, 1945 2 Sheets- Sheet; 2

INVENTOR;

VV/Y/I'am B Rhee casing, and

Patented ay 21, 1946 ascents AND -P moons n 1 sm E BONS CATIQN son urns noo- Willi B. Rhees, Augusta, 1 Application February it, sees, Serial No. 476,029

8 claims. (or. 252-323) Patent 1,531,173; the present process being carried out at a central location and above ground, and at which location the emulsified products of a plurality of wells may be treated.

A further object of this invention is the provision ci an improved process for demulsifying oil and water as it comes from the oil well in a relatively economical and continuous manner for the production of a high grade usable 011.

Other objects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawings, forming a part of this specification, and wherein similar reference characters designate corresponding parts thruout the several views,

Figure l is a vertical sectional view taken thru a heater tank; the same being a part of the ap=- paratus, and which has been more specifically illustrated, described and claimed in my copending application Serial Number 408,252, filed August 25, 19 11, which has now matured into Patent No. 2,386,661, granted @ctober 2, 1945.

Figure 2 is a somewhat diagrammatic view, with some of the parts in section, showing an im proved apparatus by means of which'the improved process can be carried out. In the drawings, wherein for the purpose of illustration is shown only a preferred embodiment of the invention, the letter A may generally designate the heating receptacle or tank in which the emulsified oil is heated. It consists of the receptacle casing ID having a main heat flue H extending therethru. A burner pot I2 is supported in the lower end of the hue by detachable means I3, and the lower end 'of the flue is preferably provided with a removable drip receptacle it which can be detachably connected as at It to the lower end of hue. The casing 50 may be provided with an apertured wall 16 spaced a desired distance from the bottom wall ll of the in the space between these walls is disposed a housing 58 similar to that shown in my application Serial Number 408,252 above referred to, to sub-divide the oil compartment from the flue. The emulsified oil of course fills the casing iii externally of the flue ii and the casing;

. to the difierence in the it. A line 2b is connected to the lower end of the casing ill, thru which the emulsified oil from the wells enters the tank.

A displacement float control for maintaining a constant level of water in the heater casing to is provided at B, and has been made the subject matter of my co-pending application Serial Number $32,351, filed February 25, 1942. It includes a float 25 pivoted at 26 and counter-balanced at 21. A water draw off line to is provided, having a valve 3! connected as at 32 with the leverage of the arm carrying thefioat 25. As the level of the water in the lower part of the tank rises, due specific gravities of the oil and water, the floatdh willcause an opening of the valve 3| and water will draw off from thetank.

In Figure 1, at 82, is designated the preferred level of the water, and thereabove the tank is filled with the emulsified oil.

It should be noted that the burner. box 62 is located in the flue above the normal level of settled water. This burner box is provided with openings designated at 8ft thru which oil can drop to the drip pan it. This prevents coking of the burner pot.

The casing it at the'top thereof is provided with an oil draw ofi dd thru which the heated oil flows into the apparatus shown in Figure 2, where it is further processed as will be hereinafter set forth.

1 prefer to feed oil as fuel to the burner pct 62 taken from the upper part of the 0 ill. To that end I provide a line fil mounted as at 42 in the tank and thin which the oil drips into the burner pot. In this line ll is located a shut-off valve it and a reading gauge M. r

I prefer to provide thermostatic means for controlling the flow of oil to the burner pot, according to the temperature of the heated oil .in the tank. This thermostatic means as preferably consists of a removable plug 5| mounted in the casing 10, the inner end of which has a receptacle 52 detachably secured thereto.

Within the chamber of this receptacle '52 is a thermostatic bellows as which controls move-,

ment of the feed needle 56. A line 56 withdraws oil from the upper part of the tank A whence it flows into the chamber 52. The line at has a tapered entrance 6G in the chamber 52 within which the needless cooperates for the regulated feeding of oil thru the line M.

A manually adjustable screw M controls the sensitiveness of the needle 65.

Referring to Figure 2, the heated oil flows detachably from the tank A thru the line 40 into a horizontally disposed receptacle '10, preferably of tubular formation, the internal diameter of which is at least several times larger than the internal diameter of the pipe 40 and within which the oil and water are subjected to a combined cooling and pressure treatment, and also a wash treatment for purposes to be subsequently deinternal diameter .the same as the conduit 10,

"which connects at its upper end with a. tank 13. The latter may be classified as a settling tank and the numeral 13 designates the division of the oil and settled water. The oil in the upper part of the tank 13 is withdrawn thru line '84 to storage. A small diametered conduit [5 draws water from the bottom of the tank. This water' enters the end of the conduit or receptacle i0 remote from the settling tank. The water fed from this line enters the conduits l0 and 2 for the purpose of coalescing water which has been separated from the oil. The conduit '55 is preferably smaller in internal diameter than the lines 48, Hi and I2 and a check valve 15 may be provided therein to prevent back pressure of water in the event the pressure in the system is built up too high. The conduit 12 may have a shut-oil valve it in the upper end thereof near the settling tank.

As shown in Figure 2, the oil entrance line 2!] may have a plizlralitt of laterals 2b which lead to various wells supplying roily oil to the tank A for treatment.

A feeder mechanism 80 may be placed in the line 4-!) adjacent to the conduit 70 for supply of an oil soluble chemical to the emulsified oil and water. Another feeder 81 may be placed at the inlet end of the conduit or receptacle lid for supplying a water soluble chemical as an accelerant for the purpose of coalescing the water particles more easily during travel thru the horizontal conduit.

Referring to the step cycle of the process, the emulsified oil enters the lower'end of the tank A thru the line and free water settles at the level 33 and is withdrawn from the bottom of the tank A by the equipment 13 above described. The oil in the tank A is maintained at constant pressure and temperature. The rate of velocity flow thru the tank is very low and while the process is continuous and oil continually drawn oil from the top of the tank thru the line 40, it takes the oil substantially one hour to flow thru the casing iii. In the tank A the temperature i maintained below boiling, preferably at 160 F. but not above 190, and the pressure therein may be maintained at 10 lbs. superatmospherie but not above 50 lbs. Since the heat is maintained below the boiling point, there will be no efiervescence in the tank A and the emulsion will be broken. There is no vapor escape. The treatment in the tank A breaks the emulsion into oil, free water and line water particles. The fine waterparticles are held in suspension so that they can readily coalesce and combine with the wash water in the treatment of the oil and '70, such as Tretolite.

water in the conduits I0 and 12 of the apparatus.

While the pressure in the tank A is superstmospheric, it must be above the vapor pressure of the particular, oil used. In this connection it should be stated that the temperature and pressure may be varied to suit the particular roily oil which is to be demulsified.

The heated oil under pressure has a very slow flow thru tank A and therefrom it enters the line 40 and flows into the inlet endof the en larged conduit or horizontal receptacle 10. The oil flow thru the receptacles 10 and 12 which contains wash water is slower than in line 40 and is cooled. It is maintained under pressure for the purpose of retaining the stability of the oil. If the treatment is carried out in a horizontal conduit such as 10 and directly therefrom flows into a settling tank, mechanical pressure can be resorted to for the purpose" of maintaining pressure during the cooling and washing of the 011. However, as shown in Figure 2, the oil and water may be maintained under a hydrostatic pressure by causing the same to flow thru a vertically disposed or inclined conduit 12. Such use is only practical where a settling tank, such as 13, can be maintained at a level considerably above the heater tank A. The oil during the treatment in the conduits 10 and 12 is cooled while being maintained under superatmospheric pressure. It is preferably not cooled lower than F., but it must be cooled below F. This cooling, while under pressure, is efiected so that when the oil is lowered to atmospheric pressure, it will remain stable.

:Flow of oil thru the conduits 70 and 12 is caused by pressure action upon the oil and partly thru thermosyphonic action. The wash water of course flows thru the line 15 by thermosyphonic action thereof.

The wash water fed into conduits 10 and 12 from the line 15 picks up and coalesces the particles of water held in suspension in the oil as the same flows thru the conduits i0 and 72. This wash water is preferably salt water and may be combined with the chemical or chemicals from the feeders 80 and 55. It is not otherwise diluted. It does not pass into the tank A or the line 40 above the horizontal. It is heated by the oil flowing thru lines 70 and 72 in a heat exchange relation.

As above stated the oil may be treated with a water soluble chemicalas it enters the conduit This is a water softener which accelerates the separation of oil and water and coalescing of the water with the wash water thruout the treatment. The treatment may also consist in the addition of a water softener, such as sodium hydroxide or ammonium hydroxide'in order to speed the coalescing of water particles. It must be remembered that the conduits 10 and 12 are many hundreds of feet in length, and to give some idea of their comparative diameters, the pipes 40, 70 and 15 may be respectively three inches, six inches and two inches. This proportion may be varied, as desired.

The chemical of course enters the settling tank 13 and is deposited in the salt water used for washing purposes and of course it is used over and over again until the solution becomes so weak that more of the water softener or chemical must be added from the feeders 80 and BI.

It is to be noted that the feeder 80 is located stances for various oils,'according to their chemical make-up, and I contemplate that-under some conditions, both chemicals may be used, ditions the water softening chemical one used in the process.

The oil withdrawn from line It has less than 1% B. S. Itis within the contemplation .or-this invention to provide other heat exchanging apparatus than the conduits Iii and 12, for the purpose of cooling the oil while under pressure.

If desired, 1 may provide a suitable mechanism for feeding natural gas into the conduit 12 at the lower end thereof, thru mechanism shown at so, for the purpose oi causing proper circulation and flow of the oil and water thru the and into the settling tank.

The element of pressure oil thruout the system is important.

the oil from boiling and efferno lossesoi volatreatment maintains and it is important altho under normal conis the only the settling tank thru thruout the treatment, including the step of cooling the same up to the time that the same enters the settling tank. If found necessary, pressure regulating valves may he placed at the top or the conduit 12 and upon the conduit 15.

Various changes in the steps of the process and in the equipment necessary to carry out the process may be made to the form oi invention herein shown and described, without departing from the spirit or the same I claim:

l. The process oi 'demulsiiying oil and water which consists in heat treating the oil and water at a temperature below the boiling point of water while under superatmospheric pressure, subsequently cooling the oil and water to a normal temperature while maintaining the same under superatmospheric pressure and during the pressure cooling or the oil and water treating the during the last mentioned ing the oil and water with a water soitenins system the oil soluble and water soluble i the said of the container go free that this pressure is maintained in a preliminary heat and pressure treatment of the same for causing a break down of the emulsion, and while the resultant product is heated causing the same to flow under hydrostatic head pressure to a point where the same is cooled to a normal treatment causing the particles of water to coa lesce thru a. water wash treatment, and subsequently causing the water to settle from the oil,

wash water being the product of settling of the water irom the oil treated.

4. In apparatus for the treatment of hydrocarbon emulsions, the combination or a container, means ior admitting to the hydrocarbon emulsions to be treated, means for withdrawing free water from the lower part of the tank to apredetermined level, and burner means for heating the oil in the tank located above the said level of water in the ta .t

demulsifying hydrocarbon and water emulsions which consists in heat treat ing the emulsions for the purpose of'breaking said emulsions, subsequently water washing the oil and any suspended water particles therein by the water- 5. The process of pressure, and subsequently separating the oil and water.

or the scope of the claims.

subsequently separating the oil and 6. The process of demulsifying hydrocarbon and water emulsions which consists in heat treatcausing under hydrostatic pressure together with a water wash solution 'for the purpose of coalescing the water particles with said wash solution, and

water.

'7. The process of demulsifying hydrocarbon and water emulsions which'consists in heat treatment oi the emulsions to initially break the same, subsequently causing the oil and water suspended therein to travel a relatively long together with a washin solution under pressure greater than atmospheric for the purpose or coalescing the water particles with the wash solution,

chemical of a nature to accelerate-water ooalesand subsequently separating the oil and water.

cence, and subsequently separating the oil and -8. The process of demulsiiying hydrocarbon water. I I r and water emulsions and the like which consists 2. The process of treating emulsified hydrosar in heat treating the oil and water for the purcarbon and water out or the well which consists in heat treating the same while under superatmospheric pressure for the purpose of a preliminary breaking of the emulsion, withdrawing whatever free water there is, subsequently treatins the remaining hydrocarbon water wash solution while maintaining the hydrocarbon under superatmospheric pressure to so pasd paths causing a wash solution to act upon the point where the same is cooled to a no said oil and water particles for the purpose of ml ere ur and subsequently separatingthe oil coalescing the water articles with said wash and water. solution, and subsequently separating the oil and 3'. The steps in the oi demulsiiying hydrocarbon and water emulsions, which pended and water with a causing the oil stantially horizontal path and then thru an upwardly disposed path under hydrostatic pressure and during the travel or the oil and water particles along the horizontal anad upwardly disthe lower part horizontal path

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