US3708960A

US3708960A - Heater-treater

Info

Publication number: US3708960A
Application number: US00114244A
Authority: US
Inventors: W Christopher; C Meyers; J Whipple
Original assignee: PROCESS TECHNOLOGISTS INTERNAT
Current assignee: PROCESS TECHNOLOGISTS INTERNAT
Priority date: 1971-02-10
Filing date: 1971-02-10
Publication date: 1973-01-09
Anticipated expiration: 1990-01-09

Abstract

In a heater-treater, a tank is divided into separate heating and treating sections, and the heating section is in turn divided into a receiving zone and an enclosed heating chamber. A pair of downcomers convey emulsion from the top of the receiving zone to the bottom of the heating chamber, and a portion of the emulsion flowing from the downcomers is directed across a discharge passageway to flush sediment and free water from the chamber. The emulsion flows diagonally upwardly in the heating chamber past a pair of firetubes and is conveyed from the top of the chamber to the bottom of the treating section by a conduit. The operation of the firetubes is controlled by thermostats located in the upper portion of the heating chamber adjacent the inlet of the conduit.

Description

United States Patent w 1 51 Jan. 9, 1973 Christopher, J r. et al;

541 HEATER-THEATER [75] Inventors: William ll.Cl11-istopher, .lr.; Charles 0. Meyers, both of Tulsa; Jack C. Whipple, Jr., Sapulpa, all of Okla.

{731 Assignee: Processv Technologists Internation Division of Trinity, Inc., Dallas, Tex.

22 Filed: Feb. 10,1971 [21' Appl.No.: 114,244

52 U.S.Cl ..55/l69,55 /l74 [511 -C'-.:-;::;- -P2 dl2 9.9 5s fiiai'iif's arcfi "55/9, 42, 45, 164, if 169,171476; 204/302, 308

[56] l References Cited UNITED STATES PATENTS 3,432,991 3/l969 Sauderetal "55 42 3,476,678 11/1969 Murdock,Sr... ..55 9x 3,389,536 6/1968 311112.; ....55/42x l2/l963 Glasgow .....=.55/42 3,255,571 6/1966 Walker et al. 2,7 l 3,919 7/1955 Walker et al ..55/42 Primary Exzirhinie'r-Samih N. Zaharna Assistant Examiner-R. W. Burks Attorney-Richards, Harris & Hubbard '57 ABSTRACT In a heater-treater, a tank is divided into separate .heating and treatin sections, and the heating section is in turn divided into a receiving zone and an enclosed heating chamber. A pair of downcomers convey emulsion from the top of the receiving zone to the bottom of the heating chamber, and a portion of the emulsion flowing from the downcomers is directed across a discharge passageway to flush sediment and free water from the'chamber. The emulsion flows diagonally upwardly in the heating chamber past a pair of firetubes and is conveyed from the top of the chamber to the bottom of the treating section by a conduit. The operation of the firetubes is controlled by thermostats located in the upper portion of the heating chamber adjacent the inlet of the conduit.

15 Claims, 3 Drawing Figures SHEEI 1 BF 2 ATTORNEYS PATENTEU JM 9 I973 FIG. 3

PATENTEU JAN 9 I973 ODOOOOOOOOQOOOOOOOOOOOOOOOOOOOOOOOOOOO 00000 000 OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOAWOOOOOOOOO v l-IEATER-TREATER BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to an improved heater-treater of the type employed in separating oil well production into oil, natural gas and free water.

Oil well production generally does not comprise pure oil, but instead includes natural gas; a water-oil emulsion which may be a water-in-oil emulsion, an oil-inwater emulsion, or both; and free water. his well known that relatively water free oil can be recovered from such production by heating the production to separate the natural gas and the free water from the emulsion, and then treating the emulsion electrostatically to coalesce the water therefrom. These operations are usually carried out in a device known in the art as a heater-treater.

Most of the oil well production heater-treaters now being manufactured comprise a large tank that is divided into separate heating and treating sections. The heating section of such a device typically includes a receiving zone and a heating chamber comprising a firetube and structure for directing at least the wateroil emulsion portion of the production into engagement with the firetube. One problem that is often encountered in the use of a heater-treater is the accumulation of sediment in the heating chamber of the heating section. Another problem that frequently arises is firetube burnout, which is caused by inadequate temperature control in the heating section.

The present invention relates to an oil well production heater-treater characterized by improved heat transfer characteristics, a self-flushing heating chamber, and improved temperature control characteristics. In accordance with the preferred embodiment of the invention, the water-oil emulsion from the production is conveyed to the bottom of an enclosed heating chamber and is directed across a discharge passageway to flush sediment and/or free water from the chamber. The emulsion then flows upwardly past a I firetube and is withdrawn from the top of the heating chamber through a conduit. The operation of the firetube is controlled by thermostats mounted in the upper portion of the heating chamber and at the inlet of the conduit, so that the thermostats sense both the total flow and the highest temperature of the emulsion.

DESCRIPTION OF THE DRAWINGS DETAILED DESC IPTION Referring now to the Drawing, and particularly to FIGS. 1 and 2 thereof, there is shown a heater-treater 10 comprising the preferred embodiment of the inven-' tion. The heater-treater 10 includes a closed, cylindrical tank 12 which is supported in a horizontal orientation by a pair of supports 14. The tank 12 is divided into a heating section 16 and a treating section 18 by a vertically extending baffle 20. The heating section 16 is in turn divided into a receiving zone 22 and an enclosed heating chamber 24 by a cylinder 26 that extends longitudinally through the mid-portion of the heating section 16 and into engagement with the baffle 20.

In the use of the heater-treater 10, oil well production is directed into the receiving zone 22 of the heating section 16 through an inlet 28 and a valve 30. Upon entering the heater-treater 10, the production strikes a baffle 32 and immediately begins to separate into its constituent fluids, i.e., natural gas, water-oil emulsion, and free water. The natural gas tends to rise in the tank 12 and is withdrawn from the upper portion of the receiving zone 22 through a gas outlet 34 and a backpressure valve 36. The free water tends to sink to the bottom of the heating section 16, whereupon it flows along the bottom of the tank 12 through a passageway 38 formed in the baffle and is withdrawn from the tank through a water outlet passageway 40' and a float controlled valve 42. Conversely, the water-oil emulsion is further processed in the heating section 16 and in the treating section 18 into relatively water free oil and additional free water.

Referring now to FIGS. 2 and 3, a gas-emulsion interface 44 extends horizontally through the upper portion of the heating section 16 of the tank 12, and an emulsion-water interface 46 extends horizontally through the entire length of the lower portion of the tank 12. An emulsion level responsive float 48 is mounted in the tank 12 and is operative to maintain the height of the gas-emulsion interface 44 in the heating section 16 of thetank 12 at the level indicated. Similarly, a water level responsive float 50 is mounted in the tank 12 and is operatively connected to the valve 42 to maintain the height of the emulsion-water interface 46 in the tank 12 at the level indicated.

Referring again to FIGS. 1 and 2, the heater-treater 10 further includes a pair of downcomers 52 each of which extends between an inlet 54 and an outlet 56. The downcomers 52 convey emulsion from the upper portion of the receiving zone 22 to the lower portion of the heating chamber 24, whereupon the emulsion flows diagonally upwardly in the chamber. A pair of fire'tubes 58 receive fuel gas through a pair of inlets 60 and a pair of thermostat controlled valves 62. The fuel gas is burned in the firetubes 58 to form products of cornbustion which are directed through the enclosed heating chamber 24. After passing through the firetubes 58, the products of combustionare discharged through a pair of stacks 64.

As the emulsion is heated in the chamber 24, additional natural gas. and additional. free water are separated from the emulsion. As is best shown in FIG. 2, thesefluids are directed to the upper and lower portions, respectively, of the heating section 16 of the tank 12 through a pipe 66 and a discharge passageway 68. At the same time, a conduit 70 having an inlet 72 and an outlet 74 conveys heated emulsion from the upper portion of the chamber 24 to the lower portion of the treating section 18 of the tank 12. The extent to which the emulsion is heated in the chamber 24 is controlled by a pair of thermostats 76 which are located adjacent outlets 56 of the downcomers 52, and the outlets 56 are positioned adjacent the cylinder26. Because of this ar rangement, a portion of the emulsion flowing through the downcomers 52 engage the cylinder 26 and is directed laterally across the inlet 78 of the passageway 68. By this means, any sedimentand/or free water that may be present in the chamber 24 is flushed out of the chamber and into .the lower portion of the tank 12. Second, the, mounting of the thermostats 76 adjacent the inlet 72 of the conduit" 70 assures that the thermostats 76 are positioned at the hottest point in the heating chamber 24 and in the path of all of the wateroil emulsion flowing therethrough. It has been found that this positioning of the thermostats 76'prevents hot spots from developing within the chamber 24 and thereby prevents burnouts from occuring at any point in the flretubes 58. Third, .the diagonally upward flow of the emulsion through the chamber 24 provides a combined counterflow and crossflow pattern of the emulsion relativeto the flow of the productsof combustion inthe firetubes 58. By this means, thorough heating of the emulsion during its flow through the heating chamber 24 is assured, and the fuel requirements of the heater-treater are reduced. 1

As is best shown in FIG. 2, a spreader plate 80 extends horizontally through the treating section 18 of the heater-treater l0.-Heated emulsion is discharged from the outlet 74 of the conduit 70 beneath the spreader plate 80 and above the interface 46.. The emulsion flows through a multiplicity of small diameter holes formed at space intervals over the entire area of the spreader plate 80, and then vertically upwardly into an electrostatic treating zone 82.

The electrostatic treating zone 82'comprises a grid 84 that is maintained at ground potential and a grid 86 that is maintained at an extremely high voltage potential by a transformer 88. In the electrostatic treating zone, the water-of the water-oil emulsion is coalesced in the conventional manner'to form relatively water free oil and discrete water droplets. The coalesced water droplets sink downwardly in the treating section 19 and combine with the free water in the bottom of the tank 12. The oil, on the other hand, flows upwardly in the treating section 18 to an oil collector 90 and is withdrawn from the heater-treater 10 through the collector 90, an oil outlet 92 and a float controlled-valve 94. The valve 94 is operatively connected to, the float 48, and therefore functions to control the levelof the gas-emulsion interface 44.

From the foregoing, it will be understood that the present invention comprises a heater-treater in which emulsion is conveyed to the bottom of an enclosed heating chamber, is directed upwardly through the chamber past a firetube, and is withdrawn from the top of the chamber through a conduit. At least a portionof the emulsion is directed laterally across a dischargepassageway to flush sediment and free waterfrom' the heating chamber. The firetube is controlled by a thermostat positioned in the top of the chamber at the inlet of the conduit.

Those skilled in the art will immediately realize the fact that the apparatus illustrated in the Drawings is useful for purposes other than separating oil well production into gas, oil and water. For example, oil well production often includes salts which must be removed prior to refining, etc. This is typically accomplished by adding water to the production to dissolve the salts, and then removing the water-dissolved salt solution in-a heater-treater. The heater-treater of the present invention is well suited for use in such a desalting operation.

Although thepreferred embodiment of the invention has been illustrated in the Drawings and described in the foregoing specification, it will be understood that the invention is not limited to the embodiment disclosed, but is capable of rearrangement, modification and substitution of parts and elementswithout departing from the spirit of the invention.

What is claimed is: 1 A heater-treater comprising: a tank including a heating section and a treating section; means forming an enclosed heating chamber with the heating section of the tank; means for directing oil w'ellproduction into the portion of the heating section of the tank outside the heating chamber; downcomer means for conveying water-oil emulsion from the upper portion of the tankto the lower portion of the heating chamber; 1 emulsion heating means mounted within the heating chamber; conduit .means for conveying emulsion from the upper portion of the heating chamber to the lower portion of the treating section of the tank so that emulsion flows upwardly in the heating chamber past the emulsion heating means; r electrostatic treating means mounted within. th

treated section for separating emulsion into oil and water, and means for withdrawing oil from the upper portion of the treating section of the tank. 7 2. The heater-treater according to claim 1 further including a discharge passageway extending between the lower portion of the heating chamber and the lower portion of the tank and means for directing emulsion across the passageway and thereby flushing sediment and/or water from the heatingchamber into the lower portion of the tank. I 3. The heater-treater according to claim 1 further including thermostat means mounted in the upper portion of the heating chamber at the inlet of the means for conveying emulsion t0 the treating section for controlling the operation of the emulsion heatingmeans.

4. The heater-treater according to claim 1 further including:

means for maintaining a gas-emulsion interface at a tank; structure surrounding the heating apparatus and dividing the tank into an emulsion receiving zone and an'enclosed heating chamber, and electrostatic treating apparatus mounted in the treating section of the tank, the improvement comprising:

a downcomer conduit for directing emulsion from the upper portion of the emulsion receiving zone of the heating section of the tank to the lower portion of the heating chamber;

a passageway extending from the lower portion of the heating chamber to the lower portion of the tank;

means for directing emulsion flowing from the downcomer across the passageway and thereby flowing sediment and/or water from the heating chamber into the lower portion of the tank;

a conduit for directing emulsion from the upper portion of the heating chamber to the lower portion of the treating section, and

thermostat means positioned in the upper portion of the heating chamber in the path of emulsion flowing into the conduit for controlling the operation of the heating apparatus.

6. The improved heater-treater according to claim 5 wherein the passageway includes an inlet, wherein the downcomer includes an outlet, and wherein the emulsion directing means includes a surface for directing emulsion flowing through the outlet of the downcomer laterally across the inlet of the passageway.

7. The improved heater-treater according to claim 6 wherein the structure surrounding the heating apparatus and dividing the heating section into an emulsion receiving zone and a heating chamber comprises a cylinder extending longitudinally through the mid-portion of the heating section of the tank, wherein the inlet of the passageway is formed in the lowermost portion of the cylinder, wherein the outlet of the downcomer is located adjacent the lowermost portion of the, cylinder, and wherein the emulsion directing surface comprises the interior of the cylinder.

8. A heater-treater comprising:

a tank including a heating section;

means separating the heating section of the tank into an upper emulsion receiving zone and a lower enclosed heating chamber;

downcomer conduit means for directing emulsion downwardly from the emulsion receiving zone to the lower portion of the heating chamber;

emulsion heating means mounted in the heating chamber;

conduit means including an inlet located in the upper portion of the heating chamber for directing emulsion out of the heating chamber, and thermostat means mounted in the upper portion of the heating chamber at the inlet of the conduit means for controlling the operation of the emulsion heating means. 9. The heater-treater according to claim 8 wherein the emulsion heating means comprises atleast one firetube extending through the heating chamber.

10. The heater-treater accordingto claim 8 wherein the downcomer conduit means includes an outlet located at one end of the heating chamber and wherein the inlet of the conduit means is located at the opposite end of the heating chamber so that emulsion flows diagonally upwardly through the heating chamber.

11. The heater-treater according to claim 8 further including a discharge passageway extending to the lower portion of the tank and having an inlet tube the upper portion of the tank to the lower portion of the heating chamber;

a passageway for conveying sediment and/or free water from the lower portion of the heating chamber to the lower portion of the tank, and

means for directing emulsion from the downcomer across the passageway and thereby flushing sediment and/or water from the heating chamber.

13. The heater-treater according to claim 12 wherein the heating chamber forming means includes a cylinder mounted within the heating section of the tank, wherein the passageway includes an inlet formed in the cylinder, and wherein the emulsion directing means directs emulsion flowing from the downcomer laterally across the inlet.

14. The heater-treater according to claim l3'wherein the downcomer terminates in an outlet and wherein the emulsion directing means directs emulsion flowing from the outlet aperture across the inlet.

15. The heater-treater according to claim 14 wherein the outlet is located at a point adjacent the cylinder and laterally displaced from the inlet, and wherein the emulsion directing means comprises a portion of the cylinder which directs at least a portion of the emulsion

Claims

1. A heater-treater comprising: a tank including a heating section and a treating section; means forming an enclosed heating chamber with the heating section of the tank; means for directing oil well production into the portion of the heating section of the tank outside the heating chamber; downcomer means for conveying water-oil emulsion from the upper portion of the tank to the lower portion of the heating chamber; emulsion heating means mounted within the heating chamber; conduit means for conveying emulsion from the upper portion of the heating chamber to the lower portion of the treating section of the tank so that emulsion flows upwardly in the heating chamber past the emulsion heating means; electrostatic treating means mounted within the treated section for separating emulsion into oil and water, and means for withdrawing oil from the upper portion of the treating section of the tank.

2. The heater-treater according to claim 1 further including a discharge passageway extending between the lower portion of the heating chamber and the lower portion of the tank and means for directing emulsion across the passageway and thereby flushing sediment and/or water from the heating chamber into the lower portion of the tank.

3. The heater-treater according to claim 1 further including thermostat means mounted in the upper portion of the heating chamber at the inlet of the means for conveying emulsion to the treating section for controlling the operation of the emulsion heating means.

4. The heater-treater according to claim 1 further including: means for maintaining a gas-emulsion interface at a predetermined point in the upper portion of the tank; means for withdrawing gas from the tank at a point above the gas-emulsion interface; means for maintaining an emulsion-water interface at a predetermined point in the lower portion of the tank, and means for withdrawing water from the tank at a point below the emulsion-water interface.

5. In a heater-treater of the type including a tank having separate heating and treating sections; heating apparatus extending through the heating section of the tank; structure surrounding the heating apparatus and dividing the tank into an emulsion receiving zone and an enclosed heating chamber, and electrostatic treating apparatus mounted in the treating section of the tank, the improvement comprising: a downcomer conduit for directing emulsion from the upper portion of the emulsion receiving zone of the heating section of the tank to the lower portion of the heating chamber; a passageway extending from the lower portion of the heating chamber to the lower portion of the tank; means for directing emulsion flowing from the downcomer across the passageway and thereby flowing sediment and/or water from the heating chamber into the lower portion of the tank; a conduit for directing emulsion from the upper portion of the heating chamber to the lower portion of the treating section, and thermostat means positioned in the upper portion of the heating chamber in the path of emulsion flowing into the conduit for controlling the operation of the heating apparatus.

7. The improved heater-treater according to claim 6 wherein the structure surrounding the heating apparatus and dividing the heating sEction into an emulsion receiving zone and a heating chamber comprises a cylinder extending longitudinally through the mid-portion of the heating section of the tank, wherein the inlet of the passageway is formed in the lowermost portion of the cylinder, wherein the outlet of the downcomer is located adjacent the lowermost portion of the cylinder, and wherein the emulsion directing surface comprises the interior of the cylinder.

8. A heater-treater comprising: a tank including a heating section; means separating the heating section of the tank into an upper emulsion receiving zone and a lower enclosed heating chamber; downcomer conduit means for directing emulsion downwardly from the emulsion receiving zone to the lower portion of the heating chamber; emulsion heating means mounted in the heating chamber; conduit means including an inlet located in the upper portion of the heating chamber for directing emulsion out of the heating chamber, and thermostat means mounted in the upper portion of the heating chamber at the inlet of the conduit means for controlling the operation of the emulsion heating means.

9. The heater-treater according to claim 8 wherein the emulsion heating means comprises at least one firetube extending through the heating chamber.

10. The heater-treater according to claim 8 wherein the downcomer conduit means includes an outlet located at one end of the heating chamber and wherein the inlet of the conduit means is located at the opposite end of the heating chamber so that emulsion flows diagonally upwardly through the heating chamber.

11. The heater-treater according to claim 8 further including a discharge passageway extending to the lower portion of the tank and having an inlet tube located in the lower portion of the heating chamber, and means for directing emulsion across the inlet of the passageway and thereby flushing sediment and/or water from the heating chamber into the lower portion of the tank.

12. A heater-treater comprising: a tank including a heating section; means forming an enclosed heating chamber within the heating section of the tank; a downcomer conduit for conveying emulsion from the upper portion of the tank to the lower portion of the heating chamber; a passageway for conveying sediment and/or free water from the lower portion of the heating chamber to the lower portion of the tank, and means for directing emulsion from the downcomer across the passageway and thereby flushing sediment and/or water from the heating chamber.

14. The heater-treater according to claim 13 wherein the downcomer terminates in an outlet and wherein the emulsion directing means directs emulsion flowing from the outlet aperture across the inlet.

15. The heater-treater according to claim 14 wherein the outlet is located at a point adjacent the cylinder and laterally displaced from the inlet, and wherein the emulsion directing means comprises a portion of the cylinder which directs at least a portion of the emulsion flowing from the outlet across the inlet.