US3001542A

US3001542A - Liquid volumetric measuring system

Info

Publication number: US3001542A
Authority: US
Inventors: Shepherd Roy; Henry F Mccabe; Jack E Fogarty
Original assignee: Union Tank Car Co
Current assignee: Union Tank Car Co
Priority date: 1956-11-29
Filing date: 1956-11-29
Publication date: 1961-09-26
Anticipated expiration: 1978-09-26

Description

SePt- 26, 1961 R. SHEPHERD ET AL 3,001,542

LIQUID VOLUMETRIC MEASURING SYSTEM Filed Nov. 29, 1956 IN VENTORS SCP- 26, 1961 R. SHEPHERD ETAL 3,001,542

LIQUID VOLUMETRIC MEASURING SYSTEM Filed Nov. 29, 195e 2 sheets-sheet 2 L? 0 INVENTORS. I 4,9 frz/203g y' j LEQUED VGLUMETRIC ,MEASURENS .SYSTEM Roy Shepherd, Tulsa, kla., Henry F. lt/ictahe, Fort Worth, rllex., and .lack E. Fogarty, Tulsa, Gkla., as-

signors, by mesne assignments, to Union Tank Car Company, Chicago, lll., a corporation oiNew Jersey Filed Nov. 29, 1956, Ser. No. 625,186 6 Claims. (Cl. 137-122) The invention involves a novel `production system for oil lwells and particularly relates -to yan arrangement for measuring the productivity.

As is well known to those familiar with thepetroleum industry, one of the major current problems lrelates vto the conservation of `product and particularly -to the elimination `of product loss due to 'vaporization rllhis problem aces the industry in all phases of petroleum reiining, including initial production of `the crude from "the well.

Additionally, it Will -be appreciated that the quantity of -production of raw usable crude from 4a well must be accurately determined for many reasons, Asuch as for example, royalty payment. With `this `in mind, it Awill 'be understood that accuracy in measuring usable crude fis of extreme importance as well as the `prevention of "loss of production through vaporization.

Several disadvantages have appeared in rthe systems currently -inuse for measuring usable crude well production. iAmong these disadvantages 'is that lthe systems currently employed are of such a Vnature that they tend ...to 'accommodate a .rather high percentage of product 'loss through vaporization. Additionally, many of these loss through vaporization, and, by relatively simple conduit arrangements tend to eliminate product loss `thrtmgh faulty pip-ing and valving.

f It is a further object of the invention to provide Aan automatic arrangement which reduces lthe manual open .aliens required in stranamente Qi this type ,and lwhich `provides `semi.automatic switching in `a series arranged .frank batteryflhese 4and other objects of the invention will become apparent 4in the course of the following `description and from an examination of .the `concerned.drawings9 where- FZIGURE 1 .is a schematic view of an ,arrangement of .the type described.

FIGURE 2 is a partially fragment-ary `side elevational view of a pair of `:aansturing V.tanks .in .the system described,

'FIGURE 3 `is a `partially firagmentary ,top :View of the structure shown `in FIGURE .2, l

FIGURE 4 is a fragmentaly sectional 4view taken .along line a-f ,of FlGURT: 3..

LFlGURE 4Ais a fragmentary. partially Sectional view taken approximately algas 'line afk-4A .cf .FIGURE nd 'FIGURE 5 is a fragmentary sectional view taken along ,line 5-`5 of FIGURE 3.

Describing the `invention `in detail and directing attendon to TIGURE 1,. jit A:will .be understood ,that a producting 'head fis indicated ,generally at 2 Said well head atent anulada' Patented Sept. 26, 1961 MAIL a Vbeing conventionally connected by conduit 4 to an Voil and gas separator device indicated at 6. As is well known in the art, product from the well is frequently composed of intermixed liquid and gas and it fis the function of the separator d to separate `the gas `from `the Voil whereby the gas may be carried through conduit 8 to some storage container or the like, While Vthe liquid lmay be carried through conduit 1li to further ,processing. Conduit itl may then carry the liquid to an emulsion treater l2 whereat the well product is further processed to separate usable oil from water and emulsion that may be intimately associated therewith. Additionally, a further separation of entrained gas maj/'here occur and it again may be carried off to storage through a conduit 14. The separated water may be carried to waste via the conduit 16. The crude oil, having been separated from undesirable matter, is now in yappropriate condition for measuring.

Another conduit 18 may be connected to the outlet ,of the treater l2, said conduit ld carrying substantially pure crude oil Ato a battery of `measuring tanks 2d, 20. lt is in these tanks Ztl that the quantity production of the given Well is determined. A novel 'feature of the invention disclosed relates to the adaptation of a :plu- Irality of floating `roof-type tanks to the measuring 'of the crude passing from the Well. ln the usual instance 'these `tanks 26.9 preferably -have diameters of 25 f eet or less. Certain important advantage app-ear in the Yuse :of

`this typeof -equipmentin that substantial elimination of =vapor space :in the tanks virtually eliminates -vapor loss during the frequent filling and emptying thereof. ,Fur-

ther, the elimination of thevapor space ten-ds to eliminate the destructive effects of corrosion on tanks themselves. After passage lfrom the measuring tanks 26, the crude may be carried via conduit 2.2 to a pipe line (not shown) and from thence to storage.

It will 'be noted `that each tank 2u vin the lbattery comprises an outer shell 24 and a rooi 26 arranged to lloat therein and raise and lower with the changing 'level of the product in the tank. For illustrative ypurposes the left hand tank in 'FIGURE l is shown completely full, the central tank in lthe process of iilling, and the righthaud tank empty. lt will also beunderstood while -FIGURE l shows a battery of three tanks and FIGURE 2 a battery -of two tanks, any lnumber oftanks may be employed `in the invention 'depending upon the requirements of the particular application.

Directing attention to FlGURE Z, which illustrates somewhat more in detail the structure arrangement of the tanks 20, Iit will be seen that each shell 2d is provided with aconed bottom 23, said coned 'bottom :having a `sump 30 'located centrally therein. A plurality of roof supports 32, 32 -are appropriately arranged around and secured to the bottom 2S to support 'the roof 26 at a determined distance from the bottom 2S when the tank is empty. The roof-26 may be of any type, but "is preferably cone shaped having `a peripheral wall 34 secured to a dished bottom `36. Centrally of the bottom 35 an outlet 38 may be provided which is operatively connected `to a -hose drain 40 to Vdrain foreign matter `such `as water and the like from the roof and avoid the sinking of the roof in the product. The Vhose drain is a'exible tube which extends downwardly in the shell 24 to `a point adjacent the bottom of the `shell,whereat vit may be sealingly passed through the shell `(in a conventional manner) to a drain (not shown). Water and the like on the roof 26 Will drain by gravity through the hose il to disposal. The sump Evil is `arranged :to ,collect foreign matter in the crude and an outlet pipe is provided to periodically drain said foreign :matter from each tank 2li. Of course, the outlet pipe may Vroof centrally located in the shell 24.

Ybe conventionally connected to a pump or the like to accomplish draining of foreign material from the sump 30. Guide rods 44 may be positioned in each tank and secured to the bottom thereof to cooperate with the'iill pipes, 4hereinafter described', to prevent unwanted rotation of the roof in the tank. If desired, each roof may be additionally provided with a hatch to accommodate inspection of the tank area under the roof.

Directing attention to- FIGURE 4, it will be seen that the arrangement of a guide rod 44 is here illustrated.

The rod 44 extends upwardly to almost the top edge of the tank and it is received within an aperture 52 formed in the roof 26 by means of a pipe and tting connection 54. Thus it will be understood that as the roof rises 'and lowers, the pipe 44 is telescoped through the aperture 52.

Referring to FIGURE 4A, it will be noted that it illustrates the connection of the lower end of the till pipe 66 to the bottom of the tank shell. The piate d@ is provided to oder a horizontal support for the arrangement. The supporting arrangement 67 comprises a vbase pipe 69 having a wide aperture 7l formed in the side thereof. A spreader hood 73 and a half coupling 475 are secured in any convenient manner, as by welding, to the upper end of the base pipe. The coupling 7S threadably receives the lower end of the fill pipe 66, while the spreader hood 73 projects outwardly from the larrangement 67 and over the opening 7l. The opening 71, of course, provides access for product into the tank, while the spreader hood 73 tends to control oil and gas splash.

The shell 24 may be provided with an angle iron 56 `rigidly -welded to the inner periphery thereof adjacent Yits upper end. The angle 56 serves to stiften the upper and open end of the tank shell 24 and aids in mainthe periphery of the roof 26 and the inner surface or" the shell 24 is sealed, which tends to red-ucc vapor loss in this very small peripheral space to a minimum. In the preferred embodiment the seal gasket 66, though eXible, is relatively stiff which aids in maintaining the Y Additionally, the seal gasket 60, at the upper portion of the roof, underlies the angle 56 which tends to prevent rain water and the like from entering the product through the rim lspace by channellng same centrally of the roof whereat 1t. may be drained od through the hose drain '49 as previously noted. In the event a certain amount of rain Water or other foreign material does succeed in entery-ing the tank proper, it will be carried to the sump 36 whereat it may be removed without substantially affectlng the purlty of the product measured in the tank.

Attention is now directed to FIGURES 2 and 5 for purposes of illustrating the novel piping arrangement here employed. It will be seen that each tank 24 is prov1ded with a valve support bracket 62 preferably mounted on its upper edge. The bracket 62;, may be 'arranged to extend inwardly of the tank and carry a tank -switching valve 64, said valve being disposed in the lill llne 18 previously noted. A bottom port of valve 64 communicates lwith a iill line 66 which, as seen in FIGURE 2, is arranged to extend downwardly in the related tank Ztl to a point adjacent the bottom whereat it is provided with a port 68. A further conduit 76 cornmunicates with another port of the valve 64 and is further connected to a second valve 64 on the adjacent tank 20. i

The roof 26 may be provided with a housing 72 which defines an aperture telescopically receiving the fill line 66. The housing 72 has a tripping linger 74 mounted thereon which extends upwardly toward the valve 64. A trip arm 76 is provided at the base of the valve 64 and is located in such a manner that the trip nger 74 will engage same as the roof moves upwardly during the tank iilling operation. Upon engagement of the nger 74 and the arm 76 and further upon a determined movement of the arm 76 during upward movement of the roof, the valve 64 is caused to switch, which diverts incoming crude from the related lill line 66 to the conduit 70 whereat it is carried to the next tank in the battery.

'Considering FIGURES 2 `and 3, it will be seen that the right hand tank in the battery has-one port of its valve 64 connected to a feed back conduit 80 which in turn communicates with the fill line 66 of the left hand tank at a point below its association with the valve 64.

The operation of the two battery tank arrangement of FIGURES 2 and 3 will irst be considered. Assuming that the left hand tank in the battery herein indicated is empty, it will be seen that the crude is carried through conduit 1S and into switch valve 64 which in its normal position will divert the crude downwardly into the associated fill line 66. At this time the roof, of course, is at the maximum bottom position and resting upon the roof supports 32. Continued crude influx will cause the associated roof to raise in the tank until said roof approaches a predetermined maximum iilled condition whereat the roof mounted finger 74 engages the trip arm 76 causing the related valve 64 to switch and divert incoming crude throughconduit '70 to the valve 64 associated with the right hand tank in the battery. The arm 76 of the right hand valve 64 is of course set downwardly and the incoming crude may be diverted into the associated tank through the related nil line 66. During the elapsing time while the right hand tank is filling the operator, upon visually observing that `the left hand tank is lled to capacity, may note same and proceed to drain the left hand tank to the pipe line via the conduit 22 by manually opening an associated valve therein. Thus the left hand tank is draining while the r-ight hand tank is filling and in normal operation should be completely drained before the right hand tank is completely filled. Upon complete draining of the left hand tank the valve to line 22 may be closed and the left hand tank is again ready for service. As the right hand tank is til-led, the finger 74 mounted on the roof therein engages the associated trip arm 76 causing the related valve 64 to divert incoming crude through the conduit 80 which returns same to fill line 66 of the left hand tank. Upon observing this condition the operator will then manually reset the trip arm 76 to the left hand valve 64 which causes the incoming crude to be directly diverted into the related line 66 by the left hand valve 64. At this time the trip arm 76 of the right hand valve 64 may be again manually reset and the sequencedescribed above repeated.

Referring again to FIGURE 1 which illustrates a more desirable arrangement in that three tanks are here employed, which increases the time lapse between the manual reset operations of the several tanks making it easier for the operator to accurately control the tanks. In this instance upon tilling of the left hand tank, the incoming crude is diverted to the center tank and, upon filling of the center tank the incoming crude is then diverted to the right hand tank. While the center or right hand tanks are undergoing the lling operation, the operator may at his convenience drain the left hand tank in order that it may be ready to receive incoming crude which is diverted thereto through return line 80 upon filling of the right handtank as `above described.

It will be understood that the linear distance of move ment of each roof 26 from its maximum downward position resting on the supports 32 to the point whereat the related finger 74 actuates the trip arm 76 may be 'accurately determined. This fact together with a knowledge of the exact volume of the tank and a proper location of the drain points connected with the conduit 22 will accurately determine or measure the total volume of the crude put through the respective tanks 24 by simply noting the number of times each one is tilled and emptied.

The accurate measurements set out above when coupled with the reduction of vapor loss as heretofore described, the prevention of corrosive eiects of vapors on the equipment and the semi-automatic feature relating to tank switching substantially improves the operation of this type of equipment as compared to those heretofore used in the art.

It will be understood that the invention as disclosed is by way of illustration and not limitation and may be subject to many minor Variations without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. In a battery of measuring tanks for use in an oil well production system, rst and second tank shells having open upper ends, first and second movable roofs in said first and second shells, respectively, arranged to float on and move vertically with the surfaces of product in the shells, said roofs including means engaging the inner peripheries of the tank shells to provide vapor seals, rst conduit means in communication with a product supply, a first till line in communication with said Erst shell and in communication with said rst conduit means, a lrst valve located in said rst conduit means, a second ll line in communication with said second tank shell, a second valve in communication with said second fill line, a second conduit means communicating between said rst valve and said second valve, a return conduit means establishing communication between said second valve and said rst mentioned ll line, said valves being normally arranged to direct product flow to each related fill line, means mounted on said rst roof and arranged to operatively engage the rst valve to halt the ow of product into the rst ll line and the first shell when the first roof is in a predetermined position and to direct product ilow to the second conduit means and to the second tank shell, and means mounted on said second roof and ar ranged to operatively engage the second Valve to halt the flow of product into the second till line and the second shell when the second roof is in a predetermined position and to direct product tlow to the return conduit means and to the irst tank shell.

2. The battery of measuring tanks of claim l wherein there is additionally provided means to drain oil from each of the tank shells.

3. A battery of measuring tanks according to claim 1, wherein said valves are located at the top of the related shells and said lill lines extend downwardly from the 6 related valves and to the associated tanks, and( means dened in each roof for accommodating its associated till line and permitting relative movement between each roof and its associated till line.

4. In a oating roof measuring tank .for use in an oil well production system, a tank shell having an open top, drain means located in the bottom of the shell and extending outboardly of the shell, a floating roof disposed within and arranged to move vertically in the shell in response to a change in the level of pro-duct in the tank shell, said roof including means engaging the inner periphery of the tank shell to provide a vapor seal, a ll line extending into the shell, a valve in the ill line externally of the shell operative to selectively close said line, roof supports in the shell and operative to limit downward movement of the roof, and means operatively connecting the roof to the valve when the roof is in a predetermined position to close the ll line and prevent entrance of oil into the tank.

5. A floating roof measuring tank usable in an oil well production system comprising a tank shell having a continuous wall closed at its bottom and open at its top, said shell containing oil well product, a iloating roof disposed in the shell to float on the product in the tank, said oating roof being adapted to move vertically within the tank in accordance with the level of the product in the tank, a seal means supported by said oating roof so as to engage the inner periphery ofthe tank shell for the purpose of providing a vapor seal, a iill line in communication with said tank shell and including a control valve means operative to selectively close the fill line, and means including means on the roof for actuating the valve means to close the ll line and stop entry of product into the tank when the roof is in a predetermined position.

6. A measuring tank according to claim 5, wherein said lill line extends downwardly into the shell, and said last mentioned means comprises tripping means on the valve means and abutment means on the roof to engage the tripping means, whereby the valve will shut oit the flow of product in the ll line.

References Cited in the tile of this patent UNITED STATES PATENTS 418,329 Wood Dec. 31, 1889 1,736,933 Morgan et al Nov. 26, 1929 1,747,814 Bradley Feb. 18, 1930 OTHER REFERENCES Periodical, Oil & Gas Journal, Oct. 17, 1955, issue, pages 111-117, article by Meyers.