US3191681A - Gas lift control system - Google Patents

Description

June 29, 1965 L. M. HUBBY eAs LIFT coNTRoL SYSTEM Filed Sept. 6, 1962 United States Patent O 3,191,681 GAS LIFT CNTRL SYSTEM Laurence M. Hubby, Bellaire, Tex., assignor to Texaco Inc., New York, N.Y., a corporation of Delaware Filed Sept. 6, 1962, Ser. No. 221,790 6 Claims. (Cl. 16652) This invention is concerned with oil iields generally and more specifically concerns a system for use in a producing oil field that is being produced by the so-called gas lift type of well iluid recovery.

Heretofore in most gas lift operations each Well in a iield is individually controlled, as to the `on-off cycles of its gas lift operation, by use lof `a spring driven clock mechanism. Under such arrangement, the clocks employed cannot be synchronized and consequently no matter how accurate they are they all run at lslightly different speeds. lFor this reason although the operating cycle of each well may be originally set so .as to stagger the on time for all of the wells in the lield to provide sequential operation, :after some time the staggered sequence will be gradually lost -by reason of the different speeds involved in the spring Wound time controls. Thus at various times there will be several of the wells having the on portion -of the cycle occur simultaneously, and this will cause overloading of the power gas supply system and in the ilow of production fluid to the tank battery since the most economical :arrangement is to provide ilow capacity only suflicient to take care of the ilow from each well separately. The indicated overloading will cause various problems, such as a higher back pressure on the llow lines which results in lower elliciency of the gas lift operation.

By employing -a system according to this invention, the actu-ation of individual well gas lift cycles may be centrally controlled in a manner such that the sequential operations of the wells are exactly synchronized in a desired sequence which cannot vary even over a long period of time. This :is possible with the system according to this invention since it enables the use of `a single motor driven cam shaft larrangement, whereby individual cams on such shaft may be set for providing the desired sequence of the wells individual gas lift cycles. The sequence cannot vary, once it has been set, by reason of the mechanical relationship of 4the cams to a -single shaft `or common direct drive for all of them. Although a synchronized system has been suggested before, it made use of electric controls that necessitated circuits connecting each well to a single point `and required use of electric power which is loften not available at a iield where gas lift pumping is being carried out.

Thus, it is an object of this invention to provide a superior gas lift control `system which gives synchronization of intermittent ilow cycles for al1 of the wells in a given field.

Another object of this invention is to provide a gas lift control system wherein the individual well gas lift timers are pneumatically powered and thus need no periodic attention, e.g. winding of a spring motor, or the like.

Another object of this invention is to provide a gas lift control system which has a central control member that may be employed to shut down the entire iield simultaneously in case of some emergency.

Another object of this invention is to provide an irnprovernent for a gas lift control system ywhereby the sole link connecting a central controller with the individual well of the field, is the product ilow line from each well to the tank battery or central collection point. With this arrangement there is provided automatically, a means whereby any well which develops a break in the ilow line therefrom becomes deactivated and will not continue its ICC gas lift pumping cycles, so long as the .break in the ilow line remains.

Briey, the invention concerns a gas lift control system. The system comprises in combination, means for receiving pneumatic iluid under presure from a source of pneumatic pressure, and means for receiving gas under pressure from a source of high pressure gas. The system also comprises a central controller for providing pneumatic control signals, a plurality of wells each having a timer associated therewith, and a tank battery having llow lines thereto from each of said wells. In addition, the system comprises means for applying said pneumatic signals to each of said llow lines in sequence, and it comprises pressure responsive means connected to each of said ilow lines adjacent to each of said timers. `Finally, the system also comprises means actuated by said pressure responsive means for initiating :a cycle by e-ach said timer. The said timer cycle actuating means acts to control introduction of said high presure gas through t-he well associated with said timer.

Again briefly, the invention concerns a gas lift control system having a plurality of wells each having a timer for controlling application of gas lift pressure thereto. The system is one wherein each of said wells has a production ilow line from said well to a tank battery and wherein the system has a central controller for actuating said timers in sequence. In the foregoing control system the improvement comprises means vfor transmitting actuating signals from said control to said timers, wherein the sole link connecting each of said wells with said central controller is the production ilow line from said well t-o the tank battery.

The foregoing and other objects and benefits of the invention will be set forth more fully below in connection with the drawing wherein the figure of drawings provides a schematic showing of a gas lift control system indicating one of a plurality of wells and the tank battery to which the wells are connected.

Referring to the figure of drawings, it is pointed out that the single ligure includes a tank battery portion of the `whole schematic diagram and an individual well portion thereof. It is to be understood that there may be any number of individual Iwells making up the entire field, all of which are connected separately to allow the produced fluids from each to flow to a central location and be collected in the tank battery. The tank battery per se (not shown) includes as the input thereof a separator 1i1 that has a product header pipe 12 which feeds the individual ilows of produced iluid into the separator. As indicated in the diagram, the output of separator 11 will be divided into its lconstituents `of. liquid (may be oil and water, or oil) and gas with both being fed to the tank battery (not shown) for collection thereof.

It will be observed that there are a plurality of ilow lines 14 and 15 connected into the product header pipe 12 (plus others depending upon the number of wells) and each of these flow lines leads from a separate well that is being produced by means of gas lift type fluid recovery. Control of each of these wells, insofar as initiation of a gas lift cycle is concerned, is carried out from a central location adjacent to the tank battery. Thus for example, there is a llow line 15 that has a check valve 16 therein (indicated schematically) close to the connection of ilow line pipe 15 with the header pipe 12. Further back (up stream) along ilow line 15, there is a diaphragm actuated type valve 17 that is under control of a pneumatic signal which is fed along a pneumatic line 18 that is connected into another pneumatic line 19. Pneumatic line 19 leads from one port of a three-way valve 22. Valve 22, in turn, is mechanically controlled by means of a cam 23 which is driven by a shaft, or other mechanical connection, 24 which in its turn is driven by a motor 25.

'It will be understood that motor 25 may take any feasible form, i.e. may be an electric motor or a pneumatic motor, etc. depending upon the convenience of a source of power therefor. It is to be noted that the motor 25 (by means of an extension of the shaft or mechanical connection 24) also drives another cam 28 that will be set at a different position relative to cam 23 so that another three-way valve 29 (corresponding to three-way valve 22) will be actuated at a different time from valve 22 and in an exactly controlled sequence, so as to maintain synchronous but staggered operation of the valves 22 and 29 and all additional valves for the remaining wells in the eld.

There is a source of pneumatic pressure (not shown) which is connected to an input pneumatic line 32 that leads to a pressure regulator 33 and then via a pneumatic line 34 to a lease shutin valve 35. It will be observed that the lease shutin valve 35 is schematically indicated as being a diaphragm actuated type. It is to be noted that although there is no showing for the details thereof, there may be any desired arrangement for controlling operation of shutin valve 35. This may be in connection with maintenance of pneumatic pressure high level in tanks or the like, so that under certain conditions (as may be predetermined) the valve 35 will be closed and thus the entire lease or field will be shut in, and the gas lift pumping operations Will cease.

The pneumatic pressure supply as introduced from the pneumatic line 32 via regulator 33 and shutin valve 35, is fed over a pneumatic supply line 36 to inputs of all of the individual elements which together go t make up the central controller for the field. As indicated above, each of the plurality of well control units are all controlled by the operation of motor 25 and the various cams, e.g. 23 and 28, operated thereby.

Since all of the individual control signal units of the central controller are substantially identical, only one need be described in detail. Thus, referring to the pneumatic pressure signal unit which feeds signals into the ow line via the illustrated elements (which include as the primary control elements therefor the three-way valve 22 operated by cam 23) there is a pneumatic line 39 leading from the supply line 36 to a pressure regulator 40 for reducing the pressure from a relatively high figure, e.g. one hundred pounds per square inch, on the supply line 36, down to a low pressure for use in actuating diaphragm control elements of pressure controlled valves, e.g. twenty pounds per square inch. Leading from the low pressure side of regulator 40 there is a pneumatic line 43 that is common to all of the control signal units. Consequently, in the unit being described (which supplies signals to flow line 15) there is a pneumatic line 44 that leads to an input port 0f the three-way valve 22 mentioned above.

Valve 22 has in addition to the port connected to pneumatic line 19 and the port connected to line 44, a port connected to an exhaust line 45, as indicated by the caption Exh. The operation of three-way valve 22 is such that the cam 23 will cause the valve to be positioned either with the line 19 port being connected alternatively with pressure line 44 or with exhaust line 45. The pressure line 44 port (of valve 22) is closed whenever it is not connected to the line 19 port.

It is to be observed that pneumatic line 19 connects to both pneumatic line 18 (leading to diaphragm actuator for the valve 17) and another pneumatic line 48 which leads to the diaphragm actuator of a valve 49. The valve 49 is connected in a pneumatic line 50 that leads directly from the supply line 36 to the valve, and then through the valve 49 and a pneumatic line 51 to a check valve 52, that has the other side thereof connected into the ow line 15.

The operation of each control unit is substantially identical, as was pointed out above, and will be readily understood by reference to the steps involved in connection with the operation of the unit feeding flow line 15, the elements of which were described in detail above. Thus the operation for creating a control signal pressure pulse, may be followed commencing with the fact that pressure on supply line 36 is transferred to the input port (line 44) for three-way valve 22. This port is either closed or opened for a short time, depending upon the position of cam 23 that actuates the valve 22. Whenever the valve 22 is actuated to open the port from the input line 44, pneumatic pressure is transferred via the pneumatic line 19 to both lines 18 and 48 s0 that the diaphragm actuators of valves 17 and 49 respectively will receive pressure. These valves (17 and 49) which are normally biased to the open and closed positions respectively, will thus simultaneously be actuated so that valve 17 is closed while valve 49 is opened. This means that pneumatic pressure will be supplied over pneumatic line 50 through valve 49, pneumatic line 51 and via valve 52, into flow line 15. At the same time valve 17 will be closed and so prevent escape of this pneumatic pressure signal along ow line 15 toward the tank battery. Consequently pneumatic pressure will build up in flow line 15 back toward the well that is connected thereto. Also, by reason of a check valve 55 in the ow line 15 near the well, the pneumatic pressure will rapidly increase and this pressure increase will actuate a pressure sensitive element 56 that is associated with a pneumatic timer 57 (captioned Pneumatic Intermitter) for controlling the gas lift operation at this Well.

Shortly after the foregoing action (which created a pressure signal) has taken place, cam 23 will return three-way valve 22 to its yother position, such that pneumatic line 44 is cut off while the line 19 is connected to the exhaust line 45. This will cause pressure to be exhausted from the diaphragm controllers of valves 17 and `49 so that they will return to their normal or biased position, which means that valve `17 wil-l 'be opened while valve `49 will be closed. Consequently the pressure signal that was applied to the flow line 15 will be dissipated by the Iopening of valve 17, and the flow line will be in condition to receive a flow of production fluid when the gas lift pressure is applied to the well.

It is to be noted that in lconnection with each Well there is a pneumatic timer, eg. timer 57, which may .take any feasible form but preferably is substantially like a timer described and claimed in a copending application Serial No. 216,836, led August 14, 1962, now Patent No. 3,152,611, which acts by means of pneumatic and hydraulic elements to control the timing of a cyclic operation of valve opening land closing. It is this valve oper-ation that acts `as the control for applying so-called power gas to the well for providing the gas lift force.

While the details of a pneumatic timer like the pneumatic timer 57 illustrated, are more fully set forth in the aforementioned copending application, the elements of the timer 57 will be described here suficiently to provide an understanding of the general operation thereof. In this connection it is pointed out that at the well there is a supply pipe `58 for introducing high pressure gas to the well to provide the so-called gas lift pressure that drives the -production fluid up through Well tubing 59 that is connected in turn to the flow line 15 via the check valve 55, already mentioned. The `operation of a gas lift fluid recovery cycle in a well, is well known and merely consists of the periodic introduction of high pressure gas to the annulus of a well -that is closed top and bottom having tubing .therein that extends down hole with `a plurality of gas lift valves and related structure `at the production fluid level. The gas pressure acts to force accumulated fluid from Within the tubing plus gas lift valve structure, up the tubing and out Vthrough the flow line connected to the Well. Application of the gas pressure is timed to lift the accumulated quantity of duid and then is cut off lfor a suicien-t period to allow a further accumulation of fluid down hole within the gas lift tubing structure.

Control of the introduction of the high pressure gas for each lift cycle is carried out by means of a valve 62 that has a diaphragm, or other type of pressure actuator 63 for opening the valve 62 when pressure is applied to the actuator. The valve is biased to a closed position in the absence of pressure on the actuator 63. The timer 57 controls the duration of the opening of valve 62 as wi-ll be described.

The elements of the timer 57 include .a pneumatic pressure line 66 that leads from the power gas supply in pipe `58 `to a pressure regulator 67. On the other side of pressure regulator 67 there is a pneumatic line 6-8 that connects to two pneumatic lines 69 and 70. Line 70 leads to an input port of a three-way valve 73 which is either closed or connected to a port leading to a pneumatic line 74 that is T connected to two additional pneumatic lines 75 and 76. The third port of three-way valve 73 is open to exhaust and the three-way Valve itself is of a type which will act to connect the pneumatic line 74 alternatively with the input port (leading to pneumatic line 70) or with the exhaust port that leads to the atmosphere. Furthermore it is to Ibe observed that three-way valve 73 is a double-diaphragm actuated type so that there is a diaphragm actuator 78 for positioning the Valve to connect line 70 with line 74, and there is another diaphragm actuator 79 that will position the valve to its other state whereby pneumatic line 70 is closed while line 74 is connected to exhaust through 4the other port of the valve 73.

`It will be observed that the pneumatic line 76 is connected to the diaphragm actuator 63 of power gas valve 62, while pneumatic line 75 connects to the upper portion of one chamber 82 that is part of lthe timing mechanism for the timer unit 57. Chamber 82 contain-s a liquid, eg. hydraulic iluid 83, during part of a cycle and has connected to the lower portion of the chamber a pair of pneumatic lines each containing a restriction 86 and `87 respectively, for regulating the rate of llow of the hydraulic fluid `83 therethrough. Iln addition, there are check valves 88 and 89 respectively, each in series in the line which contains restrictions 86 and 87 respectively, while both of these lines are joined together to carry uid ow via a line 90 to the lower portion of another chamber 91. Chamber 91 has connected to the kupper portion thereof `a pneumatic line 92 that is connected directly to the diaphragm actuator 79 of the three-way valve 73.

In addition to the above described elements of the timing unit, there is associated with the pressure responsive element 56 a three-way valve 95 .that has connected to an input port thereof `a pneumatic line 96. An output port of the valve 95 is connected to a different pneumatic line 97 which leads directly to the diaphragm actuator 78 of .three-way valve 73. The third port `of valve A95 is `left open for connecting line 97 alternatively to exhaust, i.e. the atmosphere, when the three-way valve 95 is in one of its .two positions; while the line 97 is connected to the line 96 when valve 95 is in the other of its .two positions. On the other end Aof pneumatic line 96 there is a pressure regulator ,100 that has connected to the other side thereof the pneumatic line 69, which as indicated above leads via line 68 to the low pressure side of regulator 67.

The timing unit 57 acts, as indicated previously, to open the valve 62 for a predetermined relatively short time `and then close same once more. This acts so that the high pressure gas lift is introduced into the well for `a sufficient period of time to insure the complete ejection `of all lof the produced uid from the well, which has accumulated since the previous application of `such pressure. The operation of the timing unit which determines this period of valve opening time, -may be briefly reviewed here while the full details thereof will be more fully appreciated in connection with the disclosure of .the aforementioned copending Iapplication. It is to be noted, however, that in the present application (of .a pneumatic timer according to the copending application) there is an arrangement for initiating a timing cycle upon receipt of -a pressure signal that is transmitted from a central controller location along the flow line that connects the well to the tank batte-ry where product is gathered.

Thus, a timing cycle (as initiated by receipt of a control signal) may be described with reference to the timing unit illustrated, in the following manner. When a pressure increase is received within ow line 15 (between check valve 55 and the closed valve 17) by reason of the action at the central controller which causes such pressure rise, the pressure responsive element 56 will cause actuation of the three-way valve so as to connect pneumatic pressure from line 96 to line 97 which leads to diaphragm actuator 78. Diaphragm actuator 78 will then cause three-way valve 73 to be shifted so that it connects the input pressure line 70 with output line 74 that leads to both the diaphragm 63 of gas lift valve 62 and the upper portion of chamber 82 (which at that time will contain hydraulic uid 83 therein). Consequently valve 62 will be opened to supply power gas to the well, and a timing cycle will be commenced to determine the length of time that this valve is to be held open.

This timing cycle (which may be set as desired) is determined by the ow of hydraulic `iluid from chamber 82 into chamber 91 followed by a sufficient increase in pneumatic pressure at the output (pneumatic) side of chamber 91 so as to actuate the three-way valve 73 back to its other position. The latter action takes place by means of the pressure introduced into diaphragm actuator 79. The length of time involved in this action is preset by means of the amount of liquid 83 and by the size of restriction 86 which may be variable and could take the form of a needle valve for example. The ow of uid 83 is confined to the passage through restriction 86 and not that containing restriction 87, by reason of the orientation of check valves 88 and 89. The orientation of these check valves is such that flow is permitted only in the indicated directions, i.e. flow through restriction 86 takes place when fluid is owing from chamber 82 to chamber 91 while the reverse is true when fluid is flowing back from chamber 91 to chamber 83 (when it passes only through restriction 87).

It will be observed that while tluid 83 is iiowing from chamber 82 into chamber 91, the transfer is relatively slow and the compression of the gas on pneumatic uid in chamber 91 is relatively slight, so that no actuation takes place of three-way valve 73 due to actuator 79 thereof. However, when fluid 83 has all passed out of chamber 82 and gone through restriction 86, the passage of pneumatic iluid is much more rapid (due to the difference in viscosity) and a sudden increase in the flow and in the pressure caused to pneumatic uid in chamber 91, will take place. This pressure increase will be sufficient to actuate pressure actuator 79 and shift valve 73 back to the original state thereof, since in the meantime three-Way valve 95 will have returned to its non-pressure position due to the reduction in pressure of the pressure signal within flow line 15. Consequently, the three-way valve 95 is positioned to connect diaphragm actuator 78 (via pneumatic line 97) with exhaust, while pneumatic line 96 is cut off.

When three-way valve 73 is thus shifted by action of actuator 79, the input pneumatic line 70 is cut off while output line 74 is connected to exhaust. Consequently the pressure on diaphragm actuator 63 of the gas lift valve 62 will be exhausted and simultaneously pneumatic pressure on the upper portion of chamber 82 will be also connected to exhaust. This then will set up conditions so as to commence a return of the hydraulic iluid 83 from chamber 91 back into chamber 82 via restriction 87, which in the present use of the timer will be set relatively wide open to permit quick return of the liquid. At this time (following return of the liquid 83) the timer unit will stand at rest awaiting the next pressure signal from within flow line 1S to commence another similar timing c cle.

yIt is to be understood that none of the specific elements involved in the system according to this invention contribute per se, as elements of the invention. In other words, it is pointed out that in case of three-Way valves such as valves 22, 29, 73 and 95 which are schematically illustrated, any commercial valve structure that is available and designed to accomplish the indicated results may be employed in the system. In this connection it may be reiterated that in the case of valves 22 and 29 (and all additional like valves in the system) the valve structure is one that may be operated mechanically from a central control structure such as a shaft, with cam elements for shifting the valve from one position to the other at a predetermined rotational position of the shaft. Similarly valve 73 is a three-way valve that has a pair of diaphragm actuators therefor and is not biased to either of its two operating positions. The operation is such that when pneumatic pressure is applied to either one of the diaphragm actuators the valve will be shifted to a given position as caused by that actuator. Then the valve remains in such position until pneumatic pressure is applied to the other diaphragm actuator which will shift the valve to its opposite state or position where it will remain until shifted back by the other actuator. Likewise valve 95 is a three-way valve that may be shifted from one position to which it is biased (by a spring or the like) to the other position upon receipt of pressure in the pressure sensitive control element 56. It will be appreciated by anyone skilled in the art that the element 56 may take various forms, eg., a diaphragm or a bellows type structure. The mechanical connection from element 56 to the valve 95 is schematically indicated by the dashed line shown. When such pressure is removed or falls below a given level the valve will be shifted back to the spring biased position thereof. All of the foregoing valves as well as the various other single-type valve structures illustrated, are commercially available on the open market and may be purchased for use as specified to meet the conditions required. Thus, as indicated above there is no invention in the structural details of any of the valves or similar elements in the system shown, per se. Rather, the invention lies in a pneumatic-hydraulic control system that is applicable to a gas lift operation.

It is to be observed that among the advantages of this invention is the fact that, in addition to providing a central control signal arrangement for an entire gas lift field, any break in an individual one of the fiow line connections from each well to the tank battery will automatically cause a shutdown of the well that has such a broken flow line, since the pressure signal will never be able to build up within such flow line to initiate a timing cycle for introducing gas lift pressure to that well.

While a particular embodiment of the invention has been described in considerable detail in accordance with the applicable statutes, this is not to be taken as in any way limiting the inventign but merely as being descriptive thereof.

I claim:

1. A gas lift control system for a plurality of wells comprising in combination, first conduit means for receiving and transmitting pneumatic fluid under pressure from a source of pneumatic pressure, second conduit means for receiving and transmitting gas under pressure from a source of high pressure gas to the wells of said system, a central controller for providing pneumatic control signals in the form of pressure pulses and having said first conduit means connected thereto, a plurality of wells each having a cyclically operable timer associated therewith to control the duration of application of said high pressure gas to said well, a tank battery having flow lines thereto from each of said wells, means for applying said pneumatic signals from said central controller to each of said ow lines in sequence, pressure responsive means adjacent to each of said wells and being connected to each of said flow lines adjacent to each of said timers, and means actuated by said pressure responsive means for initiating a cycle by the corresponding one of said timers.

2. The invention according to claim 1 wherein said timers are pneumatic.

3. The invention according to claim 2 wherein said pneumatic signals comprise a pressure increase sufficient in duration to cause a rise in pressure at said pressure responsive means, and said signal applying means comprises a concurrently actuated valve in each said ow line located between said tank battery and a pneumatic line connecting each pressure responsive means with the corresponding ow line.

4. The invention according to claim 3 wherein said central controller comprises a motor, a plurality of cam actuated pneumatic valves for introducing said pneumatic signals from said first conduit means to said flow lines, and cam means driven by said motor for sequentially actuating said valves.

5. The invention according to claim 4 further including a central shut-in valve associated with said first conduit means for cutting off said source.

6. In a gas lift control system having a plurality of wells each having a timer for controlling application of gas lift pressure thereto, each of said wells having a production flow line from said well to a tank battery, and a centrally located controller for actuating said timers in sequence, the improvement comprising means for transmitting pneumatic pressure signals from said controller to each of said timers solely through each said production ow line from said well to the tank battery.

References Cited by the Examiner UNITED STATES PATENTS 2,736,201 2/56 Ohlsen et al. 166--52 X 2,845,125 7/58 Truman l66-52 3,045,750 7/62 Peters 166-52 3,070,033 12/62 Welchon 103-232 CHARLES E. OCONNELL, Primary Examiner.

Claims (1)

1. A GAS LIFT CONTROL SYSTEM FOR A PLUARLITY OF WELLS COMPRISING IN COMBINATION, FIRST CONDUCIT MEANS FOR RECEIVING AND TRANSMITTING PNEUMATIC FLUID UNDER PRESSURE FROM A SOURCE OF PNEUMATIC PRESSURE, SECOND CONDUIT MEANS FOR RECEIVING AND TRANSMITTING GAS UNDER PRESSURE FROM A SOURCE OF HIGH PRESSURE GAS TO THE WELLS OF SAID SYSTEM, A CENTRAL CONTROLLER FOR PROVIDING PNEUMATIC CONTROL SIGNALS IN THE FORM OF PRESSURE PULSES AND HAVING SAID FIRST CONDUIT MEANS CONNECTED THERETO, A PLURALITY OF WELLS EACH HAVING A CYCLICALLY OPERABLE TIMER ASSOCIATED THEREWITH TO CONTROL THE DURATION OF APPLICATION OF SAID HIGH PRESSE GAS TO SAID WELL, A TAN BATTERY HAVING FLOW LINES THERETO FROM EACH OF SAID WELLS, MEANS FOR APPLYING SAID PNEUMATIC SIGNALS FROM SAID CENTRAL CONTROLLER TO EACH OF SAID FLOW IN SEQUENCE, PRESSURE RESPONSIVE MEANS ADJACENT TO EACH OF SAID WELLS AND BEING CONNECTED TO EACH OF SAID FLOW LINES ADJACENT TO EACH OF SAID TIMERS, AND MEANS ACTUATED BY SAID PRESSURE RESPONSIVE MEANS FOR INITIATING A CYCLE BY THE CORRESPONDING ONE OF SAID TIMERS.

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