The production of the gas lifting well is depended on the gas lifting valves had set and the setting
depths as well, according to the optimization design there is three type of the valves


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Dummy valve: it is blank valve without any port as shown in pic#1
Orifice valve: it is valve with ports and check valve below the packing it designed to be
open all of the injection time. As shown in pic#2
Gas lifting valve: it called charging valve also, because in these type of valves there is
nitrogen chamber inside the valve and in this chamber will charge the nitrogen with
Specific pressure based on the optimization design, as shown in pic#3
Orifice port
with specific
size
Packing
Packing
Port with
specific size
Check valve
#1 DV
#2 OV
#3 Charging Valve
As shown in the picture can found the different among these three type of valves, for the dummy
valve without any port and for the OV can see the background through the port clearly but for
the Charging valve there is chamber inside, therefor could not see the background through the
port.
In this lecture will Know these three type of valves and how to charge the valves by nitrogen.
Workshop preparation:
The main idea for the gas lifting well is to displace the hydrostatic liquid in the annulus by the
nitrogen gas through these valves on the completion assembly, once start the gas injection from
casing valves with specific pressure the gas lifting valve will start with open situation and while
the hydrostatic level in the annulus decrease the gas lifting valves will be closed one by one
except the last valve in the completion assembly will keep open all the injection time as
mentioned above, in the beginning have to do preparation for the workshop container and have
to know the PTRO (Test Rack opening Pressure) from the Design Report of each valve,
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1- Connect the air hose supply into the inlet point and for the electrical and open the
nitrogen regulator valve as well, as shown in pic#4
Electric
socket
Nitrogen cylinder
Air inlet
#4
2- Fill the storage with water and set the regulator to 16 Co and turn on the fridge, see
pic#5
Set the regulator on 16 C0
and cover the storage
Fill the storage up to this
level
Fridge push
bottom
#5
3- Prepare the valve as the design requirement include of the port size and how many
valves need to be charge with nitrogen, see pic #6.
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#6
For this table above can see the most important information like:





The first column is number of total valves planning to run with completion assembly
The second column is referring to the depth for each valve in Feet unit.
The port size column can see the valves number 6,5& 4 are 16/64 and the number 3 is
20/64 for this valve can see also is OV it is mean this valve is orifice valve will be opening
for all time.
The valves number 1&2 they are DV (Dummy Valve) without port, see pic#1.
For the last column is referring to the nitrogen charging pressure in the workshop, can
see the first valve from surface charge with 1500 psi and below is 1540 psi and the other
is 1560 psi.
From this table have to prepare three valves 16/64” and charge them with nitrogen according
to (PTRO).
#7
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4- Open the check valve and take off the backing from both side, see pic #7
5- Hold on the valve by special vise and open the cab from the top, see pic#8
#8
6- Release the pressure had trapped inside the nitrogen chamber using small pin and push
the set valve bottom softly, see pic#9.
#9
#10
7- Connect the valve into the injection port. see pic#10.
8- Start to inject the nitrogen into the valve according to the PTRO, see pic #11, the steps
below referring to the injection procedure respectively.
 Close the Test Fixture isolation valve.
 Open the Dome Charge valve.
 Close the Bleed Valve.
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Open the air supply.
Open the nitrogen supply.
Start to adjust the regulator to increase the nitrogen pressure inside the valve.
Monitor the pressure gauge and stop the injection once reach the PTRO.
Close the air and the nitrogen supply.
Open the bleed off valve to bleed the pressure.
Disconnect the valve form the injection port.
open
Adjust
close
open
Close
#11 the valves statute during the injection
Note:
Now the Valve been charged with nitrogen according to PTRO, this pressure had trapped inside
the nitrogen chamber of the valve and this pressure will keep the valve close if there is differential
pressure between the casing pressure and the PTRO, therefor we have to calibrate the valve after
charge the nitrogen to check at same PTRO the valve must be open otherwise have to decrease
the pressure inside the nitrogen chamber.
9- Put the valve inside the calibration pump, see pic#12 & #13.
Note:
In this step need to be sure if the pressure apply from the ports against the nitrogen
chamber can open the check valve in same PTRO or not and mostly can’t, if so, have to
adjust the set valve and push it bottom by small pin softly to decrease the PTRO until the
PTRO will equal the applying pressure on the ports as a requirement in the design.
 Close the bleed off both of 2 valves.
 Open the Test Fixture isolation valves for both.
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



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
Close the Dome Charge valve.
Open the air supply and the nitrogen supply
Start to adjust the regulator to increase the nitrogen pressure inside the valve.
Monitor the pressure gauge. And see the note above.
Close the air and the nitrogen supply.
Open the bleed off valve to bleed the pressure.
Push the valve from top
inside the sealing area
#12
Adjust
open
open
open
Close
#13
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Close
10- Put the cab back and put the valve inside the water with 16 C0 for one hr.
11- After one hr. in the water take the valve out and repeat step no 9 if found the PTRO same
design then ok if not same then repeat steps 7,8 & 9 and put the valve in the water for
one hr. and repeat the procedure till get same PTRO, mostly will repeat the steps for 3 or
4 times.
Note:
why put the valve in the water?
Because the nitrogen pressure is effected by the temperature, it means at different time
and different temperature the nitrogen charging pressure will be different also,
therefor, the nitrogen charging pressure must be at the standard atmospheric
temperature 16 C0 of 60 F0.
Put the valve in the water with
16C0 for one hr.
Ammar Salih Jawad
Well Testing Engineer
14th Aug 2018
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