I have spent a significant amount of time reviewing the operations and SCAD= A on the San Juan lateral over the last couple of weeks.
I've uncovered so= me issues that could significantly reduce fuel consumption on this system.
=  Listed in order of priority are:  Resolve La Plata Unit #2 flame-out problem.
Currently this unit is running=  in manual control to limit flame-outs.
This prevents the station from run= ning with only one unit at low flow conditions.
According to the La Plata = team, this will require the replacement of the fuel control valve and unit = control software changes.
Running in the manual mode is costing an additio= nal 550 MSCF/D in fuel plus the extra O&M costs associated with the fired h= ours on unit #1.
The team is expecting the new fuel valve soon but anticip= ates that they will not get the necessary downtime to install the valve unt= il after the end of the tariff months.
Due to the potential emissions issu= es associated with its current operating mode, we may have to expedite the = modifications to this unit.
Auto calculate a suction pressure setpoint for La Plata.
There are three f= low controlled interconnects on the suction side of La Plata.
Using the me= ter run pressures and/or the flow control valve position, we can maximize t= he suction pressure setpoint to achieve the interconnect flow rates.
The h= igher suction pressure reduces the power required at La Plata with an avera= ge expected fuel savings of 175 MSCF/D.
Auto calculate a suction pressure setpoint for the Bloomfield Low service s= imilar to the La Plata modification recommended above.
Estimated fuel savi= ngs of 80 MSCF/D.
Modify the controls at Gallup to enable a quick turndown for a power peak.
=  Currently when a power peak is predicted, the Gas Control operators manual= ly transmit a lower discharge pressure setpoint.
It may take a long time f= or the new setpoint to actually gain control of the unit.
The suggested mo= dification would have the Peak Power alarm I calculate automatically retran= smitted to the field and unit/station controls were modified to quickly ram= p down the unit in a controlled manner (minimize recycle and prevent unit t= rips) to minimum power.
Gas Control could then send an override signal tha= t would allow the unit to operate at higher loads if required.
Likewise, i= f my Peak Power alarm clears automatically, the unit would return back to i= ts normal process setpoint conditions.
Note that if Gas Control overrides = my alarm, the override needs to latch until my Peak Power alarm clears.
Th= e suction and discharge setpoint rate ramp limiter logic should be modified=  to make them more responsive when they are far from the process values.
B= ob McChane, Todd Ingles, and myself can develop this logic.
Modify the La Plata station control for improved load sharing.
Recommend t= he load share method be based on matching compressor flow range margins.
I=  will work with Todd Ingalls to develop the logic and code.
This control m= ethod will ensure both units are operating as close to their high efficienc= y point as possible and minimize surge recycle.
Modify the station control process setpoints logic at La Plata (Bloomfield,=  Bisti too?)
to include rate ramp limiters.
Currently, when Gas Control tr= ansmits a new setpoint, the station accepts the new value and quickly chang= es operating conditions to try and reach the new setpoint.
However, these = changes may be occurring too fast and may contribute to the flame-out probl= ems.
Again, I will work w/ Todd to develop the controls to achieve this.
In addition, it appears that the Compressor Performance utility would be he= lpful for the operating personnel in determining when one unit could handle=  all the flows at La Plata.
I'll try and package a version that can be ins= talled locally and send it to Todd  Ingalls.
Todd, I looked and I do not have a copy of the existing station control for=  La Plata.
Could you please zip it up and send it to me?
Additionally, I finally got a copy of the drawings for the Griffith Interco= nnect.
It appears our flow swings at this point can be reduced significant= ly by changing the operation of the flow control valve to a downstream pres= sure control valve with a maximum flow control override.
Todd, who is resp= onsible for the programming of the RTU for this point?
Gary Choquette

San Juan control modifications for fuel savings
I have spent a significant amount of time reviewing the operations and SCAD= A on the San Juan lateral over the last couple of weeks.
I've uncovered so= me issues that could significantly reduce fuel consumption on this system.
= Listed in order of priority are: Resolve La Plata Unit #<NUMBER> flame-out problem.
Currently this unit is running= in manual control to limit flame-outs.
This prevents the station from run= ning with only one unit at low flow conditions.
According to the La Plata = team, this will require the replacement of the fuel control valve and unit = control software changes.
Running in the manual mode is costing an additio= nal <NUMBER> MSCF/D in fuel plus the extra O&M costs associated with the fired h= ours on unit #<NUMBER>.
The team is expecting the new fuel valve soon but anticip= ates that they will not get the necessary downtime to install the valve unt= il after the end of the tariff months.
Due to the potential emissions issu= es associated with its current operating mode, we may have to expedite the = modifications to this unit.
Auto calculate a suction pressure setpoint for La Plata.
There are three f= low controlled interconnects on the suction side of La Plata.
Using the me= ter run pressures and/or the flow control valve position, we can maximize t= he suction pressure setpoint to achieve the interconnect flow rates.
The h= igher suction pressure reduces the power required at La Plata with an avera= ge expected fuel savings of <NUMBER> MSCF/D.
Auto calculate a suction pressure setpoint for the Bloomfield Low service s= imilar to the La Plata modification recommended above.
Estimated fuel savi= ngs of <NUMBER> MSCF/D.
Modify the controls at Gallup to enable a quick turndown for a power peak.
= Currently when a power peak is predicted, the Gas Control operators manual= ly transmit a lower discharge pressure setpoint.
It may take a long time f= or the new setpoint to actually gain control of the unit.
The suggested mo= dification would have the Peak Power alarm I calculate automatically retran= smitted to the field and unit/station controls were modified to quickly ram= p down the unit in a controlled manner (minimize recycle and prevent unit t= rips) to minimum power.
Gas Control could then send an override signal tha= t would allow the unit to operate at higher loads if required.
Likewise, i= f my Peak Power alarm clears automatically, the unit would return back to i= ts normal process setpoint conditions.
Note that if Gas Control overrides = my alarm, the override needs to latch until my Peak Power alarm clears.
Th= e suction and discharge setpoint rate ramp limiter logic should be modified= to make them more responsive when they are far from the process values.
B= ob McChane, Todd Ingles, and myself can develop this logic.
Modify the La Plata station control for improved load sharing.
Recommend t= he load share method be based on matching compressor flow range margins.
I= will work with Todd Ingalls to develop the logic and code.
This control m= ethod will ensure both units are operating as close to their high efficienc= y point as possible and minimize surge recycle.
Modify the station control process setpoints logic at La Plata (Bloomfield,= Bisti too?)
to include rate ramp limiters.
Currently, when Gas Control tr= ansmits a new setpoint, the station accepts the new value and quickly chang= es operating conditions to try and reach the new setpoint.
However, these = changes may be occurring too fast and may contribute to the flame-out probl= ems.
Again, I will work w/ Todd to develop the controls to achieve this.
In addition, it appears that the Compressor Performance utility would be he= lpful for the operating personnel in determining when one unit could handle= all the flows at La Plata.
I'll try and package a version that can be ins= talled locally and send it to Todd Ingalls.
Todd, I looked and I do not have a copy of the existing station control for= La Plata.
Could you please zip it up and send it to me?
Additionally, I finally got a copy of the drawings for the Griffith Interco= nnect.
It appears our flow swings at this point can be reduced significant= ly by changing the operation of the flow control valve to a downstream pres= sure control valve with a maximum flow control override.
Todd, who is resp= onsible for the programming of the RTU for this point?
Gary Choquette
gallup enable overrides alarm override ingalls develop logic valve position prevent unit rips reduce fuel consumption load share method range margins costs associated fired scad san juan