Eric,

What we have done was use meteorological data from the internet but have found that to be incorrect for remote locations.  The internet in some places reads low compared to the actuals at the stations.  I try to go by what the locals have versus the internet.  I think the internet data is more of an average versus the spots throughout the day even though they call them daily highs.  Go example is Station #1 were the internet data is about 5 - 8 degrees low compared to actuals at the station.  Same is with San Juan were I have seen temperatures in the summer hit high temps as early as 9:00 a.m.  Other factors to consider is not only the ambient temps but what the compressor unit can stand (ie; shutdowns or limit switches).  If the nightly exhaust temperature does not cool down enough at Bloomfield, the unit can be limited in power as early as 8:00 a.m. when it reaches 1400 F.  It appears that thre is plenty of power left to run but the unit can't get there.  I have seen power levels peak at 4000 Hp when the unit is site rated at 4500 Hp.  

As time goes on, I'll either help you understand more or confuse you.  Let me know which direction I'm headed from time to time.  You can't hurt my feelings.  I'm copying Kevin to keep him up to speed.  Planning is not an exact science but we use experience and whatever REAL data is available. 

Ron M.

 -----Original Message-----
From: 	Gadd, Eric  
Sent:	Thursday, February 28, 2002 10:06 AM
To:	Matthews, Ron
Subject:	RE: Sun Devil - ambient temperature affect on pipeline capacity

Ron, 

Yes, thanks very much.  I'm trying to move up the pipeline engineering + design learning curve.  

I get the impression that having different design basis conditions for each compressor station introduces a lot of complexity for calculating interruptible capacity arising from lower ambient temperatures.  It might be 75 degrees at one station and 95 degrees at another, which would act as a bottleneck.  Do we meteorological data for each station?  

 -----Original Message-----
From: 	Matthews, Ron  
Sent:	Thursday, February 28, 2002 9:54 AM
To:	Gadd, Eric; Eisenstein, Arnold L.
Subject:	RE: Sun Devil - ambient temperature affect on pipeline capacity

Each station has a different temperature based on location and elevation.  Station #2 is far less than Station #1 based on elevation.  Station #1 is 95 F and Station #2 is 90 F.  Station #2 is over 7000 feet while Station #1 is around 5000 feet.  The drop is quick because Needles is around 500 feet.  There is a 2000 feet swing between stations starting from Station #4 west.  

Does this help?

Ron M.

 -----Original Message-----
From: 	Gadd, Eric  
Sent:	Thursday, February 28, 2002 9:32 AM
To:	Eisenstein, Arnold L.
Cc:	Matthews, Ron
Subject:	RE: Sun Devil - ambient temperature affect on pipeline capacity

Was I correct on the 95 degree F set point?

 -----Original Message-----
From: 	Eisenstein, Arnold L.  
Sent:	Thursday, February 28, 2002 9:22 AM
To:	Gadd, Eric
Cc:	Matthews, Ron
Subject:	RE: Sun Devil - ambient temperature affect on pipeline capacity

in general you have an additional 3% HP available for every 10 deg F below 95 deg at each station.  During the summer Stations 1, 3, and 4 are already at MAOP and would not matter.  At station 2 the 10 deg would gain 5 mmscfd to Phoenix and mayby 3 mmscfd to Ca.   We will have run additional models to verify offcases.




Arnold Eisenstein
tel:       713-345-3666 (new)
fax:      713-646-7522
e-mail: arnold.l.eisenstein@enron.com

 -----Original Message-----
From: 	Gadd, Eric  
Sent:	Wednesday, February 27, 2002 9:34 AM
To:	Eisenstein, Arnold L.
Subject:	Sun Devil - ambient temperature affect on pipeline capacity

Arnold,

I understand that pipeline design is based on hot (95 degrees F) ambient temperature conditions.  Is this true?  If so, assuming a normal weather pattern, how much additional capacity is "created" when temperature conditions are off design basis?  I'd like to quantify the potential upside assuming that this incremental capacity would be available for interruptible transportation sales.