Citing increases in forecasted system-weighted temperatures, Northern Natural Gas said a System Underrun Limitation will be implemented in all market-area zones (ABC, D and EF) effective Saturday and running through at least Monday.

After ending OFO Action Alerts in all zones earlier in the week, Tennessee said Thursday it was lifting an imbalance warning for all zones effective immediately.

Operator Williams Field Services said the Turbo Expander Plant 4 unit at Opal Plant came back online at 1:10 a.m. MDT Thursday and was running in full processing mode. It encouraged customers to adjust their nominations to pre-outage levels effective for Thursday's gas day.

Northwest said a general Underrun Entitlement will become effective Friday for Receiving Parties north of the Kemmerer (WY) Compressor Station. To avoid a penalty, Receiving Party volumes must not exceed 5% of the party's daily entitlement or 1,000 Dth/d, whichever is larger. Jackson Prairie storage field is full, linepack is high and unseasonably warm weather has prompted excessive banking on Northwest's system, the pipeline said, so the Underrun Entitlement will remain in force until Jackson Prairie storage and linepack volumes decrease sufficiently. Although Northwest is not now requiring Receiving Parties to remove gas from the system as imbalance payback, it reserves the right to do so if system integrity requires it.

Westcoast said it has shut down the Gordondale Compressor Station temporarily due to gas sent by a third-party plant that does not meet pipeline quality specifications. Producers along the 26-inch diameter AB Line will be affected until the gas composition is brought within pipeline specifications, Westcoast said, adding that it is not asking shippers to take any action at this time.

Transco has scheduled regular maintenance on its onshore slug catcher near Bayou Black, LA, from Monday through Friday next week, during which all receipt points upstream of Compressor Station 62 will not be available for flow into the Transco system. This will impact about 250 MMcf/d of flowing supplies, Transco said.

CenterPoint said Thursday shippers are no longer under an Operational Alert implemented Oct. 16 requiring them to stay in balance on a daily basis.

©Copyright 2010 Intelligence Press Inc. All rights reserved. The preceding news report may not be republished or redistributed, in whole or in part, in any form, without prior written consent of Intelligence Press, Inc.