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RCA approves CIGGS bidirectional flow Commission gives final green light to the shipment of natural gas east to west under the Cook Inlet as gas supplies tighten Alan Bailey Petroleum News
The Regulatory Commission of Alaska has approved modifications to the Kenai Nikiski pipeline and the Cook Inlet Gas Gathering System, or CIGGS, to enable the flow of gas east to west through CIGGS under Cook Inlet. Previously gas has only been able to flow west to east through the pipeline system.
CIGGS connects gas fields and the gas pipeline infrastructure on the west side of Cook Inlet with the Kenai Nikiski pipeline, and hence the entire gas pipeline infrastructure on the Kenai Peninsula.
Chugach concerned Power utility Chugach Electric Association has been particularly concerned about the need to ship gas from the Kenai Peninsula west through CIGGS to bolster gas supplies for the gas-fired Beluga power station on the west side of the inlet, with the Beluga power plant being a major component of Southcentral Alaska power generation capacity.
The production from the Beluga gas field, adjacent the power plant, has been declining, causing Chugach to supplement its fuel supplies with gas from the Kenai Peninsula. Without the east to west flow of gas through CIGGS, Chugach has to swap gas purchased on the peninsula for gas delivered by Enstar Natural Gas Co. on the west side of Cook Inlet. But, as gas supplies from aging Cook Inlet gas fields tighten, Enstar cannot guarantee to deliver the volumes of gas that Chugach may need.
And as a new gas storage facility near Kenai, operated by Cook Inlet Natural Gas Storage Alaska, comes into operation this year, bidirectional flow in CIGGS will allow increased flexibility in managing the flow of utility gas to and from storage.
Temporary authority At the end of September, recognizing the urgency of the situation for Chugach’s gas supplies, the commission granted temporary authority for the necessary pipeline changes, to enable bidirectional flow through CIGGS before the onset of winter. And in November the commission approved changes to the CIGGS and Kenai Nikiski pipeline tariffs, to accommodate the bidirectional flow arrangements.
Although Marathon Oil Co. operates both CIGGS and the Kenai Nikiski pipeline, Chugach has been funding the pipeline system modifications, with assistance from a state grant.
Essentially, the modifications involve the installation of a compressor in the Kenai Nikiski pipeline at its junction with CIGGS; the removal from CIGGS of some check valves that prevented east to west flow; and the bypassing of some CIGGS equipment at East Foreland. The metering system at the junction between CIGGS and the Kenai Nikiski line also has to be modified to allow for bidirectional flow.
CIGGS modified Marathon spokeswoman Lee Warren told Petroleum News Jan. 18 that the modifications to CIGGS have been completed, to accommodate the flow of gas from east to west should the need arise during cold weather this winter. The new compressor has yet to be installed in the Kenai Nikiski pipeline — once that is done there will be full flexibility in changing the direction of flow through the pipeline system on a routine basis, Warren said.
“The KNPL (Kenai Nikiski pipeline)-CIGGS route provided through the east-west flow project will provide direct cross-inlet capacity from east to west to protect against the possibility of cold weather capacity constraints, outage and bottlenecks on the present system,” the commission said in its order giving final approval for the modifications. “We find that the facilities modifications and bi-directional operation proposed by KNPL and CIGGS are required by the present or future public convenience and necessity.”
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