|
CINGSA applies for higher gas pressure Says higher maximum allowed pressure in reservoir will enable facility to safely achieve required contracted storage capacity Alan Bailey Petroleum News
Cook Inlet Natural Gas Storage Inc., known as CINGSA, has applied to the Alaska Oil and Gas Conservation Commission for permission to increase the maximum allowed pressure in its natural gas storage facility south of the City of Kenai on the Kenai Peninsula. The facility, which went into operation in 2012, enables Southcentral Alaska gas and power utilities to warehouse gas produced in the summer for use in the winter, when utility gas demand is especially high.
When CINGSA shut the facility for a few days in November for pressure and mass balance testing, the company reported that the pressure in the reservoir may have exceeded the maximum allowed pressure of 1,700 pounds per square inch. At the time of the pressure measurements the gas pressure was still stabilizing across the reservoir, as injected gas moved through the underground reservoir rock — CINGSA said that it was unlikely that the maximum pressure would have been exceeded, once the pressure had evened out and stabilized.
Isolated pocket But the company now says that further analysis has suggested that one of the facility’s wells had encountered an isolated pocket of relatively high pressure gas from the original Cannery Loop gas field within which the storage reservoir is located. The facility uses a depleted reservoir within the field.
CINGSA says that, as a consequence of this isolated pocket of gas, the facility does not have the capability to store the entire 11 billion cubic feet of gas that the facility was designed to hold and that CINGSA has contracted with its customers for storage, unless the gas pressure is allowed to exceed 1,700 pounds per square inch. CINGSA has applied to the commission to permit pressures of up to 2,200 pounds per square inch, the gas pressure in the Cannery Loop field when the field was discovered. CINGSA says that the 2,200 pounds-per-square-inch pressure is well below the pressure threshold at which the rock of the reservoir might fracture.
CINGSA also told the commission that pressure testing and other monitoring has indicated that there has been no leakage of gas from the storage facility since the facility went into operation.
| 