PHMSA has issued an interim final rule (IFR) to establish – for the first time ever – minimum federal standards for underground natural gas storage facilities. The IFR imposes significant new requirements in a short timeframe for “downhole facilities,” including wells, wellbore tubing and casings at underground natural gas storage facilities. The IFR addresses construction, maintenance, risk management and integrity management procedures for these facilities and incorporates the requirements of recent API industry Recommended Practices (RPs) 1170 for salt caverns storing natural gas and 1171 for storage in depleted hydrocarbon reservoirs and aquifer reservoirs. In addition, the IFR requires underground gas storage operators to prepare and file annual reports, incident reports, safety-related condition repairs and register their facilities in the PHMSA operator registry.
In response to the Aliso Canyon leak from an underground natural gas storage well that lasted nearly four months, federal agencies with oversight of over such facilities announced workshops to gather information and solicit input on forthcoming minimum safety regulations. There are an estimated 400 interstate and intrastate underground natural gas storage facilities that operate with more than 4 trillion cubic feet of natural gas capacity. Some interstate pipeline operators rely on underground storage to facilitate load balancing and system supply on their transmission lines, while a large portion of this capacity is leased to other industry participants. In addition to serving customers, intrastate pipeline companies use storage capacity and inventories for similar purposes. Underground natural gas storage provides for flexibility in supply to accommodate daily and seasonal demand fluctuations.