Development of technologies and techniques to enhance underground natural gas storage operations: State-of-technology assessment and evaluation of gas storage well productivity enhancement techniques. Topical report No. 1, March-December 1990

A comprehensive review of the technology currently used by the industry has been prepared and storage field operator's assessments of the relative costs and benefits of the deliverability enhancement techniques being used have been obtained. A compilation of the data provided by the storage field operators indicates that the most widely used remedial techniques include washing, acidizing, reperforation, and infill drilling. An analysis of factors limiting gas storage well deliverability demonstrated that near-wellbore permeability damage could cause serious productivity decline. Analyses of remedial techniques presently used by the operators were performed. New technologies, such as extended wellbores, were evaluated for applicability to gas storage. A cost/benefit analysis of the impact of new technologies on deliverability of the reservoir classifications was performed. Improvements in deliverability of up to 700% are achievable with these techniques based on analytical modeling of generic reservoir types. If such gains can be achieved, a significant reduction of base gas can be realized, end-of-season (low-pressure) deliverability increased, and overall efficiency improved by operating fewer wells at reduced cost.