Improving Deliverability in Gas Storage Fields by Identifying the Timing and Sources of Damage Using Smart Well Technology

This report summarizes the work performed under contract DE-FC26-03NT41743. The primary objective of this study was to develop tools that would allow Underground Gas Storage (UGS) operators to use wellhead electronic flow measurement (EFM) data to quickly and efficiently identify trends in well damage over time, thus aiding in the identification of potential causes of the damage. Secondary objectives of this work included: (1) To assist UGS operators in the evaluation of hardware and software requirements for implementing an EFM system similar to the one described in this report, and (2) To provide a cost-benefit analysis framework UGS operators can use to evaluate economic benefits of installing wellhead EFM systems in their particular fields. Assessment of EFM data available for use, and selection of the specific study field are reviewed. The various EFM data processing tasks, including data collection, organization, extraction, processing, and interpretation are discussed. The process of damage assessment via pressure transient analysis of EFM data is outlined and demonstrated, including such tasks as quality control, semi-log analysis, and log-log analysis of pressure transient test data extracted from routinely collected EFM data. Output from pressure transient test analyses for 21 wells is presented, and the interpretation of thesemore » analyses to determine the timing of damage development is demonstrated using output from specific study wells. Development of processing and interpretation modules to handle EFM data interpretation in horizontal wells is also a presented and discussed. A spreadsheet application developed to aid underground gas storage operators in the selection of EFM equipment is presented, discussed, and used to determine the cost benefit of installing EFM equipment in a gas storage field. Recommendations for future work related to EFM in gas storage fields are presented and discussed.« less