A pilot study was conducted in two aquifer gas storage fields completed in Mt. Simon formation located in North Central Illinois to select candidate wells for deliverability improvements.
Eleven wells were selected to evaluate their responses to several different stimulation technique. High pressure perforation washing. Re-perforating with high density charges, extreme overbalance surging (EOBS)1-3 , selective injection packer acidizing (SIP), and coiled tubing acid injection were all used to reduce the near-wellbore pressure losses
Each well was tested before and after every treatment to select treatment types and to compare the improvement techniques. The results and the responses of the wells to these treatments will be documented for further deliverability improvements in these two fields.
Significant improvements were achieved with EOBS and SIP acidizing techniques. The techniques and the procedures used to improve the deliverability in these two gas storage fields are presented in this paper. The procedure and the well test analyses used in the four wells detailed in this paper represent the three main treatment techniques of EOBS, SIP acidizing, and coiled tubing acidizing.