| Title | Soultz-Sous-Forets: Main Technical Aspects of Deepening the Well GPK2 |
|---|---|
| Authors | Jurg Baumgartner, Andre Gerard & Roy Baria |
| Year | 1999 |
| Conference | European Geothermal Conference |
| Keywords | Deep drilling, crystalline rocks, well completion |
| Abstract | Between mid February to end of May 1999 (in 104 days) the well GPJS2 at the Soultz HDR site was successfully re-entered and deepened from 3876 m to a final depth of 5084 m and fully completed. Re-entry included the pulling of the existing 321 1 m long internal 9 5/8" by 7" casing string, fishing of a submersible pump and some 150 m of 2 3/8" tubing, sealing of a major loss zone and opening of a 6 1/4" well section in granite (321 1 - 3876 m) to 8 1/2" hole size. The well was extended to 5048 m in 8 1/2" hole size and again completed with a floating 9 5/8" by 7" casing string. The casing shoe is at 4431 m. A bottom hole core was taken in the depth range 5048 - 5051 m. The core recovery was app. 40%. A pilot hole in 6 1/4" was drilled fiom 5051 - 5084 m for in situ stress measurements. The re-entry and deepening of the well GPIQ was accompanied by several technical developments. New casing packer elements based on inflatable metal shells were developed in a close cooperation between SOCOMINE and MeSy GmbH (patent pending). These packer elements were successfully integrated into the completion of the well. The fbll weight of the casing string is supported by these elements which are filled with and imbedded in cement. High temperature cementing strategies (up to 170 - 190 "C) for the complex saline fluids encountered in Soultz (High Magnesium Resistant Cements) were developed in a cooperation between Schlumberger Dowel1 (Vechta), SOCOMINE, SI1 of Houston, Ruhr-University Bochum, BGR Hannover and IFP Paris. |