Optimizing Workover plan and completion procedure for the Karachaganak reservoir brought superior results and created development opportunities for the reservoir. The new approach is based on rigless investigation, data integration and innovative methods to overcome different well problems.
Karachaganak field is a giant gas condensate field located in the north west of Kazakhstan. The structure is sealed with a salt layer that varies in thickness across the field. Salt that are not fully protected could creep causing casing collapse especially if subjected to negative differentials.
Initial well design applied on the 240 exiting wells imposed limitations on workovers. Additional field challenges are; severely corroded and potentially stuck completion strings, poorly cemented casing, and scale deposition.
The new approach has been developed over more than four years of operations. Successfully, workover time has been reduced by more than 25%, saving about $850,000 per workover. Well risk identified and failure risk is minimized. Well abandonment recognition, planning and cost have been optimized.