LOUISVILLE GAS & ELECTRIC CO

Incident Narrative

GAS WAS DISCOVERED LEAKING AT THE SURFACE NEAR THE WELLHEAD OF THE A. SCOTT 1A OBSERVATION WELL ON OCTOBER 10TH, 2017. A CEMENT RETAINER WAS SET AT THE BOTTOM OF THE WELL AND CEMENT WAS PUMPED THROUGH THE PLUG TO FILL WELLBORE AND CASING BELOW THE PLUG ON OCTOBER 19TH, 2017 IN PREPARATION FOR WELL ABANDONMENT. A GEOPHONE ARRAY PRODUCTION SURVEY (GAPS) LOG WAS RUN ON A. SCOTT 1A OBSERVATION WELL ON NOVEMBER 7, 2017 AND A REPORT WAS RECEIVED ON NOVEMBER 9, 2017 INDICATING NO GAS WAS DETECTED LEAKING FROM THE STORAGE ZONE TO THE SURFACE. HOWEVER, GAS WAS DETECTED FLOWING FROM A POROUS ZONE AT APPROXIMATELY 120 FOOT IN DEPTH UP THE OUTSIDE OF WELL CASING TO THE SURFACE. ON NOVEMBER 8, 2017 LG&E WAS NOTIFIED BY THE LANDOWNER OF AN ADJACENT PROPERTY, OUTSIDE OF STORAGE LEASE AREA, OF THREE ABANDONED OIL WELL SITES LEAKING GAS TO THE SURFACE. A NEARBY OBSERVATION WELL (A. SCOTT 2A) RE-PLUGGED IN 2014 WAS RE-ENTERED (AFTER DRILLING OUT CEMENT) AND A GAPS LOG WAS RUN. THE GAPS LOG FOUND GAS FLOWING BEHIND THE CASING FROM THE BOTTOM OF THE WELL TO A POROUS FORMATION AT APPROXIMATELY 120 FEET IN DEPTH. THE A. SCOTT 2A WELL WAS PERFORATED AND CEMENT SQUEEZE PROCEDURE WAS PERFORMED ON NOVEMBER 27, 2017. THE WELL WAS RE-ENTERED (AFTER DRILLING OUT CEMENT AND PLUGS) AND CEMENT BOND AND GAPS LOGS WERE RUN ON DECEMBER 11TH, 2017. THE CEMENT BOND LOG INDICATED CEMENT FROM CEMENT SQUEEZE PROCEDURE WAS SUCCESSFULLY PLACED BEHIND APPROXIMATELY 100 FEET OF THE WELL CASING. THE LOG FOUND THE CEMENT SQUEEZE JOB SUCCESSFULLY SEALED OFF GAS PREVIOUSLY MITIGATING BEHIND CASING TO THE POROUS ZONE AT 120 FEET IN DEPTH (NEED TO VERIFY THIS IS CORRECT AFTER RECEIVING LOG REPORT FROM WEATHERFORD EXPECTED ON DECEMBER 13TH). LG&E IS CONTINUING TO MONITOR SURFACE GAS LEAKS TO VERIFY CORRECTIVE ACTIONS TAKEN HAVE ADDRESSED LEAKS FROM GAS STORAGE ZONE. THE ESTIMATE OF GAS LOSS IN PART A(10) ABOVE INCLUDES OUR BEST ESTIMATE OF GAS WHICH LEAKED FROM THE A SCOTT 2A WELL FROM THE DATE IT WAS RE-PLUGGED IN FEBRUARY 2014 (WHICH IS OUR BEST ESTIMATE OF THE DATE WHEN THE LEAK MAY HAVE STARTED) UNTIL THE LEAK WAS REMEDIATED ON NOVEMBER 27, 2017. NO LOSS IS ESTIMATED FROM THE A SCOTT 1A OBSERVATION WELL BECAUSE, AS NOTED ABOVE, IT WAS DETERMINED THAT NO GAS WAS LEAKING FROM THE STORAGE ZONE AT THAT LOCATION.