CHAPARRAL ENERGY, LLC

Incident Narrative

ON 1/17/2017, A LAND OWNER REPORTED TO US GROUND DISPLACEMENT AND A SMOKE-LIKE SUBSTANCE EMANATING FROM THE GROUND NEAR OUR BURIED TEXOK CO2 PIPELINE. OPERATOR PERSONNEL LOCATED AND CONFIRMED THE EXISTENCE OF A CO2 LEAK AND OBSERVED SOME DRY ICE OVER THE ROW THAT WAS SUBLIMATING INTO A GASEOUS STATE. THE AREA SURROUNDING THE LEAK WAS SECURED. THE RELEASE DID NOT RESULT IN EXPLOSION, FIRE, DEATH, PERSONAL INJURY, SIGNIFICANT PROPERTY DAMAGE, OR POLLUTION OF ANY WATER BODY, AND WAS CONFINED TO THE PIPELINE RIGHT OF WAY. THE CO2 SOURCE PLANT WAS NOTIFIED AND SHUTDOWN, AND THE LEAKING PIPELINE SEGMENT WAS ISOLATED BY CLOSING THE UPSTREAM AND DOWNSTREAM VALVES. ON 1/18/2017, THE AFFECTED SEGMENT WAS BLOWN DOWN BY OPENING ABOVE-GROUND BLOWDOWN VALVES NEAR THE UPSTREAM AND DOWNSTREAM MAINLINE VALVES. UPON EXCAVATION ON 1/18/2017, A SMALL PINHOLE LEAK WAS FOUND ABOUT 2.5 INCHES AWAY FROM A GIRTH WELD. A PORTION OF THE PIPE JOINT CONTAINING THE LEAK AND WELD WAS CUTOUT AND REMOVED, AND WAS REPLACED WITH PRE-TESTED PIPE. X-RAY OF BOTH WELDS ON THE REPLACEMENT JOINT WAS ACCEPTED. ON 1/18/2017, THE PIPELINE WAS PURGED WITH CO2 BY OPENING THE UPSTREAM VALVE. ONCE PURGING WAS COMPLETED, VALVES WERE OPENED AND THE CO2 SOURCE PLANT WAS RESTARTED, RETURNING THE PIPELINE TO REGULAR SERVICE IN A SAFE MANNER. THE EXCAVATED HOLE WAS BACKFILLED WITHOUT INCIDENT. ON 2/7/2017 CHAPARRAL ENERGY AUTHORIZED MEARS INTEGRITY SOLUTIONS TO PERFORM AN EVALUATION AND ROOT CAUSE ANALYSIS REPORT AND INVESTIGATION. ON 6/6/2017 MEARS PROVIDED THIS REPORT AND IT'S FINDINGS. THE REPORT INCLUDED AN INVESTIGATION OF THE CATHODIC PROTECTION ON THE TEXOK CO2 PIPELINE, AND ALSO AN INVESTIGATION INTO POSSIBLE DC STRAY CURRENT. MEARS PROVIDED IN THE REPORT RECOMMENDATIONS TO CONDUCT A THOROUGH COOPERATIVE INFERENCE ANALYSIS ALONG THE LINE, EVALUATE THE NEED FOR BONDS OR GALVANIC ANODE DRAINS, CONSIDERATION OF RELOCATING EXISTING FOREIGN CP SOURCES THAT ARE POTENTIALLY DETRIMENTAL TO THE STRAY CURRENT MITIGATION STRATEGY, AND ENHANCE CHAPARRAL'S EXISTING CATHODIC PROTECTION SYSTEMS TO ENSURE PROTECTION IN AREAS IDENTIFIED AS HAVING MARGINAL OR INADEQUATE CP. OTHER RECOMMENDATIONS INCLUDE THE CONSIDERATION OF INSTALLATION OF COUPON TEST STATIONS IN AREAS OF LOW POTENTIALS AND/OR LOCATIONS OF IDENTIFIED INTERFERENCE, AND ALSO PERFORMING A CLOSE INTERVAL SURVEY AFTER CP ADJUSTMENTS HAD BEEN MADE TO VALIDATE THE CHANGES ARE EFFECTIVE. AFTER RECEIVING THE REPORT FROM MEARS AND CONTINUED DISCUSSIONS OF HOW TO MOVE FORWARD, THE TEXOK CO2 PIPELINE WAS DIVESTED AS PART OF A LARGE ASSET SALE ON 11/17/2017 TO PERDURE PETROLEUM, LLC (OPID 39754).