ROSE ROCK MIDSTREAM L.P.

Incident Narrative

A LAND OWNER CONTACTED THE CONTROL CENTER AT 1055 ON 9/28/2017 INFORMING THE CONTROLLER THERE WAS A LEAK AND OIL WAS ON THE GROUND. THE CONTROLLER CONTACTED THE FIELD OPERATOR AT 1058 AND SHUT IN THE MAINLINE BOOSTER PUMP AT 1101. THE OPERATOR ARRIVED ONSITE AT 1125 AND CONFIRMED OIL ON THE GROUND THREE MILES EAST OF THE CUNNINGHAM STATION. THE OPERATOR ISOLATED THE LEAK BY CLOSING THE GOOSE CREEK VALVE AT 1140. AERIAL PATROL IDENTIFIED THE LEAK AND CONTACTED ROSE ROCK MIDSTREAM AT 1244. THE CONTROL CENTER VERIFIED 45 BBLS SPILLED WITH OVER/SHORT CALCULATIONS. THE PIPELINE WAS CLAMPED AT 1530. THE LEAK OCCURRED AT A ORIGINAL WELD LOCATION IN A LOW SPOT IN THE LINE. THE LEAK WAS A PINHOLE LEAK WHICH HAD NOT BEEN IDENTIFIED ON THE MOST RECENT ILI REPORT. THE LEAK WAS REPAIRED BY CUT OUT AND WAS PUT BACK IN SERVICE ON 10/3/2017 AT 1655. SOIL REMEDIATION WAS PERFORMED WITH 40 / 12 CU LOADS OF IMPACTED SOIL EXCAVATED AND TRANSPORTED TO THE BARTON COUNTY LANDFILL. THE SECTION OF REMOVED PIPE WAS SENT TO DNV METALURGICAL LAB FOR ANALYSIS TO DETERMINE THE ROOT CAUSE OF THE FAILURE. UPON RECEIVING THIS ANALYSIS, A SUPPLEMENTAL REPORT WILL BE COMPLETED. 01/03/2017 - ROSE ROCK MIDSTREAM RECEIVED DNV'S METALLURGICAL REPORT WHICH STATED THE ROOT CAUSE AS THE FOLLOWING; THE RESULTS OF THE ANALYSIS INDICATE THAT THE LEAK OCCURRED DUE TO INTERNAL CORROSION THAT PROPAGATED THROUGH-WALL AT THE 5:10 ORIENTATION WITHIN A GIRTH WELD. THERE IS NO CONCLUSIVE EVIDENCE FOR A SINGLE MECHANISM FOR THE CORROSION, BUT CARBON DIOXIDE CORROSION IS THE MOST LIKELY MECHANISM.