Ruptured Piston on Mud Pump Leads to Pump House Fire

Cause & Consequence

• Fire or explosion

Incident Location

Drilling unit

Incident Activity

Drilling, workover

Lessons Identified

WHAT CAUSED IT:

 The piston/pump rod covers on the on the F-1000 mud pump were left in the open position and made from expanded metal screen material which allowed the drilling fluid to spray out from the mud pump piston rod cavity and back to the engine area.

 Fire originated in pump house #1 when the drilling fluid contacted the turbo charger of the engine located in the pump house building and ignited.

 The probable cause of the fire was a ruptured piston in the mud pump that allowed invert drilling fluid to spray throughout the pump house.

 Because of the pressure in the mud pump system, aided by the turbulence in the pump house from the cooling fan on the opposite side of the engine, the oil in the invert was atomized (reduced to a fine spray) which then ignited when it came into direct contact with the nearer of the two turbochargers on the engine.

 Electrical and other mechanical causes for this fire were considered and eliminated.

Incident Recommendations

CORRECTIVE ACTIONS: To address this incident, this company did the following:

 Instructed rig personnel to install hinged plated covers or covers with Lexan® Glass inserts on all mud pumps to ensure any drilling fluid from ruptured pistons will be contained within the piston rod cavity of the mud pump. Some plate covers may require a slot to accommodate the piston lubricator hose.

 Instructed rig personnel that all pump rod covers are to be kept closed during pumping operations.

 Issued a directive that all engines located in the mud pump house will have exhaust blankets or wraps to protect the turbochargers and exhausts on the engines from being sprayed with drilling fluid.