AN OILER WAS DRIVING A LUBE TRUCK DOWN A PIT ACCESS ROAD. THE TRUCK SLID DOWN A PIT ACCESS ROAD.THE TRUCK SLID SIDEWAYS, IMPACTED A BERM WITHT HE FRONT BUMPER AND TIPPED ONTO THE PASSENGERS SI DE OF THE TRUCK. EE WAS DIAGNOSED WITH SLIGHT KNEE STRAIN AND PLACED ON RESTRICTED DUTY.