An ultra-high pressure (UHP) cutting device for insertion into a wellbore for cutting the casing of the wellbore from within the wellbore is provided. The cutting device comprises a UHP hose connector for connection with a UHP hose in communication with a fluid source; a rotatable UHP tube with a top end in fluid communication with the UHP hose connector and a bottom end opposite the top end; a rotating means in operational communication with the UHP tube for rotating the UHP tube during operation of the cutting device; and a cutter head in fluid communication with the bottom end of the UHP tube.