This invention relates to a combined tool for extended reach casing and cementing. A float collar, a
bypass valve, and an oscillating device are sequentially screwed onto the top of the power guide shoe. The oscillating device's oscillating shaft, from top to bottom, comprises an upper connector, a hexagonal tenon, a polished rod section, and a threaded section. A spring sleeve is screwed onto the upper part of the threaded section of the oscillating shaft. Disc springs are stacked above the spring sleeves, each disc spring fitting around the outer circumference of the polished rod section. A spring plug is pressed above the disc springs, and a hexagonal hole is provided along the axis of the spring plug, fitting onto the hexagonal tenon. A spring cylinder is screwed onto the lower outer circumference of the spring plug. The inner cavity of the spring cylinder has an inner step, located below the threaded section and spaced at intervals. An oscillator is installed below the inner step, its bottom abutting against the top of the lower connector. The upper external thread of the oscillating lower connector is screwed into the lower port of the spring cylinder. This tool can generate self-excited vibration, reducing friction, increasing casing running speed, and improving
cement stone strength and cementing quality.