Abstract: A supplemental horizontal section is drilled from a lower end of an existing well bore by a drilling tool which provides a short radius of the order of 20 feet of a curved section interconnecting the vertical initial section and the horizontal section. This enables the drilling to take place without expensive monitoring equipment since the distances involved are relatively small. The drilling tool includes a mud motor to which is attached a drilling section including a drill bit at the outer end thereof. The drilling section is connected to the mud motor by a knuckle joint which allows pivotal action about an axis at right angles to the longitudinal axis of the drill bit. A counterbore of increased diameter is formed at the lower end of the existing well bore and the knuckle and drill bit located therein. The knuckle is biased toward one side of the counter bore by a leaf spring so that the longitudinal axis of the drill bit takes up an inclined position with a knuckle bent at a shallow angle.

Abstract: A split-type injector for flexible drill tubing includes a pressure cylinder connected to linkage which maintains an adjustable pressure of the injection dies upon the tubing passing therethrough. The individual dies on the endless chain are constructed to grip components and tubing of different diameters which passes therethrough and also by means of a relief valve in the pressure system, to widen and close up as different diameter components or tubing pass therethrough. For example if a component such as a coupling is encountered, the halves of the injector move apart to allow it to pass yet at the same time maintain a similar contact upon the coupling and also to maintain similar pressure upon the coupling. When the component has passed, the halves close up and maintain the same pressure and substantial contact area upon the tubing as before.