Abstract: Hydraulic drilling apparatus and method in which a drill head is driven toward the formation being drilled by the force of the drilling fluid, and the rate of advancement or penetration of the drill head is controlled by entrapping a fluid in a chamber to resist advancement of the drill head and allowing a controlled amount of the entrapped fluid to pass out of the chamber through an orifice to permit the drill head to advance at a controlled rate.

Abstract: Structure is passed into an earth well including a whipstock attached to piping and a retractible anchor. The whipstock includes a number of connected guide assemblies. Erection means is connected at one end to a forward guide assembly and at the other end to an extension projecting to the earth surface. To erect the whipstock, an extension of the erection means is pulled from the surface to cause the guide assemblies to swing into a curved pathway. Thereafter, a drilling tube is passed through the whipstock into the adjacent formation. The whipstock may be deerected by releasing the extension means. Then, the anchor is released and the structure is pulled out of the well.