Abstract: A system for the formation of a bore hole, particularly for use in enhancing the recovery of oil from an oil bearing underground formation using an assembly including a piston sliding in a guide tube. The forward end of the piston body terminates in a drillhead including multiple ports for passing drilling fluid into the formation. Pressurized fluid flowing through the piston body applies pressure against the drillhead to cause it to move into the formation at the same time as it is cutting a pathway for itself. In a preferred embodiment, the forward end of the guide tube includes a whipstock through which the piston body turns from a vertical to a horizontal direction into the formation to provide a radial for the injection of steam. A rigid metal piston body may be used which plastically deforms when passing through the whipstock and becomes rigid thereafter as it moves through the formation.

Abstract: A system for the formation and use of a bore hole, particularly for the recovery of oil from an oil-bearing underground formation. An eversible elongate permeable tube, preferably formed of woven cloth, including outer and inner walls, connected at a rollover area, is urged into the formation by a driving fluid. Drilling fluid is pumped through a central passageway in the tube and carries a central pipe forward. The drilling fluid, comprising a hot acid or basic aqueous or petroleum base solution, assists break up of the formation to form a cuttings slurry which passes back along the outside of the eversible tube. Means is provided for turning the tube, as from the vertical to the horizontal, by use of a turning segment in the eversible tube, or by guiding the central pipe. Such pipe preferably includes a flexible helical segment capable of turning and of serving as the ultimate support casing. Also, gravel packing techniques and down-hole steam generators.