摘要 |
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 other 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. |