Abstract: A system for recovery of oil, particularly viscous oil, from subsurface formations penetrated by highly deviated or horizontal bore holes by circulating therethrough a heated fluid. The heated fluid is circulated through a flexible conduit which is pulled into the bore hole by thrust generating means at the forward end thereof. Power to operate the thrust generating means is also conducted through the conduit. Produced oil is returned via the conduit.

Abstract: The present invention provides an electrically powered system for advancing a rotary boring tool in situations where the inclination of the bore hole is such that the force of gravity does not provide sufficient forward thrust. One or more marine screw propellers are rotated by the motor which itself is restrained from rotation by being fixedly connected to a flexible, twist resistant conduit for conducting the drilling fluid and electric power from the surface. The system may also provide for different rotative speeds for propeller and bit and for counter-rotating propellers to minimize torque forces on the conduit.

Abstract: The present invention provides a nonstalling system for advancing a boring tool in situations where the inclination of the bore hole with respect to the vertical is such that the force of gravity does not provide effective forward thrust. A hydraulically powered marine screw propeller adjacent the boring tool provides the necessary thrust for the drilling operation. Pressurized drilling fluid provides the required hydraulic energy. The characteristics of the marine screw propeller are such that it provides maximum thrust at maximum rotative speed but should the tool stall the forward thrust drops to zero preventing stalling.

Abstract: The invention deals with running and pulling lines and tubulars in a liquid-containing well without use of heavy hoisting equipment. Sections of tubulars somewhat more dense than the well liquid are combined with less dense sections to make up a string which is essentially neutrally buoyant in the liquid. Sections of intermediate density may be included also. Examples of suitable plastic materials are given.

Abstract: The invention provides a guide means for deflecting drilling means at a desired location in a well bore to enable the drilling of either a sharply deviated extension thereof or a lateral branch bore. A frame carrying spaced drill tubing holding members is lowered along with the drill bit and tubing into the well bore. Latch means, operable from the surface, release spring members which act to deflect the lower tubing holding member, the tubing and drill bit into the desired orientation. The latch means may be reset from the surface, realigning the tubing holding members so that the guide means assembly may be readily withdrawn from the well bore.