Abstract: A method and apparatus for isolating a zone (12) of a wellbore (14) penetrated by a casing (16) and then opening ports (28) in the zone (12) for extraction or injection of fluids is provided. The zone (12) is isolated by inflating jackets (42) and then closing a safety valve (38) by sliding a sliding member (44) relative to a first conduit (46). The ports (28) are opened by sliding a piston (80) of a sliding sleeve valve (76) so that openings (84) therein align with the ports (28). The invention provides improved zone isolation and reduced wear of seals (86) in the sliding sleeve valve (76).

Abstract: A well drilled with air or gas as a circulating medium traversing pay zones with greater than normal pressures or pressures such that hydrocarbons would permeate drilling fluids and cement is drilled and completed while permitting a continuous flow of hydrocarbons from the well until it is desired to shut the well in at the surface. The intermediate casing string and the production casing string cooperate with the tubing so that the cement for the production string may be positioned without contact with the hydrocarbons.

Abstract: A method for the cementing in of a well so that the cement is not contacted by deleterious materials, such as gas, is disclosed.

Abstract: A wedge-shaped whipstock is provided for directional well drilling which tapers from the lead end to a thick section at the bottom, and is fabricated from a tough polymeric material. An adhesive coating is applied to the outside surface of the wedge for permanent adherence of the whipstock to the surface of the drill hole. A deformable highly viscous material can fill and complement the internal wedge portion to produce a cylindrical configuration prior to use. Alternatively, or in conjunction with the deformable viscous material, a compressive element having a shaped compression face and made from a frangible material may be formed on the drill bit and/or attached to the prepared whipstock for the lowering of the tool into the drill hole and bonding the whipstock in place. The bottom surface of the whipstock is reinforced for positioning in the hole over a bridge plug or broken drill pipe.