Method and apparatus for drilling a zero-radius lateral

摘要

A jet drill coupled to a distal end of a flexible jet lance is lowered into a well casing and advanced through a curved passage formed in a deflection shoe oriented to direct the jet drill through an orifice milled in the well casing. The jet drill is actuated with a pressurized fluid produced by a pump on the surface that is conveyed through a high pressure hose that runs through the flexible jet lance. Force transmitted through a thrust liner of the jet lance advances the jet drill while the lateral bore is being drilled. The thrust liner comprises helical coils of steel wire providing a high elastic modulus and buckling resistance, even while passing through the curved passage. Tension cables in the jet lance maintain tension on the thrust liner and enable the assembly to be pulled from the lateral bore and well.

主权项

1. Apparatus for drilling a lateral bore from within a well casing, comprising:
(a) a source of pressurized fluid; (b) a high pressure hose that can be introduced into the well casing, for conveying a pressurized fluid down into the well casing; (c) a jet lance that is flexible and includes a thrust liner spaced apart from and surrounding the high pressure hose, wherein the thrust liner circumferentially surrounds spacers and tension cables disposed circumferentially around the high pressure hose, and wherein the spacers provide a slip fit between the thrust liner and the high pressure hose, and the tension cables apply a tension force to the thrust liner, the thrust liner enabling the jet lance to bend around a curve within the well casing without shearing or buckling; and (d) a pressurized fluid jet drill that is coupled to a distal end of the jet lance, the pressurized fluid jet drill being actuated by the pressurized fluid to drill through a formation that surrounds the well casing to form the lateral bore.