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Title: Apparatus for extended straight line drilling from a curved borehole

Patent ·
OSTI ID:6768417

An apparatus is claimed by which a vertical borehole is curved to a new angle and extended through a production reservoir. A vertical borehole of a suitable diameter is extended downhole to the proximate depth of the production reservoir. A Zublin drill guide apparatus is employed to drill a curved section of the hole, thereby turning the borehole to a desired angle so that the lower marginal end of the borehole is directed laterally away from the vertical part of the borehole. A drill pipe string is positioned within the vertical part of the borehole. A flexible pipe is fitted to the downhole end of the drill pipe string, and a Zublin straight drill guide assembly is fitted to the end of the flexible pipe. A motor, such as an expansible gas turbine motor, for example, is connected to the end of the straight drill guide assembly. A suitable drill bit is connected to be rotated by the turbine motor. Compressible fluid is applied to the upper end of the string at the surface of the ground and drives the turbine motor, which in turn rotates the drill bit. A fluid reaction system associated with the turbine motor provides a turning moment in opposition to the rotating bit while concurrently forcing the bit forward to penetrate the formation.

Assignee:
EDB-84-115019
Patent Number(s):
US 4432423
OSTI ID:
6768417
Resource Relation:
Patent File Date: Filed date 22 Mar 1982; Other Information: PAT-APPL-360585
Country of Publication:
United States
Language:
English