| Patent Number |
Title Of Patent |
Date Issued |
| RE32267 |
Process for drilling underground arcuate paths and installing production casings, conduits, or f |
October 21, 1986 |
| A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacl |
| 4402372 |
Apparatus for drilling underground arcuate paths and installing production casings, conduits, or |
September 6, 1983 |
| A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacl |
| 4401170 |
Apparatus for drilling underground arcuate paths and installing production casings, conduits, or |
August 30, 1983 |
| A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacl |
| 4319648 |
Process for drilling underground arcuate paths and installing production casings, conduits, or f |
March 16, 1982 |
| A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacl |
