System and method for installing casing in a blind horizontal well

摘要

A system and method for installing casing in a blind horizontal well for blind horizontal directional borings. The system and method may include an example of an offset transmitter sonde assembly that contains an open central passage through which well casing can be inserted, and an example of a drill bit assembly that may be remotely uncoupled from a drill string, leaving the bit in the bore created. Remote uncoupling of the drill bit assembly tends to allow a casing to be installed in the bore while the drill string and bit remain in the bore for support during casing installation. After installation of the casing the drill bit assembly may be uncoupled from the drill string, allowing the drill string to be withdrawn from the bore, with the drill bit assembly remaining in the bore.

主权项

1. A knock off drill bit assembly comprising:
a retrievable knock off body coupled to a drilling string; a sacrificial knock off body removeably coupled by a pivoting latch mechanism to the retrievable knock off body, and including a drill bit; and whereby the sacrificial knock off body may be remotely disengaged through a forward motion of a disengagement tool causing the pivoting latch mechanism to uncouple the sacrificial knock off body from the retrievable knock off body and the sacrificial knock off body is left in a bore hole after the drilling string is withdrawn and in which a splined coupler is disposed on an interface between the sacrificial knock off body and the retrievable knock off body.