Method, kit and system for injecting grout into a borehole, method of deploying a tube into a borehole for grout injection and leader for use in a grout injection system

A method of deploying a tube into a borehole for injecting grout, said borehole comprising an open end allowing access from outside said borehole into said borehole and a bottom end opposite said open end, said method comprising:

• providing a leader comprising opposite fore and aft portions, a pressure-bearing member between said fore and aft portions, and a leader passage extending from a fore opening in said leader fore portion to an aft opening in said leader aft portion;
• providing a tube attached to said leader and connected to said leader aft opening;
• inserting said leader into said borehole with said fore portion first, with said borehole defining an upstream portion located upstream of said pressure-bearing member and a downstream portion located downstream of said pressure-bearing member;
• allowing said tube to extend outside of said borehole and to slide into said borehole as it is deployed therein;
• injecting an impelling fluid in said borehole downstream portion exteriorly of said tube resulting in pressure being applied on said pressure-bearing member and said leader consequently advancing towards said borehole bottom end, said leader carrying said tube with it to deploy said tube in said borehole;
• while upstream fluid located in said borehole upstream portion is ejected out of said borehole at least partly through said leader passage and said tube;
• and
• stopping the injection of said impelling fluid when said leader reaches a leader target position.

A grout injection kit for use in assembling a grout injection system for injecting grout into a borehole, comprising:

• a leader comprising opposite fore and aft portions, a pressure-bearing member between said fore and aft portions, and a leader passage extending from a fore opening in said leader fore portion to an aft opening in said leader aft portion;
• a tube attachable to said leader and connectable to said leader aft opening;
• a borehole interface member comprising:
• a plug;
• an inner channel extending through said plug and sized to allow said tube to loosely extend and slide therethrough;
• a tube seal in said inner channel, sized to allow said tube to extend and slide therethrough while preventing fluid flow between said tube seal and said tube;
• and
• a downstream fluid connection allowing fluid access into said inner channel exteriorly of said tube.

A grout injection system for injecting grout into a borehole, comprising:

• a leader comprising opposite fore and aft portions, a pressure-bearing member between said fore and aft portions, and a leader passage extending from a fore opening in said leader fore portion to an aft opening in said leader aft portion, said leader for insertion into said borehole with said fore portion first and said borehole thus defining an upstream portion located upstream of said pressure-bearing member and a downstream portion located downstream of said pressure-bearing member;
• a tube attached to said leader and connected to said leader aft opening;
• a plug for sealing the borehole;
• a tube channel for allowing said tube to slidingly extend into said borehole from outside the borehole;
• a downstream fluid connection for allowing fluid access into said borehole downstream portion exteriorly of said tube;
• and
• a fluid pump connectable to said downstream fluid connection.