Underground barrier for detecting hollows and a method of use thereof

Abstract

An underground barrier for detecting underground hollows, comprising: a drilling rig; at least one drillstring, a proximal end of the drillstring, fitted on the drilling rig, the drillstring capable of drilling a borehole into the ground; a directional drilling unit, fitted on a distal end of the drillstring, capable of steering the drillstring in a desired path; a sensor unit, fitted on the distal end of the drillstring, capable of mapping the ground and hollows around the drillstring; and a control station; the control station configured to preform one or more of the following: control, the directional drilling unit to steer the drillstring in a desired path; receive, mapping data of the ground around the drillstring from the sensor unit; analyze, the mapping data received to detect underground hollows; and display, to a user of the system, using a user interface, the mapping data and the underground hollows.

1 . An underground barrier for detecting underground hollows, comprising:
 a drilling rig;   at least one drillstring, a proximal end of the drillstring, fitted on the drilling rig, the drillstring capable of drilling a borehole into the ground;   a directional drilling unit, fitted on a distal end of the drillstring, capable of steering the drillstring in a desired path;   a sensor unit, fitted on the distal end of the drillstring, capable of mapping the ground and hollows around the drillstring; and   a control station;
 the control station configured to preform one or more of the following: 
 control, the directional drilling unit to steer the drillstring in a desired path; 
 receive, mapping data of the ground around the drillstring from the sensor unit; 
 analyze, the mapping data received to detect underground hollows; and 
 display, to a user of the system, using a user interface, the mapping data and the underground hollows. 
   
     
     
         2 . The underground barrier of  claim 1 , wherein the control station is further configured to control the drillstring through a generally horizontal underground path. 
     
     
         3 . The underground barrier of  claim 1 , wherein the control station is further configured to control at least two drill strings located in at least two adjacent generally horizontal underground paths. 
     
     
         4 . The underground barrier of  claim 1 , wherein the control station is further configured to perform the following for controlling the drillstring through the desired path:
 a) direct, the directional drilling unit to steer the drillstring to drill from a current location through a generally vertical path;   b) evaluate, the drillstring location to determine current depth of the generally vertical path;   c) guide, the directional drilling unit to steer the drillstring into a generally horizontal path, when a desired depth of the generally vertical path is attained;   d) examine, the drillstring location to determine length of the generally horizontal path;   e) return, the drillstring through the generally horizontal path back to the generally vertical path, when a desired length of the generally horizontal path is attained; and   f) repeat, steps a-e until parallel generally horizontal paths have been drilled, a desired overall depth of the generally vertical path is attained and underground area is mapped for hollows.   
     
     
         5 . The underground barrier of  claim 1 , wherein the control station is further configured to perform the following for controlling the drillstring through the desired path:
 a) direct, the directional drilling unit to steer the drillstring to drill from current location through a generally horizontal path;   b) evaluate, the drillstring location to determine current length of the generally horizontal path;   c) guide, the directional drilling unit to steer the drillstring into a generally vertical path, when a desired length of the generally horizontal path is attained;   d) examine, the drillstring location to determine depth of the generally vertical path;   e) return, the drillstring through the generally vertical path back to the generally horizontal path, when a desired depth of the generally vertical path is attained; and   f) repeat, steps a-e until parallel generally vertical paths have been drilled, a desired overall depth of the generally horizontal path is attained and underground area is mapped for hollows.   
     
     
         6 . The underground barrier of  claim 1 , wherein the control station is further configured to preform one or more of the following:
 monitor, the detection of one or more hollows in an underground area designated by the user of the system through the user interface; and   alert, the user of the system through the user interface when one or more hollows are detected in the underground area.   
     
     
         7 . The underground barrier of  claim 1 , wherein the sensor unit includes one or more of the following:
 a. a borehole ground penetrating radar;   b. a seismic sensor;   c. a magnetometer;   d. an electrical resistivity sensor;   e. an acoustic sensor; or   f. an electromagnetic sensor using high-frequency radio waves.   
     
     
         8 . The underground barrier of  claim 1 , wherein the directional drilling unit is a rotary steerable unit. 
     
     
         9 . The underground barrier of  claim 1 , wherein said drilling rig is a coiled tubing drilling rig. 
     
     
         10 . A method comprising:
 providing control, by a control station, of a directional drilling unit, fitted on a distal end of a drillstring, capable of drilling a borehole into the ground, at least one proximal end of the drillstring fitted on a drilling rig, to steer the drillstring in a desired path;   receiving, mapping data of the ground and hollows around the drillstring from a sensor unit, fitted on the distal end of the drillstring, capable of mapping the ground and hollows around the drillstring;   analyzing, the mapping data received to detect one or more underground hollows; and   displaying, to a user of the system through a user interface the mapping data and the underground hollows.   
     
     
         11 . The method of  claim 10 , wherein the control station is further configured to control the drillstring through a generally horizontal underground path. 
     
     
         12 . The method of  claim 10 , wherein the control station is further configured to control at least two drill strings located in at least two adjacent generally horizontal underground paths. 
     
     
         13 . The method of  claim 10 , further comprising:
 a) directing, the directional drilling unit to steer the drillstring to drill from current location through a generally vertical path;   b) evaluating, the drillstring location to determine current depth of the generally vertical path;   c) guiding, the directional drilling unit to steer the drillstring into a generally horizontal path, when a desired depth of the generally vertical path is attained;   d) examining, the drillstring location to determine length of the generally horizontal path;   e) returning, the drillstring through the generally horizontal path back to the vertical path, when a desired length of the horizontal path is attained; and   f) repeating, steps a-e until parallel generally horizontal paths have been drilled, a desired overall depth of the generally vertical path is attained and underground area is mapped for hollows.   
     
     
         14 . The method of  claim 10 , further comprising:
 a) directing, the directional drilling unit to steer the drillstring to drill from current location through a generally horizontal path;   b) evaluating, the drillstring location to determine current length of the generally horizontal path;   c) guiding, the directional drilling unit to steer the drillstring into a generally vertical path, when a desired length of the generally vertical path is attained;   d) examining, the drillstring location to determine depth of the generally vertical path;   e) returning, the drillstring through the generally vertical path back to the generally horizontal path, when a desired depth of the generally vertical path is attained; and   f) repeating, steps a-e until parallel generally vertical paths have been drilled, a desired overall depth of the generally horizontal path is attained and underground area is mapped for hollows.   
     
     
         15 . The method of  claim 10 , further comprising:
 monitoring, the detection of one or more hollows in an underground area designated by the user of the system through the user interface; and   alerting, the user of the system through the user interface when one or more hollows are detected in the underground area.   
     
     
         16 . The method of  claim 10 , wherein the sensor unit includes one or more of the following:
 a. a borehole ground penetrating radar;   b. a seismic sensor;   c. a magnetometer;   d. an electrical resistivity sensor;   e. an acoustic sensor; or   f. an electromagnetic sensor using high-frequency radio waves.   
     
     
         17 . The method of  claim 10 , wherein the directional drilling unit is a rotary steerable unit. 
     
     
         18 . The method of  claim 10 , wherein said drilling is performed using the coiled tubing drilling method.