Drill Cuttings Measurement Box and System for Controlling Pilot Hole Drilling

Abstract

A control system for a raise boring machine drilling a pilot hole and related methods are disclosed. The control system includes a cuttings box for receiving and weighing cuttings ejected from the pilot hole during drilling. The cuttings box is configured to retain an amount of cuttings indicative of advancing the pilot hole substantially the length of a drill rod. A controller in communication with the cuttings box is configured to receive a signal reflective of a weight of cuttings in the cuttings box. The controller is further configured to compare the received signal to an expected weight criteria associated with the drill rod length, and to in response to the signal satisfying the expected cutting weight criteria, have cuttings ejected from the cuttings box.

1 . A control system for drilling a pilot hole using a raise boring machine, the control system comprising:
 a cuttings box for receiving and weighing cuttings ejected from the pilot hole during drilling, the cuttings box configured to retain an amount of cuttings indicative of advancing the pilot hole substantially the length of a drill rod ;   a controller in communication with the cuttings box, the controller configured to receive a signal indicative of a weight of cuttings in the cuttings box, the controller further configured to:   compare the received signal to an expected weight criteria associated with the drill rod length; and   in response to the signal satisfying the expected cutting weight criteria, have cuttings ejected from the cuttings box.   
     
     
         2 . The system of  claim 1 , wherein the controller is further configured to:
 in response to determining the signal is below the expected cutting weight criteria, instruct a pump to increase a duration for pumping drilling fluid into the pilot hole to flush cuttings from the pilot hole.   
     
     
         3 . The system of  claim 1 , wherein the controller is further configured to:
 determine whether the signal satisfies a rate of rock drilled criterion of the expected cutting weight criteria; and  in response to determining the signal is greater than the rate of rock drilled criterion, instruct the pump to cease pumping drilling fluid into the pilot hole. 
     
     
         4 . The system of  claim 1 , wherein the controller is further configured to:
 determine a first rate of change in the signal during a first period of operation conducted with a first additive;   determine a second rate of change in the signal during a second period of operation conducted with a second additive; and   in response to determining that the second rate of change is greater than a first rate of change, conduct further drilling with at least the second additive.   
     
     
         5 . The system of  claim 1 , wherein the controller is further configured to generate an alert in response to the received signal representing a decreasing weight of cuttings indicative of cuttings box failure. 
     
     
         6 . The system of  claim 1 , wherein one or more sidewalls of the cuttings box permit fluid passage through one or more perforations. 
     
     
         7 . The system of  claim 1 , wherein the cuttings box includes a resealable outlet connected to the controller, and wherein the instructions to eject cuttings from the pilot hole control an actuator to open the resealable outlet to eject accumulated cuttings. 
     
     
         8 . The system of  claim 1 , wherein the cuttings box is configured to generate signals according to a duration associated with the expected drill rod length. 
     
     
         9 . The system of  claim 8 , wherein the duration associated with the expected drill rod length is based on previous durations associated with the expected drill rod length. 
     
     
         10 . The system of  claim 9 , wherein the controller is further configured to:
 reset the expected cutting weight criteria associated with the amount of cuttings reflective of a drill rod length in response to the transmitting the instructions to eject cuttings from the pilot hole.   
     
     
         11 . A method of drilling a pilot hole, the method comprising:
 initiating drilling with a drill rod;   pumping drilling fluid into the pilot hole to eject cuttings from the pilot hole;   pumping the ejected cuttings into a cuttings box;   generating a signal indicative of a weight of the cuttings in the cuttings box;   in response to determining that the signal satisfies expected cutting weight criteria, ejecting cuttings from the cuttings box, wherein the expected cutting weight criteria being based on an amount of cuttings indicative of advancing the pilot hole substantially the length of the drill rod; and   attaching a further drill rod and reinitiating drilling.   
     
     
         12 . The method of  claim 11 , comprising: in response to determining the signal is below the expected cutting weight criteria, pumping additional drilling fluid into the pilot hole to flush cuttings from the pilot hole prior to attaching the further drill rod and reinitiating drilling. 
     
     
         13 . The method of  claim 11 , comprising:
 determining whether the signal satisfies a rate of rock drilled criterion of the expected cutting weight criteria;   in response to determining the signal is greater than the rate of rock drilled criterion, ceasing pumping of the drilling fluid into the pilot hole.   
     
     
         14 . The method of  claim 11 , comprising:
 determining a first rate of change in the signal during a first period of drilling conducted with a first additive;   determining a second rate of change in the signal during a second period of drilling conducted with a second additive;   in response to determining that the second rate of change is greater than a first rate of change, conducting further drilling with at least the second additive.   
     
     
         15 . The method of  claim 11 , comprising:
 generating an alert in response to the received signal representing a decreasing weight of cuttings indicative of cuttings box failure.   
     
     
         16 . The method of  claim 11 , wherein the signal is generated based on a duration associated with the amount of cuttings indicative of advancing the pilot hole substantially the length of the drill rod. 
     
     
         17 . The method of  claim 11 , wherein the duration associated with the amount of cuttings indicative of advancing the pilot hole substantially the length of the drill rod is based on previous durations for previous drill rods. 
     
     
         18 . A non-transitory computer readable medium for drilling a pilot hole, the computer readable medium comprising instructions for:
 initiating drilling with a drill rod;   pumping drilling fluid into the pilot hole to eject cuttings from the pilot hole;   pumping the ejected cuttings into a cuttings box;   generating a signal indicative of a weight of the cuttings in the cuttings box;  in response to determining that the signal satisfies expected cutting weight criteria, ejecting cuttings from the cuttings box, wherein the expected cutting weight criteria being based on an amount of cuttings indicative of advancing the pilot hole substantially the length of the drill rod; and
 attaching a further drill rod and reinitiating drilling.