The companies have tapped bond markets rather than banks in part because of the longer tenors available in the bond market which match the long investment horizons of these projects. Another reason is that a number of these resources companies are able to access financial markets at a cheaper price than the banks themselves can.
There are plenty of options, the Fed will get the job done, so the elimination of Treasury debt would not undermine the effectiveness of monetary policy. Before proceeding, I note that the views I am presenting today are my own. I am not speaking for the Board of Governors or the FOMC.