An Energy Drill is a large machine capable of drilling through thick walls, even with security fields in place. The only limit on what an energy drill can penetrate is how much power it is supplied with. If the drill is supplied with more power than the security field on a wall then the drill can penetrate the wall.
Megabyte used an energy drill to penetrate the security field surrounding the Mainframe Archives. The drill was set up in the Utility Tunnels just below the Principal Office where it could drill through the floor of the Archives. The only problem was that the Archives are protected by a security field second only the Mainframe Core. Megabyte had to have a power source for the drill just as powerful as the cities core.
To generate that kind of power, Megabyte used a Leech Command to suck power from Game Cubes to power the drill. Game Cubes contain their own energy, more powerful than anything on the Net. The only drawback was that as the Games lost power they began to slow down and eventually crash. The first Cube to be drained allowed the drill to almost penetrate the security barrier around the Archives. The second drained even more power and the energy drill penetrated the Archives, allowing viral spies to access the Archives and steal the control circuitry for the Gateway Command. (When Games Collide)