Adventure games weren't the only kind of games Sierra made during the 80s and 90s. They also made games like Oil's Well, a game similar to pacman except that you control a pipe from an oil rig trying to collect points as you went deeper and deeper underground. You had to watch out for bugs damaging the pipe though!
Apparently, there was a 1983 version of the game and that's where the cover comes from for the video. I on the other hand actually played the 1990 version and this is the theme you hear in this music video.
Many thanks to the website Sierra Chest for resurrecting these classics!