The Shulchun Orech in OH 671 says that if you put a few wicks in a bowl, if you don't cover it that every wick has it's own opening, it's like a bonfire and not a flame, abd you're not Yoitzeh.

The famous question is why not, when you light the first one you lit a flame.Afterwards, when you light the second, thus creating the bonfire, is no worse than the light being put out, which you need not to bother with.

Rabbi A.M. Horowitz (in th back of the Gemaras) answers that we're refering to a case that he lights the 2 wicks at the same time. This is a problem, since The Ran in Beitzeh says it's impossible to light 2 wicks at exactly the same time.

I would like to answer with what the Briska RAv compares the lighting the Menorah in one lighting to doing a Bris on Shabbos. That even if what's left does not make the Milah invalid, as long as you hadn't removed your hand from lighting, it's all one action and it's part of you original action of Milah that pushes off Shabbos. So to lighting the wicks one after the other without stopping is considered one action of lighting, see his peice . If that is true, he didn't finish the action of lighting until after he finish lighting ALL the wicks, thus, at that time, it's all ready a bonfire.

Another possible answer, is that since the Mitzvah is the lighting, this which you need a measurement of oil, is that to make my lighting, a lighting that is of that measurement, not that it actually needs to go that long. This is why if it goes out in the middle you need not to relight it, since the lighting was Kosher.

In BK there is a concept of your fire is like your arrow. That everything that burns afterwards is considered as you shot it and is your action. The Nimukai yosef explains, that it's all considered as you shot it at the time that you lit it, just like the arrow, that even though it's your action what it does afterwards, but it's all considered part of your action of shooting it. Thus by Chanuka, that what it burns afterwards is all considered part of your original lighting, this is why it's considered the lighting to be lighting of a half-hour. If it goes out before, since you did a kosher lighting, we consider this as a condensed lighting, and you need not to relight. But if the light is not put out, but rather ruined in making it a bon fire, since ther is still residue of the 1st fire, which is considered as part of the 1st lighting, and it's now Pusel, this makes the original lighting from which this comes from passul, and that's why you are not Yoitzeh and need to light again.