"small conversation" is correct and usable in written English.
You can use it to refer to a conversation that is informal, short, or otherwise unimportant. For example, you could say "We had a small conversation about the weather before the meeting began."
It started out with a small conversation about what art is and analyzing a quote by Robert Rauschenberg.
In some small conversation someone suggested we get through the holiday by going to a restaurant buffet.
"About three weeks ago we had a small conversation," he related on the night of the trade.
Alcohol enables big talk, but tea is for small conversation, and that's the good bit that makes us know each other.
Perhaps he did in fact, but Mr Rose said modestly in a small conversation before his talk that he never feared for his personal safety, even at the height of the crisis.
It was this small conversation, Watson would later say, that first kindled "a canal flame in my mind".
Probably, at first, we thought it was a small-scale conversation with friends which people might overhear, but not listen to.
Their daily experiences and small conversations are the most effective elements of the film.
In order to get all the key players into the decision to invade Iraq, Stone and Weiser have had to combine many meetings, many memos and small conversations.
PLAYLIST Beneath the murmur of a thousand small conversations, an iPod cranks out an all-star indie playlist at the bar.
Last night, anarchism left the graffitied walls, small conversations, and online forums of Egypt, and came to life in Cairo, declaring itself a new force in the ongoing social revolution sparked two years ago with multiple firebombings against Muslim Brotherhood offices.
