Under tournament rules, officials out in the middle can refer any decision to the third umpire, not just stumpings and run outs.
Of the 24 referrals during the first six matches, eight were for lbws and three for catches, with three of the lbws adjudged to be out and none of the catches.
It has taken on average one minute for the third umpires to give a decision after studying TV replays and there have been no significant hold-ups to games as a result.
"Any definitive conclusions on this trial will obviously have to wait until the end of the tournament, but these early figures give an interesting insight into progress so far," said David Richardson, the ICC's General Manager-Cricket.
If the experiment is judged a success and is supported by the various member countries of the ICC, the system could be introduced for all one-day games and Tests.
Cashing in
The Sri Lankan economy, meanwhile, is expcted to benefit to the tune of $25m from hosting the tournament.
Hundreds of players, officials, journalists, broadcasters and fans are on the island and Sri Lanka believes that TV exposure will also boost its appeal as a holiday destination.
"Every telecast of every game in this tournament has a potential viewing audience of 800 million people in countries including India, Australia, England and South Africa," said ICC chief executive Malcolm Speed.
"With the event proceeding smoothly, we are now on target for Sri Lanka to deliver the most successful ICC championship in the event's history."