Oa, a developing fast bowler, will join the Scorchers as the Club's Association Rookie from 28 December to 8 January and is one of eight such players heading to Australia this summer.
The ICC Rookie Placement Program is a two-week opportunity aimed at providing players from developing cricket nations with an opportunity to experience the high performance environments of elite nations.
The intent is for those players to return to their national teams and impart their learnings to assist in the growth of the sport.
Oa, who last season spent time immersed in the Adelaide Strikers setup, said the ICC Rookie Placement Program had proven invaluable for developing nations.
"The best thing about the program is being selected to play and train with experienced female cricketers, who have participated in ICC World Cup and other International ICC matches and being part of the Perth Scorches Team," Oa said.
"The ICC have created that opportunity to play at that state level, which I am privileged to be selected and being part of team.
"I am looking forward to (joining) the Perth Scorches team and gaining that experience in the Women's Big Bash League, which will be a boost in my cricket career."
The joint initiative between Cricket Australia (CA) and the International Cricket Council (ICC) enters its third consecutive season and will have cricketers from Scotland, Bangladesh, Ireland, Papua New Guinea and the Netherlands head to Australia to join to each of the WBBL Clubs.
Head of Big Bash Kim McConnie said she was delighted to be able to work with the ICC on such a beneficial project.
"The WBBL has gone from strength to strength and it's pleasing to again have the ICC's support in making this initiative possible," McConnie said.
"Women's cricket across the globe is continuing to advance and we're proud to support this initiative to not only grow these member countries' players, but also continue to develop the WBBL and some of the best players around the world.
"Last year we saw Ireland's Kim Garth become the first rookie to represent their club and she ended up being part of the Sydney Sixers championship winning side, so we are excited to see what this year's crop has to offer."