Without naming the client, the South Korean yard revealed the order in a regulatory filing that stated it was for an Africa-based company.
The contract is running through April 2016, according to Reuters.
In the absence of further details on the deal, speculations are that the contract may have been struck in Nigeria or Angola, assuming the platforms are for production drilling.
Both countries have established producing fields and are looking to ramp up output.
Nigeria, in particular, is desperately trying to boost offshore oil production from known reserves to offset onshore setbacks due to militant activity that have hit its output. Its output is currently far below its 4 million barrel-per-day capacity.
Daewoo already has a joint venture for oil transportation with state-owned Nigeria National Petroleum Corporation, NNPC, formed five years ago.
Named Nigeria Daewoo Shipping, NIDAS, Daewoo holds a 49% stake in the joint venture with NNPC holding the remainder.