No reserves because they haven't drilled yet. The Gutavson report on the Mongolia assets is at http://www.manaspetroleum.com/i/pdf/20101110%2051-101%20Manas%20Mongolia1109.pdf
They say 341 million barrels of prospective oil resources. This info comes from before the latest seismic so it may be outdated.
The latest on the project is located at http://www.manaspetroleum.com/s/Mongolia.asp
They said the drilling will begin by July 15, but no word on the rig.