From my experience on the SOA Architect tool, there is not direct way to port models to OBPM using 'Share Blueprint' option.
XPDL export of BPMN 2.0 models is not applicable as Oracle Tutor does not support it yet.
XPDL export of BPMN 1.x models is not available with the SOA Architect tool.
Exporting models as xml and porting them to other intermediate tools is necessary to port the models to OBPM 11g.
This is the situation atleast until SoftwareAG comes up with a 'share blueprint' option currently slated to release by end of 2012.
Kindly confirm/correct me if I missed anything.
Thanks in advance,