Pl see these MOS Docs
Integrating Oracle E-Business Suite 12.1.3 with BPEL in SOA Suite 11g [Document 1070257.1]
Oracle E-Business Suite Integrated SOA Gateway Release Notes for Release 12.1.3 [Document 1096553.1]
Please see these docs.
Integrating Oracle E-Business Suite Release 12 with Oracle BPEL available in Oracle SOA Suite 11g [ID 1321776.1]
Troubleshooting and Known Issues for EBS SOA Suite Deployment in R12.1.1 [ID 797596.1]