Once you install the Jdeveloper 11g, you cannot Create or Open SOA projects in it. In order to use Jdeveloper 11g for SOA project development, you need to install SOA Extensions in Jdeveloper 11g.
I installed Jdeveloper 18.104.22.168.0 version and followed below steps to install the SOA extensions –
1) Open your Jdeveloper 11g and Click on Help menu and select “Check for Updates” as shown below
2) A wizard “Check for Updates” is displayed as shown below and click “Next”
3) Under ‘Search Update Centers‘, select “Oracle Fusion Middleware Products” and “Official Oracle Extensions and Updates” options as shown below & Click Next
4) You will view all the available Extensions and Updates in the wizard as shown below
5) Search for SOA from the available list as shown below
6) Select the “Oracle SOA Composite Editor 22.214.171.124.0.25.57” and click Next. Now the extension will get downloaded and installed in to your Jdeveloper 11g. You can see the progress bar as shown below
7) Once the extension is installed click “Finish“.
Now you will be able to Create or Open the SOA projects in the Jdeveloper 11g.