You need to install silk in your machine. Then u have to declare the windows using "Record Window Declaration", then u have to record some scripts/testcases for single actions.
Its a long process. Hope this helps for now.
I haven't worked on Oracle Financials/Projects for a while now, but the answer used to be no or that if you could, it was a PITA to set up/run, (that was back in the ST v5-v6 days), all my contacts in the OF world are using Win/LoadRunner.
IIRC, Oracle Forms had custom APIs to manage forms handling with all sorts of internal hooks to do this, that and the other, so I wouldn't be at all surprised if Oracle Forms support still isn't available in ST v7.n.
If this is the case, then TBH, this is one of the very very few times that I'd definitely recommend *NOT* using Silktest. You're better off using Win/LoadRunner. As I recall, automating OF apps using these two was a breeze.