In recent times I was working on a project where we migrate the database from Microsoft SQL server to Oracle (With SDL Tridion 2013 SP1). Once trying to installing Content Delivery Server Roles as .NET Web application (HTTPUpload) with Oracle Database I have faced 1 issue which is unusual. So I have planned to consolidate the steps followed to fix the issue -

Issue Detail:

Unable to load DLL 'xmogrt': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

Resolution:

I am assuming that you have followed the documentation at the time of installation, and in case you are facing the above mentioned issue after the installation, then follow the below steps –

1.  First check if Microsoft visual c++ 2010 redistributable is installed or not.If not then install it according to the .Net web application version(x86/x64) you have installed.
   
   
2. Once the installation is done then copy that xmogrt dll from the installed folder and put it into the below location –

[Reason: xmogrt.dll is not a .NET assembly and in case of windows dll,if same module name is already loaded in memory then system uses the loaded DLL otherwise the system searches the dll in system directory locations.]

• windows\System32\(If you are installing 32bit)
• windows\SysWOW64\(If you are installing 64bit)

This will definitely resolve your issue. Restart the Web application and try.