Yes but with limitations.
We often we get this question. The answer is yes, but...
The two modules can be integrated, but are not built with that in mind. As a result, the integration has limitations, and is not recommended as an enterprise solution, even though each module separately is.
How to:
If O-DL uses the portal option of storing files, the files will be stored under the dnnroot/Portals/0/your_root folder.
You can point O-SE to that folder through the administration module, by using the directory indexing method.
All contentent of that directory and sub-directories (which is your O-DL root folder) will be indexed.
Limitations:
The limitations of the integration are the following:
1. O-DL cannot use the "Secure Files" option.
2. The O-SE spider needs to point to the root directory through the "Directory Indexing" section.
3. O-SE will index all contents in the root as well as all subdirectories, but it will not respect the access rights assigned through O-DL (this is the single most important restriction). This means that a user may not have access to a document through the O-DL interface, but it will see it in the search results.
Note: O-DL integrates with the default DNN search engine. The access restrictions are the same as above, and the other difference is that O-SE will index content, while the DNN search only indexes metadata.