no official "Portable" version of Microsoft Word 2013 released by Microsoft. Standard versions of Office 2013 are designed for a one-time installation on a single PC.
If you have a Microsoft account (Outlook, Hotmail), you can use Word Online for free. It runs in a browser, requires no installation, and your documents are saved to the cloud (OneDrive). It is compatible with .docx files. microsoft word 2013 portable
Word remembers where you left off in a document, even if you close and reopen it. In a portable setup, this data saves to the USB drive, not the host PC. no official "Portable" version of Microsoft Word 2013