For a freshly loaded SERP page, your Xpath should return the destination URL for each SERP listing.  It appears as though it's extracting Google's tracking URL instead.
Whenever a SERP link is clicked, a JavaScript event rewrites the original @href value with an internal Google URL that tracks the click before redirecting you to the desired page.  The JS function also adds a new attribute called @data-href that contains the original URL.  You can visualize this by hovering over a link, then comparing the URL shown in the status bar before and after right-clicking the link.  Here's what happens to the <a> tag when that JavaScript fires:
Before click:

Same listing, After click:

Normally, the tracking URL begins with /url?....  I believe the /search?... instance you're getting may be the Related Searches at the bottom of the SERP?
Hopefully this is the right track.
-Tim