SQL Substring Variable Text Within URL String

I'm trying to parse information from a column of URLS in sql server 2012

The basic structure is

http://ift.tt/1ecof9b ftp&catgory=brnd

where I need to grab the parameters from the kwd= value. In the above example, it would be the 'jdc ftp', but this would might be different for all the urls in my column. I've tried charindex and len, but I can't seem to put the syntax together correctly.