I believe that you can just install the package libreoffice-writer, but
will probably have to do it from the commandline or from Synaptic. I don't
think that Software centre can do it. It will want to install dependencies,
but you should not get calc and draw etc.

sudo apt-get install libreoffice-writer

If you have the whole suite installed you can de-install the parts you do
not want or remove the whole thing and re-install just writer. If you ask
to remove a part Synaptic will say remove libreoffice, but it means the
suite and not all parts. By removing a part of the suite you no longer have
the suite, but just parts of it.

You could also consider Caligra Words. Again it is part of a suite, so just
install the one package. Abiword is okay, but not great. It has the benefit
of being lighter weight.

Word Perfect will not work in Wine or Play on Linux. My wife needs it for
work and I have tried. Older version would but since about 12 it hasn't
worked. It is little used and there seems to be no incentive to get it to
work in Wine. I don't like it and I have used it extensively.