Steps to take from a paper to a patent?
What you can and cannot claim in a patent is a highly debated area. You should really consult a legal expert.

If you're affiliated with a college or university, they probably have an office that handles these sorts of things. They'll guide you through the patent process and help cover some/all of the fees. You might not have any choice of working with them. Depending upon your contract, the school might own part of your work and have the legal option to attempt to monetize it first.

If you're not with an organization or you know that you're free from any legal obligations, you should get in touch with a patent lawyer. They can help you draft the patent, help look for prior work, and advise you on the intricacies of international IP. 

You can try to patent it on your own, but I really advise against it. A lawyer will help you understand what parts of your work you can patent. They will also help to draft the patent in as broad a way as possible to allow you to claim as much as you can.