Sadly you cannot use the days left on an older Visa to come back to Russia. Once a new Visa is issued, all other visa's are automatically cancelled. If someone can send you an official invitation you can stay for another three month period. If you are then in Russia you can apply for a Permit which is valid for 3 years. Papers needed are numerous for the permit and includes a police clearance with an Apostille. You will go through a myriad of medical tests that will take the best part of three weeks and travel all over the city you plan to stay, as the clinics are widely spread. Bring all your academic diplomas and certificates and proof of employment. Have all of it Apostilled If you are divorced you need to bring your divorce paper translated to English with an Apostille. All your papers will have to be translated in Russia before you can start your application. An arduous and complex process. Once you have passed this barrier, you can apply for Residency after the first year, with another round of medical test but now it gets tricky. You need to pass a Certificate of competence for Russian which is quite difficult if you don't already speak Russian. Your three years will be spent working really hard to pick up a proficiency in Russian which will assist in obtaining the Proficiency Certificate......and I am sure I have left out some detail. The process is not easy, costly and fraught with misunderstanding and spending endless hours in bureaucratic offices. In all not easy. But good luck with your endeavor. Your will to succeed will be the only factor that will help you through this process.
I am really sorry I do not have better news, but we have the Americans to thank for the process getting more and more arduous. President Putin - a man I really admire as the best world leader - is taking a tough stance against Americanism and unwanted elements and are cracking down on the quality of person allowed into Russia. And please do not see this as an attack on you personally. It is just a observation that is about the real world issues.....
But the good news....once past the worst you will find Russia to be the most open and tolerant country in the world. In the five years I have been in Omsk, I have I have not been robbed once, heard of one murder in the news and have found the Russians to be be the kindest and most warm nation on earth. Once a friend of a Russian always a friend.
