Common law marriages are only recognized in a few states. I do not know if OK is one of them. Even in the states that do recognize them, there can be a number of technicalities to overcome. However, even with a "valid" common law marriage you still will have to prove, to Social Securities' satisfaction that it is a valid marriage. The only thing you can do is go to your local SSA office and inquire. .
There is information on what kind of evidence of common-law marriage Social Security wants here: http://www.socialsecurity.gov/OP_Home/handbook/handbook.17/handbook-1717.html
It may depend on where you and your common law spouse lived during the time of your "marriage" because Social Security accepts state law as controlling in the issue of whether someone is married or not. Generally (not always) you would've had to have met the requirements for common law marriage in that state while you were living there.
Even if you can provide valid proof of a common law marriage, you probably would have to meet the requirements to receive retirement benefits as a divorced spouse. See this link for information. http://www.ssa.gov/pubs/10035.html#divorce
You may wish to find an attorney in your area who can assist you in investigating whether or not you were in a valid common law marriage and if so obtaining the evidence you need and resolving the other issues (valid divorce? etc.) your question raises.
The response provides information only and does not create or establish an attorney-client relationship. It is also general advice or information based on the information provided by the question, therefore if additional or different information were provided, the information or response might be different or change. The attorney is licensed to practice only in Oregon.