Most people here will say that you shall not just copy-paste parts from your viva in the paper. However, I copy-paste large parts from my PhD with no shame. I am aware that this is self-plagiarism, however, I cannot find a way to describe my methodology or write a general introductory paragraph without self-plagiarising!
Generally, the paper needs to be a shorter and denser version of the PhD. Yes, you can use your results, but because the paper is shorter it has to be focused on one specific finding.