Bill,
Sorry for the confusion, what I meant is that as a Working Interest owner, you are responsible for P&A expenses. So, if you requested abandonment of the well(s) and it was accepted by all parties, you might be responsible for this additional expense. As was mentioned, the JOA should outline all of the details in your specific circumstance. Of course, if you sold the interest then you would be transferring that liability to the buyer.
Thanks,
Matt