43 CFR 3106.7-2 - If I transfer my lease, what is my continuing obligation?
(a) You are responsible for performing all obligations under the lease until the date BLM approves an assignment of your record title interest or transfer of your operating rights.
(b) After BLM approves the assignment or transfer, you will continue to be responsible for lease obligations that accrued before the approval date, whether or not they were identified at the time of the assignment or transfer. This includes paying compensatory royalties for drainage. It also includes responsibility for plugging wells and abandoning facilities you drilled, installed, or used before the effective date of the assignment or transfer.