43 CFR § 3162.2-8
Does my responsibility for drainage protection end when I assign or transfer my lease interest?
June 11, 2020
If you assign your record title interest in a lease or transfer your operating rights, you are not liable for drainage that occurs after the date we approve the assignment or transfer. However, you remain responsible for the payment of compensatory royalties for any drainage that occurred when you held the lease interest.
[66 FR 1893, Jan. 10, 2001]