Decimal interest determination?

Drilling Permit issued by Tx RR Com states " acreage 2550". Our lease with the oil company for mineral rights is for part of one specific abstract to " include 630 acres more or less". The surface owner has numerous abstracts in their ranch & that is whose name is under "Lease" on the permit. When calculating decimal interest, the surface owner, who also owns half of mineral rights in our abstract, would be to advantage if oil company uses total acres 2550 instead of 630. I have contacted the oil company to verify total acres 630 before division order developed without response. Do I wait until division order received then dispute if based on 2550 acres?

Yes, I would wait until DO is received and confirm your decimal interest is correct. If it is not, raise the issue with the company and get an explanation.