The field property_delivery_carrier_id can be found in the table ir_property, in which the field "field_id" relates to the table ir_model_fields where you can actually see the name property_delivery_carrier_id.

And also the fact that this field is there and not like the other fields is simply because it starts with "property_" and Odoo stores this field differently.

Here is a rather better accurate explanation about this backend feature:

https://www.odoo.com/forum/help-1/what-is-ir-property-used-for-48299#answer-48710

Hope it helps :)