1. An integrated well optimization unit for performing an adaptive drilling operation at a wellsite, the unit comprising: a transceiver operatively connected to a controller at the wellsite for communication therewith; a base model unit for generating a base model from pre-drilling data; an overburden model unit for generating an overburden posterior model based on the base model and wellsite data received during overburden drilling; and a reservoir model unit for generating a reservoir posterior model based on the base model, the overburden posterior model and wellsite data received during reservoir drilling; wherein the base model, the overburden posterior model, and the reservoir posterior model are integrated for passing data therebetween and whereby a drilling operation may be adapted as the models are generated.