All operations including, but not limited to, the commencement, drilling or operation of a well upon a drilling unit for which a pooling order has been entered, shall be deemed for all purposes the conduct of such operations upon each separately owned tract in the drilling unit by the several owners thereof. That portion of the production allocated to a separately owned tract included in a drilling unit shall, when produced, be deemed for all purposes to have been actually produced from such tract by a well drilled thereon.