When does the work of a production engineer begin?

In the field of petroleum engineering, the work of a production engineer begins upon the completion of the well.1

At this stage, the production engineer is responsible for directing the selection of producing intervals and making the necessary arrangements for various accessories, controls, and equipment required to bring the well into operation. Following this initial phase, their role expands to include controlling and measuring produced fluids, designing and installing gathering and storage systems, and managing the delivery of raw products to pipeline companies.1