Rein studied Mechanical Engineering at Polytechnic College in Leeuwarden (HTS), after which he joined Shell to work as international drilling staff member.
In 1989 Rein emigrated with his young family to the UK to work as a Drilling Engineer and Drilling Supervisor for Shell UK Exploration and Production from Lowestoft. After six years of service he was moved to the Sultanate of Brunei, where he worked on a wide variety of oil- and gas wells, both onshore and offshore, ranging from new-drilled wells, to repairs and workovers, abandonments and interventions. He worked as Drilling Engineer, HSE focal point and Drilling Supervisor, was closely involved in the set-up of Emergency Command and Control for drilling operations and with the so-called “Technical Limit” approach. He coached several local staff through their Round I and II self-study packages.
Rein returned to the Netherlands in 2000 and quit Shell in 2001 to set-up a drilling consultancy business, eventually named Roaring Forties B.V. Besides some minor projects he worked for Clyde Petroleum, Nederlandse Aardolie Maatschappij, Wintershall Noordzee, Vermilion Oil and Gas Netherlands, Vermilion REP SAS (France) and Oranje-Nassau Energy B.V.
In 2017 Roaring Forties B.V. merged with Spidron B.V. to form Spidron Weco B.V.