DEA’s CEO Maria Moraeus Hanssen (pictured above) said Mexico is a growth market for DEA's gas and oil business. "Following the combination of the new Sierra portfolio and the existing DEA assets, we will have a very active year ahead in terms of operations. The acquisition of Sierra is a fantastic opportunity for us to become a very serious player with a significant portfolio in the country. We are building a leading private upstream company in Mexico.”

DEA will now incorporate Sierra into its own Mexican assets to form a single unit, it said. DEA's country head Juan Manuel Delgado said the new unit would be "very well equipped to deliver results in all parts of our enlarged operations, and that will serve as the foundation for further growth.”

Via Sierra, DEA holds now a 40% non-operated working interest in Block 7, containing a significant part of Zama, one of the largest shallow water oil discoveries of the past 20 years globally. As a whole, Zama is estimated to hold 400mn - 800mn barrels of recoverable oil equivalent and expected to start production by 2022/23.

DEA also adds non-operated interests in five highly prospective exploration blocks to its portfolio. Sierra’s exploration blocks cover some 9,400 km² in the core part of Mexico’s Sureste basin. DEA also operates the onshore Ogarrio oil field, in partnership with state Pemex, and holds interests in four exploration blocks in the Tampico Misantla and Sureste Basins, three of which it operates.

DEA itself is to become part of Wintershall some time before the end of Q2 2019, if all goes to plan.