Oil services giant Schlumberger has signed a memorandum of understanding (MoU) to study several onshore oil fields in Iran, according to reports.

Schlumberger signed a preliminary deal with National Iranian South Oil Company (NISOC) – a subsidiary of state oil producer National Iranian Oil Company (NIOC) – for feasibility studies at the Shadegan, Parsi and Rag-e-Safid fields in Khuzestan province, Oil Ministry news service Shana reported.

Schlumberger, which has several international headquarters including Houston, Texas, is incorporated on the island Curacao in the Caribbean Sea. The MoU could give the group its first presence in Iran since it left in 2010 as new sanctions were introduced.

NISOC Managing Director Bijan Alipour told Shana that the MoU for a non-disclosure agreement would be in force in six months.

The deal is one of the most high-profile international agreements signed in Iran’s oil and gas sector since the lifting of nuclear-related sanctions were lifted in January 2016.

Earlier in November, France’s Total and China National Petroleum Corporation (CNPC) signed a heads of agreement (HoA) with NIOC to develop phase 11 of the South Pars offshore gas field.

However, the sanctions relief provided by the US government in January is now under threat following the election of Donald Trump, who is due to be appointed US president in January.