Japanese oil group Inpex has agreed to extend its joint venture agreement on two offshore oil fields in Abu Dhabi by an additional 24 years.

Inpex, through its subsidiary Japan Oil Development Company (Jodco), said it has agreed “in principle” to extend its joint operation of the Satah and Umm al-Dalkh oil fields until 31 December 2042. They are currently set to expire on March 2018.

The Japanese group will also increase its stake in the Umm al-Dalkh asset to a total participating interest of 40 per cent, up from a current stake of 12 per cent, while retaining a 40 per cent interest in the Satah field.

The remaining 60 per cent in both cases is held by state-owned Abu Dhabi National Oil Company (Adnoc). The Satah and Umm al-Dalkh fields are producing 20,000 barrels a day (b/d) and 15,000 b/d respectively.

“Both oil fields have abundant reserves and have stably produced oil for many years based on a strong partnership between Adnoc and Inpex. This stable production is expected to continue over the long term,” said Inpex in an announcement.

“Going forward, Inpex will continue to strive to strengthen its oil development activities in Abu Dhabi in which it has engaged for over 40 years, as well as help further deepen the strong relations between Abu Dhabi and Japan,” the company added.

In January 2014 Inpex extended its interest in the much larger Upper Zakum field by 15 years to expire on 31 December 2041. The company has a 12 per cent stake in Upper Zakum with US-based ExxonMobil holding 28 per cent and Adnoc the remaining 60 per cent.

All three fields form part of the Zakum Development Company (Zadco) – a joint venture of Adnoc, ExxonMobil and Jodco. Zadco is set to be merged with Abu Dhabi’s other major offshore oil producer Abu Dhabi Marine Operating Company (Adma-Opco).

Inpex also has a 12 per cent stake in Adma-Opco as well as a 5 per cent interest in Abu Dhabi’s largest onshore producer Abu Dhabi Company for Onshore Petroleum Operations (Adco), which it was awarded in 2015.