During early June 2016, Sonatrach made an oil and gas discovery in Algeria with its Oued Noumer Sud 1 (ONRS 1) new field wildcat. The discovery is located on the Zelfana exploration licence, about 200 km south of the capital, Algiers, in the northern part of the Oued Mya Basin.
The Oued Mya Basin lies in north-central Algeria and is one of the most important petroliferous basins in the country, after the Ghadames and Illizi basins. The stratigraphic section consists of about 5,000m of Palaeozoic and Mesozoic sediments. Exploration in this basin started in 1956 and it contains a number of important fields, including Berkaoui, Benkahla, Aitkheir and Oued Noumer. Oued Noumer Sud 1 lies to the south of the Oued Noumer oil field, which was discovered in 1969, about 30 km west of the town of Ghardaia. On stream since December 1985, Oued Noumer has a system recovering gas, a 50 km gas-gathering pipeline and a three-train compression plant with processing lines for dehydration and gas-oil separation.
ONRS 1 was spudded on 13 March 2016 and drilled using the ENAFOR #51 rig. It reached a TD of 2,950m in the Ordovician micro-conglomerate on 1 May 2016. A cased-hole DST of the Triassic T2A interval between 2,743–2,760m was carried out by Schlumberger. The well flowed at a maximum rate of 3,722 bopd and 4.6 MMcfgpd, on a 32/64” choke and at a WHP of 2,180 psi. Production tubing has now been set at 2,715m.
Sonatrach was awarded Zelfana in September 2015 and operates the licence with 100% equity.