Petrogas E&P LLC has a 50% working interest in the Block-5 Contract Area held by their wholly owned subsidiary Mazoon Petrogas SAOC. Mazoon Petrogas SAOC has a 50% ownership of the Daleel Petroleum Co. LLC, a joint venture with the China National Petroleum Corporation. Daleel Petroleum Co. LLC is the operator in Block 5 and has managed operations since Year 2002. 

Block-5 covers an area of 992 km2 and contains four producing fields. The four fields are the Daleel (Shuaiba) field, the Shadi field, the Mazoon field and the Bushra field. Of the four producing fields, The Daleel (Shuaiba) field is by far the most prolific field with more than 50 million barrels produced to date. It consists of several fault blocks N-S oriented, each with different hydrocarbon distribution and pressure regime.

The Daleel (Shuaiba) field was brought into production in 1990 and a total of 115 appraisal and development wells have been drilled of which some 70 are currently producing and 8 injecting water. The Shadi field was brought on stream in 2001 and produces from 2 wells. The Mazoon field came on stream in 2002 and is producing from 8 wells. The Bushra field started production in 2003 from 1 well but it was shut down in 2004 when production became uneconomical. It was recently put back to production along with several recent oil bearing discoveries in the Bushra cluster area.

While most wells in Block-5 are free flowing, artificial lift is increasingly required in the Daleel (Shuaiba) field to produce depleted wells and wells that see increasing water production as a result of water flooding. The major enhancement to production in the Daleel (Shuaiba) field is through water flooding that has shown the ability to improve the sweep and recovery rate from the reservoirs. The water flood project began as a pilot project in 2002 and, given its success, water flood is now being implemented on a phased basis to all producing blocks.

The Block-5 facilities have been upgraded to handle 25,000 barrels a day of produced fluid and 60,000 barrels of water injection. Further facilities expansion will be required as the total produced fluids and oil production increase through the full implementation of the water flood project to 35,000 bopd and 90,000 bwd. At the B block and at Daleel main station, oil production is separated and stabilized and exported via an 8 inch spur line to the PDO-Lekhwair-Fahud pipeline and then onto the oil export terminal at Mina Al Fahal. Production from Mazoon, Shadi and Bushra are transported by tanker to the Daleel facilities for export.

Production from the Contract Area achieved a temporary plateau, under depletion, in 1995 at around 10,000 barrels a day and this rate declined to around 4,500 barrels of oil per day by 2002. However, with the increased development drilling and water injection, production has now (end of Q1 2008) reached approximately 18,000 barrels a day and is planned to increase to 30,000 bopd when water flood is fully implemented. At end 2007 the total cumulative production from Block-5 was 59 million barrels.


Light 30-39°API oil is produced in the Daleel, Mezoon and Bushra cluster fields from Cretaceous Upper Shuaiba and Natih A-D reservoirs. The Upper Shuaiba Daleel accumulation is stratigraphically trapped on the flank of the Lekhwair High. The Natih reservoirs occur both in truncation traps on the eastern flank of Daleel and as fault-dip closures in the Bushra cluster fields. Both the Upper Shuaiba and Natih reservoirs have tilted oil-water contacts due to Plio-Pleistocene regional deformation. Oils are typed to North Oman Huqf and Natih source rocks. Ongoing exploration activities are focussed on Natih and Shuaiba prospects to the east and west of Daleel.