Abu Dhabi - Zakum Development Co.

Upper Zakum, a super-giant found in 1964 by ADMA, is 30 km long and 25 km wide located south-east of Umm Shaif. Its producing JV was until last June owned 88% by ADNOC and 12% by the Japan Oil Development Co. (JODCO). It is one of the most complex fields in the oil industry, because of high rock porosity and low pressure. This is why BP and Total in ADMA refused to invest in the field, not even after world oil prices quadrupled in 1974, despite the fact that it had up to 50 bn barrels of oil in place.

In June 2004, months after approval by the SPC, ADNOC designated ExxonMobil as the 28% strategic partner in Upper Zakum with the prime task of the further developing the field from 550,000 b/d to 750,000 b/d by 2008 or 2009. ADNOC gave the 28% out of its own 88% share. The deal with ExxonMobil was closed in March 2006.

The Upper Zakum crude is 35[degrees] API with 1.8% sulphur. Because of heavy spending on it, this field is a priority for ADNOC and its production at capacity is allowed at the expense of the other operators (see background in Vol. 60, No. 2).

Upper Zakum produces gas. This has been supplied since May 1984 to ADNOC's GG-II gas gathering plant, where condensate is extracted and sent to Upper Zakum's Central Supercomplex for a further stabilisation of the field's oil production. In late 1985, the Zakum Central Gas Treatment Plant (CTP) came on stream to supply lean gas to ADMA-OPCO's production complexes at Lower Zakum. The second phase was launched in October 1989. John Brown Offshore of the UK was awarded the main contract for this in February 1992. Work involved the drilling of 100 additional wells, five new platforms, gas lift facilities, a new power plant and new storage tanks. For the gas lift, non-associated gas was to be supplied from the Khuff reservoir at the nearby Abu al-Bukhoosh field (operated by Total). The field's capacity was raised to 400,000 b/d in January 1994. After further expansion, this rose to 470,000 b/d in the fourth quarter of 1994, to 500,000 b/d in mid-1995 and to 540,000 b/d by end-1998. It capacity is 550,000 b/d.

In 1994, ZADCO launched a project to install gas compression and dehydration facilities on the nearby Zirku Island. This recovers associated gas which used to be flared at Upper Zakum. A 40-km, 10-inch marine pipeline supplies the gas to the LNG complex on Das Island. The field's installations and processing plants also serve the other offshore fields which have been taken up by Japanese companies.

The capacity of ZADCO's crude oil processing facilities on Zirku island are to be expanded from 600,000 b/d to 750,000 b/d by 2008/09. This will be done through a debottlenecking of the three existing trains and a standby unit.

JODCO's involvement in ADMA in the 1970s and in Upper Zakum (ZADCO) in the 1980s led to other E&P partnerships with ADNOC. Thus two new ventures were established, one for Umm Al Dalkh field and another for Satah field, both offshore operated by ZADCO. On Jan. 1, 1994, ZADCO became the operator of the Arzanah offshore field, which was discovered in 1973 and relinquished by Amerada Hess of the US after 20 years of operation. Located in the north-east of Abu Dhabi's waters, the field's capacity is 20,000 b/d, of 44[degrees] API oil with 0.8% sulphur.

ZADCO has three wellhead platforms and a central production manifold platform in the field, and a 55 km pipeline carrying the oil to a processing plant on Arzanah island. Arzanah can produce up to 76 MCF/d of gas.

Zadco was in December 2006 reported to be is seeking an international consultant to provide programme management consultancy (PMC) services on its major offshore upstream oil development schemes. Invited companies had been given until Dec. 17 to respond to an initial inquiry for the contract. The tender is the first of its kind to be issued in the emirate's hydrocarbons sector and is part of Zadco's efforts to lock in programme managers for a five-year period. Called Upper Zakum major projects, a total capital expenditure of $1,500m is planned for the proposed projects, which are: Offshore produced water facilities - the installation of water separation and disposal facilities at the existing satellite production platforms to handle increased water cuts and reduce water separation; Upper Zakum gas treatment plant (GTP) expansion - the installation of two compressors and the debottlenecking of the GTP; new main oil line (MOL) - a tender is due to be issued in 2007 for the estimated $100m contract covering the fabrication and installation of a 60-km, 42-inch MOL to be installed from the Zakum central complex to Zirku island; west area development programme - the installation of gas injection pipelines, platforms and topsides to increase production from the western area; east area development programme - the installation of two new wellhead platforms and four pipelines to increase output from the east of the field; facilities build-up - installation of 20 new wellhead platforms, 21 pipelines with a total length of 115 km, four new gas injection topsides and eight gas lift units aimed at increasing production capacity to 750,000 b/d from 500,000 b/d; and downstream facilities build-up - water separation/treatment, a GTP and oil pumping stations.

The successful PMC will be responsible for managing pre-feasibility studies and FEED packages, as well as overseeing engineering, procurement and construction (EPC) and engineering, procurement and construction management (EPCM) contracts.