home > Our Business > Development of Oil Fields

Development of Oil Fields

ADOC is currently operating three oil fields in offshore Abu Dhabi area namely, Mubarraz, Umm Al-Anbar (AR) and Neewat Al-Ghalan (GA) Fields.

Exploration

The first seismic survey was carried out over the concession area in 1968. Mubarraz Field, which is composed of low relief domal structures with less than one degree dip in flank, was found as a result of careful interpretation works with paper outputs of seismic sections. The first exploratoty well (MR-1) was spudded in a prospective structure and Mubarraz Field was discovered in 1969.

A seismic survey was carried out in the West Mubarraz concession in 1979 and 1980 and oil in two domal structures in shallow water area was discovered in 1982 and 1983, they were named Umm Al-Anbar and Neewat Al-Ghalan Fields, respectively.

Geology of ADOC Oil Fields

There are two major reservoir horizons in offshore Abu Dhabi area, which are Lower Cretaceous Thamama Group and Upper Jurassic Arab Formation. Oil was discovered in several reservoirs in Thamama Group at a depth of 8,800 – 11,000 feet in the Mubarraz Field. Reservoir rocks of the field are limegrainstone with some dolomite.

AR and GA Fields produce oil from Arab Formation at a depth of 10,700 – 11,600 feet. Reservoir rocks are limegrainstone deposited in shoal or tidal channel and dolomite formed in arid tidal flat.

Anhydrite of Hith/Arab Formations is the main cap rock for Arab reservoirs. It becomes thinner toward the east and constrains hydrocarbon distribution in the region. That is , oil was trapped in Arab Formation in West Mubarraz area with thick anhydrite, whilst oil was trapped in over-lying Thamama Group in the Mubarraz Field where the anhydrite is thin or nil.

Schematic Geologic Section

Evaluation of Reservoir Rocks

Reservoir models that are utilized for maximizing field production are constructed summarizing well correlation, log interpretation, core analysis, structural maps and other geological studies. In addition to the conventional evaluation, ADOC is challenging to apply new evaluation with advanced technologies such as NMR ( Nuclear Magnetic Resonance ) measurement, X-ray CT scanning and fluid inclusion, etc.

Development and Production of Oil

Geological models and integrated numerical reservoir models are fully utilized to calculate Original Oil In Place (OOIP), to predict the future oil production behavior of the reservoir and to establish a development plan. These models are constructed utilizing all of the data obtained throughout the exploratory activities. Once a decision for the development of the reservoir is made, surface facilities are to be designed and constructed to meet the production requirements.

The Mubarraz, AR, and GA Fields all passed through these processes, and they began production in 1973, 1989, and 1995, respectively.

→ Maximizing The Oil Recovery