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Page added on May 29, 2012

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The trouble with Persian Gulf islands

Geology

States on the Arabian shore of the Persian Gulf have long regarded their offshore islands as special places.

There are several reasons for this, all linked to the islands’ shared geology and the resulting regional distribution of sweet water and oil resources.

Until the last century, the reservoirs of fossil water, not too far below ground, were easily the more important. Their existence accounted for the early human settlement of islands such as Dalma off the UAE emirate of Abu Dhabi, Failakan offshore Kuwait and Bahrain, a sovereign Arab state nestled between Saudi Arabia and Qatar. All have been inhabited, initially by groups oroginating from the Persian mainland, for the past 7,000 to 8,000 years.

This is confirmed by extensive archeological evidence from excavations of burial complexes and temples suggestive of entrenched, sophisticated societies with the wealth and leisure to pursue decorative arts. Evidence of imported materials, including precious stones, suggests these were predominantly mercantile trading societies. However, the people in these island settlements also relied on plentiful local supplies of commodities including palm products, marine materials such as shells and pearls, and bitumen from natural tar seeps, used to waterproof boats and baskets.

Bahrain, in particular, was known for bountiful springs of both water and bitumen, the former making the island famous for its now much diminished palm groves. The latter resulted in the first commercial oil discovery on the Arabian side of the Gulf, in the center of the island. The Bahrain or Awali oil field, with about 125 million barrels or proven oil reserves, still produces roughly 40,000 b/d of crude and is the subject of a major enhanced oil recovery project aimed at restoring lost output that peaked decades ago at 75,000 b/d. Some analysts put the mature field’s remaining technically recoverable oil at more than 1 billion barrels.

Dalma and Failakan are similar in geological structure to Bahrain and also have served as reliable indicators of the presence of large Persian Gulf oil fields, in these cases located offshore. Even little Abu Musa, its ownership hotly contested between the UAE and Iran, sits near the UAE’s recently exhausted Mubarak oil field which, in its heyday, was among the OPEC oil exporter’s biggest producing fields outside Abu Dhabi.

Bahrain’s oilfield is also notable for being on trend with at least one major offshore field now in Saudi territory.

Under its 1958 maritime border treaty with Saudi Arabia, Bahrain is entitled in perpetuity to half the oil revenue resulting from Saudi output from the Abu Safa field, which was recently raised to 300,000 b/d. In 2011, that revenue accounted for about 85% of Bahrain government revenue, the International Monetary Fund recently estimated, making the tiny island state’s economy one of the most oil dependent in the Middle East.

The reason for island links to water and oil resources is that their geological foundations are massive, impermeable salt domes protruding above the Persian Gulf’s shallow waters, serving to trap sweet water from infrequent rains near the ground surface and sometimes oil below.

These salt upwellings were due to volcanic activity in the ancient Tethys Sea, which hundreds of millions of years ago covered much of the Arabian Peninsula. The warm, shallow sea, rich in lipid-storing plankton, was fertile ground for the formation of petroleum deposits in the sediments that gradually accumulated under the sea. The process can even today be observed on mud flats flanking the Persian Gulf, where the sediment below surface mats of cyanobacteria (previously known as blue-green algae) is stained black by contemporary oil desposits.

The salt domes provide the cap-rock needed to trap migrating oil in underlying sandy or chalky sediments, but how did they form? Jean-Paul Berger, a Dubai-based geologist, explains that the weight of accumulating sediment that originally formed above more ancient layers of gypsum and other salty minerals, combined with upwards surges of molten magma from below the earth’s crust, subjected the subterranean salts to increasing temperatures and pressures until they melted.The molten salts forced channels through overlying sediment until they reached the surface and spread out to form domes.

The periodic magma surge also sometimes broke through to the surface as active volcanoes, explaining the occurrence on certain islands such as Dalma of massive natural rubble piles consisting of angular gypsum fragments mixed with various heavily crystallized rocks and boulders containing often brightly colored ores of metals such as iron, copper and manganese.

So far, this potential treasure trove of exposed metallic ores remains unexploited.

Not so the oil beneath at least some salt domes, so it is hardly surprising that several Persian Gulf islands are strategically positioned with respect to regional oil reserves and tend to be magnets for geopolitical strife.

Bahrain is eyed protectively by its large Saudi neighbor as it is positioned close to Saudi Arabia’s biggest offshore and onshore oil fields as well as the kingdom’s most important oil export terminal at Ras Tanura.

Iranian officials from time to time issue provocative statements to the effect that Bahrain was historically Persian territory – a dubious claim that nonetheless always sparks a vitriolic response from Riyadh, which fears any increased Iranian presence in Bahrain.

Riyadh was also quick to back the UAE in objecting to Tehran’s recently stepped-up campaign to claim sovereignty over Iranian occupied Abu Musa. The small island, now the site of Iranian military installations, may no longer be near a producing oil field but remains close to the strategic Strait of Hormuz at the mouth of the Persian Gulf, which Tehran seeks to control.

In a development that may have been spurred by the March visit of Iranian president Mahmoud Ahmadinejad to Abu Musa, a proposed political union between Saudi Arabia and Bahrain was discussed in May at the most recent Gulf Cooperative Council summit. This was seen as a possible precursor to the formation of a GCC political bloc along the lines of the EU. However, no decision on either potential union was forthcoming.

Indeed, given that the GCC states – Saudi Arabia, Kuwait, Bahrain, Qatar, UAE and Oman – have so far succeeded in building just one cross-border regional pipeline – the Dolphin undersea gas line from Qatar to the UAE – an EU-style political union of Arab states may be a far-fetched pipe dream. Still, some analysts regard an eventual merger of Saudi Arabia and Bahrain as inevitable.

In the meantime, many Bahrainis continue to greet each other with a jaunty “choni” – a colloquial expression of distincly Persian origin.

Platts



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