OMAN - Gas Reserves.

Oman's reserves of natural gas are officially estimated at 35 TCF. This is just enough to meet present domestic needs and export commitments. According to a 1998 report from the Riyadh-based secretariat of the GCC, Oman's proven gas reserves then had reached 30 TCF. On Jan. 1, 1997, the official estimate was put at 28.48 TCF (800 BCM) for "total expected reserves" and 19.1 TCF for the proven reserves. The target, which PDO is to meet in its capacity as a contractor for the government, is to find 1 TCF per annum for the next 16 years. New targets are to raise the proved reserves to 45 TCF by 2007 and to 50 TCF by 2012.

Oman's non-associated gas in the central region is of good quality. It is free of carbon dioxide, nitrogen and sulphur (inert gases usually found in neighbouring countries). The gas has a high heating value, therefore, and is ideal for export in LNG form or by pipeline to other markets. Once reaching the other markets, this can be blended with lower quality pipe gas from elsewhere to reduce the content of inert gases and to raise the energy carrying capacity of regional pipelines. The gas contains about 7% of ethane, a key feedstock for ethylene, plus 3.5-5% of propane and butane (LPG). The rest is methane which can be liquefied into LNG.

The proven reserves of associated gas have been estimated at 3 TCF, up from 2.95 TCF at the end of 1996. This is the main source for LPG and other gas liquids. Nearly all this gas is produced by PDO. This includes gas re-injected into the oilfields and supplies to the domestic market.

It was thanks to new discoveries from 1989 that the government allocated $3.38 bn for a 1991-95 programme to maintain high levels of oil and gas production as well as get reserves to be increased. Of this, $923m went to exploration and $1.145 bn to drilling and production. Another $1.317 bn went for the purchase of equipment. Under a 1996-2000, plan, about $6 bn were invested by the government and foreign partners in exploration, development and the other requirements for oil and gas. An outlay of over $7.2 bn was spent under the 2001-2005 plan. A major spending outlay was to be announced in early 2006 for the plan covering 2006-10.

There is keen interest among foreign companies in areas once judged to be unimportant, like the string of fields in central Oman which contain large reserves of condensate as well as gas. These reserves have been developed for a new condensate stream of 80,000 b/d, which in 1999 was spiked into crude oil to raise the country's oil production. Now Oman's condensate production is averaging about 68,000 b/d.

In the 1980s the companies were not keen on gas. The government launched a 10-year programme for gas exploration through PDO (owned 60% by the state, 34% by Shell, 4% by Total and 2% by Partex). This led to the discovery in 1991 of 7 TCF of non-associated gas, which were enough to back a 6.6m t/y LNG venture, in central Omani fields - Saih Rawl, Saih Nihayada, Barik and Mabruk. (Mabruk was formerly known as Mahjour). A third train has been built which has raised the LNG exports capacity to more than 10m t/y.

Oman has the biggest number of oil and gas fields in the Gulf, in excess of 110. It was said in early 2000 that the number of PDO's producing wells will more than triple by 2008. Oman is a good market for a variety of upstream contractors, particularly for those specialised in deep logging, having to deal with extremely high temperature and pressure, hydrogen sulphide (H2S), etc.

Exploration Background: The search for oil in Oman began in 1925, soon after D'Arcy Exploration Co. won a two-year licence. Then the country was a British protectorate. The company made geological surveys but failed to find oil. In 1937, after oil discoveries in Bahrain and bigger ones in Saudi Arabia's Eastern Province, the BP-led Iraq Petroleum Co. (IPC) came to Oman and established Petroleum Development (Oman & Dhofar) Ltd. PDOD was awarded concessions and options in areas around Muscat and the town of Dhofar, the latter then under a separate administration.

The outbreak of World War II interrupted PDOD's work. PDOD was owned by BP, Shell, Total, Exxon, Mobil, with 5% held by Callouste Gulbenkian (the famous broker called "Mr. 5%" whose company was later named Partex and registered in Portugal).

PDOD resumed exploration in the late 1940s. It had to relinquish Dhofar and by then it has already changed its name to PDO. The political situation worsened in the mid-1950s, and rebels in Dhofar threatened to undermine PDO's operations because of British support for the then sultan, Said bin Taymour. In 1956 PDO managed to spud its first exploration well at Fahud. This turned out to be a dry hole.

In 1954, Cities Service and Richfield Oil of the US came to Oman and found the Marmul field in the south in 1956. But the two companies relinquished the field to PDO as the oil was very heavy and the area was affected by political turmoil. PDO failed to find oil elsewhere and Marmul was shut in. This led to the departure from PDO of BP, Compagnie Francaise des Petroles (CFP - now Total), Exxon and Mobil. That was in 1960. Shell stayed behind with 85% in PDO, along with 5% for Partex and 10% for the government. In 1962, Shell found Yibal field, with a major oil reserve. Later it discovered Natih (1963) and Fahud and al-Ghubar (1964).

These discoveries attracted Total back to PDO and had sufficient reserves to warrant development. PDO built an export terminal at Mina al-Fahal, just north of Muscat. Oil exports began in 1967 as Total rejoined PDO. Exploration intensified and led to the discovery of Lekhwair and al-Huwaisah in 1968; Qarn Alam, Habur, Ghaba North and Saih Nihaydah in 1972; Amal and Saih Rawl in 1973; Anzauz and Barik in 1974; Shibkah in 1976; Rahab in 1977; and Birba and Qaharir in 1978.

By late 1973, oil prices had quadrupled and encouraged PDO to increase exploration as well as speed up development of these fields.

Following the trend in the OPEC world (though Oman never joined OPEC or OAPEC), Muscat took 25% in PDO at the beginning of 1974 and raised this to 60% in mid-1974. Shell's holding fell to 34%, Total's 10% fell to 4% and that of Partex dropped to 2%. After an oil glut in 1977, Muscat was compelled to improve E&P incentives, with emphasis on Dhofar. It signed a five-year agreement which PDO judged satisfactory. As a result, PDO found Mahjour, Runib, Qata, Rima and Jalmud in 1979 - when crude oil prices rose sharply, encouraging PDO to develop them at top speed. It found Nimr and Thulailat in 1980, Zauliyah and Thayfut in 1981 and many others in the later years.

By then several other companies had relinquished their blocks and left the country. Elf Aquitaine in 1973 acquired an offshore block off the Musandam peninsula in the Strait of Hormuz, where it found gas/condensate fields at Bukha and Henjam in 1976. But it relinquished them later. In partnership with Sumitomo and Wintershall, Elf had also acquired an onshore block in the Sahmah area and in 1978 found the Sahmah oilfield which it developed. Elf sold its interests to the local company Petrogas, as its output fell, and left Oman in 1999 (Elf was absorbed by Total). Safah was found in 1983 by Quintana/Gulf Oil and was developed by Occidental Petroleum. The oil producing Wadi Aswad fields in onshore Block 5 were found in 1984 and developed by Japex Oman of Japan (Japex & JNOC). But the Japanese partnership decided not to renew its 20-year concession in late 2001 and sold its Oman assets to Petrogas, which is a subsidiary of the local MB Petroleum (see Part 2).

Exploration in non-PDO areas was limited and mostly involved little-known firms. These included Compact Oil (of Bermuda-based Transworld Oil, owned by John Deuss) which had a 50,000 sq km tract along the northern coast. Arakis of Canada and Aegis of the US got the Jebel Aswad block, under a contract signed in mid-1989.

Blocks offered since then have been part of areas relinquished by PDO. To boost exploration, Muscat in late 1994 pressed PDO to abandon areas where it was not operating. In early 1995, PDO relinquished about 95,662 sq km onshore and offshore (see detailed background in Vol. 62, Gas Market Trends No. 5).

There have been major development in the petroleum sector since the last survey of Oman was published in February 2004. The government was not happy with Shell's PDO performance as its expensive enhanced oil recovery (EOR) systems had failed to stop a steady decline in oil production since 2000. A crucial step was taken in December 2004 as PDO's concession in Block 6, covering most of Oman, was extended until 2044. Originally signed in 1937, the agreement had been due to expire in 2012.

Particularly unhappy with Shell's plans for the Mukhaizna field of heavy oil, the state finally transferred this from PDO to a partnership of Occidential Petroleum (Oxy) of the US and Liwa Energy of Abu Dhabi in an exploration and production sharing agreement (EPSA) signed in June 2005. That was a major setback for Shell.

Under its December 2004 agreement with the government, PDO in June 2005 had to relinquish 10% of its 114,000 sq km concession area in Block 6. The Petroleum Concessions & Exploration Services division of the Ministry of Oil & Gas took the ceded area and then began work on dividing it into a number of blocks.

The division's head, Adel Jaman was in late 2005 quoted as saying he hoped these blocks would be put to tender by year's end or in early 2006. Winning bidders for these and other blocks on offer will be signing EPSAs (see Part 2 in next week's Review).