Saudi Aramco is to revise its long-term oil field development plans, with its Manifa and Dammam fields being prioritised at the expense of the remote Shaybah acreage.

Two sources close to the state-run firm tell MEED that the Manifa and Dammam fields, which both hold heavy oil reserves, are under study for further increases in production.

The move is being made after Aramco became concerned that its plans to boost production at its Shaybah field in the Rub al-Khali (Empty Quarter) would involve a costly upgrade to site facilities.

The upgrade at Shaybah was to have been used to balance declines in production at other maturing fields.

It is understood that this production shortfall will now be mitigated by fast-tracking upgrades at Manifa and Dammam.

The $11bn Manifa programme – the largest offshore oil field development ever undertaken by Aramco – which aims to deliver 900,000 barrels a day (b/d) of Arabian Heavy crude by 2011, may be increased to 1.1 million b/d.

According to one executive working with Aramco on the Manifa project, discussions have started over a medium-term increase in the overall capacity of the project.

“This 1.1 million-b/d figure might not be something that kicks in until well into the next decade, but Aramco is considering it, especially as some of its older fields will tail off in the next five to 10 years,” he says.

In June, Italy’s Snamprogetti, Japan’s JGC Corporation and Spain’s TR secured the three main engineering, procurement and construction deals on the current Manifa development (MEED 6:6:08).

Aramco has also sought expressions of interest from international oil contractors for a feasibility study to increase output at its Dammam field to 100,000 b/d.

The field has not produced for more than 20 years, but after conducting 3D seismic testing over the past 18 months, Aramco is pushing ahead with a preliminary study, according to one Dhahran-based contractor approached by the firm.

“We have been told there will be a contract for a 120-day feasibility study to be awarded in the first quarter of next year,” he says.

Despite these planned increases, Aramco is understood to have postponed plans for a further 250,000-b/d expansion of its Shaybah field.

Under studies initiated last year, the field was to become one of six in the kingdom with a production capacity of at least 1 million b/d (MEED 21:11:07).

But the Dhahran contractor says Aramco is wary of the additional cost needed to increase output at Shaybah and, as a result, has placed the targeted increase on hold.

The planned increase would require the additional expansion of central processing facilities, and the construction of another gas-oil separation plant on the field.

The 500,000-b/d field is already being expanded by an additional 250,000 b/d, which is being carried out by Canada’s SNC Lavalin. That will take capacity to 750,000 b/d and should be completed by February 2009.

The Shaybah field is estimated to have reserves of 14.3 billion barrels of crude oil and 25 trillion cubic feet of associated gas.