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Today in Energy

November 1, 2013

Enhanced oil recovery techniques helped Oman reverse recent production declines

map of oman selected EOR sites, as explained in the article text
Source: U.S. Energy Information Administration, IHS EDIN
Note: Click to enlarge.

Republished November 7, 2013, to correct an error in the text.

Oman is the largest oil and natural gas producer in the Middle East that is not a member of the Organization of the Petroleum Exporting Countries (OPEC). Oman's average annual crude oil production peaked in 2000 at 970,000 barrels per day (bbl/d), but dropped to just 710,000 bbl/d in 2007. Oman successfully arrested that decline, and annual crude oil production rose in each of the next five years, hitting 919,000 bbl/d in 2012. Improved enhanced oil recovery (EOR) techniques helped drive this turnaround, although the country also experienced some additional production gains as a result of recent discoveries.

graph of oman crude oil and lease condensate production, as explained in the article text
Source: U.S. Energy Information Administration, International Energy Statistics

Enhanced Oil Recovery

Enhanced oil recovery (EOR), also known as Improved Oil Recovery (IOR), can maintain or increase the ability of oil to flow to a well by injecting water, chemicals, or gases into the reservoir or by changing the physical properties of the oil. Chemicals may include polymers, caustic solutions, and special molecules designed to attract oil. Injected gas may include nitrogen, carbon dioxide, steam, natural gas, and liquefied petroleum gas (LPG).

After declining for several years in the early 2000s, EOR techniques have been a key driver of Oman's rebounding oil production since 2007. At the center of Oman's EOR activities is Block 6, operated by Petroleum Development Oman (PDO), a joint venture majority-owned by the government of Oman that accounts for 70% of the country's oil production. Within Block 6, there are a number of projects currently using a range of EOR techniques (see below). PDO expects 16% of its oil production to come from EOR projects by 2016, up from just 3% in 2012. EOR techniques are critical to Oman's future production plans, and, as such, developments in those technologies are important to Oman's future production. For example, in late 2012 Shell and several partners invested more than $25 million in a solar-powered EOR process.

Other EOR techniques currently in use in Oman include:

Polymer injection. When reservoirs contain heavier grades of crude, the viscosity of the oil restricts its flow to the well. With such a heavy grade of crude, water injection might not prove effective, as the disparity in viscosity causes the water to pass the oil instead of pushing it to the well. At Oman's Marmul project, with its heavy oil, injecting polymer fluid is more effective than other EOR techniques such as steam injection. In 2012, Marmul produced approximately 75,000 bbl/d.

Miscible gas injection. Miscible gas injection involves pumping gas, often toxic, that dissolves in the oil, facilitating higher flow rates. Operators at Oman's Harweel oil field cluster use this technique in their operations. As a result, Harweel produced an additional 23,000 bbl/d in 2012, and production could continue to increase by another 30,000 bbl/d in the near term.

Steam injection. Thermal EOR entails the injection of steam in various ways and durations to facilitate the flow of heavier oil to the well. In Oman, operators use thermal EOR methods at Mukhaizna, Marmul, Amal-East, Amal-West, and Qarn Alam fields, among others. Thermal EOR could increase production at both Amal-East and Amal-West to 23,000 bbl/d by 2018. Furthermore, the steam injection at Qarn Alam should increase production by 40,000 bbl/d by 2015 through a novel process in which the steam drains oil to lower producer wells.

Other large EOR projects include:

  • Karim Cluster - a cluster of 18 small oil fields all flowing to the Nimr production facility, operated by Medco (Indonesia). Currently producing 18,000 bbl/d, PDO aims to boost production to around 35,000 bbl/d in the short term.
  • Harweel Cluster - PDO estimates a capacity of 100,000 bbl/d from the current 44,000 bbl/d in the next five years.
  • Growth of up to 70,000-80,000 bbl/d is expected from five clusters, such as the Rima Cluster, through various efficiency gains and EOR applications.

For more information, see EIA's Country Analysis Brief (CAB) for Oman.

Principal contributor: Mark J. Eshbaugh