An operator on Oct. 25 discovered the new release on a water-injection pipeline at Shekilie oil field, about 50 km northwest of Zama City, while investigating a volume discrepancy.
Internal data indicate the release began Oct. 3. Apache estimates volume of the release at 1,800 cu m of produced water and size of the affected area at 5.09 ha. The water contained trace amounts of hydrocarbons.
The cause is under investigation.
Earlier, Apache reported stress corrosion cracking of a water-injection pipeline as the likely cause of a June release of produced water at its Zama operations, which include an enhanced oil recovery pilot based on injection of carbon dioxide (OGJ Online, Oct. 22, 2013).
Neither release endangered the public, Apache said.
The company said it is installing real-time monitoring involving supervisory control and data acquisition to its four water-injection systems in the Zama operations area.