Petronas, a New Player in the Zambezi Delta Block, Offshore Mozambique

David M. Schiller, Alexander Tarang, Othman Ali Mahmud, Megat Iskander, Ahmad F. Bakar, Peter Abolins, and Amiruddin Mansor
Exploration Division, Petronas Carigali, Kuala Lumpur, Malaysia

The Zambezi Delta Block (ZBD),located off the coast of Mozambique covers 44,154 km2. The block was signed on 5 June 2002. PETRONAS Carigali Mozambique E&P Ltd (PCMEP) is the operator with 42.5% interest with partners PetroSA (25.5%),Petrobras (17%)and ENH (15%).

Hunt Petroleum drilled the Zambezi-1 and Zambezi-3 wells in the block in 1971 which tested two seismic anomalies. The wells were dry with minor gas shows and traces of dead oil and tar. New mapping has confirmed that both wells were drilled off-structure.

The ZBD is centered over the Zambezi Delta Depression (ZDD) - a NE-SW trending sub-basin of the Mozambique Basin with over 14,000m of Jurassic to Recent sediments. Along the southeast flank, Cretaceous to Recent sediments onlap the Beira High - a prominent basement high that is believed to be composed of attenuated continental crust.

The only hydrocarbon production in Mozambique is from the onshore Pande and Temane gas fields, located 325 km from the center of the ZDB. The gas is believed to have been sourced from the ZDD since the Early Cretaceous Lower Domo Shale and Lupata Formation source rocks are immature onshore.

The ZBD is remarkably unstructured, thus most of the plays are stratigraphic. Numerous slope, basin floor, canyon fill and ponded turbidites of Tertiary and Cretaceous age have been mapped from 21,495 km of 2D seismic data.

The ZD-E-1 well was drilled in May-August 2007 to test multiple targets that included a Paleogene paleogeomorphic trap, Miocene slope fan turbidite drape traps, and a basal Eocene carbonate stratigraphic trap. The Miocene objectives contained 430m of reservoir quality sandstones, however, only traces of gas were found. In the Paleogene objective, sandstone facies were missing. The carbonate was not penetrated due to an early TD. The well is believed to have failed due a lack of migration/emplacement.

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