No abstract

The Tiguentourine field is located in the southern part of the Illizi Basin in eastern Algeria and is operated by the In Amenas Association, a joint venture between BP, Sonatrach and Statoil. Ordovician-aged hydrocarbon reservoirs in the Illizi Basin consist predominantly of tight clastic rocks with a complex depositional history. Production data suggests that open fractures may play an important role in determining individual well productivity. In 2004 a seismic acquisition and processing study was performed to investigate whether wide azimuth seismic data and subsequent azimuthal anisotropy analysis could provide information about fracturing in these tight reservoirs. A full-surface (non-sectored), azimuthally varying velocity analysis technique was used to measure the azimuthal velocity anisotropy. Results indicate highly variable azimuthal velocity anisotropy throughout the area and within the reservoir zone. If the seismic anisotropy can be related to lateral variations in fracture orientation and density, then well productivity could be maximized by drilling wells to intersect major fracture networks.