Geology

PGS seismic data from the East Mediterranean support new exploration activities offshore Greece, Cyprus, Egypt, and in the Levant Basin.

The eastern Mediterranean is a geologically complex region, with multiple plate boundaries, subduction zones and associated accretionary wedges, major suture zones, fold and thrust belts, and fault systems. Adding to this complexity are extensive Messinian aged evaporites across the region, which complicate seismic imaging. The presence of salt has its advantages. It provides an excellent seal for hydrocarbon reservoirs (e.g. for the Zohr field) and it controls the thermal regime in the subsurface, which has been a contributing factor in the production of biogenic gas in the region. While there is extensive biogenic gas in the offshore discoveries, some discoveries (e.g. Karish North) also indicate the presence of a working thermogenic source in the offshore region.

New opportunities abound across the Eastern Mediterranean, and include

  • Potential presalt carbonate build-ups offshore Crete, west Egypt, and Cyprus
  • Shelfal plays offshore west Egypt that have direct analogs to the onshore Western Desert
  • Additional clastic plays offshore west Egypt, Cyprus and Lebanon that are comparable to the Nile Delta plays (pre- and postsalt clastic plays)

The Zohr Discovery Game-Changer

The early exploration focus in the offshore Nile and Levantine basins targeted Tertiary clastic systems, sourced by the river Nile. These plays have proven successful. However since the Zohr gas discovery in 2015, the focus has broadened to include carbonate build-up reservoirs in the deeper water acreage, particularly those sealed by Messinian aged evaporites. Subsequent successful exploration drilling in Cyprus, supported by PGS’ MC3D data in the region, has proven there are working analogs to Zohr (e.g. Glaucus 1).

A More Proximal Sediment Source

While a large proportion of the sediment fill in the northern Levantine Basin is likely to be sourced from the Nile, the PGS Lebanon PSDM MegaSurveyPlus reveals that there is clearly additional sediment being sourced from the east and north (see figure below). The quality of these sediments in terms of potential clastic reservoirs is yet to be tested by drilling, but could potentially be evaluated in an upcoming well in Block 4.

PGS_Lebanon_PSDM_MegaSurveyPlus
PGS Lebanon MegaSurveyPlus: Upper Miocene amplitude extraction. Anomalies observed along the slope and margin indicate fan and channel systems also enter the basin from the east and north.

The most recent MC2D acquisition across the Nile Delta, processed using depth imaging, provides a bridge in understanding between the more studied Nile Delta discoveries and Egypt’s western offshore domain. Additional information can be drawn from the onshore Western Desert Basin, particularly for the offshore shelf areas.

MC3D_offshore_Egypt_Pliocene
Coherency slice through MC3D offshore Egypt showing Pliocene channel systems from the Nile delta extending into offshore western Egypt.

 

PGS_MC2D_GeoStreamer_data_offshore_Greece
PGS MC2D GeoStreamer data offshore Greece reveals very large carbonate build-up structures sealed by Messinian evaporites.