Sedimentology, Stratigraphy, Petrography of Mid Pliocene Productive Series, Azeri Field (Offshore Azerbaijan) South Caspian Basin

Elnur Binyatov¹ and Elshan Rzayev^2
1Geological Engineering, METU, Ankara, Turkey
²BP, Baku, Azerbaijan

The ACG (Azeri, Chirag, Gunashli) field is located offshore Azerbaijan. The reservoirs are multilayered sandstones forming traps within a major anticlinal structure. Proven crude oil reserves are estimated to contain 5.4 billion barrels of oil.

The anticline, known as the Absheron Ridge, marks the boundary between the South and Middle Caspian seas. During deposition of part of the latest Miocene (5.5 MA) to Pliocene (3.34 MA). The trap, which forms the giant ACG Oil Field is a NW-SE trending, steeply dipping thrusted anticline. Balakhany sediments record sand-prone and shale-prone stacking patterns associated with alternation between more proximal and distal environments of deposition. Delta plain facies are more sand-rich and have better connectivity than delta front facies. The cyclicity records delta advance and retreat related to climate changes in the palaeo-Volga system producing variations in lake level.

This study will focus on reservoir-scale facies distributions and vertical stacking patterns of sandstones seen in approximately 44 wells from the Azeri field. Special attention will be given to the Balakhany X formation within the Productive Series which is considered to be one of the significant producing horizons.

However, the entire Productive Series will be studied to gain insights on climatic, depositional, and tectonic events leading to and following the deposition of the Balakhany Suite. Depositional controls for stacking patterns and cycles will be postulated and supported through detailed correlation and facies interpretations.

Sedimentary, petrographic, XRD and SEM analysis on thin sections in the Azeri Field C-01well of Balakhany-X Formation will be carried out to bring some insight into sediment provenance and reservoir characterization studies.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas