Hydrocarbon prospectivity of the Zykh field associated with Pliocene-Miocene deposits in view of new 3D seismic survey data (Absheron oil and gas bearing region, Azerbaijan)

Abstract

Background. The hydrocarbon potential of the Zykh-Hovsan area is predominantly associated with the Lower Pliocene deposits of the Productive Series. However, at present, the main hydrocarbon-bearing unit in the Zykh-Hovsan field is the Qala Suite (QaS). The Miocene deposits underlying the Qala Suite have also been of particular interest in recent years. The present seismic studies were conducted in the view of new 3D seismic survey data. The purpose of the studies was to detail the geological models of the Zykh structure, to identify and trace the zones of development of faults and to identify oil and gas prospects of both the Qala Suite and Miocene.

Methods. Seismic stratigraphy and sequence stratigraphy methods were chosen as the main research methods. Attribute analysis was also carried out.

Results. In order to expand the resources of the Zykh field, recommendations were prepared for drilling of exploratory and appraisal well №2 based on 3D seismic survey data. Geological and geophysical materials were prepared and analyzed to justify the selection of the location of exploratory wells. After analyzing the seismic cubes, 3 location points of the project prospecting wells were selected, from which the first priority well – Zykh-2 – was selected and recommended for drilling. The recommended exploratory well Zykh-2 is located on the eastern steep slope of the Zykh uplift, in an area where prospective seismic facies in the Qala Suite intervals and prospective targets in the Miocene section are reliably and confidently identified in the section. The presence of well-defined seismic attributes as well as seismic classes in the predicted part of the section all indicate the presence of probable traps here. The well solves the task of both searching for the lower part of the sedimentary cover not explored by drilling and exploring the peripheral (eastern) part of the reservoir of the Sub Kirmaky Suite.

Сonclusions. The studies have shown that the prerequisites for oil and gas bearing capacity on the eastern slope of the Zykh uplift are the existing favorable regional conditions of petroleum system development, and also local favorable conditions, which consist in the presence of a screening formation elongated in the submeridional direction. The negative factors include the steep eastern slope of the Zykh uplift. Taking into account the results obtained and analytical data, the Zykh-2 exploratory well is recommended for drilling in the project location.