Hydrocarbon prospectivity of pinch-out zone of Jurassic deposits in Southwestern part of South Taimyr Monocline

Abstract

A comprehensive analysis has been conducted on the geological structure of the entire Jurassic interval within the southwestern part of the South Taymyr Monocline, which has allowed a more precise understanding of the structure of the Khabei gas field and the identification of prospective objects of similar geological pattern. The study utilized CDP 2D seismic data, covering a total length of 7835 kilometers, as well as results from exploratory and appraisal drilling. Based on visual analysis of temporal cross-sections, an assumption has been made regarding the correlation between reservoir development zones and paleo-channel systems of the Lower-Middle Jurassic deposits. In order to identify and locate such systems, an analysis of temporal cross-sections, maps of total Jurassic deposit thickness, and maps of dynamic attributes were conducted. As a result, areas of development of large paleo-channel systems (paleo-valleys) within the South Taymyr Monocline have been delineated through integration. These identified zones are characterized by relatively shallow burial depths of up to 2.5 km, the absence of abnormally high reservoir pressures (AHBP), and comparably high filtrationcapacity properties for Jurassic reservoirs (porosity – 22%, permeability – 25–50 mD).
However, considering the complexity of these objects’ structures and the uncertainties caused by the low degree of geological-geophysical exploration in the study area, it is recommended to conduct additional seismic surveys (CDP 3D) to maturate the objects for exploration drilling.