Creation of a Sequence-Stratigraphic Model to Clarify the Geological Structure of Coastal-Continental Sediments of the Tanopchinskaya Suite

Abstract

A sequence-stratigraphic model of the Tanopchinskaya Suite of coastal continental genesis was constructed in order to establish the distribution patterns of reservoir properties, clarify the geometry of sand bodies, and identify the main hydrocarbon concentration zones within the studied sediments. The system approach to well correlation was substantiated, which formed the basis for creating a model of Cretaceous sediments with high predictive ability. Regional peculiarities of the structure of the Tanopchinskaya Suite of a large field in the Yamalo-Nenets Autonomous District of the Russian Federation were analysed; core and GIS data from 64 exploration wells and 224 production wells in TP1–TP26 formations were analysed; an algorithm for building a sequence-stratigraphic model that takes into account sedimentation peculiarities was formulated; peculiarities of sand bodies formation were revealed for the whole Cretaceous section. As a result of the analysis, all wells in the Tanopchinskaya Suite interval (TP1–TP26 formations) were correlated with the definition of facies environment and the main surfaces of sedimentation regime change (flooding surfaces, erosion incisions, transgressive surfaces). Taking into account the correlation of formations for the entire well stock, a geostatistical section was constructed and sequence-stratigraphic subdivisions characterising the Tanopchinskaya Suite formations were identified. The 1D sequence-stratigraphic model of wells was analysed for the main hydrocarbon accumulation zones, taking into account open deposits, and the regularities of their location in the section were formulated.

Keywords

• sequence stratigraphy
• coastal continental sediments
• tanopchinskaya suite
• system approach