ProGREss’21

One of the promising directions for the development of the resource base in Western Siberia is the deposits of the Achimov strata, which characterized by high lateral and vertical variability, which complicates both the correlation of well sections and the delineation of traps. Within the framework of the Achimov strata studies, conducted in the southern part of the Nadym and Purovsky districts of the Yamalo-Nenets Area, a complex of works was carried out, including sedimentological analysis of the core, selection of electrofacies in well sections, tracing of seismic reflectors together with stratigraphic dissection and well correlation, and dynamic analysis of seismic data. The integrated use of all available geological and geophysical data made it possible to isolate, geometrize and systematically assess the prospects of the Achimov deposits over a large area of the southern part of the Nadym and Purovsky districts of the Yamalo-Nenets Area.

modern challenges of seismic exploration; - the process of digitalization of production in seismic exploration; - pilot tests of the Digital Dispatcher system

One of the main objectives of the petroleum industry is to increase the resource base. For oil and gas companies, the recovery of hydrocarbons from the unallocated subsoil fund is of great importance. The decisions to purchase an asset are made based on feasibility studies. Competent planning of exploration processes and subsequent development of the oil and gas potential of the territories is required. The Information System Subsoil Block Evaluation (SBE) has been created to ensure operational evaluation and effective decision- making related to promising subsoil blocks. The system development began with the features of consolidation and analysis of economic assessments of the unallocated subsoil blocks. Now the SBE is a unique and modern IT product with a user-friendly interface that allows for prompt investment assessment starting from geology to economic efficiency, taking into account the synergy of combining the blocks into clusters. Project optimizers search for optimal solutions in the simulation chain of development, infrastructure, and economics. Built-in algorithms allow to automatically search for the most effective development scenarios. The system helps to reduce the risk of unjustified capital expenditures related to the purchase of an illiquid asset. The tools support high-level decision-making on license areas development.

License blocks containing oil producing fields in the West-Siberian Basin are quite often covered by 3D seismic surveys. Commonly, seismic interpretation results rely solely on exploratory wells and describe the only variant of geological structure not covering the wide range of uncertainties concerned with reservoir structure and petrophysical properties. This paper describes the cases of application of 3D seismic data for non-structural trap identification for probabilistic resource assessment and following exploration. The integrated analysis of 3D seismic together with well data allowed to locally update geological models of prospective Neocomian and Vasygan reservoirs in the vicinity of producing oil fields. Non-structural traps were identified using paleotectonic analysis, seismic attribute analysis, and signal-change tracing near oil fields within the Nizhnevartovsky Arch and Frolovskaya Megadepression.

Anisotropy in seismic data is usually associated with areas of increased fracturing and/or stress. Reservoirs with a parallel fracture set could be described by an effective model of a transversely isotropic (TI) medium with a symmetry axis normal to the fracture planes. In the case of sub-vertical fracturing the model is HTI (with horizontal symmetry axis). The traditional AVAZ analysis is based on the linearized Ruger approximation for P- wave reflection coefficients from boundary between isotropic and anisotropic HTI media. But it is valid only in the case of weak anisotropy with a difference in elastic parameters at the boundary ≤10–15%. In this paper, AVAZ inversion algorithm based on exact formulas is considered. This algorithm is implemented in Petrel software and allows to use migrated data (with true amplitudes), as well as initial data (CDP seismograms). Developed plug-in pursue the aim to integrate cycles of seismic data processing and interpretation, which is necessary for local analysis of complex target objects.

The main hydrocarbon deposits associated with the Upper Jurassic-Cretaceous sediments of the West Siberian oil and gas province have already been discovered. Further prospects are associated with the bottom of sedimentary cover and the upper part of the pre-Jurassic complex. However, these sediments have an extremely complex geological structure. In this situation, increasing the efficiency of exploration is important. This is ensured by the reliability of the geological model of the reservoir. The construction of the model is carried out by combining all types of heterogeneous geological and geophysical data. This requires an integrated approach to the analysis of all data to make the conceptual geological model of the studied object as the basis.

The article provides a description and mapping of an unique sequence in the Lower Cretaceous deposits of the north of the West Siberian oil and gas basin, assumptions are made about its genesis and possible connections with the reservoir properties of the Achimov deposites.

Within the framework of this work, the results of reprocessing and interpretation of seismic survey 2D of the 1980–1988 seasons, at the licensed area of PJSC Gazprom Neft, obtained in a short time to reduce geological and economic risks and refine the assessment of the resource base, are presented.

The latest changes in the energy industry have put a lot of constraints on seismic acquisition, especially onshore, where more nimble systems are required to respond to the continuous need of better seismic images at lower cost, lower environmental impact and lower safety exposure. Cabled systems have dominated the seismic acquisition market for a while, however, equipment weight and volume have been a real burden on cr ews, restricting access (difficult terrain, urban areas) or at best slowing them down and increasing chances of downtime. The very high safety risk, environmental impact and cost associated with line cutting, a common practice when using cable systems in forested areas, have made it prohibitive to acquire denser surveys in such environments. Existing nodal systems - although lifting some of those constraints - were still not small, light, and low-cost enough to enable autonomous nodes to take off until the arrival of a new generation of nimble nodes. These new autonomous nodes, with a size and a weight approaching those of a geophone, are changing the way seismic is acquired, especially in difficult terrains, and are making high density seismic affordable to all industries.