Facies variability of sediments in the Jurassic productive strata of the Burmasha oilfield

Background: The foundation for field development and the justification of oil recovery factors relyies on a precise geological model. The reliability of this geological model depends on the specific characteristics of the deposit structure. Challenges in constructing the model arise from the significant lithological and facies variability of rocks. This article examines the structural features of the Yu-IX horizon of the Middle Jurassic Bajocian Stage of the Burmasha oilfield, incorporating new seismic data using the 3D common depth point (3D CDP) method and well drilling data. Aim: Presentation of a new geological model of the productive strata of the Burmasha oilfield based on the 3D CDP and drilling data, and determination of sedimentation conditions during the deposit formation. Materials and methods: The study applies new data from the interpretation of the 3D CDP seismic survey. It analizes cross slices of the eXchroma attributes, spectral decomposition (SD), RMC and Vp/Vs within the productive horizon, as well as drilling data from the entire well stock of the field. Results: The study results in the clarification of the boundaries of paleorusic deposits of the productive horizon and the determination of the sedimentation conditions in the productive strata. The data obtained show the importance of using modern exploration methods to provide a reliable geological model. Conclusion: The findings of this study provide a more accurate representation of the geological structure, estimate the reserves of hydrocarbon raw materials (hereinafter HRM), and enable further planning of a efficient system for the field development. All this will enhance the efficiency of hydrocarbon production, mitigate the risk of penetrating the clay-rich sections, and enable strategically position of new wells in areas with beneficial reservoir properties.