Increasing the reliability of effective thickness allocation in texturally heterogeneous reservoirs of the PK1 formation in the Pokur deposits

UDK: 553.98:622.276.031

DOI: 10.24887/0028-2448-2026-5-56-62

Key words: Pokur deposits, PK1 formation, textural heterogeneity, terrigenous reservoir, effective thickness, well logging, petrophysical model, thin-layered structure, log data deconvolution, resolution capability, core analysis, reservoir quality, reservoir identification

Authors: V.M. Yatsenko (Rosneft Oil Company, RF, Moscow); V.I. Baryshev (Branch of RN-GRD in Ufa – BashNIPIneft, RF, Ufa); A.V. Akinshin (RN-GRD LLC, RF, Tyumen; Industrial University of Tyumen, RF, Tyumen); S.M. Rogovtseva (Rosneft Oil Company, RF, Moscow); B.R. Sharipov (SevKomNeftegaz LLC, RF, Gubkinsky)

The article addresses the challenge of accurate effective thicknesses allocation of thin-layered reservoirs using the example of the PK1 formation within the Pokur deposits of a major field operated by Rosneft Oil Company in Western Siberia. The thin layering and high textural heterogeneity complicate well logging data interpretation, causing persistent discrepancies between intervals classified as non-reservoirs by conventional geophysical logging and observed hydrocarbon inflows during reservoir testing. The key difficulty is that productive layer thicknesses are often below the vertical resolution of standard log measurements, leading to signal averaging and loss of reservoir characteristics. To overcome this problem, the hypothesis proposes enhancing the vertical resolution of geophysical logging methods while maintaining standard reservoir identification criteria. This is achieved by applying deconvolution techniques to processed porosity logs to compensate for instrument blurring and recover high-frequency details. This method enables the identification of thin productive zones within intervals previously classified as non-reservoirs and more accurate characterization of reservoir heterogeneity. Results demonstrate that the improved resolution approach explains hydrocarbon inflows in intervals formerly deemed non-reservoirs, reduces geological risks, and refines reserve estimates. When combined with detailed petrophysical modeling of textural heterogeneity, this methodology offers a robust tool for reservoir characterization and more effective field development planning in complex thin-layered reservoirs.

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