The Shawan Formation in the Chepaizi region of the Junggar Basin represents a strata containing both oil and uranium, and the exploration and development of uranium resources remain in their early stages. Therefore, utilizing existing oilfield data to investigate uranium reservoir characteristics is highly significant for refining uranium exploration targets, enhancing mining design strategies, and improving resource development planning. On the basis of limited logging data, this study systematically analyzed the stratigraphic attribute parameters of the Shawan Formation, such as stratigraphic boundaries, sedimentary facies, lithology, porosity, permeability, and gamma ray (GR) values. A 3D petrophysical property model was constructed via ordinary kriging, SGS/SIS algorithms, and spherical variogram. The results showed that the Shawan Formation generally presents characteristics of being high in the north and low in the south, and this stratigraphic elevation pattern is conducive to fluid migration and uranium element enrichment. The N1s11 and N1s13 strata are mainly composed of braided river-delta fronts, fan-delta fronts, and fan-delta plains facies, with lithologies of glutenite intercalated with mudstone, porosities generally greater than 20%, permeabilities mostly greater than 30 mD, and frequent abnormally high-GR values. The N1s12, N1s2, and N1s3 strata are dominated by shore-shallow-lake facies, with lithologies mainly mudstone, porosities mostly less than 10%, permeabilities mostly less than 30 mD, and no abnormal GR values. These characteristics indicate that the study area possesses favorable structural and sedimentary conditions conducive to uranium mineralization. According to uranium industry classification standards, this study categorizes uranium mineralization into five levels: I (uranium content ≥ 0.02%), II (0.015% ≤ uranium content < 0.02%), III (0.01% ≤ uranium content < 0.015%), IV (0.005% ≤ uranium content < 0.01%), and V (uranium content < 0.005%). Among these, types I–III possess economic mining value. Using a uranium mineralization model for estimation, the total uranium resources of the Shawan Formation are 43,574.95 tons, of which 24,739.59 tons (56.78%) are economically recoverable. Notably, 89.91% of these resources are concentrated in the N1s13 stratum, reaching the scale of an extra-large sandstone-type uranium deposit.

3D Modeling of Tectonostratigraphic, Petrophysical, and Uranium Mineralization Properties for Sandstone-Type Uranium Reserve Assessment in the Shawan Formation, Chepaizi Area, Junggar Basin

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发表日期：

2026年1月6日

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Taping He,
Yaoqi Zhou,
Yuanhao Li,
Zhaobing Chen

摘要

The Shawan Formation in the Chepaizi region of the Junggar Basin represents a strata containing both oil and uranium, and the exploration and development of uranium resources remain in their early stages. Therefore, utilizing existing oilfield data to investigate uranium reservoir characteristics is highly significant for refining uranium exploration targets, enhancing mining design strategies, and improving resource development planning. On the basis of limited logging data, this study systematically analyzed the stratigraphic attribute parameters of the Shawan Formation, such as stratigraphic boundaries, sedimentary facies, lithology, porosity, permeability, and gamma ray (GR) values. A 3D petrophysical property model was constructed via ordinary kriging, SGS/SIS algorithms, and spherical variogram. The results showed that the Shawan Formation generally presents characteristics of being high in the north and low in the south, and this stratigraphic elevation pattern is conducive to fluid migration and uranium element enrichment. The N₁s₁¹ and N₁s₁³ strata are mainly composed of braided river-delta fronts, fan-delta fronts, and fan-delta plains facies, with lithologies of glutenite intercalated with mudstone, porosities generally greater than 20%, permeabilities mostly greater than 30 mD, and frequent abnormally high-GR values. The N₁s₁², N₁s₂, and N₁s₃ strata are dominated by shore-shallow-lake facies, with lithologies mainly mudstone, porosities mostly less than 10%, permeabilities mostly less than 30 mD, and no abnormal GR values. These characteristics indicate that the study area possesses favorable structural and sedimentary conditions conducive to uranium mineralization. According to uranium industry classification standards, this study categorizes uranium mineralization into five levels: I (uranium content ≥ 0.02%), II (0.015% ≤ uranium content < 0.02%), III (0.01% ≤ uranium content < 0.015%), IV (0.005% ≤ uranium content < 0.01%), and V (uranium content < 0.005%). Among these, types I–III possess economic mining value. Using a uranium mineralization model for estimation, the total uranium resources of the Shawan Formation are 43,574.95 tons, of which 24,739.59 tons (56.78%) are economically recoverable. Notably, 89.91% of these resources are concentrated in the N₁s₁³ stratum, reaching the scale of an extra-large sandstone-type uranium deposit.