3D Static Geological Model and Volumetric Assessment of the Upper Qishn Clastic in Al Roidhat Field, Yemen
This study addresses a critical knowledge gap by presenting the first comprehensive 3D static geological model of the heavy-oil-bearing Upper Qishn Clastic Member in the Al Roidhat Field, Yemen. The model integrates data from eight wells. The workflow encompassed structural modeling, stratigraphic zonation into three reservoir units (S1, S2, S3), facies modeling using Sequential Indicator Simulation (30 realizations), and petrophysical property modeling using Sequential Gaussian Simulation. Probabilistic volumetric assessment was based on 100 stochastic realizations. Uncertainty analysis yields a P50 Stock-Tank Oil Initially in Place (STOIIP) of 56.81 million barrels (P10–P90 range: 44.40–73.39 MMSTB). The S3 unit exhibits the best reservoir quality (62.8% sand, 0.15 porosity, 47mD permeability), while the S1 unit shows good quality (48.1% sand, 0.14 porosity, 60 mD permeability). Yet, the S1 unit contains 58% of the STOIIP because it lies entirely within the oil column, whereas a significant portion of S3 is submerged below the oil-water contact. Together, S1 and S3 account for approximately 85% of the total resource. This pioneering 3D model quantifies reservoir heterogeneity and structural controls, establishing an essential digital foundation for the field. It demonstrates that structural position can override intrinsic rock quality in governing hydrocarbon distribution, and it clearly identifies the S1 and S3 units as priority targets for future development and enhanced oil-recovery planning in this challenging heavy-oil reservoir.
المقاييس
هذا العمل مرخص بموجب Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
