Structural analysis, faulting system distribution, and geomechanical modeling of the Najmah Formation for improved drilling efficiency and well stability in Raudhatain and Sabriyah fields, North Kuwait

• Published in: Environmental earth sciences 2024-12, Vol.83 (23), p.658, Article 658
• Main Authors: Afife, Mohamed M., Amawy, Maher El, Mohammed, Ahmed A., Ahmed, Mohammed A.
• Format: Article
• Language: English
• Subjects: Alignment; Biogeosciences; Calcite; Carbonates; Cores; Drilling; Drilling fluids; Earth and Environmental Science; Earth Sciences; Efficiency; Environmental Science and Engineering; Fault detection; Geochemistry; Geology; Geomechanics; Hydraulic fracturing; Hydrology/Water Resources; Image enhancement; Image processing; Optimization; Organic matter; Original Article; Permeability; Pore pressure; Pore water pressure; Reservoir management; Reservoirs; Risk assessment; Seismic data; Seismological data; Slurries; Storage capacity; Storage conditions; Structural analysis; Structural members; Structural stability; Terrestrial Pollution; Well completion; Wells
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-024-11906-6

The North Kuwait region has been facing with a range of challenges related to inconsistent drilling downtime and varying sealing conditions caused by abnormal pore pressure. In order to address these issues effectively, a comprehensive analysis was conducted using image logs, well cores, and seismic data collected from 23 wells in the Sabriyah field and 35 wells in the Raudhatain field. The primary objective was to improve drilling efficiency and well completion, identify key structural phases and fault orientations, evaluate the relationships between fractures and other structural elements, gain valuable insights into fractures and stress conditions, and optimize reservoir management to enhance productivity and efficiency. It was observed that open fractures in both the Sabriyah and Raudhatain fields align predominantly in a northeast-southwest direction. This alignment significantly increases storage capacity, improves permeability, and facilitates the implementation of more efficient hydraulic fracturing techniques. The dominant alignment of fractures in the north-northeast direction, which aligns with the present-day orientation of the maximum principal stress, has a distinguished impact on well perforation and subsequent efforts to enhance production. However, the presence of cemented fractures filled with calcite and organic matter has the potential to impede production rates, particularly in over-pressured reservoirs. Formation micro-imager (FMI) logs have proven to be vital in identifying drilling-induced tensile fractures. These logs provide insights into the structural history, geomechanical properties, and overall stability of the wellbore. The discrepancy in fault occurrences between the Sabriyah and Raudhatain fields highlights the heightened complexity encountered during drilling operations in the Sabriyah field, where faults are more frequent compared to the Raudhatain field. A 1D geomechanical model facilitates the adoption of strategic drilling operations, enhances the evaluation of reservoir risks, and ultimately elevates overall operational efficiency. The available data presents important information regarding the geomechanical attributes and the influence of natural fractures on reservoir efficacy. A successful approach encompasses the application of horizontal or directional wells, hydraulic fracturing methods, and customized designs for drilling fluid and cement slurry. Furthermore, it is crucial to consider optimal perforation posit