A Comprehensive Approach to Understanding Sedimentary Carbonate Basins: Combining Near Wellbore Acoustic Reflection Imaging, High-Resolution Borehole Imaging, and Advanced Logging Technologies: A case study from Thamama Group, Onshore UAE Field
Authors: Pal A. , Sharma A. , Bradley T. , Girinathan S. , Aouacheri A. , Deng L. , Ibe E. , Kim H. , Elabsy E. 
Published: November 2024

Objectives/Scope

The Study presents how an integrated approach, through deploying various new technologies, helped to address exploration challenges associated with subsurface structure and hydrocarbon traps of an exploration well in a newly identified Prospect. The absence of nearby well control and seismic uncertainty increase geological uncertainties and characterize Upper and Lower Cretaceous target reservoirs. Integration of comprehensive subsurface data acquisition provides valuable insights to unlock hydrocarbon potential of the area, thereby guiding future exploration and development plan.

Methods, Procedures, Process

The holistic approach of analysis Mud log data, Well-bore Imaging, Acoustic Logging, Nuclear Magnetic Resonance, Pressure Testing and Fluid Sampling. Advanced near wellbore acoustic reflection Imaging Technology was deployed for the first time in the asset. Employing an integrated analysis with advanced services extract and correlate key features included fracture attributes information (density, orientation and character), lithological boundaries, near-well stress-induced features, borehole shape, and stress field orientation.

Through the integration of diverse datasets, thorough assessment of subsurface characteristics and stress regimes, thereby contributing to the refinement of reservoir characterization and future well planning for field development.

Results, Observations, Conclusions

This case study employs near-wellbore acoustic reflection, serves as a potent technique for precisely detecting features such as fractures away from the borehole, while also capable of mapping subsurface geological characteristics. Near-wellbore acoustic reflection provides a more detailed depiction of acoustic reflectors away from the borehole, with much higher resolution than surface seismic processing allows. This analysis combines acoustic logging and seismic processing techniques, bridging the resolution and depth of investigation gap between conventional logging and advanced services, and seismic approaches. Consequently, it enables more effective reservoir management and optimization of hydrocarbon production, particularly in exploration fields with limited offset wells for correlations. Integrating logging data with near-wellbore acoustic reflection facilitates reservoir characterization and reduces uncertainty in field development, ultimately enhancing overall reservoir production.

The robust methodology and process workflows employed in this study suggest the potential for expanding upon the current structural framework of these formations. This study provides significant insights into the nature of reservoir and formation characteristics through integrated analysis and more specifically in areas with minimal well control. Overall, the results of this study provide a pathway for conducting more extensive studies of similar nature to provide a detailed understanding of the subsurface.

Novel/Additive Information

The case history demonstrated the importance of understanding the geological challenges addressed by fault zones, and necessity of integrating different disciplines to optimize drilling, well placement, formation evaluation and completion operations.

This work demonstrates the role of in-depth, refined data interpretation and integration in identifying possibly subsurface features through the integration of new technologies. The results of this work can be used as a basis for the understanding geological uncertainties and unlocking hydrocarbon potential in the prospect area and other similarly prospects in the study area and beyond.