Technology Focus: Formation Evaluation (February 2026)

_ Major oil and gas companies are implementing cost-cutting measures amid falling crude prices and increased consolidation. This accelerates “the big crew change” and creates a significant experience gap. Formation evaluation professionals must preserve core expertise while evolving to shape future energy solutions. This Technology Focus highlights three developments in formation evaluation related to measurement, interpretation, and integration. Logging while drilling (LWD) offers real-time measurement before significant mud invasion. While many LWD suites match wireline quality, nuclear spectroscopy requires further development to improve lithology interpretation. Paper SPE 228060 introduced a new LWD tool combining a 14-MeV pulsed-neutron generator with a high-resolution LaBr3 scintillator, enabling advanced gamma-ray spectroscopy for elemental, mineralogical, and sigma and carbon measurements. The tool accuracy and repeatability were demonstrated by extensive comparisons with wireline logs and core analyses. Formation testing focuses on fluid and dynamic properties of reservoirs. Paper SPE 229928 integrated advanced well logging and formation testing to improve fluid typing and reservoir evaluation. New-generation formation testing was used to perform in-situ constant composition experiments and dynamic testing, leading to the identification of a saturated oil reservoir and the gas/oil contact. The productivity assessment showed great consistency with subsequent drillstem-testing measurement. Maximizing the effect of formation evaluation requires integration with broader subsurface disciplines and upscaling to reservoir scale. Paper SPE 225023 tackled rock compressibility in naturally fractured carbonate reservoirs using data from more than 126 core samples and pressure-interference tests. Correlations for matrix and fracture compressibility were developed based on porosity, pore pressure, and effective stress, linking laboratory-scale measurements to reservoir-scale behavior. Summarized Papers in This February 2026 Issue SPE 228060 - Pulsed-Neutron Logging-While-Drilling Tool Enables Direct Carbon Measurement by Gregory Schmid, SPE, Jiaxin Wang, and Jeffrey Crawford, Halliburton, et al. SPE 229928 - New-Generation Formation Testing Advances Evaluation of Volcanic Breccia Formations by Fang Tao and Yuan Chao, PetroChina, and Fan Zhaoya, SLB, et al. SPE 225023 - Formation and Fracture-System Compressibility Tracked Through Interference Testing by Ricardo Alcantara, SPE, Pemex and University of Aberdeen; Jose L. Bashbush, SPE, UNAM; and Gorgonio Fuentes-Cruz, SPE, IMP, et al. Recommended Additional Reading at OnePetro: www.onepetro.org. SPE 227346 - Thru-Drillpipe Cross-Dipole Array Acoustic-Logging Tool Capable of Mapping Deep Shear Wave Reflectors Away From the Wellbore by Javier A. Franquet, Baker Hughes, et al. URTeC 4257509 - Optimizing Field Development for the Vaca Muerta Play Using Oil and Water Geochemical Fingerprinting Technology by Ruben Cisneros, RevoChem, et al. SPE 226725 - Best Practices and Lessons From the Extended Pilot CO2-Injection Test on Leman Ultradepleted Gas Field, UK, Southern North Sea by N. Dupouy, Perenco, et al.