This study demonstrates the use of low‑field NMR relaxometry for rapid, in‑situ determination of SARA fractions (saturates, aromatics, resins, and asphaltenes) in crude oils. Compared to the conventional ASTM D 4124 column chromatography method, LF‑NMR requires no solvents or sample fractionation, preserves the native crude oil colloidal structure, and delivers results within minutes. By analyzing T₂ relaxation signals, the technique effectively distinguishes asphaltenes, resins, and the combined saturates + aromatics fraction. Correlation with ASTM reference data confirms its reliability across a wide range of crude oil types (API 4.6–42.0°). While it cannot separately quantify saturates and aromatics individually, it offers a fast, low‑cost, and non‑destructive alternative for oilfield screening, heavy oil evaluation, and asphaltene stability assessment.

Portable NMR technology addresses the critical need for real‑time, non‑invasive petrophysical analysis at oilfield sites, enabling rapid reservoir evaluation, drilling fluid monitoring, fracture characterization, and mature well re‑assessment. Niumag‘s portable NMR system delivers reliable stability and repeatability with intelligent software integration, enhancing operational efficiency and decision‑making in harsh field environments.

Two‑dimensional NMR T₁–T₂ precisely differentiates fluid types in tight gas cores, revealing that micropores suffer permanent water blocking while increasing flowback pressure effectively reduces damage in meso‑ and macropores, guiding fracture cleanup optimization.

This study uses low‑field NMR (LF‑NMR) to characterize pore structure evolution in coal during hydraulic fracturing, quantifying micro‑, adsorbed, and free porosity to guide enhanced coalbed methane recovery.

Low-field nuclear magnetic resonance (LF-NMR) technology, due to its sensitivity to molecular motion, has demonstrated unique advantages in characterizing polymer crosslinked networks in recent years. It enables rapid and quantitative detection of crosslinking degree in samples, and has emerged as a novel method for analysing the crosslinking degree of HPG fracturing fluids.

Traditional completion fluid systems, such as brine-based and polymer-based fluids, are generally prone to failure at high temperatures, highlighting the urgent need for precise thermal stability evaluation methods.In response to this challenge, low-field nuclear magnetic resonance (LF-NMR) has emerged as a promising technique for investigating the high-temperature thermal stability of completion fluids.

Low-field nuclear magnetic resonance (LF-NMR) technology enables real-time monitoring of fluid distribution, migration, and interactions within the core during injection-based stimulation, providing critical insights for studying stimulation mechanisms and optimising injection parameters.

Portable NMR analysis technology for oilfield applications has become a significant breakthrough in oil and gas exploration in recent years.Niumag’s portable NMR system has earned strong recognition from clients for its outstanding stability and repeatability.

Niumag's constant gradient-based layering technology fundamentally and completely eliminates the influence of end effects from a technical perspective, enabling a more authentic evaluation of core displacement efficiency.This technology maintains the original precision of NMR measurements and is applicable to various types of core samples, including sandstone and shale, without being limited by low-permeability or tight formations.

Low-Field NMR Technology for Dynamic Monitoring of Polymer Injection Processes in Reservoir Cores for Enhanced Oil Recovery