Downhole NMR Fluid Analyzer for Hydrocarbon Molecular Size Estimation

The patent applies parameter changes by utilizing multiple NMR measurement parameters (chemical shift, diffusion coefficient, relaxation times) to characterize hydrocarbons. By measuring and analyzing multiple physical parameters simultaneously, the system can distinguish between different hydrocarbon types that have similar chemical characteristics, thereby improving measurement precision without requiring overly complex analytical chemistry methods

The patent uses NMR as an intermediary measurement technique that indirectly characterizes hydrocarbons through their magnetic properties and molecular motion. Instead of directly analyzing chemical structure, the NMR instrument measures physical properties (chemical shift, diffusion, relaxation) that serve as intermediaries to infer hydrocarbon type and composition, improving accuracy while maintaining manageable device complexity

The patent employs periodic action by performing multiple NMR measurements with different pulsed magnetic field gradient magnitudes in a systematic sequence. Each measurement uses a specific gradient strength, and by periodically varying this parameter across multiple measurements, the system accumulates data needed to accurately determine molecular size distribution through diffusion coefficient analysis

The patent applies preliminary action by first acquiring multiple NMR measurements with varying gradients before performing the complex data transformation and analysis. The raw data from these preliminary measurements are then processed through Fourier transformation and diffusion model fitting to extract molecular size information, separating the measurement phase from the computationally intensive analysis phase