ANALYSIS METHOD OF ROCK NMR AND ITS APPLICATION IN OILFIELD EXPLORATION

Analysis of rock NMR(Nuclear Magnetic Resonance)is a new well logging technique developed in recent years,which is based on hydrogen atomic nucleus forming phenomena NMR under an additional magnetic field.Through repeatly measuring signal of NMR and cutoff value of T₂ at different processing phase,many geological parameters such as porosity,permeability,movable fluid saturation of reservoirs can be acquired.The measurement result is only related to pore structure,interstitial fluid properties and storage state,independent of mineral composition of rock frame,which is useful for the judgement of pore structure and fluid property in low porosity and low permeability,low resistivity and unusual lithology reservoir when facing difficulties in oilfield exploration.This technique realizes migration of reservoir property analysis from indoor conditions to drilling site and extension of analyzed objects from core samples to cuttings.And it has many advantages such as less sample consumption,fast analysis,lower cost,obtaining more parameters and high accuracy.The analysis result can evaluate reservoir property more effective in time combining with other data of detection logging.