Spontaneous Imbibition Experiment and Main Influence Factors in Ultra-Low-Permeability Reservoirs

The imbibition has an important influence on the water injection development of ultra-low-permeability reservoirs. In this paper, nuclear magnetic resonance (NMR) high-temperature and high-pressure displacement system was used to simulate formation temperature pressure spontaneous single porosity medium dual (containing fractures), experiments at different rates were carried out. NMR T2 spectrum curves simulated oil signals in pores, throats, fractures obtained. characteristics content change efficiency under experimental conditions quantitatively evaluated, contribution clarified. results show that is lower than medium. smaller pore is, greater speed rate is. porosity, permeability, maximum throat radius are positively correlated with but poorly action displacement. poor correlation also includes median pressure, mercury saturation, radius, rate. Fractures play a positive role improving efficiency.