Characteristics and influencing factors of movable fluid in low permeability sandstone reservoir-by taking Chang-6 reservoir in Jiyuan oilfield of Ordos basin as an example

In order to evaluate Chang-6 tight sandstone reservoir in Jiyuan area,advanced experimental testing methods such as constant-rate mercury intrusion and nuclear magnetic resonance were carried out to test reservoir samples,the micro pore throat and the distribution of movable fluid and its affecting factors were discussed.The research results show the saturation of movable fluid in Chang 6 reservoir is low.Larger pore throat radius ratio,narrower distribution range and smaller mainstream throat radius are key factors which lead to poor reservoir property,complicated pore structure and low movable fluid content in Chang 6 low-permeability reservoir,thus some characteristics such as high displacement pressure,developed small throat and low degree of movable fluid.Movable fluid filling and displacement is affected by the relationship between pore throat characteristics and configuration.Low degree of movable fluid is an important factor that leads to poorer development effect of tight sandstone reservoir,the reservoir development by the occurrence characteristics of movable fluid can be predicted.