Investigation on Characteristics of Granulometric Distribution of Sediments in Lowpermeability Sandstone Reservoir

Key words: 
• lowpermeability sandstone reservoir /
• granulometric distribution of sediments /
• parameters of granulometric characteristics /
• normal distribution /
• mixed  normal distribution

Abstract: The granularities of more than 2000 samples from 82 wells in the lowpermeability sandstone reservoirs of Shengli oilfield were tested by the MS2000 laser granulometric analyzer. The experiment showed that the granulometric distributions of sediments in low permeability sandstone reservoir behave as three modes, and each mode has its own characteristics and is related with certain sedimentation process. It is also found that the median distribution of granularity, the shale content of lowpermeability reservoir rock and the classified degree are the three key factors, which influence its permeability, and normal distribution or mixed  normal distribution, can preferably describe the granulometric distribution characteristics of sediments in lowpermeability sandstone reservoir.