Comparison of Various Particle Size Distribution Measurement Methods:Role of Particle Shape Descriptors

摘要

Sieve analysis,sedimentation and laser diffraction have been the methods of choice in determining particlesize distribution(PSD)for sand control design.However,these methods do not provide any informationregarding the particle shape.In this study,we introduce the application of Dynamic Image Analysis(DIA)to characterize particle sizes and shape descriptors of sand bearing formations.Dynamic Image Analysis,an advanced method of particle size and shape characterization,along withother PSD measurement methods,including sieving combined with sedimentation,and laser diffraction,was utilized to study size and shape variations of 372 unconsolidated formation sand samples from NorthAmerica,Latin America,and the Middle East.Different methods were compared for the estimation of PSDand fines content,which is important for sand control design.Through minimizing the sampling and measurement errors,the deviation between different PSDmeasurement techniques was attributed solely to the shape of the particles and the amount of fine fraction.For fines content measurement,the values obtained through Feret Min.parameter values(the minimumsize of a particle along all directions)calculated by DIA and sieving measurement are comparable within a5% confidence band.The deviation between the results of different methods becomes more significant byincreasing fines content.Moreover,this deviation increases for less isodiametric grains.The fines and claycontent show higher values when measured by any wet analysis.Laser diffraction also tends to overestimatethe fines fraction and underestimate silt/sand fraction compared to other dry techniques.By comparing thedeviation of the DIA and sieving at standard mesh sizes,an algorithm has been developed which choosesthe equivalent sphere sizes of DIA with minimum deviation from sieving.This study performs several measurements on formation sands to illustrate the real advantage of the newmethods over traditional measurement techniques.Furthermore,particle shape descriptors were used toexplain the deviation between the results of different PSD measurement methods.