Calculation method of porosity based on formation component analysis

Porosity calculation is the key for the evaluation of volcanic rocks,carbonate rocks,tight sands and other heterogeneous reservoirs.The method based on formation component analysis was proposed to calculate porosity.With the full use of conventional logging data and ECS(Elemental Capture Spectroscopy) logging data,the log data sensitive to formation component were selected,the theoretical log response of formation component was determined by making crossplot.The equation was established based on the formation component analysis.The volume content of the formation components was calculated by least squares method,and then the porosity was determined.This calculation method was applied to the evaluation of igneous reservoir in A study area of Santanghu Basin,and good result has been achieved.And it provides some reference for other unconventional reservoir about porosity calculation.