Abstract: It is rather difficult to calculate clay bound water volume and cation exchange capacity from well log data. Based on modern nuclear magnetic resonance log (nmrl), porosity interpretation model is improved and ten a new approach to calculate the volume and capacity is pointed out by using cur data and con-
ventional log data together. And some programs are developed and some well’s log curves from real formation are processed and interpreted point by point. Its result is satisfactory and showed this method excels conventional log interpretation

Key words: clay, bound water volume, cation exchange capacity, nuclear magnetic resonance log, conventional porosity log, log interpretation