Abstract：Ordinary existing logging methods involve three kinds of porosity logging data from acoustic,density and neutron loggings;however,only one kind of data are used in usual logging data interpretation to lose a great deal of very useful informadons.For this reason,the simultaneous equations for jointly interpreting the three kinds of porosity logging data are developed by using acoustic logging,density loggrog and neutron logging data,and they are solved to obtain some formulae of final solution by using Cramer law.It has been proved that the formulae are reliable and applicable to the interpretation of three kinds of porosity logging data.
