Multirate flowing fluid electric conductivity logging method

Abstract

The flowing fluid electric conductivity logging method involves the replacement of well bore water by deionized or constant-salinity water, followed by constant pumping with rate Q, during which a series of fluid electric conductivity logs are taken. The logs can be analyzed to identify depth locations of inflow and evaluate the transmissivity and electric conductivity (salinity) of the fluid at each inflow point. The present paper proposes the use of the method with two or more pumping rates. In particular, it is recommended that the method be applied three times with pumping rates Q, Q/2, and 2Q. Then a combined analysis of the multirate data allows an efficient means of determining transmissivity and salinity values of all inflow points along a well with a confidence measure, as well as their ambient or "far-field" pressure heads. The method is illustrated by a practical example.