To ensure that all presently producing natural gas accumulations are being produced optimally it is important to be able to evaluate the producing characteristics of the wells draining the accumu- lation. Through the use of Production Logs this can be achieved. However, as most of the major accumulations contain sour gas, i.e. H2S gas, a means had to be found to effectively inhibit the common steel wire line from the corrosive nature of these gases before the surveys could be run. Many approaches to inhibition were tried but until the development of a system to inject the inhibitor into the wire line under pressure, none were successful.