Value Of The Index Of Chemical Oxygen Demand As Measure Of The Methanol Content In Return Underground Local-Water Of Oil And Gas Condensate Fields

The method of the methanol content control in samples of return underground local-water of oil and gas condensate fields is described. The determination is based on a preliminary estimation of the chemical oxygen demand index, using an accelerated technique with potentiometric redox titration of potassium dichromate excess. On water-methanol solutions of known composition using the “added-found” method, it was proved that under the conditions of the chosen procedure, the methanol is completely oxidized; the value of the relative standard deviation of the determination results does not exceed 3 %. The interfering influence of the components of highly mineralized water samples on the integral assessment of chemical oxygen demand was studied. The accuracy of the determination of methanol in real water samples is proved by the method of standard additives.