This article provides insight into flow measurement techniques in water injection wells in oil production fields, with a particular focus on the initial phases of operation. Consequently, the method created by Ramey in 1962, originally intended for estimating the temperature of the injection fluid, has been adapted to calculate the flow rate. In this technique, the calculation This procedure is based on the correlation between the thermal flux formed in the well. The discrepancy between the temperatures of the injected liquid and the geothermal temperature of the reservoir is the main source of the systematic errors in Ramey’s technique. To a lesser extent, but still significant, failure to observe the injection time in a fluid variation also results in an error problem that needs the failure to adhere to the scheduled injection time for a fluid alteration also yields a notable error dilemma that needs to be fixed. The reduction of listed systematic errors is the product of the main part of this article.