The surveying of multiphase flow wells by use of sequential logging methods may lead to an inaccurate interpretation of the flow regime. This interpretation problem can be caused by the unsteady flow and fluid parameters which can change from one survey to another. To improve log interpretation accuracy in these type of wells, a set of new instruments has been designed. These instruments provide simultaneous measurements of the downhole fluid properties and flow rates. Advantages of this tool string over the sequential instruments include depth-correlated data from all instruments in the string in motion or stationary, recorded accurately in multiphase flow. Also, due to a faster operation, required logging time in a producing well is less. Several tests have been performed with this tool string at Dresser Atlas’s Multiphase Flow Research Center. The test results at each flow rate and angle are compared and discussed. A logging procedure is recommended for multiphase flow and for deviated wells. These steps will help to interpret production logs more accurately, improve log quality in unsteady wells, and lead to better reservoir management.