Determining rate profile in gas wells from pressure and temperature depth distributions

Abstract

Gas flow profile along the wellbore is an important piece of information for reservoir and production management purposes, since it provides flow contribution from each producing interval along the wellbore, which is critical for optimizing well performance and maximizing recovery of reserves. Traditional methods are expensive, particularly in high temperature wells and involve running production logsging tools (PLT's) along with flowmeters. Deployment of production logging tools into a well can be operationally difficult and typically requires flow to be suspended temporarily to allow the tools to be run in hole. This can have a negative impact on the quality of data collected, potentially making it un-representative of normal producing conditions. A simple and effective method of the gas rate prediction from temperature and pressure data is discussed in this paper. Solving the inverse problem allows determination of the flow rate and thermal conductivity of the formation by matching the gas pressure and temperature distributions with measured profiles. The results of field data treatment show good agreement with the model prediction and are consistent with flowmeter (PLT) data. Besides, the approximate estimate from direct averaging using the measured data shows good accuracy of rate and thermal conductivity prediction.