Evaluating Pressure Losses in Vertical Gas Wells under Surfactant Injection in the Cooper Basin Area
Rohaizak, Muhammad and Yahya, Muhammad
Engineering Honours Degree, 2013
Liquid loading becomes more and more problematic as gas wells in the Cooper basin are depleted. The build-up of liquids downhole may significantly impact the performance of wells leading to lower production rates, sometimes even killing the wells completely. Engineers from Santos Ltd. have been successfully implementing a technique where surfactant injection through small-sized (1/4" to 3/8") coiled tubing is used in order to create a stable foam to help lift liquids out of the liquid loaded wells and consequently assist in production.
Unfortunately, the numerous established wellbore pressure correlations that are being used in the industry today have failed to give an acceptable result when used to model the wellbore pressure under foam assisted flow. Therefore, efforts are made to explore the nature of flow in these wells and to evaluate the pressure losses using an Excel based mathematical approach model. As a result of our investigation, we conclude that a possible correlation can be applied to predict the pressure losses for gas wells in the Cooper basin undergoing surfactant treatment. Although, field testing will be necessary in order to confirm the validity of the pressure predictions using the suggested correlation.