CHARACTERIZATION OF CRITICAL GAS FLOW RATE TO PREVENT LIQUID LOADING

This report presents the research completed for the Final Year Project entitled ‘Characterization of Critical Gas Flow Rate to Prevent Liquid Loading’. The project is aimed to develop a work flow that predicts critical gas flow rate (minimum required gas flow rate) to prevent liquid loading based on the published literature and to analyse effects of temperature, pressure, conduit size, producing depth and inclination on the critical gas flow rate. Turner et al Model and Guo et al Model are selected to be developed in the work flow. Liquid loading is a very common problem in mature gas wells. Hence, it is required to check for the occurrence of the liquid loading problem. It is hoped that by having this project, a better prediction and hence management of the liquid loading problem can be yielded. Scope of study of the current project includes estimation of presence of liquid loading problem by estimating critical gas flow rate to prevent liquid loading and to conduct sensitivity studies for effects of temperature, pressure, conduit size, producing depth and inclination on critical gas flow rate. Fluid characterization is performed by using the necessary fluid properties inputs based on that stated in the papers. In this report, literature review is conducted on the introduction to critical gas flow rate and available models in predicting critical gas flow rates. Project methodology and activities have been planned and the milestones for this project have been designed. The equations included in the work flow and flow charts of the work flow are also included in the report. This report presents the work flow (spread sheet) with two functions, which are estimating critical gas flow rate and performing sensitivity study. The analyses of the results from both functions are also included in this report. It is found that prediction of critical gas flow rate by the Turner et al Model is lower than that of the Guo et al Model at most of the time. Outcomes of the sensitivity studies demonstrate that critical gas flow rate will be increased if temperature is reduced; pressure is increased; conduit size is increased; producing depth is increased or inclination is reduced. In conclusion, the project has been successfully completed and it is hoped that the work flow can be applied in the industry.