Process and Procedure for Gas Well Deliquification

Research output: ThesisMaster's ThesisResearch



In the production of natural gas, along with gas, a small amount of liquid is produced. The liquids produced along with gas may have varying sources which depend on the condition and type of the reservoir: 1. There may be an aquifer underneath the gas zone which may either lead to water coning or water cusping. 2. The origin of liquids may be another zone (or zones) than from the produced/perforated horizon (e.g. flow behind pipes, well integrity issues) 3. The water produced may be condensed or free water present in the formation. Towards the maturity of gas wells the production rate decreases due to decreasing bottom-hole pressure (depletion), which leads to a lower production velocity resulting in an inability to carry liquids to the surface. When these liquids aren’t completely removed from the well with the gas production flow, they can accumulate downhole, causing the gas to flow intermittently, lowering production and eventually killing the well. This issue is called liquid loading and at this point the liquids must be artificially removed. As liquid loading occurs it is crucial to recognize the problem at early stages and select a suitable prevention method. There are 6 main methods to prevent liquid loading such as: 1. Tubing sizing to increase velocity (e.g. velocity string design) 2. Decrease Wellhead flowing pressure (e.g. compression) 3. ESP and positive displacement lift systems 4. Fluid power / Gas lift systems 5. Foam lift systems 6. Plunger lift systems This project is aimed at describing the methodologies & examples of best practise to identify, qualify and to mitigate liquid loading issues in gas wells within an OMV process and procedures document for gas well deliquification.


Original languageEnglish
  • Hofstätter, Herbert, Supervisor (internal)
  • Elhooni, Adel, Supervisor (external), External person
  • Marschall, Christoph, Co-Supervisor (external), External person
Award date7 Apr 2017
StatePublished - 2017